Long Long summary FINAL THESIS
INAUGURAL - DISSERTATION
zur
Erlangung der Doktorwürde
der
Naturwissenschaftlich-Mathematischen Gesamtfakultät
der
Ruprecht-Karls-Universität Heidelberg
vorgelegt von
MSc. Basem Hasan Shomar
aus: Gaza-Palästina
Tag der mündlichen Prüfung: 17/02/2005
Inorganic and Organic Environmental Geochemical
Issues of the Gaza Strip-Palestine
Gutachter: Prof. Dr. Dr. hc. mult. German Müller (Emeritus).
Prof. Dr. Heinfried Schöler.
Berichte aus der Umweltwissenschaft
Basem Shomar
Inorganic and Organic Environmental Geochemical
Issues of the Gaza Strip-Palestine
Gedruckt mit Unterstützung des Deutschen Akademischen
Austauschdienstes
Shaker Verlag
Aachen 2005
‫ﻱ ﻭﺃﻥ ﺃﻋﻤﻞ‬
 ‫ﻲ ﻭﻋﻠﻰ ﻭﺍﻟﺪ‬ ‫” ﺭﺏ ﺃﻭﺯﻋﲏ ﺃﻥ ﺃﺷﻜﺮ ﻧﻌﻤﺘﻚ ﺍﻟﱵ ﺃﻧﻌﻤﺖ ﻋﻠ‬
‛‛‫ﺻﺎﳊﹰﺎ ﺗﺮﺿﺎﻩ ﻭﺃﺩﺧﻠﲏ ﺑﺮﲪﺘﻚ ﰲ ﻋﺒﺎﺩﻙ ﺍﻟﺼﺎﳊﲔ‬
“O my Lord! So order me that I may be grateful for Thy favours, which Thou has bestowed
on me and on my parents, and that I may work the righteousness that will please Thee: and
admit me, by Thy Grace, to the ranks of Thy Righteous Servants”
To my parents, Raeda, Yara and beloved Hasan
Acknowledgments
I would like to extend my thanks and appreciation to Prof. Dr. German Müller for giving me
an open chance and scientific freedom to fulfill a dream: to compile the Gaza environment
investigation that I initially planned. Similarly, I would like to thank Dr. A. Yahya for
providing all means of support needed to collect, transport and analyze the environmental
samples.
Special thanks go to Prof. Dr. W. Shotyk, whose encouragement and faith in this PhD project
was instrumental to its achievement and who gave advice and help whenever needed. The
author wishes to pay tribute to Prof. Dr. R. D. Schuiling, Prof. Dr. Heinfried Schöler, Prof.
Dr. Jalal Hawari, and Dr. Juliet VanEenwyk who contributed significantly to the accuracy,
quality, and usability of this report.
The author wishes to acknowledge the following individuals in Gaza who provided the
foundation for information on the collection and processing of environmental samples: Said
Ghabayen, Sami Abu Fakher, Imad Sharif, Baha’ Al Falooji, Ahmad Maghari, and the staff
of Gaza Environmental and Information Center in the Governorate of Gaza.
Thanks also go to several people helped with various aspects of the experimental work: S.
Rheinberger, C. Shultz, A. Cheburkin, G. Kilian, M. Gastner, and M. Ruckwied.
The research was funded by Bundesministerium für Bildung und Forschung-BMBF,
Germany through a project called "Monitoring of Groundwater and Soil Pollution Levels in
Gaza Strip". This publication was made possible through the kind help and support offered by
the Deutsche Akademische Austauschdienst (DAAD) beside the generous scholarship
granted to the author during his stay in Germany.
SUMMARY
The multi-faceted nature of the environmental issues in the Gaza Strip, Palestine requires an
interdisciplinary, integrated approach to management strategies. The Palestinian Ministry of
Environmental Affairs (MEnA) has set research priorities based on an understanding of the
complexity of the Gaza environment through many years of study. The top priority has been
and will remain the human health risks and hazards due to the deterioration of the water, air,
and soil. Environmental deterioration is not a new problem. It is rather an accumulation of
natural, political, economic, and social conditions. These conditions add a layer of
complexity to ameliorating the environmental problems. Although this research mainly
focuses on the scientific side, the researchers recognize that addressing political, economic,
and social factors is essential for any proposed solution to the deteriorated environment.
While this study focuses on Gaza, some of the research extended to areas beyond Gaza.
Environmental problem generally extend beyond small geographic areas and do not respect
political boundaries. Thus, it is important to understand the regional environmental situation
so as to establish regional cooperative efforts that are based on scientific awareness.
This study was conducted in parallel with a research project (Gaza Project) that is funded by
the German Ministry of Education and Scientific Research. Through this project, we
collected and tested the required samples and consulted with the local experts. This study has
combined two branches of science that are rarely combined dissertation projects; the organic
and the inorganic geochemistry. For this reason, knowledge not only in organic and inorganic
geochemistry but also in many other relevant subjects was necessary. Examples of these
subjects include, but not limited to, water quality, water quality management, soil science and
geology, microorganisms and biology, and statistics and its applications. Moreover, it was
also important to follow some of available literature, specialized lectures, local and
international conferences, and weekly meetings at the institute where this study was
conducted.
Each chapter in this study reflects a focused scientific approach that essentially allows it to
stand by itself as independent study. The chapters contain some repetitions especially in
describing sampling methods and the study area (Gaza Strip). These repetitions result
because each chapter constitutes an article that has been published or is in the process of
being published in a specialized international scientific journal. All these articles are put
together to form one complete study.
The sequencing of the chapters is not based on chronological order, but on the priorities of
the national Palestinian environmental strategy. Hence, water and public health come first
followed by wastewater, solid waste, land use, agricultural practices and their impacts. The
first chapter focuses on the geochemistry of groundwater while the second studies examples
of pollutants and their impacts on the public health. The third and fourth chapters tackle
wastewater issues, including reuse potential, and the impact on soil and groundwater. Wadi
Gaza, which is a hub for wastewater and solid waste disposal, is the fifth chapter. The sixth
chapter looks at geochemical properties of the soil in Gaza, while the final two chapters focus
on the effect of agricultural practices on the soil, including pesticide concentrations and
transport in soil and groundwater, and trace metals concentrations. The following is a brief
description of each chapter.
i
Chapter One: Groundwater. In a course of a 3-year monitoring program, the results show that
the trace elements in the groundwater of the Gaza Strip do not generally pose any health or
environmental hazard. In spite of that, only 10 % of the municipal wells meet the World
Health Organization (WHO) standards. Cl-, NO3- and F- concentrations are 2-5 times higher
than the WHO standards in 90 % of the wells tested with average concentrations of 750, 75
and 1.6 mg/l, respectively. Several private wells should not be used for drinking purposes as
the average levels of Zn, Cd, Pb, Fe and As were 58, 30, 270, 468 and 10 µg/l, respectively.
A severe water dilemma will appear in the near future from both quality and quantity aspects.
Chapter Two: Fluoride: an example of groundwater pollution and the impact on human
health. Fluoride is selected to represent groundwater pollution and the impact on human
health. Monitoring of fluoride levels in 73 groundwater wells and 20 topsoil samples for the
last three years revealed a general trend of increasing levels from north to south of the Gaza
Strip. However, X-ray diffraction (XRD) showed that none of the four major fluoride
minerals were detected in soil samples. The PHREEQC model showed that fluorite (CaF2)
was the main donating mineral of fluoride ions to groundwater. A high positive correlation
was found between fluoride concentrations in groundwater and occurrence of dental
fluorosis. Among 353 school children of the five geographic areas of the Gaza Strip, 60% had
signs of dental fluorosis in permanent dentitions. The highest occurrence, 94%, was in Khan
Yunis, followed by 82% in Rafah, 68% in the middle area, 29% in Gaza and the lowest
occurrence of 9% was in the northern area. These percentages were directly proportional to
the average concentrations of fluoride in groundwater of each area: 2.6, 0.9, 1.7, 1.2, and 0.7
ppm, respectively. The occurrence of the disease was due to intake of high amounts of
fluorides in drinking water, tea and fish.
Chapter Three: Wastewater in the Gaza Strip. About 40% (50,000 m3/day) of the wastewater
generated in Gaza is currently discharged into the sea; a minor part infiltrates into the soil and
contaminates the groundwater. Up to now there has been very little production of sludge as
all existing wastewater treatment plants are deficient and operating with old technologies.
The main objective of this chapter is to describe the concentrations of trace metals and some
major parameters of domestic and industrial wastewater and sludge for the first time.
Moreover, the chapter tries to highlight the various options that aim to reuse the treated
wastewater and sludge in the Gaza Strip in a manner that will ensure agriculturally
sustainable development. The results revealed that domestic wastewater effluent contains
considerable amounts of trace metals and the partially functional treatment plants of Gaza are
able to remove 40-70% of most metals during the treatment process. Trace metals in 31
industrial wastewater effluents are within the ranges of international standards and the
existing treatment plants are capable of absorbing the industrial effluents with no significant
impact on treatment bioprocesses.
Although there are no treatment facilities for sludge within the treatment plants, the results
indicated that sludge in general does not contain trace metals. Only zinc showed 2000 mg/kg
in more than 85% of sludge samples. AOX was 550 mg Cl/kg for the same sludge samples.
Both Zn and AOX exceed the standards of all industrial countries for sludge to be used in
land application.
Chapter Four: Impact of wastewater on soil and groundwater. The aim of the study was to
determine the interaction between the natural geochemistry and anthropogenic activities
through developing trace element profiles in an area of the Gaza Strip with a high potential
for pollution. Five boreholes were dug in the area of the Gaza wastewater treatment plant.
Several analytical techniques were used to study the geology, and mineralogy of the soil, and
ii
the geochemistry of wastewater, sludge, soil, and groundwater. Among 26 elements analyzed,
only a few trace metals showed environmental importance: As, Cd, Cr, Hg, Zn, and to a
lesser extent Pb.
The results of the geochemical investigations confirmed that the upper 40 cm of soil were
affected by wastewater and sludge. The trace metal accumulations were characterized by a
large spatial variability, with some ‘hot spots’ of Cu and Zn reaching topsoil concentrations
of up to 240 and 2005 mg/kg, respectively. In spite of that, the results of the groundwater
testing revealed that no trace metals were detected at concentrations that exceeded the WHO
(World Health Organization) standards. Moreover, it was shown that both anthropogenic
activities as well as seawater intrusion caused the high levels of nitrate and salinity. The study
describes the infrastructure needed for further research focusing on the natural infiltration
potential and artificial recharge of groundwater, and the impact of agricultural activities. The
study results can be used as baseline measures, since this was the first time these parameters
have been quantified in soil and groundwater.
Chapter Five: Wadi Gaza. Water and sediment samples were collected from 18 sampling
stations in Wadi Gaza for two successive years in order to: (1) establish baselines for the
geochemistry of surface water and sediments; (2) assess the impact of seasonal variation on
distribution of trace metals and major ions; and (3) identify possible natural and
anthropogenic sources of pollution. The trace metal concentrations in the sediments of the
lake (downstream) were higher than those of the eastern eight stations (upstream) where the
water was shallower. The discharge of wastewater from an olive oil mill was evident in the
Ca, Na, Mg, K and P concentrations in sediments of one of the sampling stations.
Water in shallower areas showed greater temporal variation than deeper areas. Several
elements (P, Fe, Mn and As) showed the greatest temporal variability. For example, in the
winter rainy season these elements decreased 2-10 times compared to their values in summer.
Additionally, Ca, Na, Cl, PO4, and NO3 decreased 3, 3, 5, 2, 4 times, respectively. Some of
the trace metals were more abundant in these waters compared to the domestic wastewaters
of the study area. The averages of Cd and Co were 6 and 43 µg/l, respectively and they were
50 times higher than the domestic wastewater results.
Chapter Six: Soil geochemistry. The aims of this study were to establish the current types and
concentrations of trace metals and major elements in agricultural soils of the Gaza Strip, and
to identify the main anthropogenic inputs affecting trace metals. An extensive soil survey was
conducted in agricultural and non-agricultural areas. One hundred sixty sites were selected
representing a broad range of soil types and locations. The results revealed that soils fall
within the range of the uncontaminated to slightly contaminated category. Up to 90% of the
tested soils had trace metal concentrations representing the international background values.
Ten percent showed slight contamination mainly by Zn, Cu, As and Pb due to anthropogenic
inputs, and their mean concentrations were 180, 45, 13 and 190 mg/kg, respectively. The
trace metal concentrations vary with the highest concentrations detected in the southern
regions (clay soil and low precipitation) and the lowest in the northern areas (sandy soil and
high precipitation). The soil geochemistry is dependent on soil type and location and to a
lesser extent on crop pattern and fertilizer and fungicide application. Anthropogenic inputs
lead to the enrichment of Zn, Pb, Cu and Cd in the agricultural soils. Pollution of several sites
was found to be most severe for Zn, Pb, Cu and Cd and to a somewhat lesser extent for As,
whereas anthropogenic input of Hg, Ni and Co seem to be less important. The application of
Cd-containing phosphate fertilizers coupled with Cu-containing fungicides may be important
sources of Cd and Cu in several soils. High Zn levels (1000 ppm) in several soils may be
caused by sewage sludge that has an average Zn content of 2000 ppm. Saline-sodic soils were
iii
found in the central and southern regions where the soils are characterized by high contents
of Na and salty groundwater. Elevated Cl, Na, Zn and Pb concentrations in some areas need
further investigation for their ecological and health implications.
Chapter Seven: Fate of pesticides in the Gaza Strip. Agricultural activities in the Gaza Strip
have associated with excessive and uncontrolled use of dozens of pesticides. Accordingly,
groundwater and soil are potentially contaminated causing severe threat to the crowded
population. The present study describes in a 3-year monitoring program types and level of
contamination by various pesticides used in Gaza. Two analytical instruments (GC/MS and
HPLC/MS) were applied to achieve this objective.
More than 92% of targeted pesticides in groundwater were much lower than their allowable
limit of the World Health Organization. However, the municipal groundwater wells showed
better quality as they are located in the residential areas than the private wells in the
agricultural regions. Atrazine, atrazine-desisopropyl, propazine, simazine were detected in
water samples with average concentrations of 3.5, 1.2, 1.5 and 2.3 µg/l, respectively. A linear
correlation was found between the chloride concentrations in groundwater and atrazine for
the same geographic areas. Generally speaking, shallow aquifers of low annual precipitation
in the southern areas of Gaza showed detectable concentrations of pesticides. In soil,
pesticides presence was found to depend on type of soils. Clay soils for instance, showed 3-4
times more than sandy soils for the same pesticide species.
A linear regression analysis found a correlation coefficient of r = 0.87 between the strawberry
greenhouses and the occurrence of propazine, sebutylazine, terbutylazine, 4,4’-DDT, 4,4’DDE, and 4,4’-DDD in soil. The averages of propazine, sebutylazine and terbutylazine were
19, 13 and 39 µg/kg, respectively. One soil sample showed contents of 4,4'-DDE and 4,4'DDT up to 1104 and 793 µg/kg , respectively.
Chapter Eight: Trace metals in pesticides: Two different techniques were used to determine
different elements in pesticides; a semi-quantitative EMMA-XRF technique followed by
ICP/OES was used to test the concentrations of Al, As, Ba, Br, Ca, Cd, Co, Cr, Cu, Fe, K,
Mn, Ni, Pb, Rb, Sc, Se, Sr Ti and Zn in the most used 53 different species of solid pesticides
collected from many markets of the Gaza Strip. The results revealed that the pesticides
contain considerable amounts of trace metals and they do not comply with the expectedtheoretical structure of each species; moreover, they do not reflect the actual constituents
mentioned in the trade labels. Interviews with market owners and field surveys confirmed
that pesticides were not pure and they have been mixed in local markets with minor inorganic
species without a scientific basis; or they have been smuggled to Gaza with different
impurities. The results propose that pesticides should be considered as a source of some trace
metals (Cu, Mn, and Zn) and other elements (Br, Sr and Ti) that may affect their mass
balances in soil and groundwater as well as plant uptake. Models of trace metal transport in
soil and groundwater of the Gaza Strip should include pesticides as an additional source of
certain trace metals.
In summary, this series of studies describes some important aspects of soil and water in the
Gaza Strip. It forms the basis for additional specialized research related to the interaction of
the environment and human health in the region.
iv
ZUSAMMENFASSUNG
Die Vielfalt der Umweltemissionen im Gazastreifen, Palästina, erfordert einen
interdisziplinären, ganzheitlichen Ansatz für Managementstrategien. Das Palästinensische
Umweltministerium (MEnA) legt den Forschungsschwerpunkt seit vielen Jahren auf ein
Verständnis der Komplexität der Umwelt in Gaza. Das Hauptaugenmerk lag und liegt
weiterhin auf der Abschätzung des Risikos und der Gefahr für die menschliche Gesundheit
durch die Schädigung von Wasser, Luft und Boden. Die Zerstörung der Umwelt ist kein
neues Problem. Es ist vielmehr die Ansammlung natürlicher, politischer, wirtschaftlicher und
sozialer Gegebenheiten. Dies veranschaulicht die Komplexität und führt so zu einer
Verdeutlichung der Umweltprobleme. Obwohl sich diese Arbeit hauptsächlich mit der
wissenschaftlichen Seite befasst, ist es den Forschern klar, dass zur Lösung der
Umweltprobleme auch die politischen, wirtschaftlichen und sozialen Faktoren angesprochen
werden müssen.
Obwohl sich diese Studie mit der Umweltsituation des Gaza Streifens befasst, können einige
erzielte Forschungsergebnisse über das Gebiet hinaus übertragen werden. Da die
Umweltprobleme sich generell nicht nur über kleine geographische Einheiten erstrecken und
nicht an politischen Grenzen enden, ist es deshalb wichtig, die örtliche Umweltsituation zu
verstehen um regionale Kooperationen aus dem wissenschaftlichen Bewusstsein heraus
aufzubauen.
Diese Studie wurde im Rahmen des Forschungsprojektes "Monitoring of Groundwater and
soil pollution levels in Gaza Strip", das vom Bundesministerium für Bildung und Forschung
(BMBF) gefördert wird, durchgeführt. In Zusammenarbeit mit den örtlichen Experten in
Gaza konnten im diesem Rahmen alle benötigten Beprobungen und Feldmessungen
durchgeführt werden.
In dieser Arbeit werden mit organischer und anorganischer Geochemie zwei
Wissenschaftszweige zusammengefasst, die im Rahmen von Dissertationen nur selten
gemeinsam bearbeitet werden. Aus diesem Grund war nicht nur Wissen auf diesen sondern
auch auf damit verbundenen Gebieten nötig. So wurden Kenntnisse aus der Bodenkunde,
Geologie, Biologie, der Trinkwasserbehandlung und Statistik miteinbezogen.
Jedes Kapitel dieser Arbeit spiegelt einen eigenständigen wissenschaftlichen Ansatz wider.
Da jedes Kapitel einen Artikel repräsentiert, der in einem internationalen Journal publiziert
wurde oder den entsprechenden Prozess gerade durchläuft, waren Wiederholungen der
Beschreibung von Probenahmen, Untersuchungsgebieten und Methodik sowie der
Formatierungen der Kapitel unvermeidlich. Die Arbeit fasst alle diese Artikel zu einer
Übersicht zusammen.
Die Reihenfolge der Kapitel richtet sich nicht nach der chronologischen Abfolge ihres
Erscheinens sondern nach den Prioritäten der Umweltprobleme im Untersuchungsgebiet, die
wie auch von der palästinensischen Umweltplanung mit Wasser und öffentlicher Gesundheit
beginnen und von Abwasser, Abfall, Landnutzung und Landwirtschaft und deren negativen
Auswirkungen, gefolgt werden.
Im ersten Kapitel wurde die Geochemie des Grundwassers erläutert. Im zweiten werden
Beispiele von Verunreinigungen und deren Wirkungen auf die Gesundheit aufgezeigt.
Abwasserprobleme und die Beeinflussung von Boden und Grundwasser sowie Möglichkeiten
v
der Wiederverwendung des Abwassers wurden im dritten und im vierten Abschnitt
untersucht.
Wadi Gaza als zentraler Ort für Abwasser und Mülldeponie ist Gegenstand des fünften
Kapitels, während der sechste Beitrag die Geochemie des Bodens in Gaza untersucht.
Schließlich werden in den letzten zwei Abschnitten die Einflusse der Landwirtschaft auf den
Boden beleuchtet. Gehalte und Transportvorgänge von Pestiziden und Schwermetallen im
Boden und Grundwasser wurden untersucht.
Eine kurze Beschreibung der einzelnen Kapitel kann nachfolgend entnommen werden:
Kapitel Eins: Das Grundwasser: Obwohl 10 % der kommunalen Brunnen
Spurenelementgehalte, die die Standards der World Health Organisation (WHO) erreichen,
zeigen die erzielten Ergebnisse im Verlauf des dreijährigen Monitoring Programms, dass die
Spurenelemente im Grundwasser des Gaza Streifens generell keine gesundheitliche oder
umweltrelevante Gefährdung darstellen. Die Konzentrationen von Cl-, NO3- und F- sind mit
jeweils durchschnittlichen Werten von 750, 75 und 1,6 mg/l in 90% der getesteten Brunnen
zwei- bis fünffach höher als die WHO Standards.
In einigen privaten Brunnen wurden Durchschnittgehalte für Zn, Cd, Pb, Fe und As von
jeweils 58, 30, 270, 468 und 10 µg/l gemessen, was für eine Benutzung zum Zweck einer
Trinkwasserförderung nicht zu empfehlen wäre. Die Untersuchungen zeigen, dass in der
nahen Zukunft eine drastische Verschlechterung der Trinkwassersituation, was Qualität und
Quantität betrifft, erwartet werden kann.
Kapitel Zwei: Fluorid: Die Untersuchungen von Fluorid sind ein Beispiel, wie
Grundwasserbelastungen direkte Auswirkungen auf die menschliche Gesundheit verursachen
können. Die Überwachung der Fluorid-Gehalte in 73 Brunnen und 20 Bodenproben zwischen
2001 und 2003 lässt einen klaren Trend erkennen: Die F-Werte steigen in dem
Untersuchungsgebiet vom Norden nach Süden auf das dreifache.
Untersuchungen mit dem Röntgendiffraktometer (XRD) zeigen allerdings, dass keines der
vier häufigsten Fluorid Minerale in den Bodenproben vorkommt. Modellierungen mit
PHREEQC haben ergeben, dass Fluorit (CaF2) die größte Quelle für Fluorid-Ionen im
Grundwasser darstellt. Weiterhin wurde eine hohe positive Korrelation zwischen FluoridGehalten im Grundwasser und dem Auftreten von Erkrankungen der Zähne bei Schulkindern
durch Fluor beobachtet.
Die Untersuchungen von 353 Schulkindern aus 5 verschiedenen Gebieten des Gaza Streifens
zeigen, dass 60% der Untersuchten Anzeichen von Zahnschäden durch Fluor aufweisen.
Davon wurde der Maximalwert von 94% in Khan Yunis im Süden des Gaza Streifen, 82% in
Rafah, 68% im mittleren Gebiet, 29% in Gaza und der geringste Prozentsatz von 9% im
nördlichsten Gebiet ermittelt. Diese Zahlen stehen direkt proportional zu den
durchschnittlichen Fluorid-Konzentrationen der jeweiligen Grundwässer der verschiedenen
Gebiete von 2.6, 0.9, 1.7, 1.2 und 0.7 ppm. Dabei wird die Vermutung verstärkt, dass das
Auftreten der Krankheit durch die Aufnahme von großen Mengen Fluorid neben dem
Trinkwasser, auch aus Tee und Fisch resultierte.
Kapitel Drei: Abwasser im Gaza Streifen: Bisher werden ca. 40% (50,000 m3/Tag) der
Abwässer des Gaza Streifens in das Meer ungeklärt eingeleitet. Ein kleiner Teil sickert in den
Boden und stellt eine Bedrohung für das Grundwasser dar. Auf Grund mangelhaft
ausgerüstete Kläranlagen sowie fehlende Technologien wird nur eine geringe Menge an
Klärschlamm produziert. In diesem Kapitel wird erstmalig für den Gaza Streifen die
Bestimmung der Spurenmetall-Konzentrationen sowie andere wichtigste Parameter in
vi
kommunalem und industriellem Abwasser und Klärschlamm durchgeführt. Weiterhin
werden die verschiedenen Möglichkeiten der Wiederverwendung des Abwassers und des
Schlammes im Rahmen einer landwirtschaftlich nachhaltigen Entwicklung im Gaza Streifen
erkundet. Die Ergebnisse zeigen, dass kommunales Abwasser beträchtliche Konzentrationen
von Schwermetallen aufweist. 40-70% der meisten dieser Metalle können jedoch während
des Klärprozesses in den Kläranlagen entfernt werden. Die Ergebnisse der Untersuchungen
zeigen, dass die Schwermetallkonzentrationen von 31 industriellen Abwässern sich innerhalb
der Grenzen der internationalen Standards bewegen. Die existierenden Kläranlagen sind in
der Lage diese Abwässer zu absorbieren, ohne dass sich Auswirkungen auf die biologischen
Klärprozesse zeigen.
Generell weist der anfallende Klärschlamm nur geringe Schwermetallgehalte auf. Eine
Ausnahme wurde für Zink bestimmt, das erhöhte Konzentrationen aufweist. Mehr als 85%
der Schlammproben zeigen für Zink Durchschnittkonzentrationen um 2000 mg/kg. Auch die
AOX-Werte lagen erhöht im Klärschlamm vor. Mit >2000 mg/kg für Zn und 550 mgCl/kg
für AOX wurden die Standards aller Industrieländer für landwirtschaftlich nutzbaren
Klärschlamm überschritten.
Kapitel Vier: Der Einfluss von Abwasser auf Boden und Grundwasser: Durch die
Untersuchung von Spurenelement-Profilen einer der umweltrelevantesten Gegenden des
Gaza-Streifens war das Ziel dieser Arbeit die Ermittlung der Wechselwirkungen zwischen
der natürlichen Geochemie und dem anthropogenen Einfluss im Boden. Es wurden fünf
Bohrungen in der Umgebung der Kläranlage von Gaza niedergebracht. Neben
Untersuchungen der Geologie, Mineralogie und Geochemie der Bodenprofile wurde die
Geochemie des Abwassers, des Klärschlamms und des Grundwassers durch verschiedene
analytische Methoden bestimmt. Die Arbeit stellt in Gaza die ersten Grundlagen, um weitere
Untersuchungen durchführen zu können, vor.
Von 26 analysierten Elementen wurden nur einige Schwermetalle als umweltrelevant
eingestuft. Vor allem As, Cd, Cr, Hg, Zn und zu einem geringeren Anteil auch Pb sind für die
Umwelt in Gaza von Bedeutung. Die Ergebnisse der geochemischen Untersuchungen
bestätigen, dass die oberen 40 cm des Bodens durch Abwasser und Klärschlamm
beeinträchtigt wurden. Die Schwermetallvorkommen in den Böden sind durch eine große
räumliche Variabilität mit einigen lokalen Anreicherungen von Cu, Zn gekennzeichnet, die
jeweils Konzentrationen von 240, 2005 mg/kg erreichten. Trotz dieser Anreicherungen in den
Bodenprofilen, zeigen die Grundwasseranalysen, dass im Grundwasser keines dieser
Elemente Konzentrationen erreicht, die die Standards der WHO (World Health Organisation)
überschreitet. Weiterhin konnte gezeigt werden, dass die hohen Nitratwerte und die hohe
Salinität anthropogen verursacht sind und dem Eindringen von Meerwasser in den Aquifer
resultieren.
Kapitel Fünf: Wadi Gaza: An insgesamt 18 Beprobungsstellen im Wadi Gaza sind innerhalb
von zwei aufeinander folgenden Jahren Wasser- und Sedimentproben entnommen und
untersucht worden. Dabei sollten folgende Forschungsaufgaben durchgeführt werden: a) die
geochemischen Hintergrundbedingungen des Oberflächenwassers und des Sediments
ermitteln; b) den Einfluss saisonaler Schwankungen auf die Verteilung von Schwermetallen
und Hauptionen abschätzen; und c) potenzielle Quellen natürlicher und anthropogener
Verunreinigungen identifizieren.
Die Ergebnisse haben gezeigt, dass die Schwermetallkonzentrationen im Sediment des Sees
(abstromig) höher als diejenigen der östlichen acht Beprobungsstellen (oberstromig) lagen
und die durch flacheres Wasser gekennzeichnet waren.
Sedimentproben einer
vii
Beprobungsstelle belegten den Abfluss von Olivenölmühlen-Abwasser anhand ihrer Ca, Na,
Mg, K und P Konzentrationen.
Im Flachwasser wurden größere saisonale Schwankungen der Konzentrationen als im
Tiefwasser des Sees festgestellt. Einige Elemente wie P, Fe, Mn und As zeigten die größte
zeitliche Variabilität. Für diese Elemente nahmen z.B. die Werte innerhalb der
niederschlagsreichen Wintersaison um das 2- bis 10-fache gegenüber Werten im Sommer ab.
Ferner nahmen Ca, Na, Cl, PO4 and NO3 um das 3-, 3-, 5-, 2- bzw. 4-fache ab. Einige
Spurenmetalle kamen in den Wässern des Wadis häufiger vor als in häuslichen Abwässern
des Untersuchungsgebietes. Die Durchschnittswerte von Cd and Co lagen bei 6 bzw. 43 µg/l
und waren 50-mal höher als Messwerte häuslicher Abwässer.
Kapitel Sechs: Boden Geochemie: Die Ziele dieser Untersuchung waren die rezenten Gehalte
von Schwermetallen und Hauptelementen in landwirtschaftlich genutzten Böden des Gaza
Streifens zu bestimmen, sowie die hauptsächlichen anthropogenen Einträge zu identifizieren,
welche die Schwermetallgehalte beeinflussen. Eine ausgedehnte Erfassung von Böden in
landwirtschaftlich und nicht-landwirtschaftlich genutzten Gebieten wurde durchgeführt.
Insgesamt 160 Flächen wurden ausgewählt, die einen weiten Bereich von Bodenarten und
Lokalitäten repräsentieren. Die Ergebnisse zeigten, dass die untersuchten Böden in die
Kategorie nicht bis schwach kontaminiert fallen. Bis zu 90% der untersuchten Böden wiesen
Schwermetallgehalte im Bereich internationaler Hintergrundgehalte auf. 10% zeigten eine
schwache Kontamination hauptsächlich durch Zn, Cu, As and Pb aufgrund anthropogenen
Eintrags, bei mittleren Konzentrationen von 180, 45, 13 bzw. 190 mg/kg. Die Schwermetalle
variieren zwischen hohen Gehalten in den südlichen Regionen (Lehmböden und geringer
Niederschlag) und geringen Gehalten in den nördlichen Gebieten (sandige Böden und hoher
Niederschlag). Die geochemischen Bedingungen des Bodens sind abhängig von der Bodenart
und der Lokalität sowie zu einem geringeren Ausmaß von der angebauten Fruchtart und der
Anwendung von Dünger und Fungizid. Anthropogene Einträge führen zu einer Anreicherung
von Zn, Pb, Cu und Cd in landwirtschaftlich genutzten Böden. Die Verunreinigung
verschiedener untersuchter Flächen stellte sich als am schwersten für Zn, Pb, Cu und Cd
heraus sowie in einem etwas geringeren Ausmaß für As, während der anthropogene Eintrag
von Hg, Ni und Co weniger bedeutend zu sein scheint. Die Ausbringung Cd-haltiger
Phosphatdünger in Kombination mit Cu-haltigen Fungiziden sind möglicherweise bedeutende
Quellen für Cd und Cu in einigen Böden. Hohe Zn-Gehalte (1000 ppm) in verschiedenen
Böden werden möglicherweise durch Klärschlamm verursacht, der einen mittleren Zn-Gehalt
von 2000 ppm aufweist. Sodasalinare Böden wurden in den zentralen und südlichen
Regionen gefunden, in denen die Böden durch hohe Na-Gehalte und salzhaltiges
Grundwasser charakterisiert sind. Erhöhte Cl-, Na-, Zn- und Pb-Gehalte in einigen Gebieten
bedürfen weiterer Untersuchungen bezüglich ihrer ökologischen und gesundheitlichen
Folgen.
Kapitel Sieben: Erfassung von Pestiziden im Grundwasser und im Boden des Gaza Streifens:
Landwirtschaftliche Nutzung ist im Gaza Streifen mit einer exzessiven und unkontrollierten
Anwendung duzender Pestizide einhergegangen. Dementsprechend sind Grundwasser und
Boden potenziell kontaminiert und stellen eine mögliche Bedrohung für die dicht siedelnde
Bevölkerung dar. Die hier vorgestellte Untersuchung beschreibt in einem dreijährigen
Erhebungs-Programm die Arten und das Ausmaß der Kontamination durch verschiedene
Pestizide, die im Gaza Streifen verwendet werden. Um dieses Ziel zu erreichen, wurden zwei
Messgeräte eingesetzt (GC/MS und HPLC/MS).
Mehr als 92% der erfassten Pestizide im Grundwasser lagen weit unterhalb ihres zulässigen
Grenzwertes der Weltgesundheitsorganisation. Insgesamt zeigten die in Wohngebieten
viii
gelegenen städtischen Grundwasserbrunnen eine bessere Qualität als die in landwirtschaftlich
genutzten Regionen gelegenen privaten Brunnen. Atrazin, Atrazin-Desisopropylen, Propazin
und Simazin wurden in Grundwasserproben mit Konzentrationen von 3,5, 1,2, 1,5 bzw.
2,3 µg/l nachgewiesen. Zwischen den Chlorid- und Atrazin- Konzentrationen in
Grundwasserproben desselben geographischen Gebiets wurde eine lineare Korrelation
beobachtet. Im Allgemeinen zeigten flache Grundwasserleiter mit einem geringen
Jahresniederschlag in den südlichen Gebieten des Gaza Streifens nachweisbare
Konzentrationen von Pestiziden. Das Vorkommen von Pestiziden im Boden stellte sich als
abhängig von der Bodenart heraus. Lehmböden zeigten z.B. für dieselbe Pestizidspezies 3-4
mal so hohe Werte wie sandige Böden.
Durch eine lineare Regressionsanalyse wurde zwischen Erdbeergewächshäusern und dem
Auftreten von Propazin, Sebutylazin, Terbutylazin, 4,4’DDT, 4,4’DDE und 4,4’DDD im
Boden ein Korrelationskoeffizient von r = 0,87 nachgewiesen. Mittlere Propazin-,
Sebutylazin- and Terbutylazin- Konzentrationen lagen bei 19, 13 bzw. 39 µg/kg. Eine
Bodenprobe zeigte 4,4’DDE- und 4,4’DDT- Gehalte bis zu 1104 bzw. 793 µg/kg.
Kapitel Acht: Schwermetalle in Pestiziden: Zur Bestimmung verschiedener Elemente in
Pestiziden wurden zwei verschiedene Methoden angewendet; eine semiquantitative EMMAXRF Methode gefolgt durch ICP/OES wurde verwendet, um die Konzentrationen von Al, As,
Ba, Br, Ca, Cd, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, Rb, Sc, Se, Sr, Ti und Zn in den 53 meist
benutzten festen Pestiziden zu bestimmen, die von Märkten im Gaza Streifen
zusammengetragen wurden. Die Ergebnisse belegten, dass die untersuchten Pestizide
bemerkenswerte Mengen an Schwermetallen enthalten, und dass jede Spezies nicht der
theoretisch zu erwartenden chemischen Struktur entspricht; darüber hinaus zeigen sie nicht
die tatsächlichen Inhaltsstoffe, die in der Warenbeschriftung angegeben sind. Befragungen
von Marktbetreibern und Felduntersuchungen bestätigten, dass Pestizide unrein waren und
dass sie auf lokalen Märkten ohne eine wissenschaftliche Grundlage mit geringen Anteilen
anorganischer Spezies vermengt wurden; oder sie sind mit verschiedenen Unreinheiten in den
Gaza Streifen geschmuggelt worden. Die Ergebnisse lassen vermuten, dass Pestizide als eine
Quelle bestimmter Schwermetalle (Cu, Mn und Zn) und anderer Elemente (Br, Sr and Ti)
angenommen werden sollten, die sowohl ihre Massenbilanz im Boden und Grundwasser, als
auch die Aufnahme durch Pflanzen beeinflussen kann. Verschiedene Szenarios und
Modellierungen des Schwermetalltransports im Boden und Grundwasser des Gaza Streifens
sollten Pestizide als zusätzliche Quelle bestimmter Schwermetalle berücksichtigen.
Diese Arbeit offenbart einige der aktuellsten wissenschaftlichen Forschungen im
Zusammenhang mit dem Gaza Streifen. Sie bildet die Basis für weitergehende Forschungen
auf dem Gebiet der Umwelt und Gesundheit in der Region.
ix
‫ﺍﳋﻼﺻﺔ‬
‫ﺗﺘﺪﺍﺧﻞ ﺍﻟﻘﻀﺎﻳﺎ ﺍﻟﺒﻴﺌﻴﺔ ﰲ ﻗﻄﺎﻉ ﻏﺰﺓ )ﻓﻠﺴﻄﲔ( ﺇﱃ ﺣﺪ ﻳﺼﻌﺐ ﻓﻴﻪ ﺍﻟﺘﻌﺎﻃﻲ ﻣﻊ ﺃﻳﻬﺎ ﺩﻭﻥ ﺍﻷﺧﺮﻯ‪ ،‬ﻭﻣﻦ ﺧﻼﻝ ﺇﺩﺭﺍﻙ ﺍﻟﻮﺍﻗـﻊ‬
‫ﺍﻟﺒﻴﺌﻲ ﻭﺗﻌﻘﻴﺪﺍﺗﻪ ﻭﻋﻠﻰ ﻣﺪﺍﺭ ﺳﻨﻮﺍﺕ ﻃﻮﻳﻠﺔ‪ ،‬ﺃﻣﻜﻦ ﻭﺿﻊ ﺃﻭﻟﻮﻳﺎﺕ ﲝﺜﻴﺔ‪ ،‬ﺍﻧﺴﺠﻤﺖ ﻣﻊ ﺍﻻﺳﺘﺮﺍﺗﻴﺠﻴﺔ ﺍﻟﻮﻃﻨﻴﺔ ﺍﻟﻔﻠﺴﻄﻴﻨﻴﺔ ﻟﻠﺒﻴﺌـﺔ‬
‫ﻭﳋﻄﺔ ﺍﻟﻌﻤﻞ ﺍﳌﻨﺒﺜﻘﺔ ﻋﻨﻬﺎ‪ ،‬ﻭﻳﺄﰐ ﻋﻠﻰ ﺭﺃﺱ ﻫﺬﻩ ﺍﻟﻘﻀﺎﻳﺎ ﺍﳌﺨﺎﻃﺮ ﺍﻟﺼﺤﻴﺔ ﺍﻟﱵ ﻳﺘﻌﺮﺽ ﳍﺎ ﺍﻹﻧﺴﺎﻥ ﺟﺮﺍﺀ ﺗﺮﺩﻱ ﺍﻟﺒﻴﺌﺔ ﺍﻟﱵ ﻳﻌﻴﺶ‬
‫ﻓﻴﻬﺎ‪ ،‬ﻣﺜﻞ ﺍﳌﺎﺀ ﻭﺍﳍﻮﺍﺀ ﻭﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﻭﺍﻟﻨﻔﺎﻳﺎﺕ ﺍﻟﺼﻠﺒﺔ ﺇﱁ‪ ،‬ﻭﻛﻠﻬﺎ ﺃﻣﺜﻠﺔ ﳍﺬﻩ ﺍﳌﺨﺎﻃﺮ‪ .‬ﻭﺍﳌﺸﻜﻼﺕ ﺍﻟﺒﻴﺌﻴﺔ ﰲ ﻗﻄﺎﻉ ﻏﺰﺓ ﻟﻴﺴﺖ‬
‫ﻭﻟﻴﺪﺓ ﺍﻟﻠﺤﻈﺔ‪ ،‬ﺑﻞ ﻓﺎﻗﻤﺘﻬﺎ ﺍﻟﻈﺮﻭﻑ ﺍﻟﺴﻴﺎﺳﻴﺔ ﻭﺍﻹﻗﺘﺼﺎﺩﻳﺔ ﻭﺍﻹﺟﺘﻤﺎﻋﻴﺔ ﻭﺍﻟﻄﺒﻴﻌﻴﺔ ﺃﻳﻀﺎ‪ .‬ﻭﻫﺬﻩ ﺍﻟﻈﺮﻭﻑ ﺃﻋﻄﺖ ﺃﺑﻌﺎﺩﺍ ﺇﺿﺎﻓﻴﺔ ﻻ‬
‫ﳝﻜﻦ ﲟﻌﺰﻝ ﻋﻨﻬﺎ ﻭﺿﻊ ﺍﻷﻃﺮ ﺍﻟﺰﻣﻨﻴﺔ ﻭﺍﳋﻄﻂ ﺍﻟﻌﻤﻠﻴﺔ ‪‬ﺎ‪‬ﺔ ﺍﻟﻮﺍﻗﻊ ﺍﻟﺒﻴﺌﻲ ﺍﳌﺘﺮﺩﻱ‪ .‬ﺇﻥ ﻫـﺬﻩ ﺍﻟﺪﺭﺍﺳـﺔ ﻭﺇﻥ ﺍﺷـﺘﻤﻠﺖ ﻋﻠـﻰ‬
‫ﻣﻮﺿﻮﻋﺎﺕ ﻋﻠﻤﻴﺔ ﲝﺘﺔ ﺃﹸﻋﻄﻴﺖ ﳍﺎ ﺍﳌﺴﺎﺣﺔ ﺍﻷﻛﱪ‪ ،‬ﻓﺈ‪‬ﺎ ﻻ ﺗﻘﻠﻞ ﻋﻠﻰ ﺍﻹﻃﻼﻕ ﻣﻦ ﺃﳘﻴﺔ ﺍﻟﻈـﺮﻭﻑ ﺍﻟﺴﻴﺎﺳـﻴﺔ ﻭﺍﻹﻗﺘﺼـﺎﺩﻳﺔ‬
‫ﻭﺍﻹﺟﺘﻤﺎﻋﻴﺔ ﺍﻟﱵ ﱂ ﺗﻨﺎﻗﺶ ﻫﻨﺎ ﻷﺳﺒﺎﺏ ﻋﻠﻤﻴﺔ ﻣﻨﻬﺠﻴﺔ‪ .‬ﻭﻣﻊ ﺫﻟﻚ ﻓﻬﻨﺎﻙ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﻹﺷﺎﺭﺍﺕ ﺍﳍﺎﻣﺔ ﰲ ﺍﻟﻜﺜﲑ ﻣﻦ ﺍﳌﻮﺍﺿﻊ ﺍﻟﱵ‬
‫ﳛﺘﺎﺟﻬﺎ ﺍﻟﺴﻴﺎﻕ‪.‬‬
‫ﻭﺣﻴﺚ ﺃﻥ ﺍﻟﺒﻴﺌﺔ ﺑﻌﻨﺎﺻﺮﻫﺎ ﺍﳌﺘﺪﺍﺧﻠﺔ ﻻ ﺗﻨﺤﺼﺮ ﰲ ﻣﻜﺎﻥ ﺻﻐﲑ ﻣﺜﻞ ﻏﺰﺓ‪ ،‬ﺑﻞ ﺇ‪‬ﺎ ﺗﺘﺄﺛﺮ ﲟﺤﻴﻄﻬﺎ ﺍﻷﻗﻠﻴﻤﻲ ﻋﻼﻭﺓ ﻋﻠﻰ ﺃ‪‬ﺎ ﺗـﺆﺛﺮ‬
‫ﻓﻴﻪ ﻭﻟﻮ ﺑﻨﺴﺒﺔ ﺃﻗﻞ‪ ،‬ﻟﺬﺍ ﺗﺄﰐ ﻫﺬﻩ ﺍﻟﺪﺭﺍﺳﺔ ﻟﺘﱪﺯ ﺑﻌﻀﺎ ﻣﻦ ﺍﻹﺷﻜﺎﻻﺕ ﺍﻟﺒﻴﺌﻴﺔ ﺍﻟﱵ ﲤﺘﺪ ﺧﺎﺭﺝ ﺍﳌﻜﺎﻥ ﻭﺗﺘﻄﻠﺐ ﺟﻬﻮﺩﺍ ﻣﺘﻜﺎﻣﻠـﺔ‬
‫ﻭﻋﻠﻰ ﺻﻌﺪ ﺷﱴ‪ ،‬ﻟﺮﺳﻢ ﺻﻮﺭﺓ ﺑﻴﺌﻴﺔ ﺃﻛﺜﺮ ﻓﻬﻤﺎ‪ ،‬ﳝﻜﻦ ﲟﻮﺟﺒﻬﺎ ﺍﻟﻌﻤﻞ ﺍﳌﺸﺘﺮﻙ ﻋﻠﻰ ﺃﺳﺲ ﻋﻠﻤﻴﺔ ﻭﺍﻋﻴﺔ‪.‬‬
‫ﺇﻥ ﻫﺬﻩ ﺍﳌﺴﺎﺣﺔ ﺍﻟﱵ ﺗﻌﺞ ﺑﺎﻟﻘﻀﺎﻳﺎ ﺍﻟﺴﻴﺎﺳﻴﺔ ﻋﻠﻰ ﻣﺪﺍﺭ ﺍﻟﺴﺎﻋﺔ‪ ،‬ﲢﺘﻮﻱ ﰲ ﺫﺍﺕ ﺍﻟﻮﻗﺖ ﻋﻠﻰ ﻣﻮﺿﻮﻋﺎﺕ ﺑﻴﺌﻴﺔ ﺳﺎﺧﻨﺔ ﺟﺪﺍ‪ ،‬ﻭﻣﺎ‬
‫ﺗﻠﻮﺙ ﺃﻛﺜﺮ ﻣﻦ ‪ % 90‬ﻣﻦ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ ﺑﺎﻷﻣﻼﺡ ﻭﺍﻟﻨﺘﺮﺍﺕ ﻭﺍﻟﻔﻠﻮﺭ ﻭﻏﲑﻫﺎ ﺍﻟﻜﺜﲑ‪ ،‬ﻋﻼﻭﺓ ﻋﻠﻰ ﻧﺪﺭﺓ ﻣﺼﺎﺩﺭ ﺍﳌﻴـﺎﻩ ﺃﺻـﻼ‪،‬‬
‫ﻭﺍﻟﺘﻠﻮﺙ ﺍﳊﺎﺻﻞ ﺟﺮﺍﺀ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﻭﺍﻟﻨﻔﺎﻳﺎﺕ ﺍﻟﺼﻠﺒﺔ ﺇ ﹼﻻ ﺃﻣﺜﻠﺔ ﺑﺴﻴﻄﺔ ﻋﻠﻰ ﻋﻈﻢ ﺍﳌﺸﻜﻠﺔ‪.‬‬
‫ﺇﻥ ﻫﺬﻩ ﺍﻟﺪﺭﺍﺳﺔ ﺟﺎﺀﺕ ﺑﺎﻟﺘﻮﺍﺯﻱ ﻣﻊ ﺃﺣﺪ ﺍﳌﺸﺎﺭﻳﻊ ﺍﻟﺒﺤﺜﻴﺔ ﺍﳍﺎﻣﺔ ﺑﺎﳉﺎﻣﻌﺔ )ﻣﺸﺮﻭﻉ ﻏﺰﺓ( ﻭﺍﻟﺬﻱ ﲤﻮﻟﻪ ﻭﺯﺍﺭﺓ ﺍﻟﺘﻌﻠﻴﻢ ﻭﺍﻟﺒﺤـﺚ‬
‫ﺍﻟﻌﻠﻤﻲ ﺍﻷﳌﺎﻧﻴﺔ‪ ،‬ﻭﻣﻦ ﺧﻼﻝ ﺍﳌﺸﺮﻭﻉ ﺃﻣﻜﻦ ﺗﺄﻣﲔ ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﺒﻴﺌﻴﺔ ﺍﻟﻼﺯﻣﺔ‪ ،‬ﻭﺍﻟﺘﺸﺎﻭﺭ ﻣﻊ ﺍﳌﺨﺘﺼﲔ ﰲ ﻏﺰﺓ ﻭﺍﻹﻓﺎﺩﺓ ﻣﻨﻬﻢ‪.‬‬
‫ﻟﻌﻠﻪ ﳚﺪﺭ ﺍﻟﺘﻨﻮﻳﻪ ﺇﱃ ﺃﻥ ﺍﻟﺪﺭﺍﺳﺔ ﲨﻌﺖ ﺑﲔ ﻓﺮﻋﲔ ﻳﻨﺪﺭ ﻭﺟﻮﺩﳘﺎ ﰲ ﺃﻃﺮﻭﺣﺎﺕ ﺩﺭﺟﺔ ﺍﻟﺪﻛﺘﻮﺭﺍﺓ‪ ،‬ﻭﳘﺎ ﺍﳉﻴﻮﻛﻴﻤﻴﺎﺀ ﺍﻟﻌﻀـﻮﻳﺔ‬
‫ﻭﻏﲑ ﺍﻟﻌﻀﻮﻳﺔ‪ ،‬ﻭﻟﺬﺍ ﻓﻘﺪ ﺗﻄﻠﺒﺖ ﺍﻟﺪﺭﺍﺳﺔ ﺍﻹﳌﺎﻡ ﻟﻴﺲ ﻓﻘﻂ ﺑﺎﻟﻜﻴﻤﻴﺎﺀ ﺍﻟﻌﻀﻮﻳﺔ ﻭﻏﲑ ﺍﻟﻌﻀﻮﻳﺔ‪ ،‬ﺑﻞ ﺑﺎﻟﻌﺪﻳﺪ ﻣـﻦ ﺩﺭﻭﺏ ﺍﳌﻌﺮﻓـﺔ‬
‫ﺫﺍﺕ ﺍﻟﻌﻼﻗﺔ‪ ،‬ﺟﻮﺩﺓ ﺍﳌﻴﺎﻩ ﻭﺇﺩﺍﺭ‪‬ﺎ‪ ،‬ﺍﳉﻴﻮﻟﻮﺟﻴﺎ ﻭﻋﻠﻮﻡ ﺍﻟﺘﺮﺑﺔ‪ ،‬ﺍﻟﺒﻴﻮﻟﻮﺟﻴﺎ ﺍﻟﻌﺎﻣﺔ ﻭﺍﻷﺣﻴﺎﺀ ﺍﻟﺪﻗﻴﻘﺔ‪ ،‬ﺍﻹﺣﺼﺎﺀ ﻭﺗﻄﺒﻴﻘﺎﺗـﻪ‪ ،‬ﻭﻫـﺬﻩ‬
‫ﺑﻌﺾ ﺍﻷﻣﺜﻠﺔ‪ ،‬ﻋﻼﻭﺓ ﻋﻠﻰ ﺍﻹﻓﺎﺩﺓ ﺍﳌﺒﺎﺷﺮﺓ ﻣﻦ ﺑﻌﺾ ﺍﳌﻘﺮﺭﺍﺕ ﺍﻟﺪﺭﺍﺳﻴﺔ‪ ،‬ﻭﺍﻷﺩﺑﻴﺎﺕ ﺍﳌﺘﺎﺣﺔ ﺑﺎﳌﻜﺘﺒـﺔ ﺍﳉﺎﻣﻌﻴـﺔ‪ ،‬ﻭﺍﶈﺎﺿـﺮﺍﺕ‬
‫ﺍﻟﺘﺨﺼﺼﻴﺔ‪ ،‬ﻭﺍﳌﺆﲤﺮﺍﺕ ﺍﶈﻠﻴﺔ ﻭﺍﻟﻌﺎﳌﻴﺔ‪ ،‬ﻭﺍﻟﻠﻘﺎﺀﺍﺕ ﺍﻟﻌﻠﻤﻴﺔ ﺍﻷﺳﺒﻮﻋﻴﺔ ﰲ ﺍﳌﻌﻬﺪ ﺣﻴﺚ ﺃﺟﺮﻳﺖ ﻓﻴﻪ ﺍﻟﺪﺭﺍﺳﺔ‪.‬‬
‫ﻭﻟﺬﺍ ﻓﺈﻥ ﻛﻞ ﻓﺼﻞ ﰲ ﺍﻟﺪﺭﺍﺳﺔ ﻳﻌﻜﺲ ﺗﻮﺟﻬﺎ ﻋﻠﻤﻴﺎ ﺃﺳﺎﺳﻴﺎ ﻭﳏﻮﺭﻳﺎ‪ ،‬ﻓﻀﻼ ﻋﻦ ﺍﻷﺳﺎﺳﻴﺎﺕ ﺍﻟﻌﻠﻤﻴﺔ ﺍﻷﺧﺮﻯ ﺍﻟﱵ ﲡﻌﻞ ﻣﻦ ﻛﻞ‬
‫ﻓﺼﻞ ﺩﺭﺍﺳﺔ ﻗﺎﺋﻤﺔ ﺑﺬﺍ‪‬ﺎ‪ .‬ﻭﺍﻟﺪﺭﺍﺳﺔ ﻻ ﲣﻠﻮ ﻣﻦ ﺑﻌﺾ ﺍﻟﺘﻜﺮﺍﺭ ﻭﺧﺼﻮﺻﺎ ﰲ ﻃﺮﻕ ﺍﻟﻘﻴﺎﺱ ﺍﳌﺨﱪﻳﺔ ﺃﻭ ﻣﻜﺎﻥ ﺍﻟﺪﺭﺍﺳﺔ )ﻗﻄـﺎﻉ‬
‫ﻏﺰﺓ(‪ ،‬ﻭﻫﺬﺍ ﻣﺮﺩﻩ ﺃﻥ ﻛﻞ ﻓﺼﻞ ﳝﺜﻞ ﺩﺭﺍﺳﺔ ﰎ ﻧﺸﺮﻫﺎ ﺃﻭ ﰲ ﻃﺮﻳﻘﻬﺎ ﻟﻠﻨﺸﺮ ﰲ ﳎﻠﺔ ﻋﻠﻤﻴﺔ ﻋﺎﳌﻴﺔ ﻣﺘﺨﺼﺼﺔ‪ ،‬ﻭﻭﺿـﻌﺖ ﻛـﻞ‬
‫ﺩﺭﺍﺳﺔ ﰲ ﻓﺼﻞ ﻟﺘﻠﺘﺄﻡ ﲜﻤﻌﻬﺎ ﺍﻟﺪﺭﺍﺳﺔ ﺍﻟﻜﻠﻴﺔ‪.‬‬
‫ﻭﻟﻘﺪ ﰎ ﺗﺮﺗﻴﺐ ﻓﺼﻮﻝ ﺍﻟﺪﺭﺍﺳﺔ ﻟﻴﺲ ﻋﻠﻰ ﺃﺳﺎﺱ ﺯﻣﲏ ﺃﻭ ﻭﻓﻖ ﻧﺸﺮﻫﺎ ﰲ ﺍ‪‬ﻼﺕ‪ ،‬ﻭﺇﳕﺎ ﺑﻨـﺎﺀ ﻋﻠـﻰ ﺃﳘﻴﺘـﻬﺎ ﺍﻟـﱵ ﺣـﺪﺩ‪‬ﺎ‬
‫ﺍﻷﺳﺘﺮﺍﺗﻴﺠﻴﺔ ﺍﻟﻮﻃﻨﻴﺔ ﺍﻟﻔﻠﺴﻄﻴﻨﻴﺔ ﻟﻠﺒﻴﺌﺔ‪ ،‬ﻓﺎﳌﻴﺎﻩ ﻭﺍﻟﺼﺤﺔ ﺍﻟﻌﺎﻣﺔ ﲢﺘﻞ ﺍﳌﺮﺗﺒﺔ ﺍﻷﻭﱃ‪ ،‬ﺗﻠﻴﻬﺎ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣـﺔ‪ ،‬ﰒ ﺍﻟﻨﻔﺎﻳـﺎﺕ ﺍﻟﺼـﻠﺒﺔ‪،‬‬
‫ﻭﺍﺳﺘﺨﺪﺍﻡ ﺍﻷﺭﺍﺿﻲ‪ ،‬ﻭﺍﻟﻨﺸﺎﻁ ﺍﻟﺰﺭﺍﻋﻲ ﻭﺁﺛﺎﺭﻩ‪ ،‬ﺇﱁ‪ .‬ﻭﻟﺬﺍ ﰎ ﺗﺮﺗﻴﺐ ﺍﻟﺪﺭﺍﺳﺔ ﲝﻴﺚ ﻳﻜﻮﻥ ﺍﻟﻔﺼﻞ ﺍﻷﻭﻝ ﻟﻠﻤﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ‪ ،‬ﰒ ﺃﻣﺜﻠﺔ‬
‫ﻋﻠﻰ ﺁﺛﺎﺭ ﺗﻠﻮﺛﻬﺎ ﻋﻠﻰ ﺍﻟﺼﺤﺔ ﺍﻟﻌﺎﻣﺔ‪ ،‬ﺗﻠﻰ ﺫﻟﻚ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﻭﺇﻣﻜﺎﻧﻴﺔ ﺍﻹﻓﺎﺩﺓ ﻣﻨﻬﺎ‪ ،‬ﻭﺁﺛﺎﺭﻫﺎ ﻋﻠﻰ ﺍﻟﺘﺮﺑﺔ ﻭﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ‪ ،‬ﰒ ﻭﺍﺩﻱ‬
‫ﻏﺰﺓ ﺍﻟﺬﻱ ﺗﺼﺮﻑ ﺇﻟﻴﻪ ﺍﻟﻨﻔﺎﻳﺎﺕ ﺍﻟﺴﺎﺋﻠﺔ ﻭﺍﻟﺼﻠﺒﺔ‪ ،‬ﻭﺍﳋﺼﺎﺋﺺ ﺍﳉﻴﻮﻛﻴﻤﻴﺎﺋﻴﺔ ﻟﻠﺘﺮﺑﺔ ﰲ ﻏﺰﺓ‪ ،‬ﻭﻛﻴﻒ ﻳﺆﺛﺮ ﺍﻟﻨﺸﺎﻁ ﺍﻟﺰﺭﺍﻋﻲ ﻓﻴﻬﺎ‪،‬‬
‫‪x‬‬
‫ﻭﺃﺧﲑﺍ ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﻭﻣﺼﲑﻫﺎ ﰲ ﺍﻟﺘﺮﺑﺔ ﻭﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ‪ ،‬ﰒ ﻣﺪﻯ ﺃﺣﺘﻮﺍﺋﻬﺎ ﻋﻠﻰ ﺍﳌﻌﺎﺩﻥ ﺍﻟﺜﻘﻴﻠﺔ‪ .‬ﻭﻓﻴﻤﺎ ﻳﻠﻲ ﻋﺮﺽ ﺳﺮﻳﻊ ﻟﻜﻞ‬
‫ﻓﺼﻞ ﻣﻊ ﺑﻌﺾ ﺍﻟﺘﻮﺻﻴﺎﺕ ﺍﻟﻌﺎﻣﺔ‪.‬‬
‫ﺍﻟﻔﺼﻞ ﺍﻷﻭﻝ‪ :‬ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ‪ :‬ﻋﱪ ﻗﺎﻋﺪﺓ ﻟﻠﺒﻴﺎﻧﺎﺕ ﺍﺷﺘﻤﻠﺖ ﻋﻠﻰ ﲢﻠﻴﻞ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ ﻷﻛﺜﺮ ﻣﻦ ﺗﺴﻌﲔ ﺑﺌﺮﺍ‪ ،‬ﻭﳌﺪﺓ ﺛﻼﺙ ﺳـﻨﻮﺍﺕ‬
‫ﻣﺘﺘﺎﻟﻴﺔ‪ ،‬ﺃﻣﻜﻦ ﺍﻟﺘﻌﺮﻑ ﻋﻠﻰ ﺗﺮﻛﻴﺰ ﳐﺘﻠﻒ ﺍﻟﻌﻨﺎﺻﺮ ﺳﻮﺍﺀ ﺗﻠﻚ ﺍﻟﱵ ﳝﻜﻦ ﲢﻠﻴﻠﻬﺎ ﰲ ﻏﺰﺓ ﺃﻭ ﺗﻠﻚ ﺍﻟﱵ ﻳﺼﻌﺐ ﲢﻠﻴﻠﻬﺎ‪ ،‬ﻧﻈﺮﺍ ﻟﻘﻠـﺔ‬
‫ﺍﻟﺘﺠﻬﻴﺰﺍﺕ ﺍﳌﺨﱪﻳﺔ ﺍﻟﻼﺯﻣﺔ‪ .‬ﻭﻗﺪ ﺃﻇﻬﺮﺕ ﺍﻟﻨﺘﺎﺋﺞ ﺃﻥ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ ﲢﺘﻮﻱ ﻋﻠﻰ ﻧﺴﺐ ﺿﺌﻴﻠﺔ ﻣﻦ ﺍﳌﻌﺎﺩﻥ ﺍﻟﺜﻘﻴﻠﺔ ﻭﻫﻲ ﺿﻤﻦ ﻣﻌﺎﻳﲑ‬
‫ﻣﻨﻈﻤﺔ ﺍﻟﺼﺤﺔ ﺍﻟﻌﺎﳌﻴﺔ‪ ،‬ﰲ ﺣﲔ ﻛﺎﻧﺖ ﻧﺘﺎﺋﺞ ﻛﻞ ﻣﻦ ﺍﻟﺰﻧﻚ ﻭﺍﻟﻜﺎﺩﻣﻴﻮﻡ ﻭﺍﻟﺮﺻﺎﺹ ﻭﺍﳊﺪﻳﺪ ﻟﺒﻌﺾ ﺍﻵﺑﺎﺭ ﺍﳋﺎﺻﺔ ﺍﻟﱵ ﺗﺴﺘﺨﺪﻡ‬
‫ﰲ ﺍﻟﺰﺭﺍﻋﺔ ﺗﺰﻳﺪ ﻋﻠﻰ ﺗﻠﻚ ﺍﳌﻌﻴﲑ‪ ،‬ﺍﻷﻣﺮ ﺍﻟﺬﻱ ﻳﺘﻄﻠﺐ ﻣﺰﻳﺪﺍ ﻣﻦ ﺍﳌﺮﺍﻗﺒﺔ ﻭﲢﺪﻳﺪﺍ ﻟﻮﻇﺎﺋﻒ ﻫﺬﻩ ﺍﻵﺑﺎﺭ‪ .‬ﻭﻣﻦ ﻧﺎﻓﻠﺔ ﺍﻟﻘﻮﻝ ﺍﻟﺘﺄﻛﻴـﺪ‬
‫ﻋﻠﻰ ﺃﻥ ﺃﻛﺜﺮ ‪ % 90‬ﻣﻦ ﺍﻵﺑﺎﺭ ﺍﳉﻮﻓﻴﺔ ﲢﺘﻮﻱ ﻧﺴﺒﺎ ﻣﻦ ﺍﻟﻜﻠﻮﺭ ﻭﺍﻟﻔﻠﻮﺭ ﻭﺍﻟﻨﺘﺮﺍﺕ ﺗﺰﻳﺪ ﻋﻠﻰ ‪ 5-2‬ﺃﺿﻌﺎﻑ ﻋﻦ ﺍﳌﺴـﻤﻮﺡ ﺑـﻪ‬
‫ﺻﺤﻴﺎ‪ .‬ﻭﰲ ﺿﻮﺀ ﺫﻟﻚ ﻳﻠﺰﻡ ﺍﲣﺎﺫ ﺧﻄﻮﺍﺕ ﻋﻤﻠﻴﺔ ﻋﺎﺟﻠﺔ ﻭﻋﻠﻰ ﻛﻞ ﺍﳌﺴﺘﻮﻳﺎﺕ ﻟﻠﺤﺪ ﻣﻦ ﺗﺪﻫﻮﺭ ﺟﻮﺩﺓ ﺍﳌﻴﺎﻩ ﻭﺇﻻ ﻓﺈﻥ ﺍﳌﻨﻄﻘـﺔ‬
‫ﻣﻘﺒﻠﺔ ﻋﻠﻰ ﺃﺯﻣﺔ ﺣﻘﻴﻘﻴﺔ ﺧﻼﻝ ﺍﻟﺴﻨﻮﺍﺕ ﺍﻟﻘﻠﻴﻠﺔ ﺍﻟﻘﺎﺩﻣﺔ‪.‬‬
‫ﺍﻟﻔﺼﻞ ﺍﻟﺜﺎﱐ‪ :‬ﺃﻣﺜﻠﺔ ﳌﻠﻮﺛﺎﺕ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ ﻭﺁﺛﺎﺭﻫﺎ‪ :‬ﻳﻌﺮﺽ ﻫﺬﺍ ﺍﻟﻔﺼﻞ ﳌﺜﺎﻝ ﻫﺎﻡ ﻭﻭﺍﺿﺢ ﻟﻪ ﺃﺑﻌﺎﺩ ﺻﺤﻴﺔ ﺧﻄﲑﺓ‪ ،‬ﻭﻫﻮ ﺍﻟﻔﻠـﻮﺭ‪،‬‬
‫ﰲ ﺣﲔ ﺃﻥ ﺍﻟﻮﻗﺖ ﱂ ﻳﺴﻌﻔﻨﺎ ﻟﻜﻲ ﻧﻀﻢ ﻧﺘﺎﺋﺞ ﺍﻟﺒﺤﺚ ﺍﻟﻌﻠﻤﻲ ﺍﳌﻮﺳﻊ ﺣﻮﻝ ﺍﻟﻨﺘﺮﺍﺕ‪ ،‬ﻭﺍﻟﱵ ﻻ ﺯﺍﻝ ﺍﻟﻌﻤﻞ ﺟﺎﺭﻳﺎ ﻓﻴﻬـﺎ ﺣـﻮﻝ‬
‫ﻭﺟﻮﺩﻫﺎ ﰲ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﻪ‪ ،‬ﻭﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ‪ ،‬ﻭﺍﳊﻤﺄﺓ‪ ،‬ﻭﺍﻟﺘﺮﺑﺔ‪ ،‬ﻭﺍﻷﲰﺪﺓ ﻭﺍﳌﺨﺼﺒﺎﺕ‪ ،‬ﻭﻛﺬﻟﻚ ﻗﻴﺎﺱ ﻧﻈﺎﺋﺮ ﺍﻟﻨﻴﺘـﺮﻭﺟﲔ ﰲ ﺍﳌﻴـﺎﻩ‬
‫ﺍﳉﻮﻓﻴﺔ ﻟﺘﺤﺪﻳﺪ ﻣﺼﺪﺭ ﺇﺭﺗﻔﺎﻉ ﺍﻟﻨﺘﺮﺍﺕ ﰲ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ ﺑﺸﻜﻞ ﺩﻗﻴﻖ‪ ،‬ﻭﻗﺪ ﺗﺄﺧﺮﺕ ﻧﺘﺎﺋﺞ ﺍﻟﺪﺭﺍﺳﺔ ﻷﺳﺒﺎﺏ ﻓﻨﻴﺔ ﲝﺘﺔ ﺗﺘﻌﻠﻖ ﺑﻌﻤﻞ‬
‫ﺍﻷﺟﻬﺰﺓ ﺍﻟﻼﺯﻣﺔ‪.‬‬
‫ﻟﻘﺪ ﺃﻇﻬﺮﺕ ﺍﻟﺪﺭﺍﺳﺔ ﺍﻷﻭﱃ ﺃﻥ ﺍﻟﻔﻠﻮﺭ ﺗﺮﺗﻔﻊ ﻧﺴﺒﺘﻪ ﰲ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﻣﻨﺎﻃﻖ ﻗﻄﺎﻉ ﻏﺰﺓ ﻋﻦ ﻣﺎ ﻗﺮﺭﺗﻪ ﻣﻨﻈﻤﺔ ﺍﻟﺼﺤﺔ ﺍﻟﻌﺎﳌﻴﺔ ) ‪1.5‬‬
‫‪ ،(mg/l‬ﺍﻷﻣﺮ ﺍﻟﺬﻱ ﺃﻭﺟﺪ ﻣﺮﺿﺎ ﻳﻌﺮﻑ ﺑﺘﺒﻘﻊ ﺍﻷﺳﻨﺎﻥ ﻭﻫﺸﺎﺷﺘﻬﺎ‪ .‬ﻭﻧﺘﺎﺋﺞ ﺍﻟﺪﺭﺍﺳﺔ ﺍﳌﻌﻤﻠﻴﺔ ﺃﻇﻬﺮﺕ ﺍﺗﻔﺎﻗﺎ ﰲ ﺗﺮﻛﻴﺰ ﺍﻟﻔﻠﻮﺭ ﰲ‬
‫ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ ﻭﺍﻟﺘﺮﺑﺔ‪ ،‬ﺍﻷﻣﺮ ﺍﻟﺬﻱ ﻳﺮﺟﺢ ﺃﻥ ﻳﻜﻮﻥ ﻣﺼﺪﺭ ﺍﻟﻔﻠﻮﺭ ﰲ ﺍﳌﻴﺎﻩ ﻃﺒﻴﻌﻴﺎ‪ ،‬ﻭﳌﻌﺮﻓﺔ ﺃﻱ ﺃﻣﻼﺡ ﺍﻟﻔﻠﻮﺭ ﻳﺰﻭﺩ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴـﺔ‬
‫ﺑﺄﻳﻮﻧﺎﺕ ﺍﻟﻔﻠﻮﺭ ﻋﱪ ﺍﻟﺘﺤﺎﻟﻴﻞ ﺍﳌﺨﱪﻳﺔ ﻭﺑﺮﺍﻣﺞ ﺍﻟﻜﻤﺒﻴﻮﺗﺮ ﺍﳋﺎﺻﺔ‪ ،‬ﺃﻣﻜﻦ ﺍﻟﻘﻮﻝ ﺃﻥ ﻓﻠﻮﺭﻳﺪ ﺍﻟﻜﺎﻟﺴـﻴﻮﻡ )‪ (CaF2‬ﻫـﻮ ﺍﳌﻐـﺬﻱ‬
‫ﺍﻷﻛﱪ‪ .‬ﺇﻥ ﺍﺭﺗﻔﺎﻉ ﻧﺴﺒﺔ ﺍﻟﻔﻠﻮﺭ ﰲ ﻣﻴﺎﻩ ﺍﻟﺸﺮﺏ ﻟﺒﻌﺾ ﺍﳌﻨﺎﻃﻖ ﻋﻼﻭﺓ ﻋﻠﻰ ﻭﺟﻮﺩﻩ ﻋﺎﻟﻴﺎ ﰲ ﺍﻟﺸﺎﻱ ﻭﺍﻟﻐﺬﺍﺀ‪ ،‬ﺃﻭﺟﺪ ﺃﻃﻔﺎﻻ ﺃﻛﺜـﺮ‬
‫ﻋﺮﺿﺔ ﻟﻺﺻﺎﺑﺔ ﺑﺘﺒﻘﻊ ﺍﻷﺳﻨﺎﻥ ﻭﺧﺼﻮﺻﺎ ﰲ ﻣﻨﻄﻘﺔ ﺧﺎﻧﻴﻮﻧﺲ ﺍﻟﱵ ﻳﺰﻳﺪ ﻓﻴﻬﺎ ﺍﻟﻔﻠﻮﺭ ﻋﻦ ﺛﻼﺛﺔ ﺃﺿﻌﺎﻑ ﺍﳌﻌﻴﺎﺭ ﺍﳌﺴﻤﻮﺡ ﺑﻪ‪ .‬ﻭﻟﺬﺍ‬
‫ﻓﺈﻥ ﻫﺬﺍ ﺍﳌﺮﺽ ﻳﺼﻞ ﺇﱃ ﺣﺪ ﺍﻟﻮﺑﺎﺀ ﻭﳚﺐ ﺍﻟﺘﻌﺎﻃﻲ ﻣﻌﻪ ﻭﻓﻖ ﺍﳌﻘﺮﺭﺍﺕ ﺍﻟﻌﻠﻤﻴﺔ ﺍﻟﱵ ﺃﺭﺳﺘﻬﺎ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﳉﻬﺎﺕ ﺍﳌﻌﻨﻴﺔ ﻋﺎﳌﻴﺎ ﻭﻋﻠﻰ‬
‫ﺭﺃﺳﻬﺎ ﻣﻨﻈﻤﺔ ﺍﻟﺼﺤﺔ ﺍﻟﻌﺎﳌﻴﺔ‪.‬‬
‫ﺍﻟﻔﺼﻞ ﺍﻟﺜﺎﻟﺚ‪ :‬ﻭﺍﻗﻊ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﻭﺇﻣﻜﺎﻧﻴﺔ ﺍﻹﻓﺎﺩﺓ ﻣﻨﻬﺎ‪ :‬ﺗﻌﺎﱐ ﺍﳌﻨﻄﻘﺔ ﻣﻦ ﺷﺤﺔ ﻭﻧﺪﺭﺓ ﰲ ﺍﳌﻴﺎﻩ‪ ،‬ﺍﻷﻣﺮ ﺍﻟﺬﻱ ﳚﻌﻞ ﻣﻦ ﺇﻣﻜﺎﻧﻴـﺔ‬
‫ﺍﻹﻓﺎﺩﺓ ﻣﻦ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﺍﳌﻌﺎﳉﺔ ﺃﻣﺮﺍ ﺣﻴﻮﻳﺎ ﻭﻣﻠﺤﺎ‪ ،‬ﻫﺬﺍ ﺇﺫﺍ ﻋﻠﻤﻨﺎ ﺃﻥ ﺃﻛﺜﺮ ﻣﻦ ﻣﺎﺋﺔ ﺃﻟﻒ ﻣﺘﺮﺍ ﻣﻜﻌﺒﺎ ﻳﺘﻢ ﺗﺼﺮﻳﻔﻬﺎ ﺇﻣﺎ ﻟﻠﺒﺤﺮ ﺃﻭ‬
‫ﺇﱃ ﺍﻟﻮﺩﻳﺎﻥ ﻭﺍﻷﻣﺎﻛﻦ ﺍﳌﻔﺘﻮﺣﺔ‪ ،‬ﻭﻟﺪﺭﺍﺳﺔ ﻫﺬﺍ ﺍﳋﻴﺎﺭ ﻭﺇﻗﺮﺍﺭﻩ ﻟﻸﳘﻴﺔ‪ ،‬ﺃﹸﺟﺮﻳﺖ ﺍﻟﺪﺭﺍﺳﺔ ﻋﻠﻰ ﳏﻄﱵ ﻏﺰﺓ ﻭﺑﻴﺖ ﻻﻫﻴـﺎ‪ ،‬ﻭﺫﻟـﻚ‬
‫ﻟﺘﺒﻴﺎﻥ ﻧﻮﻋﻴﺔ ﻫﺬﻩ ﺍﳌﻴﺎﻩ ﺍﻟﺪﺍﺧﻠﺔ ﻭﺍﳋﺎﺭﺟﺔ )ﺍﳌﻌﺎﳉﺔ( ﻭﻏﻄﺖ ﺍﳉﺎﻧﺐ ﺍﻟﻜﻴﻤﻴﺎﺋﻲ ﺑﺎﻟﺘﻔﺼﻴﻞ‪ ،‬ﻣﻊ ﺇﺩﺭﺍﻛﻬﺎ ﻷﳘﻴﺔ ﺍﳉﺎﻧﺐ ﺍﻟﺒﻴﻮﻟﻮﺟﻲ‬
‫)ﺍﻟﺒﻜﺘﲑﻱ ﻭﺍﻟﻔﲑﻭﺳﻲ(‪ .‬ﻛﻤﺎ ﻭﻏﻄﺖ ﺍﻟﺪﺭﺍﺳﺔ ﻭﺑﺸﻜﻞ ﻣﺴﺘﻔﻴﺾ ﺍﳌﻮﺍﺻﻔﺎﺕ ﺍﻟﻜﻴﻤﻴﺎﺋﺔ ﻟﻠﺤﻤﺄﺓ )‪ .(Sludge‬ﻭﺧﻠﺼﺖ ﺍﻟﺪﺭﺍﺳﺔ‬
‫ﺇﱃ ﺃﻥ ﳏﻄﺎﺕ ﺍﳌﻌﺎﳉﺔ ﺍﳌﺘﻮﺍﺿﻌﺔ ﰲ ﺃﺩﺍﺋﻬﺎ‪ ،‬ﻗﺎﺩﺭﺓ ﻋﻠﻰ ﺍﺳﺘﻴﻌﺎﺏ ﻭﻣﻌﺎﳉﺔ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﺍﻟﱵ ﺗﺼﻞ ﺇﻟﻴﻬﺎ‪ ،‬ﻛﻤﺎ ﺃ‪‬ﺎ ﻗـﺎﺩﺭﺓ ﻋﻠـﻰ‬
‫ﻣﻌﺎﳉﺔ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﺍﻟﺼﻨﺎﻋﻴﺔ ﺍﻟﱵ ﺗﺼﻞ ﺇﻟﻴﻬﺎ )ﺣﱴ ﻭﻗﺖ ﺍﻟﺪﺭﺍﺳﺔ(‪ ،‬ﲝﻴﺚ ﺃﻥ ﺍﳌﻴﺎﻩ ﺍﳌﻌﺎﳉﺔ ﺍﳋﺎﺭﺟﺔ ﻣﻦ ﺍﶈﻄﺘﲔ ﺗﺘﺸﺎﺑﻪ ﺇﱃ ﺣﺪ‬
‫‪xi‬‬
‫ﻛﺒﲑ ﻭﺗﻨﺴﺠﻢ ﻭﺍﳌﻌﺎﻳﲑ ﺍﻟﻌﺎﳌﻴﺔ‪ ،‬ﻭﻟﺬﺍ ﺗﻮﺻﻲ ﺍﻟﺪﺭﺍﺳﺔ ﺑﺎﻹﻓﺎﺩﺓ ﻣﻦ ﻫﺬﻩ ﺍﳌﻴﺎﻩ ﺍﳌﻌﺎﳉﺔ‪ ،‬ﻭﺍﻋﺘﺒﺎﺭﻫﺎ ﻣﺼﺪﺭﺍ ﻫﺎﻣﺎ ﻟﻠﻤﻴﺎﻩ ﳚﺐ ﻋـﺪﻡ‬
‫ﺍﻟﺘﻔﺮﻳﻂ ﻓﻴﻪ‪ ،‬ﻭﺍﺳﺘﺨﺪﺍﻣﻬﺎ ﰲ ﻗﻄﺎﻉ ﺍﻟﺰﺭﺍﻋﺔ ﻭﺧﺼﻮﺻﺎ ﺍﻷﺷﺠﺎﺭ‪ ،‬ﺃﻭ ﻧﻘﻠﻬﺎ ﺇﱃ ﻭﺍﺩﻱ ﻏﺰﺓ ﺿﻤﻦ ﺧﻄﺔ ‪‬ﺪﻑ ﺇﱃ ﺍﻟﻨﻬﻮﺽ ‪‬ـﺬﺍ‬
‫ﺍﻟﻘﻄﺎﻉ ﺍﻟﺒﻴﺌﻲ ﺍﳊﻴﻮﻱ ﺍﳍﺎﻡ‪ ،‬ﺿﻤﻦ ﺩﺭﺍﺳﺎﺕ ﻋﻠﻤﻴﺔ ﻭﺍﻋﻴﺔ‪.‬‬
‫ﺇﻻ ﺃﻥ ﻣﺎﻧﻌﺎ ﻫﺎﻣﺎ ﳛﺪ ﻣﻦ ﺇﻣﻜﺎﻧﻴﺔ ﺍﻹﻓﺎﺩﺓ ﻣﻦ ﺍﳊﻤﺄﺓ ﰲ ﺍﻟﺰﺭﺍﻋﺔ ﺃﻻ ﻭﻫﻮ ﺇﺭﺗﻔﺎﻉ ﻧﺴﺒﺔ ﻛـﻞ ﻣـﻦ ﺍﻟﺰﻧـﻚ )‪(>2000 mg/l‬‬
‫ﻭﺍﳍﺎﻟﻮﺟﻴﻨﺎﺕ ﺍﻟﻌﻀﻮﻳﺔ ﻭﺍﳌﺬﺍﺑﺔ )‪ (Adsorbable Organic Halogens‬ﺇﱃ ﺃﻛﺜﺮ ﻣﻦ )‪ (500 mg Cl/kg‬ﻭﻫﺬﻩ ﺍﻟﻨﺴـﺐ‬
‫ﺗﺰﻳﺪ ﻋﻦ ﻣﻌﺎﻳﲑ ﺍﻟﺪﻭﻝ ﺍﻟﺼﻨﺎﻋﻴﺔ‪.‬‬
‫ﺍﻟﻔﺼﻞ ﺍﻟﺮﺍﺑﻊ‪ :‬ﺁﺛﺎﺭﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﻋﻠﻰ ﺍﻟﺘﺮﺑﺔ ﻭﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ‪ :‬ﲤﺖ ﺩﺭﺍﺳﺔ ﺁﺛﺎﺭ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﻭﺍﳊﻤﺄﺓ ﻋﻠﻰ ﺍﻟﺘﺮﺑﺔ ﻭﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴـﺔ ﰲ‬
‫ﻣﻨﻄﻘﺔ ﳏﻄﺔ ﺍ‪‬ﺎﺭﻱ ﺍﳌﺮﻛﺰﻳﺔ ﰲ ﻏﺰﺓ‪ .‬ﻭﻗﺪ ﰎ ﺣﻔﺮ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﻵﺑﺎﺭ ﺳﻮﺍﺀ ﺩﺍﺧﻞ ﺃﺣﻮﺍﺽ ﺍﳌﻌﺎﳉﺔ ﺃﻭ ﺣﻮﳍﺎ‪ ،‬ﻭﰎ ﲨﻊ ﻋﻴﻨـﺎﺕ‬
‫ﺍﻟﺘﺮﺑﺔ ﻣﻦ ﺍﻷﻋﻤﺎﻕ ﺍﳌﺨﺘﻠﻔﺔ ﻭﺻﻮﻻ ﻟﻠﻤﻴﺎﻩ ﺍﳉﻮﻓﺔ ﺍﻟﱵ ﰎ ﲨﻌﺎ‪ ،‬ﻭﺣﺎﻭﻟﺖ ﺍﻟﺪﺭﺍﺳﺔ ﺇﳚﺎﺩ ﺍﻟﺮﺍﺑﻂ ﺑﲔ ﺍﻟﺴﻄﺢ ﻭﺍﳊـﻮﺽ ﺍﳉـﻮﰲ‪.‬‬
‫ﻭﺧﻠﺼﺖ ﺍﻟﺪﺭﺍﺳﺔ ﺇﱃ ﺃﻥ ﺍﻟﻄﺒﻘﺔ ﺍﻟﺴﻄﺤﻴﺔ )‪ (40 cm‬ﻣﻦ ﺍﻟﺘﺮﺑﺔ ﻫﻲ ﺍﻟﱵ ﺗﺘﺄﺛﺮ ﻣﺒﺎﺷﺮﺓ ﲟﺎ ﻳﻌﻠﻮﻫﺎ ﻣﻦ ﻣﻴﺎﻩ ﻋﺎﺩﻣﺔ ﺃﻭ ﲪﺄﺓ‪ ،‬ﻭﺑﻌﺪ‬
‫ﺫﻟﻚ ﺗﺒﺪﻭ ﺍﻟﺘﺮﺑﺔ ﺃﺑﻌﺪ ﻣﺎ ﻳﻜﻮﻥ ﻋﻦ ﺍﻟﺘﺄﺛﺮ‪ ،‬ﻛﻤﺎ ﺃﻇﻬﺮﺕ ﺍﻟﺪﺭﺍﺳﺔ ﺍﻹﺭﺗﺒﺎﻁ ﺍﻟﻮﺛﻴﻖ ﺑﲔ ﺃﻧﻮﺍﻉ ﺍﻟﺘﺮﺑﺔ ﻭﻣـﺪﻯ ﺃﺣﺘﻮﺍﺋﻬـﺎ ﻋﻠـﻰ‬
‫ﺍﻟﻌﻨﺎﺻﺮ‪ ،‬ﻓﺎﻟﻘﻄﺎﻋﺎﺕ ﺍﻟﻄﻴﻨﻴﺔ ﺃﻛﺜﺮ ﺃﺣﺘﻮﺍﺀ ﻣﻦ ﺍﻟﺮﻣﻠﻴﺔ‪ ،‬ﻭﺍﻷﻭﱃ ﺗﺸﻜﻞ ﻃﺒﻘﺔ ﻏﲑ ﻣﻨﻔﺬﺓ ﺗﻘﺮﻳﺒﺎ ﺍﻷﻣﺮ ﺍﻟﺬﻱ ﻳﻔﺴﺮ ﺍﻟﺘﺮﻛﻴﺰ ﺍﻟﻘﻠﻴـﻞ‬
‫ﻟﻠﻌﻨﺎﺻﺮ ﻣﺒﺎﺷﺮﺓ ﲢﺖ ﺍﻟﻘﻄﺎﻋﺎﺕ ﺍﻟﻄﻴﻨﻴﺔ‪ .‬ﻭﺑﺎﺳﺘﺜﻨﺎﺀ ﺍﻟﻨﺘﺮﺍﺕ ﺍﻟﱵ ﻣﺼﺪﺭ ﺑﻌﻀﻬﺎ ﻣﻦ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ‪ ،‬ﻓﺈﻥ ﳎﻤﻞ ﺍﻟﻌﻨﺎﺻـﺮ ﺍﻟﺜﻘﻴﻠـﺔ‬
‫ﻭﺍﻷﻳﻮﺍﺕ ﺍﻟﺸﺎﺋﻌﺔ ﻧﺴﺒﺘﻬﺎ ﲤﺎﺛﻞ ﻧﻈﲑ‪‬ﺎ ﰲ ﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ ﻟﻠﻌﺪﻳﺪ ﻣﻦ ﺍﻵﺑﺎﺭ ﺍﶈﻴﻄﺔ‪ ،‬ﻭﺗﻮﺻﻲ ﺍﻟﺪﺭﺍﺳﺔ ﻣﻦ ﺟﺪﻳﺪ ﺑﺈﻣﻜﺎﻧﻴﺔ ﺍﻹﻓﺎﺩﺓ ﻣﻦ‬
‫ﺍﳌﻴﺎﻩ ﺍﳌﻌﺎﳉﺔ ﰲ ﺍﻟﺰﺭﺍﻋﺔ ﺧﺼﻮﺻﺎ ﻟﻸﺷﺠﺎﺭ ﺍﻟﱵ ﻳﺰﻳﺪ ﻋﻤﻖ ﺟﺬﻭﺭﻫﺎ ﻋﻦ ﺍﻟﻨﺼﻒ ﻣﺘﺮ‪.‬‬
‫ﺍﻟﻔﺼﻞ ﺍﳋﺎﻣﺲ‪ :‬ﻭﺍﺩﻱ ﻏﺰﺓ‪ :‬ﻟﻘﺪ ﺣﻈﻲ ﻭﺍﺩﻱ ﻏﺰﺓ ﲜﻬﺪ ﳑﻴﺰ ﺧﻼﻝ ﺍﻟﺴﻨﻮﺍﺕ ﺍﻟﻘﻠﻴﻠﺔ ﺍﳌﺎﺿﻴﺔ‪ ،‬ﻋﱪ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﳌﺸﺎﺭﻳﻊ ﺍﳉﺎﺩﺓ ﺍﻟﱵ‬
‫‪‬ﺪﻑ ﺇﱃ ﺍﻟﻨﻬﻮﺽ ‪‬ﺬﺍ ﺍﳌﺮﻓﻖ ﺍﳊﻴﻮﻱ ﺍﻟﻮﺣﻴﺪ ﻣﻦ ﻧﻮﻋﻪ ﰲ ﻗﻄﺎﻉ ﻏﺰﺓ‪ ،‬ﻭﻗﺪ ﺭﻛﺰﺕ ﺍﳌﺸﺎﺭﻳﻊ ﻋﻠﻰ ﺩﺭﺍﺳـﺔ ﺍﻟﺘﻨـﻮﻉ ﺍﳊﻴـﻮﻱ‬
‫ﻭﺍﻟﺘﺤﺪﻳﺎﺕ ﺍﻟﺮﺍﻫﻨﺔ‪ ،‬ﻭﺍﻟﺘﻌﺮﺽ ﺍﻟﺪﺍﺋﻢ ﻟﻠﻤﺨﻠﻔﺎﺕ ﺍﻟﺼﻠﺒﺔ ﻭﺍﻟﺴﺎﺋﻠﺔ ﻭﺍﻟﺴﻴﺎﺳﺎﺕ ﺍﻟﻼﺯﻣﺔ ﳉﻌﻞ ﺍﻟﻮﺍﺩﻱ ﳏﻤﻴﺔ ﻃﺒﻴﻌﻴﺔ ﻭﺍﻋﺪﺓ‪ ،‬ﻟﻜـﻦ‬
‫ﻫﺬﺍ ﺍﻟﻔﺼﻞ ﻳﻘﺪﻡ ﻟﻠﻤﺮﺓ ﺍﻷﻭﱃ ﻣﻌﻠﻮﻣﺎﺕ ﻋﻦ ﺍﳋﺼﺎﺋﺺ ﺍﳉﻴﻮﻛﻴﻤﻴﺎﺋﻴـﺔ ﳌﻴـﺎﻩ ﻭﺍﺩﻱ ﻏـﺰﺓ ﻭﺍﻟﺮﻭﺍﺳـﺐ ﺍﻟﺮﻣﻠﻴـﺔ ﻭﺍﻟﻄﻴﻨﻴـﺔ‬
‫)‪ ،(Sediments‬ﻭﺍﻟﻌﻼﻗﺔ ﺍﻟﻜﻴﻤﻴﺎﺋﻴﺔ ﺍﻟﺘﺒﺎﺩﻟﻴﺔ ﺑﻴﻨﻬﺎ‪ ،‬ﻋﻼﻭﺓ ﻋﻠﻰ ﺗﺄﺛﲑ ﺍﻹﺧﺘﻼﻑ ﺍﻟﻔﺼﻠﻲ )ﺍﻟﺼﻴﻒ ﻭﺍﻟﺸﺘﺎﺀ( ﰲ ﻫﺬﻩ ﺍﳋﺼﺎﺋﺺ‪.‬‬
‫ﻛﻤﺎ ﻭﺗﻮﺿﻊ ﺍﻟﺪﺭﺍﺳﺔ ﺑﻌﺾ ﺍﻟﺘﻮﺻﻴﺎﺕ ﺍﳍﺎﻣﺔ ﺍﻟﻼﺯﻣﺔ ﻟﺘﺤﺴﲔ ﺍﳌﻴﺎﻩ ﰲ ﺍﻟﻮﺍﺩﻱ ﻭﺍﻟﺮﻭﺍﺳﺐ‪.‬‬
‫ﺍﻟﻔﺼﻞ ﺍﻟﺴﺎﺩﺱ‪ :‬ﺍﳋﺼﺎﺋﺺ ﺍﳉﻴﻮﻛﻴﻤﻴﺎﺋﻴﺔ ﻟﻠﺘﺮﺑﺔ ﰲ ﻏﺰﺓ‪ :‬ﺭﻏﻢ ﺻﻐﺮ ﻣﺴﺎﺣﺔ ﻗﻄﺎﻉ ﻏﺰﺓ ﻓﺈﻥ ﻫﻨﺎﻙ ﺗﻨﻮﻋﺎ ﻭﺍﺿﺤﺎ ﰲ ﺃﻧﻮﺍﻉ ﺍﻟﺘﺮﺑﺔ‬
‫ﻓﻴﻪ‪ ،‬ﻭﻗﺪ ﺭﺻﺪﺕ ﺍﻟﺪﺭﺍﺳﺔ ﻫﺬﻩ ﺍﻷﻧﻮﺍﻉ ﻭﺗﻮﺯﻳﻌﻬﺎ‪ ،‬ﻭﺭﻛﺰﺕ ﻋﻠﻰ ﺗﺄﺛﲑ ﺍﻟﻨﺸﺎﻁ ﺍﻟﺒﺸﺮﻱ ﻋﻠﻰ ﺍﳋﺼﺎﺋﺺ ﺍﳉﻴﻮﻛﻴﻤﻴﺎﺋﻴﺔ ﻟﻠﺘﺮﺑﺔ‪ .‬ﺇﻥ‬
‫ﺍﻟﻌﻴﻨﺎﺕ ﺍﻟﱵ ﲨﻌﺖ ﲤﺜﻞ ﻛﺎﻓﺔ ﺍﳌﻨﺎﻃﻖ ﰲ ﺍﻟﻘﻄﺎﻉ‪ ،‬ﻭﲤﺜﻞ ﻛﺬﻟﻚ ﺍﻟﺘﺮﺑﺔ ﲢﺖ ﺗﺄﺛﲑ ﺯﺭﺍﻋـﺎﺕ ﳐﺘﻠﻔـﺔ‪ ،‬ﺍﻟﺒﻴـﻮﺕ ﺍﻟﺒﻼﺳـﺘﻴﻜﻴﺔ‪،‬‬
‫ﺍﳋﻀﺮﻭﺍﺕ ﺍﻟﺼﻴﻔﻴﺔ ﻭﺍﻟﺸﺘﻮﻳﺔ‪ ،‬ﻭﺍﻷﺷﺠﺎﺭ ﺍﳌﺜﻤﺮﺓ‪ .‬ﻛﻤﺎ ﱂ ﺗﻐﻔﻞ ﺍﻟﺪﺭﺍﺳﺔ ﺗﺄﺛﲑ ﺍﳌﻴﺎﻩ ﺍﻟﻌﺎﺩﻣﺔ ﻭﺍﳊﻤﺄﺓ ﻭﺍﻟﻨﻔﺎﻳﺎﺕ ﺍﻟﺼـﻠﺒﺔ ﻋﻠـﻰ‬
‫ﺍﻟﺘﺮﺑﺔ‪ ،‬ﺇﺿﺎﻓﺔ ﳌﻮﻗﻊ ﺍﻟﺘﺮﺑﺔ ﻭﻗﺮ‪‬ﺎ ﻣﻦ ﻃﺮﻕ ﺍﳌﻮﺍﺻﻼﺕ ﺍﻟﺴﺮﻳﻌﺔ ﻭﺗﺄﺛﺮﻫﺎ ‪‬ﺎ‪ .‬ﻭﻗﺪ ﺃﻓﺎﺩﺕ ﺍﻟﺪﺭﺍﺳﺔ ﻣﻦ ﲢﻠﻴﻞ ﺍﻟﻌﻨﺎﺻﺮ ﺍﻟﺜﻘﻴﻠﺔ ﻷﻫﻢ‬
‫ﺍﻷﲰﺪﺓ ﻭﺍﳌﺨﺼﺒﺎﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﻭﺗﺄﺛﲑﻫﺎ ﰲ ﺍﻟﺘﺮﺑﺔ‪.‬‬
‫ﺍﻟﻔﺼﻞ ﺍﻟﺴﺎﺑﻊ‪ :‬ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﻭﻣﺼﲑﻫﺎ ﰲ ﺍﻟﺘﺮﺑﺔ ﻭﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ‪ :‬ﻳﻌﺎﱐ ﻗﻄﺎﻉ ﻏﺰﺓ ﻣﺜﻠﻪ ﻣﺜﻞ ﺑﺎﻗﻲ ﺍﳌﻨﻄﻘﺔ ﺍﻟﻌﺮﺑﻴﺔ‪ ،‬ﻳﻌﺎﱐ ﻧﻘﺼﺎ‬
‫ﺣﺎﺩﺍ ﰲ ﺍﳌﻌﻠﻮﻣﺎﺕ ﺍﳌﺘﻌﻠﻘﺔ ﺑﻮﺟﻮﺩ ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﰲ ﺍﻟﺒﻴﺌﺔ‪ ،‬ﻣﺼﺎﺩﺭﻫﺎ‪ ،‬ﺗﺼﻨﻴﻌﻬﺎ‪ ،‬ﺍﺳﺘﺨﺪﺍﻣﻬﺎ‪ ،‬ﻭﺁﺛﺎﺭﻫﺎ‪ .‬ﻭﺫﻟﻚ ﻟﻌﺪﺓ ﺃﺳﺒﺎﺏ‬
‫‪xii‬‬
‫ﺃﳘﻬﺎ‪ ،‬ﻏﻴﺎﺏ ﺃﻧﻈﻤﺔ ﺍﻟﺮﻗﺎﺑﺔ ﻭﺍﻟﺘﻔﺘﻴﺶ‪ ،‬ﻭﻗﻠﺔ ﺍﻟﻮﻋﻲ ﻟﺪﻯ ﺍﻟﺒﺎﻋﺔ ﻭﺍﳌﺰﺍﺭﻋﲔ‪ ،‬ﻭﻧﻘﺺ ﺍﻟﺘﺠﻬﻴﺰﺍﺕ ﺍﳌﺨﱪﻳﺔ ﻭﺍﳋﱪﺍﺕ ﺍﻟﺒﺸﺮﻳﺔ‪،‬‬
‫ﻛﺬﻟﻚ ﺍﻟﻄﺮﻕ ﺍﳌﻌﻘﺪﺓ ﻭﺍﳌﻜﻠﻔﺔ ﻭﺍﻟﱵ ﺗﺴﺘﻐﺮﻕ ﻭﻗﺘﺎ ﻃﻮﻳﻼ ﻟﻠﻘﻴﺎﻡ ﺑﺎﻟﺘﺤﺎﻟﻴﻞ ﺍﻟﻼﺯﻣﺔ‪ .‬ﻟﺬﺍ ﲡﻲﺀ ﻫﺬﻩ ﺍﻟﺪﺭﺍﺳﺔ ﺍﻷﻭﱃ ﻣﻦ ﻧﻮﻋﻬﺎ ﰲ‬
‫ﺍﳌﻨﻄﻘﺔ‪ ،‬ﻟﺘﺠﻤﻊ ﺃﻛﺜﺮ ﻣﻦ ﺛﻼﺙ ﻣﺎﺋﺔ ﻋﻴﻨﺔ ﺑﻴﺌﻴﺔ ﻭﻋﱪ ﺛﻼﺙ ﺳﻨﻮﺍﺕ ﰎ ﲡﻬﻴﺰ ﻫﺬﻩ ﺍﻟﻌﻴﻨﺎﺕ ﻭﲢﻠﻴﻠﻬﺎ‪ ،‬ﻭﻣﻦ ﰒ ﳏﺎﻭﻟﺔ ﺍﻹﺟﺎﺑﺔ ﻋﻠﻰ‬
‫ﺍﻟﺴﺆﺍﻝ ﺍﳍﺎﻡ‪ :‬ﺃﻳﻦ ﺗﺬﻫﺐ ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﺍﻟﱵ ﺗﺴﺘﺨﺪﻡ ﰲ ﻏﺰﺓ ﻋﱪ ﻭﺟﻮﺩﻫﺎ ﰲ ﺍﻟﺘﺮﺑﺔ ﻭﺍﳌﻴﺎﻩ ﺍﳉﻮﻓﻴﺔ؟ ﻟﻘﺪ ﺍﻗﺘﺮﻥ ﺍﻟﻨﺸﺎﻁ‬
‫ﺍﻟﺰﺭﺍﻋﻲ ﰲ ﻗﻄﺎﻉ ﻏﺰﺓ ﺑﺎﺳﺘﺨﺪﺍﻡ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﺍﻷﻣﺮ ﺍﻟﺬﻱ ﻫﺪﺩ ﻛﻼ ﻣﻦ ﺍﻟﺘﺮﺑﺔ ﻭﺍﳌﻴﺎﻩ ﻭﺟﻌﻠﻬﻤﺎ ﻋﺮﺿﺔ ﻟﻠﺘﻠﻮﺙ‪.‬‬
‫ﻭﻗﺪ ﲤﺖ ﻣﺮﺍﻗﺒﺔ ﻛﻞ ﺁﺑﺎﺭ ﺍﻟﺒﻠﺪﻳﺎﺕ ﻭﺑﻌﺾ ﺍﻵﺑﺎﺭ ﺍﳋﺎﺻﺔ ﻭﻋﻠﻰ ﻣﺪﺍﺭ ﺛﻼﺛﺔ ﺃﻋﻮﺍﻡ ﻋﻼﻭﺓ ﻋﻠﻰ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﻋﻴﻨﺎﺕ ﺍﻟﺘﺮﺑﺔ ﺍﻟﱵ ﺗﻐﻄﻲ‬
‫ﳐﺘﻠﻒ ﻣﻨﺎﻃﻖ ﺍﻟﻘﻄﺎﻉ‪ .‬ﻭﺃﻇﻬﺮﺕ ﺍﻟﻨﺘﺎﺋﺞ ﺃﻥ ﺍﳌﺒﻴﺪﺍﺕ ﰲ ﺃﻛﺜﺮ ﻣﻦ ‪ %92‬ﻣﻦ ﺍﻵﺑﺎﺭ ﲢﺖ ﺍﳌﺴﺘﻮﻯ ﺍﻟﺬﻱ ﻗﺮﺭﺗﻪ ﻣﻨﻈﻤﺔ ﺍﻟﺼﺤﺔ‬
‫ﺍﻟﻌﺎﳌﻴﺔ‪ .‬ﺇﻻ ﺃﻥ ﺍﻟﻨﺴﺒﺔ ﺍﻟﺒﺎﻗﻴﺔ ﺃﻇﻬﺮﺕ ﺃﺭﻗﺎﻣﺎ ﻣﺮﺗﻔﻌﺔ ﻟﺒﻌﺾ ﺍﳌﺒﻴﺪﺍﺕ‪ .‬ﻭﻫﺬﻩ ﺍﻷﺭﻗﺎﻡ ﲡﺎﻭﺯﺕ ﺑﻜﺜﲑ ﻣﺎ ﻫﻮ ﻣﺴﻤﻮﺡ ﺑﻪ ﻋﺎﳌﻴﺎ ﰲ‬
‫ﻣﻴﺎﻩ ﺍﻟﺸﺮﺏ‪ .‬ﻛﻤﺎ ﺃﻇﻬﺮﺕ ﺍﻟﺪﺭﺍﺳﺔ ﺗﻼﺯﻣﺎ ﻭﺍﺿﺤﺎ ﺑﲔ ﻣﻠﻮﺣﺔ ﺍﳌﻴﺎﻩ ﻭﺗﺮﻛﻴﺰ ‪ .Atrazine‬ﻭﻋﻤﻮﻣﺎ ﻓﺈﻥ ﺁﺑﺎﺭ ﺍﻟﺒﻠﺪﻳﺎﺕ ﺃﻓﻀﻞ‬
‫ﻣﻦ ﺍﻵﺑﺎﺭ ﺍﻟﺰﺭﺍﻋﻴﺔ ﺍﳋﺎﺻﺔ‪ ،‬ﻋﻠﻤﺎ ﺑﺄﻥ ﺑﻌﺾ ﺁﺑﺎﺭ ﺍﻟﺒﻠﺪﻳﺎﺕ ﺍﻟﱵ ﺍﺳﺘﺨﺪﻣﺖ ﻟﻌﻘﻮﺩ ﻣﺎﺿﻴﺔ ﻛﺂﺑﺎﺭ ﺯﺭﺍﻋﻴﺔ ﺃﻇﻬﺮﺕ ﺗﻠﻮﺛﺎ ﺑﺒﻌﺾ‬
‫ﺍﳌﺒﻴﺪﺍﺕ‪ .‬ﻭﺃﻣﺎ ﻋﻴﻨﺎﺕ ﺍﻟﺘﺮﺑﺔ ﻓﺈﻥ ﺍﻟﻌﺪﻳﺪ ﻣﻦ ﺍﳌﺒﻴﺪﺍﺕ ﺍﳌﻤﻨﻮﻋﺔ ﺩﻭﻟﻴﺎ ﻗﺪ ﻭﺟﺪﺕ ﺑﻨﺴﺐ ﻋﺎﻟﻴﺔ ﻣﺜﻞ ‪ DDT‬ﻭﻣﺸﺘﻘﺎﺗﻪ‪.‬‬
‫ﺍﻟﻔﺼﻞ ﺍﻟﺜﺎﻣﻦ‪ :‬ﻣﺪﻯ ﺃﺣﺘﻮﺍﺀ ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﻋﻠﻰ ﺍﳌﻌﺎﺩﻥ ﺍﻟﺜﻘﻴﻠﺔ‪ :‬ﺗﻠﺘﻔﺖ ﺍﻷﻧﻈﺎﺭ ﻋﺎﺩﺓ ﺇﱃ ﺍﻟﻜﻴﻤﻴﺎﺀ ﺍﻟﻌﻀﻮﻳﺔ ﻋﻨـﺪﻣﺎ ﺗـﺬﻛﺮ‬
‫ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ‪ ،‬ﻟﻜﻦ ﺍﻟﻜﻴﻤﻴﺎﺀ ﻏﲑ ﺍﻟﻌﻀﻮﻳﺔ ﻟﻠﻤﺒﻴﺪﺍﺕ ﻻ ﲢﻈﻰ ﺑﺎﻹﻫﺘﻤﺎﻡ ﺍﳌﺸﺎﺑﻪ‪ ،‬ﻭﰲ ﺫﻟﻚ ﻛﻞ ﺍﳊﻖ‪ ،‬ﻫﺬﺍ ﺇﺫﺍ ﺍﻓﺘﺮﺿﻨﺎ ﻭﺟﻮﺩ‬
‫ﺭﻗﺎﺑﺔ ﺩﺍﺋﻤﺔ ﻋﻠﻰ ﺗﺼﻨﻴﻊ ﻭﺍﺳﺘﲑﺍﺩ ﻭﺗﺴﻮﻳﻖ ﺍﳌﺒﻴﺪﺍﺕ‪ ،‬ﺍﻷﻣﺮ ﺍﻟﺬﻱ ﻣﺂﻟﻪ ﺍﻟﺘﻄﺎﺑﻖ ﺍﻟﺘﺎﻡ ﺑﲔ ﺍﻟﺘﺮﻛﻴﺐ ﺍﻟﻜﻴﻤﻴﺎﺋﻲ ﺍﻟﻨﻈـﺮﻱ ﻟﻠﻠﻤﺒﻴـﺪ‬
‫ﺍﻟﺰﺭﺍﻋﻲ ﻭﺗﺮﻛﻴﺒﻪ ﺍﻟﺬﻱ ﺗﻜﺸﻔﻪ ﺍﻟﻔﺤﻮﺻﺎﺕ ﺍﳌﺨﱪﻳﺔ‪ ،‬ﺇﻧﻪ ﻣﻦ ﺧﻼﻝ ﺇﺩﺭﺍﻙ ﻭﺍﻗﻊ ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﰲ ﻏﺰﺓ‪ ،‬ﳔﻠﺺ ﺇﱃ ﺍﻟﻘﻮﻝ ﺑﺄ‪‬ﺎ‬
‫ﰲ ﺳﻮﺍﺩﻫﺎ ﺍﻷﻋﻈﻢ ﻣﺴﺘﻮﺭﺩﺓ ﺃﻭ ﻣﻬﺮﺑﺔ‪ ،‬ﻭﺍﻟﻘﻠﻴﻞ ﻣﻨﻬﺎ ﻣﺼﻨﻊ ﳏﻠﻴﺎ‪ .‬ﻭﺇﻥ ﻏﻴﺎﺏ ﺃﻧﻈﻤﺔ ﺍﳌﺮﺍﻗﺒﺔ ﻭﺍﻟﺘﻔﺘﻴﺶ ﻋـﻼﻭﺓ ﻋﻠـﻰ ﺍﳉﻬـﻞ‬
‫ﺑﺄﺳﻠﻮﺏ ﺍﻟﺘﻌﺎﻣﻞ ﻣﻊ ﺍﳌﺒﻴﺪﺍﺕ ﻭﻃﺮﻕ ﺣﻔﻈﻬﺎ ﻭﲣﺰﻳﻨﻬﺎ ﻭﺗﺮﻛﻴﺒﻬﺎ ﻭﺑﻴﻌﻬﺎ ﺃﻇﻬﺮ ﺃﻥ ﻣﻌﻈﻢ ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﰲ ﺍﻷﺳﻮﺍﻕ ﻻ ﻳﺘﻔـﻖ‬
‫ﺗﺮﻛﻴﺒﻬﺎ ﺍﻟﻜﻴﻤﻴﺎﺋﻲ ﺍﳌﻮﺿﺢ ﻋﻠﻴﻬﺎ )ﺇﻥ ﻭﺟﺪ( ﻣﻊ ﺍﻟﻨﺘﺎﺋﺞ ﺍﻟﻌﻤﻠﻴﺔ ﻟﻠﺘﺤﺎﻟﻴﻞ ﺍﳌﺨﱪﻳﺔ‪ ،‬ﻭﺗﺮﺟﺢ ﺍﻟﺪﺭﺍﺳﺔ ﺃﻥ ﺗﻜﻮﻥ ﺍﻷﺳﺒﺎﺏ ﻋـﻼﻭﺓ‬
‫ﻋﻠﻰ ﻣﺎ ﺳﺒﻖ‪ ،‬ﻫﻲ ﺧﻠﻂ ﺍﳌﺒﻴﺪﺍﺕ ﺍﻟﺰﺭﺍﻋﻴﺔ ﺩﻭﻥ ﺃﺳﺲ ﻋﻠﻤﻴﺔ ﻭﻟﻜﻦ ﳌﻌﺎﻳﲑ ﻣﺎﺩﻳﺔ ﲝﺘﺔ‪ ،‬ﻭﻛﺬﻟﻚ ﲣﺰﻳﻨﻬﺎ ﰲ ﻋﺒﻮﺍﺕ ﺗﺆﺛﺮ ﻭﺗﺘـﺄﺛﺮ‬
‫ﺑﺎﳌﺒﻴﺪﺍﺕ‪.‬‬
‫ﺧﺘﺎﻣﺎ‪ ،‬ﻓﻘﺪ ﻃﺮﺣﺖ ﺍﻟﺪﺭﺍﺳﺔ ﻣﻮﺍﺿﻴﻊ ﻋﻠﻤﻴﺔ ﻟﻠﻤﺮﺓ ﺍﻷﻭﱃ ﰲ ﻗﻄﺎﻉ ﻏﺰﺓ‪ ،‬ﻭﻫﻲ ﺗﺸﻜﻞ ﺃﺳﺎﺳﺎ ﻟﻠﻌﺪﻳﺪ ﻣﻦ ﺍﻷﲝﺎﺙ ﺍﻟﺘﺨﺼﺼـﻴﺔ‬
‫ﺍﳌﺘﻌﻤﻘﺔ ﻣﺴﺘﻘﺒﻼ‪ ،‬ﻭﺧﺼﻮﺻﺎ ﺗﻠﻚ ﺍﻟﱵ ﺗﻌﲎ ﺑﺎﳌﺴﺘﻘﺒﻞ ﺍﻟﺒﻴﺌﻲ ﻟﻠﻤﻨﻄﻘﺔ ﻭﺻﺤﺔ ﺍﻹﻧﺴﺎﻥ‪.‬‬
‫‪xiii‬‬
BACKGROUND FOR GROUWNDWATER, WASTEWATER, SOIL,
WADI GAZA AND PESTICIDES IN THE ENVIRONMENT OF THE
GAZA STRIP
FOREWORD
The issue of environmental protection is one of the top priorities to governments and
individuals of all countries. The problems of environmental pollution are of global concern
due to drastic effects they have on human health, on air, water and soil, on ecological systems
and on all kinds of life on the planet earth. Nowadays, pollution is considered the first priority
among the environmental problems facing the contemporary world.
The environment in Palestine suffers from considerable strains. The severe effects of
occupation and the shortage and pollution of resources, coupled with high population growth
and insufficient job opportunities have created many environmental hazards. Shortage of
water and deterioration of water quality constitute a limiting factor in the economic
development of Palestine. Occupation’s security pretexts and frequent closures of Palestinian
territories caused disruption of economic and municipal activities and aggravated the existing
pollution in every city, town or village in Palestine.
The Gaza Strip as one of the most densely populated areas in the world with limited and
deteriorated resources has already started to suffer the outcomes of environmental quality
deterioration. The situation in the Gaza Strip is below the desired standard which is attributed
to the prolonged occupation and the absence of environmental legislation and the public
awareness. Therefore, there should be collective and serious efforts on the local, regional and
international levels to improve and protect the environment by prevention and monitoring the
environmental themes with emphasis on the environmental hot spots.
The earth witnesses today an unprecedented increase in environmental problems. The
enormous overall population growth and consequent industrial, agricultural, energy
generation and communication boom of activities have led to the disturbance of
environmental equilibrium dynamics.
The following section summarizes the PhD work according to the guidelines and instructions
of the Faculty for accumulative thesis. The section shows major units of the work starting
from the main objectives, methodology, results, conclusions and recommendations. It was so
hard to bring different topics in one section, so the following section treats these topics on
scientific bases with logical framework keeping details, figures, tables in the main chapters of
the study. The structure of this section integrates water issues in one unit, then wastewater
and sludge, soil, Wadi Gaza and pesticides. The sequence is based on the fact that more
population causes more stress and pressure on the available-limited natural resources in terms
of exploitation and contamination.
Groundwater is the only source of water in Gaza and several factors are causing the
deterioration of water quality. The study tries to find these factors and the role of each factor.
The generated wastewater is affecting most of environmental elements in Gaza,
contamination of sea and seashore, soil, wadies, and groundwater.
I
1. Groundwater Quality
Objectives
1. To achieve an understanding of the quality of the groundwater as it currently exists and to
determine if any of the parameters tested pose a threat to human health in the Gaza Strip.
2. To determine the average levels of fluoride in groundwater and top soils of the Gaza Strip.
3. To determine the levels of fluoride in the prepared tea and tea leaves used in Gaza.
4. To identify the major fluoride minerals in soil that may supply groundwater with fluoride
ions.
5. To determine the dental fluorosis index (DFI) for school children of both sexes in the age
range 5-16 years, and then the community fluorosis index (CFI) followed by the number of
teeth with caries.
General Methodology (Sampling and Analysis)
Groundwater (and surface water) samples were collected in laboratory certified clean bottles
and labeled as to the well location, date and time of sample collection, analyses to be
performed, and field preservation performed, if any. Preservation of samples in the field was
done to avoid revisiting the wells if mistakes occurred while adding the chemicals to the
samples.
One-liter samples were collected and placed in a sampling ice-box and transferred to the
laboratory. The sample was divided into two subsamples: the first (500 ml) was filtered in an
acid-washed filter holder and through 0.45 µm pore size membrane filters, the first few
milliliters were used for rinsing, then they were discarded, and the filtrate was transferred to
clean acid-washed polyetheylene bottles and acidified by concentrated nitric acid (Ultrapur,
Merck, v/v), and stored at 4 oC until analyses by ICP/MS (Perkin Elmer-Sciex, Elan 6000).
The total content of Ag, Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Ni, Pb, Sr and Zn was
determined next to the cations of Ca, K, Mg and Na. The other part of the water was filtered
with no additives and stored at 4 oC for anion analyses by Ion Chromatography (IC). Several
parameters were measured in the water samples during the fieldwork: temperature, turbidity,
electric conductivity and pH; other parameters were measured in the laboratory.
As excessive fluoride concentrations are known to be problematic in this area, fluorides were
measured also, using Ion Selective Electrode (ISE) according to the American standard
methods (APHA, 1995).
Fluorides in tea and soil were determined in composite soil samples. Samples were collected
using a stainless steel dredge; approximately 0.5 kg was put in polyethylene cups and stored
at 4 oC during its transport to laboratories where the soil was dried in an oven at 50 oC until it
reached a constant weight. Then the samples were shipped to Germany in plastic sampling
bags. The samples were sieved through a 20-µm sieve and ground to a very soft powder by
using a sand mill (FRITSCH-Labor Planeten Mühle, pulverisette 5). Approximately 50 mg of
sample was placed in a nickel crucible, then 2 g of 1:1 Na2CO3-K2CO3 (anhydrous dried at
110 oC overnight) was added to the sample in the crucible. The crucibles were placed in a
muffle furnace at 800 oC for 15 min.
After cooling, 15 ml of 1 M citric acid was added to the crucible and the mixture was allowed
to digest until CO2 evolution was no longer detected (3-4 h, or preferably overnight). Then 25
ml of sodium citrate buffer (1M) was added to the contents of the crucible. Finally, the
mixture was transferred to a 100-ml polypropylene volumetric flask where it was diluted to
the mark by deionized H2O.
II
The semi-quantitative X-ray diffraction technique (XR Diffractometer-SIEMENS) was used
to identify the major fluoride minerals in soil samples; the four major fluoride minerals were
investigated (topaz: Al2(F,OH)2SiO4; fluorite: CaF2; fluoroapatite: Ca10(PO4)6F2; cryolite:
Na3AlF6). Moreover, PHREEQC (a small program for speciation, batch-reaction, onedimensional transport, and inverse geochemical calculations) was applied to achieve the same
purpose by using groundwater data of five wells in the area of Khan Yunis where the fluoride
level is high.
Main Results
The best aquifer -in terms of fresh water- was located in Beit Lahia at the north western
corner of the Gaza Strip; the lowest EC value was 520 µS/cm and the highest was about 1000
µS/cm. The most deteriorated and salty water was in the regions of Khan Yunis and Rafah.
Approximately 85% of the wells sampled showed nitrate levels above the WHO standard (50
mg/l). The lowest value of chloride in the north area was 40 mg/l while the highest value in
the eastern parts of Rafah area was 3000 mg/l.
The results showed that the trend of the fluoride in the groundwater of the Gaza Strip was
similar to Cl, with some exceptions in the middle area. Most of the wells in Gaza have levels
less than the WHO standard (1998) of sulfate (250 mg/l), while phosphates were not detected.
Approximately 65 of the wells tested (>50% of the wells sampled) had sodium levels higher
than the WHO standard (200 mg/l). The value of K was less than 5 mg/l.
The average of Ca was 93 mg/l and the Mg/Ca ratio showed almost all points with about a
1:1 ratio.
The high fluoride contents in the groundwater (1.8 to 4 mg/l) were the main reason of the
dental fluorosis disease for school children of the Gaza Strip. Soil samples showed the same
trend of fluoride contents as the water samples. The fluoride contents in tea was 2.7 - 4.7
ppm. The average number of cups drank per person per day is indicated, the highest, 3.19
cups, being in Rafah and the lowest, 2.50 cups, in Khan Yunis. Overall, the DFI increased
going from north to south as the lowest value being in the northern area of Jabalia, 2.85, and
the highest value, 4.39, in eastern villages of Khan Yunis. The CFI for the Gaza Strip as a
whole was calculated as 2.42. Results of PHREEQC model found that the main donating
fluoride mineral is fluorite (CaF2).
The Fe, Zn, Mn, Cd, Cr, Co, Al, Hg and Ni concentrations were lower than the WHO
standards.
Discussion
The results of fluoride study will be discussed in this section. The sources of fluorides in the
groundwater of Gaza Strip are believed to be natural bedrock that supplies the fluoride ions to
the water. The results of soil samples showed good correlation with the groundwater results,
as the same general increase of fluoride is shown from north to south. For the soil samples
and the wells nearby, the correlation coefficient r of soil/water fluoride was 0.93. None of
the four fluoride minerals screened by the XRD were found in the tested soil samples. The
semi-quantitative analysis and the limit of detection of the XRD showed that there were no
distinguished peaks for the four major fluoride minerals tested. In spite of that the computer
model suggested fluorite (CaF2) as a donating fluoride mineral to groundwater.
DFI showed a slight increasing trend going from north to south. Linear regression analysis
found a correlation (r = 0.72) between the level of fluorides in drinking water and the DFI. It
must be noted here that dental fluorosis was formed during the tooth development period and
III
years before the water was analyzed, suggesting that water resources have recently been
altered.
The CFI for Gaza as a whole was calculated to be 2.42. According to Dean (1942) if the CFI
rises above 0.6, it begins to constitute a public health problem warranting increasing
consideration.
An epidemiological study of Rugg-Gunn et al., (1997) suggested that the prevalence of dental
fluorosis was high among children suffering from malnutrition. Some correlation between
drinking water type fluorosis and the population's socio-economic condition and nutritional
status is indicated. Fluorosis prevalence increases through the agricultural towns of Khan
Yunis to urban regions.
General Conclusions
1. Water in both municipal and private wells is polluted by one parameter or another;
however, the municipal groundwater wells are less polluted. The results showed that 80% of
the groundwater wells are not suitable for drinking purposes because of the high contents of
nitrates, chlorides and fluorides and some heavy metals which exceed 2-7 times the WHO
standards. Some wells have a permissible limit of nitrates but high amounts of chloride or
fluoride and vice verse.
2. The governmental classification of the Gaza Strip into five regions correlates with the
quality of the groundwater of each region.
3. The average results of trace elements in the groundwater indicated that they do not
generally pose any health or environmental hazard in the Gaza Strip. In spite of that several
private wells showed concentrations of Zn, Pb, As and Cd of more than the WHO standards.
These wells should not be used for drinking purposes. These wells are exposed to the
contaminants of the leachate of solid waste, wastewater and manure.
4. The well depth does not affect its water quality, while the location does. The ion ratios
indicated that the high levels of chloride and other ions do not appear to be due to seawater
intrusion into the aquifer only, but other water sources, including through flow from Israel,
and natural chemical changes due to soil/water interactions may cause the majority of the ion
variability in the aquifer.
5. The results of the study and the archive of groundwater geochemistry additional to the ion
ratios revealed that the reasons of the anomalous-elevated levels of Cl and other ions are the
anthropogenic factors, the lateral groundwater flow and the natural chemical changes and to a
lesser extent the seawater intrusion.
6. The levels of fluorides found in groundwater and topsoil showed a general increasing trend
from northern to southern areas of the Gaza Strip. Dental fluorosis occurred in many areas
especially in Khan Yunis (south and south-east) where the average level of fluoride for all
tested wells was 2.6 mg F/l.
7. The sources of fluorides in groundwater are believed to be natural bedrock that supplies
fluoride ions to the groundwater; however the XRD results showed that none of the major
fluoride minerals tested in soil samples were detected, the computer model-PHREEQC
revealed that fluorite (CaF2) was the donating mineral of fluoride ions to the groundwater.
IV
General Recommendations
1. Several studies should be conducted mainly on the health risk assessment and water
toxicology.
2. To improve our understanding of water quality in the aquifer an integrated monitoring
program should be conducted. The municipal wells should be sampled 2-4 times a year for
the analysis of anions, cations, heavy metals and pesticides. The data of the groundwater
quality should be centralized in a data bank or a water archive.
3. The risk of deterioration of water quality is an urgent theme. The objective of the
Palestinian water institutions should be how to safeguard the water resources system from
pollution.
4. The situation in which fluorides play an important factor in public health must be
addressed on an urgent basis to avoid an environmental health catastrophe. One of the
recommendations we suggest is integrating the water supply for Gaza as a whole.
2. Wastewater and Sludge
Objectives
1. To introduce the concentration of trace metals and some major parameters in domestic,
industrial wastewater and sludge for the first time.
2. To highlight the various options that aim to reuse the treated wastewater and sludge in the
Gaza Strip in a manner that will ensure agriculturally sustainable development.
General Methodology (Sampling and Analysis)
Grab samples of wastewater were combined in a container to form a composite sample.
Finally, one liter of the mixture was taken in an acid-washed bottle and transferred to the
laboratory, where it was filtered in an acid-washed filter holder and through 0.45 µm pore
size Sartorius membrane filters; the first few milliliters were used for rinsing, then discarded,
and the filtrate was transferred to clean acid-washed polyethylene bottles and acidified by
concentrated nitric acid (Ultrapur, Merck, v/v) to pH <2 and stored at 4 oC until analyses by
the inductive coupled plasma mass spectrometer (ICP/MS - Perkin Elmer-Sciex, Elan 6000)
were performed. Several parameters were measured during the fieldwork: temperature,
electric conductivity, and pH; other parameters (Settleable solids SS, total suspended solids
TSS, total dissolved solids TDS, chemical oxygen demand COD, and biochemical oxygen
demand BOD5) were measured a few hours later according to the American standard methods
(APHA, 1995). All other parameters were analyzed as described for groundwater samples.
Analysis of sludge samples was the same as soil and sediment mentioned below.
Main Results
The averages of calculated total organic carbon TOC for sludge are 17-22 % for Beit Lahai
and Gaza, respectively, while the results of nitrogen for the two plants showed averages that
V
are less than 2% (the American standards); nitrogen in Beit Lahia WWTP was 1.35% while it
was 1.6 in Gaza WWTP. This range puts the sludge of Gaza in an acceptable ranking for land
application.
The average of phosphorus in the sludge of Gaza plant was 0.7% while it was only 0.4% in
the sludge of the Beit Lahia plant.
Fe, Cr, Co and As have similar concentrations and no significant changes occurred during the
3 years of monitoring; however the results for As and Zn were 2-3 times higher in the years
2001 and 2002, respectively. Nickel was 2-3 times higher in Beit Lahia WWTP while Mn
and Pb were 2 times higher in the sludge of Gaza WWTP; the reason is expected to be the
fluctuation of industrial activities and the irregular production load of these elements in the
industrial wastewater. The high concentrations of Na in the sludge of Gaza (2-3 times) may
be connected to the same ratio of Na in groundwater and wastewater for the two areas.
It was found that concentration of Adsorbable organic halogens (AOX) is in the range of 200600 mg Cl/kg, while the German and EU standard is 500 mg Cl/kg.
Discussion
The results indicated that the concentrations of major anions (Cl, F, NO3 and SO4) and major
cations (Na, Ca, Mg and K) in wastewater were similar to their values in the groundwater of
the area of each treatment plant.
This raises the question about the main sources of Zn in sludge. Based on the field surveys,
the Zn sources are expected to be domestic and commercial in origin. Domestic sources of Zn
are corrosion and leaching of plumbing, water-proofing products, anti-pest products, wood
preservatives, deodorants and cosmetics, medicines and ointments, paints and pigments,
printing inks and coloring agents. The commercial sources are galvanization processes, brass
and bronze alloy production, tires, batteries, paints, plastics, rubber, fungicides, paper,
textiles, taxidermy, building materials, special cements, and also cosmetics and
pharmaceuticals.
It is proposed that the main source of AOX in sludge was the 26 paper industries distributed
in Gaza and the northern area. These industries were using old technologies and they
represented the largest consumer of chlorine and the greatest source of toxic organochlorine
discharges directly into waterways.
General Conclusions
1. The existing wastewater treatment plants in Gaza show a similar performance and the
heavy metal contents of the effluent are less than that of the standards of neighboring
countries, and the treated wastewater could be used in agriculture with respect to heavy
metals.
2. The industries in Gaza are light and they have no treatment facilities. Some individual
industries produce high amounts of heavy metals in their effluents but the wastewater
treatment plants have the capability to absorb the industrial effluents with no significant
impact on the treatment bioprocesses.
3. The existing plants produce small amounts of sludge with low contents of all tested heavy
metals except Zn, which exceeds the standards of all industrial countries. This is additional to
the AOX which is found to be more than 500mg Cl/kg in some sludge samples of Gaza
treatment plant while more than 85% of the samples have less than 500mg Cl/kg.
VI
General Recommendations
1. In addition to total metal concentrations the determination of specific chemical forms of
heavy metals and their mode of binding in soil is very important in order to estimate their
mobility, bioavailability and related ecotoxicity. Education, information, and training of
farmers also play an important role in promoting sensible reuse practices.
2. Gaza Strip is a good example for similar studies in all neighboring countries which have
similar conditions of metrology and climate, environment and natural resources, population
growth, water scarcity, wastewater management problems and finally socio-economic
situations. The findings and conclusions of wastewater reuse and sludge application could be
imitated in these similar areas not only in the region but also in many developing countries.
3. By the reuse of treated wastewater, Gaza can not only reduce the pollution load of the
Mediterranean Sea by wastewater contaminants but also consider wastewater as a precious
source of water which could be used in agriculture.
3. Soil Profile and Topsoil
Objectives
1. To establish the topsoil geochemistry in the Gaza Strip.
2. To identify the major anthropogenic inputs affecting soil geochemistry.
3. To introduce all relevant information from the Gaza central wastewater treatment plant on
hydrogeology, geochemistry, and geology.
4. To study the geochemical characteristics of an on site column of wastewater, sludge, soil,
and groundwater in the area of the Gaza central wastewater treatment plant.
General Methodology (Sampling and Analysis)
Soil samples were properly labeled and placed in waterproof plastic bags before being placed
in wooden boxes. Approximately 0.5 kg of soil was put in polyethylene cups and stored at 4
o
C during transport to laboratories where soil was dried in an oven at 50 oC until constant
weight. Then they were shipped to Germany in plastic sampling bags.
Samples were freeze-dried until complete dryness and sieved through a 2-µm sieve and
ground to a powder by using a ring mill (FRITSCH-Labor Planeten Mühle, pulverisette 5).
Approximately 0.5 to 1.0 g of each homogenized sample was dissolved in 10.5 ml of
concentrated HCl (37% p.a.) and 3.5 ml of concentrated HNO3 (65% p.a.) in 50 ml retorts.
The samples were degassed (12 h) then heated to 160 °C on a sand bath until a complete
extraction had taken place (3 h). After cooling, the solutions were diluted with distilled water
in 50 ml volumetric flasks and kept in 100 ml polyethylene bottles for analysis.
Elements were analyzed by different instruments; a flame atomic absorption (AAS vario 6Analytik Jena) for determination of Ca, Cu, K, Li, Mg, and Na; an ICP/OES (VARIAN,
VISTA-MPX) for determination of As, Cd, Co, Cr, Fe, Mn, Ni, Pb, Sr, and Zn; and an
energy-dispersive miniprobe multielement analyzer (EMMA-XRF) (Cheburkin and Shotyk,
1996) for determination of Br, Rb, Se, Th, U, Y and Zr. Mercury concentrations were
determined using atomic absorption spectroscopy after thermal combustion of freeze-dried
VII
samples (50-100 mg) and Hg pre-concentration on a single gold trap by means of an AMA
254 solid phase Hg-Analyzer (LECO).
Total carbon and sulfur were determined directly in dried samples by using a carbon-sulfur
determinator (LECO CS-225); and finally carbonates were measured directly by a carbonate
bomb (Müller and Gastner, 1971). The total organic carbon (TOC) was calculated by the
subtraction of inorganic carbon from total carbon. The distribution of total P represented as
(PO4) was measured according to APHA (1995).
Adsorbable organic halogen (AOX) was determined by a Euroglas organic halogen analyzerThe Netherlands according to the DIN 38414 S18 Deutsche Einheitsverfahren zur Wasser,
Abwasser und Schlammuntersuchung, Sludge and Sediment (Group S) Determination of
AOX (DIN, 1989).
In order to determine soil mineralogy, a semi-quantitative X-ray Diffraction technique (XR
Diffractometer, SIEMENS) (Moore and Reynolds, 1989) was used.
Main Results
The upper 40-50 cm represent a mixture of sludge and fine sand and its color starts from dark
black in the surface layer up to very light dark downward. A well-distinguished soil appears
from 20 cm depth and more. The four examples of X-ray diffractograms show that the soil
mineralogy is mainly composed, in order of abundance, of quartz, calcite, kaolinite, and some
feldspars.
Among a total of 27 elements analyzed, only a few trace elements showed environmental
relevance in Gaza: As, Cd, Cr, Hg and to a lesser extent Pb. The trace metal accumulations in
the soils affected by sludge were characterized by a large spatial variability, with some ‘hot
spots’ of Cu and Zn with concentrations of up to 1220, 1500 mg/kg, respectively.
The results of Ni, As, Se, Rb, Y and Zr were below the detection limit of the analytical
procedure. The AOX in the soils of Gaza was very low and it ranged between the detection
limit (0.5) and 20 mgCl/kg. A few sites showed high AOX values of 250 mgCl/kg due to
their location near the sludge disposal areas and solid waste dumping sites.
Total P concentration in the top soil varies between about 0.4 and 1.2 gP/kg, and total C was
between 0.5-3%. The lowest percentage of S in the soils of the Gaza Strip was 0.016% while
the highest was 0.07%. CaCO3 was 1.6-19%, while Ca was between 0.7 and 5.4%. Several of
the residual soils in Gaza are relatively low in Mg (0.03%). Sodium contents in soils were
110-825 mg/kg. The lowest and the highest K averages were 330 and 4500 mg/kg,
respectively.
Fe in the soils of Gaza ranging between 0.2 and 2% and Mn levels were between 37 to 542
mg/kg. The median of Cu in soils of the Gaza Strip was 10 mg/kg. The lowest Zn (2 mg/kg)
was found in the local reference samples, with the highest (1800 mg/kg) being found in the
soils exposed directly to domestic sludge. More than 75% of the soil samples showed Cd
results below the detection limit (10 µg/kg).
Nickel was low with an average of 28 mg/kg and one guava farm showed a high level of Pb
(145 mg/kg) while the rest of the soils showed an average of 30 mg/kg. An anomalous result
for Cr (472 mg/kg) was found in the area of Beit Hanoun. The averages of Co, As for all soils
was 6 mg/kg and e average of As was 2.2 mg/kg, while the site near the solid waste dumping
site reached 19 mg/kg. Finally, the average of Hg in the soils of Gaza was 10 µg/kg with
many samples being below the detection limit of the analytical method.
VIII
Discussion
The wastewater treatment plant was able to remove >92%, >88%, >60% of BOD5, COD, and
both total P and total N, respectively. This indicates that the majority of the metals have been
transferred from the wastewater to the sewage sludge where Zn, Pb, Cu, and Cr in the sludge
were 2100, 125, 240, and 75 mg/kg, respectively. The new results agree with the findings of
Shomar et al., (2004), however, 20% may be lost in the treated effluent, depending on the
solubility, and this may be as high as 40-60% for the most soluble metal, Ni (Scancar et al.,
2000). The average of Zn removal in the treatment process was 55%; this ratio finds its way
to the sludge and this may explain the high contents of Zn in the sludge (>2100 mg/kg).
The most affected zone by wastewater and sludge is the upper 40-50 cm of the soil profile
and the metal content decreased with depth. Element mobility sequence was Ni>Ca>Cu>>Fe
where the concentrations in the upper 5 cm were 40 mg/kg, 10%, 240 mg/kg, and 1.5% and
in the lower 40 cm were 2, 0.5, 5, and 0.3, respectively. This result agrees with that of Legret
(1993) and Cornu (2001). Nickel is the most soluble metal in sludge, and thus the most
mobile (Henry and Harrison, 1992).
It was found that the soil metal content was affected by soil structure. The total contents of
studied elements indicate that the concentrations of Zn, Mn, Cu, Fe, and partly As and Pb
correlate with the clay content in the individual soil profile.
The results revealed that the occurrence of trace metals in the different soils of the Gaza Strip
was dependent not only on the soil type but also on the location of the soil, the vegetation
cover, the climatic conditions and the agricultural activities.
General Conclusions
1. A very good agreement was observed between soil physical characteristics and the vertical
distribution of metals. The trend of most elements was: clay>sandclay>loose
sandstone>sandstone>fine sand. The trend showed that the clay layer of 6-9 m depth had high
contents of Al, Ca, Cr, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Sr, Th, Y, Zn, and Zr, and to a lesser
extent of Cd, Co, and Hg.
2. Except for the upper half-meter of the soil profile which is directly affected by waster and
sludge, the lateral distribution of elements was dependent on the physical characteristics of
the soil and not on the depth.
3. The treated wastewater is a promising water resource for agriculture, and regular
monitoring systems on soil, crops and groundwater should be adopted. Sludges, on the other
hand, have high Zn (>2000 mg/kg) and AOX (>500mg Cl/kg) concentrations, which exceed
the standards of all industrialized countries for land application.
4. Although the groundwater samples were collected from the aquifer below the wastewater
treatment plant, no anomalous concentrations were found with respect to metals. However,
several studies showed that elevated salinity, nitrate, chloride, and sulfate are believed to be a
result of both anthropogenic and natural sources.
5. The soil types, crop patterns, and specific location factors largely control the distribution of
trace metals (Pb, Cu, Zn, Cd and Mn) in soils. Linear regression analysis found a correlation
IX
coefficient of r =0.85 between Zn and Cd concentrations in soils and the presence of
highways nearby.
6. The irrigation water, the applied fertilizers and fungicides, and the sludge and wastewater
nearby have played a major role and contributed significantly the enrichment of several soils
with Zn, Pb, Cu and Fe. Affected soils by sludge, solid wastes and wastewater showed
similar contents of trace metals.
7. With respect to the global comparison, it may be noted that the values for the trace metals
in the different soils of the Gaza Strip were well within the worldwide soil average values.
These levels were still low and probably harmless to the soil ecosystem. However, the
distribution pattern for Zn, Cd, and Cu in several soils clearly indicated that their
contamination due to anthropogenic factors were on the rise and may become alarming if
mitigation measures are not taken.
General Recommendations
1. Soil information system in the Gaza Strip should be established for classification,
identification of the hot spots and sensitive areas, protection of soils against pollution and
degradation.
2. For soil related issues great consideration should be given: soil rating; environmental
protection; urban planning; agricultural needs; education, research and publicity; and
accessibility to scientific information.
3. Considering some suggested strategies for soil such as: soil quality promotion; soil
conservation; building a comprehensive soil information system in a well defined national
and international networks; climatic aspects; geochemical studies; monitoring changes in land
use; urbanization; increasing and preserving the areas of high productivity; social and
educational programs; and strengthening and upgrading the institutional capacity building.
4. Wadi Gaza
Objectives
1. To establish a baseline study of water and sediment quality of the Wadi Gaza.
2. To identify the extent to which the relevant water and sediment quality parameters vary
seasonally.
General Methodology (Sampling and Analysis)
Generally, water of Wadi Gaza was analyzed as the same as groundwater samples while
sediment samples were similar to soil samples.
Main Results
The heavy metal concentrations in the sediments of the lake (downstream) were higher than
those of the eastern eight stations (upstream) where the water was shallower. The discharge
X
of olive oil mill wastewater was recorded in the Ca, Na, Mg, K and P concentrations in
sediments of one of the sampling stations.
Water in shallower areas showed greater temporal variation than deeper areas. Several
elements (P, Fe, Mn and As) showed the greatest temporal variability. For example, in the
winter rainy season these elements decreased 2-10 times compared to their values in summer.
Moreover, Ca, Na, Cl, PO4, and NO3 decreased 3, 3, 5, 2, 4 times, respectively. Some of the
trace metals were more abundant in these waters compared to the domestic wastewaters of
the study area. The averages of Cd and Co were 6 and 43 µg/l, respectively and they were 50
times higher than the domestic wastewater results.
Discussion
The wastes of the olive oil mill in the Wadi reduced the pH of surface water in summer and
increased the Na, Mg, Ca and P concentrations. Water of Wadi Gaza was oxygenated (DO =
9.6 mgO2/l) and the Fe and Mn were in the oxidized soluble forms.
The impact of seasonal variation was recorded for As and Cd and they showed opposite
behavior, while Pb, Co, and Cu were not significantly affected.
Phosphorus in sediment followed an opposite trend to P in water; P in sediment was high in
winter and low in summer.
During the summer sampling, some medical wastes were found in the area, as a result of the
disposal activities by local clinics. The recent observations agreed with the findings of
Zoarob (1997) who identified Wadi Gaza as a disposal site of medical wastes. This is
probably the main source of Hg in the area. Mercury values were not affected by seasonal
variation.
The summer season had many impacts on water and sediment and the sediment-water
exchange of P was much dependent on the season. In the summer the sediment released P
whereas in the winter, a P accumulation took place. In the summer season this phosphorus
was used as a main source of nutrients needed for water plants covering the Wadi. Higher
temperatures could lead to anoxic conditions in sediment resulting in Fe and P release. In
winter the sediments are oxygen-rich, and Fe is in the Fe(III) form, which forms an insoluble
bond with phosphate. Under anaerobic conditions of summer (to be more specific, at redox
potentials below 150 mV), the Fe(III) was reduced to Fe(II). Since Fe(II)-phosphates are 100
times more soluble than Fe(III)-phosphates, this gave rise to a P release from Fe-P bondings.
General Conclusions
1. The results obtained served to increase our knowledge of the geochemistry of water and
sediment of the Wadi Gaza. In spite of this, the study has highlighted the need for further
research, by increasing sampling density and regularity to better characterize the geochemical
conditions of the Wadi.
2. Excluding Station 7, no major contamination of Fe, Zn, Cu, Mn, As, Pb, Cr, Cd, and Co
was found in water at most of the stations. Sediments in only two stations had high Hg, Cd,
Fe and Zn compared to background values of Turekian and Wedepohl (1961). Heavy metal
contents in sediment samples were low in the eastern stations and higher in the lake.
3. The various anthropogenic inputs may lead to the enrichment of many metals in the
sediments of Wadi Gaza. Pollution of several sites was found to be considerably high for Hg,
Cd, Fe and Zn and to a somewhat lesser extent for As, Pb, Ni, Cu and Co, whereas
anthropogenic input of Ga, Se and Th seems to be less important.
XI
4. The chemical composition of water and sediments exhibited seasonal variation. The human
inputs affect the concentrations of the tested parameters in summer; while the precipitation
inputs in winter diluted pollutants to minimum levels.
General Recommendations
1. Wadi Gaza is the only wetland in the Gaza Strip and its unique habitat and species warrant
careful management. The opportunity exists to apply measures which can bring both
ecological and socio-economic benefits. Measures to clean up and restore the wetland would
bring ecological, landscape and visual improvements. This may improve the health and the
environmental conditions for local people, bring new opportunities in education, recreation,
tourism and research, as well as maintain a range of cultural, social and historical heritage
values.
2. The main pressures should be reduced in short, medium and long term measures. These
pressures include overgrazing, pollution from the untreated wastewater, discharge of oils and
pesticides, cutting and burning of natural vegetation, building roads, agricultural
encroachment, hunting and poaching. By reduction of these pressures, the ecosystem
functions and productivity will be restored. Examples of short term measures would be to
open the mouth of the Wadi to the Mediterranean Sea and to stop the use of oil and pesticides
for combating mosquitoes. Examples of medium and long term measures would be to stop
the discharge of raw wastewater to the Wadi and to cooperate with the upstream regions in
management of the Wadi water resources. Because the Wadi is subject to many jurisdictions,
local, governmental, and nongovernmental institutions should all play a role in protecting and
conserving the Wadi. The efforts should aim to support the conservation of the wetland by
implementing activities such as: (a) cleaning campaigns, (b) removal of construction debris,
(c) development of recreational areas, (d) building of bridges of culverts, hiking trails,
observation towers, and water retention structures and (e) planting of trees in the site.
5. Pesticides in Groundwater and Topsoil
Objectives
1. To identify and quantify the concentration of pesticides in the groundwater and the topsoil
of the Gaza Strip.
2. To introduce a general method for determination of heavy metals in solid pesticides; and to
reveal the heavy metal contents and some elements in 53 pesticides which are intensively
being used in Gaza.
3. To prove that even pesticides originally with no heavy metals in their chemical structure
have impurities of such metals that have been added by local markets.
General Methodology (Sampling and Analysis)
Water was collected in 1-liter glass bottle and treated with 5 ml phosphoric acid (85%,
analytical grade) followed by 100 µl internal standard solution (5 µg/ml) of 2,4dichlorophenoxyacetic acid (Ring 13C6) in methanol. The bottles were thoroughly shaken and
placed in an ice cooling box and later extracted using a solid phase extraction (SPE-cartridge
type: Oasis HLB, 200 mg, 6 ccm, 30 µm grain size) technique as described by Stan (1995).
XII
The SPE was rinsed with 3 ml ethyl acetate (analytical grade) followed by 3 ml Milli-Q
water. The water sample was extracted through the SPE with fixed filtration flow rate of 10
ml/min. At the end of the extraction step, the SPE was washed with 5 ml Milli-Q water and
some air was sucked through the cartridge for several seconds. The SPE cartridges were
wrapped in aluminum foils in order to protect them from contamination and were kept frozen
until they have been sent to Germany for analysis.
For the final preparation of water samples, the solid phase extractors were cleaned by 6 ml
methanol/ tert-butyl- methyl ether (TBME), 20:80 (v:v). Then 100 µl of internal standard mix
33 (5 µg/ml) was added. The final volume was reduced to 0.5 ml by a gentle stream of N2
where it was transferred into measuring vials. 100 µl diazomethane solution were added and
the vials were degassed and kept at 4 oC.
Soil samples were freeze-dried for 48 h until complete dryness and sieved through a 2-mm
sieve. Approximately 10 to 20 g was placed in a Soxhelt extraction-cartridge and extracted
over night (12 h) with 75 ml n-hexane/ethylacetate (100:2 v/v). To the extract, 100 µl of the
internal standard for the GC/MS (Ehrenstorfer internal standard mix 33, (5µ/ml) was added
followed by 1 g anhydrous Na2SO4. The samples were evaporated to about 6 ml through a
rotary evaporator, then to 1 ml by a gentle stream of N2. About 0.8 g home made silica
gel/AgNO3 (100:5 wt:wt ) was poured into the SPE followed by few drops absolute methanol
for activation. The SPE cartridges were conditioned by 6 ml n-hexane/ethylacetate. The
extract was cleaned by 6 ml n-hexane/ethylacetate where they were received in glass tubes
and reduced by a gentle stream of N2 to 0.5 ml, so an enrichment factor of 20 was reached.
A gas chromatograph mass spectrometer (GC/MS) and a high performance liquid
chromatograph mass spectrometer (HPLC/MS) were used for determination of
organochlorine pesticides in extracted water and soil samples.
Pesticides, fertilizers and fungicides were freeze-dried and ground to powder. Determination
of trace elements in major pesticides, fertilizers and fungicides was measured using EMMAXRF for K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr and Pb. As the results of the
EMMA-XRF are semi-quantitative and showed a signal to go for detailed quantitative
determination, full digestion procedure and ICP instrument was used. The samples were
handled with great care, under a hood, and about 0.5 to 1.0 grams of the homogenized sample
were dissolved with 10 ml of concentrated nitric acid (Merck 65% p.a.) in 50 ml retorts. The
samples were allowed to degas (24 h), and then they were heated on a sand bath to 50 oC for
30 minutes then to 160 °C for 3 hours. After cooling, the solutions were diluted with Milli-Q
water in 50 ml volumetric flasks, then filtered through 0.45 µm pore size membrane filters
and transferred in 100 ml polyethylene bottles for analysis. Elements (Al, Ba, Cd, Co, Cr, Cu,
Fe, Mn, Ni, Pb, Sc, Sr and Zn) were analyzed by ICP/OES (VISTA-MPX, VARIAN). The
detection limit of the ICP/OES was estimated 10% less than the lowest standard used for
calibration.
Main Results
Despite the fact that more than 52 different pesticides were applied across agricultural
farmlands in Gaza, only few pesticides were detected in the soils of Gaza and many were
found in the groundwater.
The LC/MS and GC/MS results showed that 92% of target pesticides in the groundwater
were less than the instrumental detection limit.
XIII
Also, the results of the analysis indicated low levels of pesticides in 13 of the 94 wells tested.
Of the 13 wells, 5 were agricultural wells, and the remaining were municipal wells. The wells
are mostly in the areas of Khan Yunis and Rafah.
Bromacil was 0.5 µg/l in Safa 1 and Atrazine-desisopropyl was 0.1 µg/l in Safa 2 (R/25a).
Most results of the GC/MS of other target pesticides were generally less than the detection
limit. Several private wells in Rafah area showed traces of endrin, heptachlorepoxide, DDT,
DDE, and DDD.
Atrazine was detected in 47% of groundwater samples, while atrazine-desisopropyl,
propazine, simazine were detected in 40%, 24%, and 13% of water samples, respectively. All
showed results above the instrumental detection limit. Two water samples showed 5 µg/l of
triadimenol, the wells are private and located in the area of Gaza wastewater treatment plant.
Several soil samples of strawberry greenhouses in Beit Lahia showed detectable values of
propazine, sebutylazine, terbutylazine, 4,4’-DDT, 4,4’-DDE, and 4,4’-DDD. The averages of
propazine, sebutylazine and terbutylazine were 19, 13 and 39 µg/kg, respectively. A linear
regression r = 0.87 was obtained between the occurrence of detected pesticides and soils of
strawberry greenhouses.
The results showed that one soil sample had high contents of 4,4'-DDE and 4,4'-DDT which
were 1104 and 793 µg/kg , respectively. This sample was collected from the northern area of
Beit Lahia in a vegetable farm.
The calculated value of each element in the analyzed pesticides is much higher than the
measured value. Al, for example, in fosetyl-aluminum was 4 times higher than the measured
value and it was 3 times higher in the second sample of the same pesticide; Zn was 11, 6, 1
and 12 in propineb, mancozeb, metiram, and zineb respectively; Mn was 4 and 9 times higher
than the measured value in mancozeb and maneb respectively; Br 3 times higher in the two
samples of bromacil; while it is 6895 and 9480 times higher in the two samples of
bromadiolone; and finally Cu was 2 times higher in both copper oxychloride and copper
sulfate.
Discussion
The levels of pesticides found in 92% of the tested wells were below the WHO allowable
drinking water standards. Approximately half of the wells, in which pesticides were detected,
were below the detection limit for the pesticide in question, and therefore should be used with
caution, since at these low levels, the results may not be repeatable; wells P/10 and P/10a are
examples of these wells. Some private wells showed a sum of detected pesticides more than
the EC standards (1998) and the German legislation (Trinkwasserverordnung, 2001).
The higher detection of pesticides in the groundwater of the southern areas may be due to the
presence of large number of greenhouses, which possibly use large quantities of pesticides.
The area in the north near well E/45 is also heavily agricultural, with strawberries being a
main crop.
The differences in the results of the 3 consecutive years for the same well was insignificant
while there was a significant variation in pesticide concentrations for the well depth and
location. The deeper the water table, the less likely that pesticides reach groundwater. Most
of groundwater wells that showed detectable pesticides have 25-50 m depth. A deep aquifer
of municipal wells provides more opportunities and time than does a shallow aquifer of
private wells for pesticide adsorption, degradation and other processes to occur. The recharge
of rainwater and agricultural activities can carry pesticides down to the aquifer.
XIV
There was a correlation between the occurrence of some pesticides in groundwater such as
atrazine and water salinity (r = 0.64) and this conclusion agrees with Gascon et al., 1998.
Most of agricultural wells of the southern area have average Cl concentrations of 1200 mg/l
and the highest values of atrazine range between 6-20 µg/l. Wells D20 and E11b in the
northern area showed anomalous results as they are old and were used for decades as private
wells before they became municipal.
The field surveys revealed that the potential sources of pesticide contamination of private
wells include sites used for pesticide storage mainly in the well building, mixing, loading,
disposal, or application. Most of private wells are located inside the farm and surrounded by
intensive agriculture.
It is found that farmers of Gaza use atrazine more than any other pesticide because it is highly
effective and less expensive compared to other herbicide options currently available. One of
the reasons why all atrazine containing products are classified as restricted use pesticides is
that atrazine is relatively mobile and can move with water or sediment, through runoff or
leaching (USNRCS, 2004).
General Conclusions
1. Several pesticides were detected in the groundwater of Gaza and the minority has
concentrations exceeded their respective WHO maximum contaminant levels or health
advisory levels for drinking water.
2. Private groundwater wells showed higher contents of pesticides than the municipal wells.
The levels of pesticides found in the municipal wells were at levels well below the water
quality guidelines, and many were at levels close to the detection limit for the method and
should therefore be used with caution.
3. Several factors affecting the occurrence of pesticides in the groundwater of Gaza; soil type,
aquifer characteristics and meteorological conditions, well location, well depth and
groundwater quality.
4. Tested pesticides have considerable amounts of heavy metals and there is no agreement
between measured and calculated values; the calculated values are much higher.
5. The same pesticides have different names in the same shop and in different shops, as well
as different amounts of the same heavy metals.
6. Many tested pesticides have no heavy metals in their chemical structure in the pure form
but they have them in the marketed forms in Gaza.
7. The field surveys revealed that the contamination of pesticides by heavy metals may occur
due to bad procedures of storage and preservation; mixing of some pesticides in the market
itself without scientific rules; and finally the absence of legislations and governmental
inspection programs.
8. Pesticides should be considered as a source of some heavy metals in soil and groundwater
of the Gaza Strip and they should be included in mass balance and geochemical cycle of
some heavy metals.
XV
General Recommendations
1. Special care should be given to the pesticide markets, storage, preservation and labeling to
regulate the banned and restricted pesticides.
2. The results propose that pesticides should be considered as a source of certain trace metals
(Cu, Mn, and Zn) and other elements (Br, Sr and Ti) that may affect their mass balances in
soil and groundwater as well as plant uptake; and different scenarios and calculation models
of heavy metal transport in soil and groundwater of the Gaza Strip should include pesticides
as an additional source of certain heavy metals.
3. As the environment of Gaza is extremely susceptible to contamination, regular monitoring
programs of pesticides in soil, groundwater and crops should be conducted. As well as
epidemiological studies are needed with detailed exposure assessment for individual
pesticides, taking measures to reduce risk into consideration.
4. As pesticides are often misused by the non-professional, inexperienced farmers, awareness
campaigns and training courses for all relevant people and in all levels should be
implemented.
XVI
REFERENCES
APHA. 1995. Standard Methods for examination of water and wastewater. APHA, AWWA
and WPCF (eds). APHA Publishing, Washington, D. C.
Cheburkin, A. K., Shotyk, W. 1996. An Energy-dispersive Miniprobe Multielement Analyzer
(EMMA) for direct analysis of Pb and other trace elements in peats, Fres. J. Anal. Chem.
354, 688-691.
Cornu, S., Neal, C., Ambrosi, J. P., Whitehead, P., Neal, M., Sigolo, J., Vachier, P. 2001. The
environmental impact of heavy metals from sewage sludge in ferrasols (Sao Paulo, Brazil).
Sci. Total Environ. 271, 27-48.
Dean, H. 1942. The investigation of physiological effects by the epidemiological method. In:
Fluoride and dental health. American Association for Advancement of Science, Washington,
DC.
DIN. 1989. Bestimmung adsorbierbarer organisch gebundener Halogene (AOX) DIN 38414
S18 Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung
Schlamm und Sedimente (Gruppe S). Deutsche Industrie Norm. Beuth Verlag, Berlin.
EC. 1998. European Commission Directive 98/83/EC Nr. L330, pp. 32.
Gascon, J., Salau, J., Oubina, A., Barcelo, D. 1998. Monitoring of organonitrogen pesticides
in the Ebro river. Preliminary loadings estimates. Analyst 123, 941-945.
Henry, C. L. Harrison, R. B. 1992. Fate of trace metals in sewage sludge compost. In:
Adriano DC, editor. Biochemistry of Trace Metals. Lewis Publishers, pp195-216.
Legret, M. 1993. Speciation of Heavy metals in sewage sludge and sludge-amended soil.
Inter. J. Environ. Anal. Chem. 51 (1-4), 161-165.
Moore, D. M., Reynolds, R. C. 1989. X-Ray Diffraction and the Identification and Analysis of
Clay Minerals, 2nd edn. Oxford University Press. 332 p.
Müller, G., Gastner, M. 1971. The carbonate bomb, a simple device for the determination of
carbonate content in the sediments, soils and other materials, Neues Jahrbuch für
Mineralogie 466-469.
Rugg-Gunn, A. J., Al-Mohammadi, S. M., Butler, T. J. 1997. Effects of fluoride level in
drinking water, nutritional status, and socio-economic status on the prevalence of
developmental defects of dental enamel in permanent teeth in Saudi 14-year-old boys. Caries
Research 31, 259.
Scancar, J., Milacic, R., Strazar, M., Burica, O. 2000. Total metal concentrations and
partitioning of Cd, Cr, Cu, Fe, Ni and Zn in sewage sludge, Sci. Total Environ. 250, 9-19.
Shomar, B., Yahya, A., Müller, G. 2004. Potential use of treated Wastewater and Sludge in
Agricultural Sector of the Gaza Strip. Clean Technol. Environ. Policy 6, 128-137.
XVII
Trinkwasserverordnung. 2001. TrinkwV Bundesgestzblatt 2001, Teil 1, Nr. 24, Bonn.
USNRCS. 2004. Guidelines for atrazine use and application for groundwater and surface
water protection, Best management practices, BMP-6, 2004. U.S. Natural Resources
Conservation Service Kentucky Department of Agriculture, Syngenta.
WHO. 1998. Guidelines for Drinking Water Quality Addendum to Volume 2, Second
Edition, Health Criteria and Other Supporting Information (WHO/EOS/98.1), World Health
Organization, Geneva.
Zoarob, Z. 1997. Hazardous Waste Management in the Gaza Strip. MSc. Thesis-DEW5,
IHE, Delft, The Netherlands. 86 pp.
XVIII
Publications from this thesis in international journals
1. Shomar B. Müller G. Yahya A. (2004) Deterioration of Groundwater Quality in the
Gaza Strip: Alarm for Actions. Journal of Water Research, (submitted).
2. Shomar B. Müller G. Yahya A. Askar S. Sansur R. (2004) Fluorides in
groundwater, soil and infused-black tea and the occurrence of dental fluorosis
among school children of the Gaza Strip. Journal of Water and Health, 2(1), 23-36.
3. Shomar B. Müller G. Yahya A. (2004) Potential use of treated wastewater and
sludge in the agricultural sector of the Gaza Strip. Journal of Clean Technologies
and Environmental Policy, 6(2), 128-137.
4. Shomar B. Müller G. Yahya A. (2004) Geochemical characterization of soil
and water from a wastewater treatment plant in Gaza. Soil and Sediment
Contamination: an International Journal, (in press).
5. Shomar B. Müller G. Yahya A. (2004) Seasonal variations of chemical
composition of water and bottom sediments in the wetland of Wadi Gaza, Gaza
Strip. Journal of Wetlands Ecology and Management, (in press).
6. Shomar B. Müller G. Yahya A. (2004) Geochemical Features of Topsoils in the
Gaza Strip: Natural Occurrence and Anthropogenic Inputs. Journal of Environmental
Research, (in press).
7. Shomar B. Müller G. Yahya A. (2004) Monitoring of Pesticides in the Groundwater
and the Topsoil of the Gaza Strip. Chemosphere, (submitted).
8. Shomar B. Müller G. Yahya A. (2004) Heavy Metals in Major Solid-Pesticides
Used in the Gaza Strip. Chemosphere, (submitted).
International conferences
1. Performance of Wastewater Treatment Plants in the Gaza Strip, Current situation
and future approach. Proceedings of the International Water Association (IWA)
Specialist Conference, BIOSOLIDS 2003, Wastewater Sludge as a Resource,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway, June
23-25, 2003. pp. 429-437.
2. Environmental Aspects of the Gaza Strip, Case Studies: Soil Geochemistry and
Fluoride Geochemistry. Bilateral Meeting, Environmental research and Wildlife
Development Agency, Abu Dhabi, United Arab Emirates, 25-30 February 2004.
3. Fluorides in groundwater, soil and infused-black tea and the occurrence of dental
fluorosis among school children of the Gaza Strip. Third International Conference on
Children’s Health and the Environment, London, UK, 31 March-2 April 2004.
XIX
4. Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions.
Proceedings of 2nd International IWA Conference on Automation in Water Quality
Monitoring, AutMoNet 2004, Vienna, Austria, April 19-20, 2004. pp. 373-378.
5. Gaza Streifen: eine brisante Umweltsituation auf heißem Terrain, Umweltbörse,
institut für Umwelt Geochemie, University of Heidelberg, 1 July 2004.
6. Seasonal variations of chemical composition of water and bottom sediments in the
wetland of Wadi Gaza, Gaza Strip. The 7th INTECOL International Wetlands
Conference, Utrecht, the Netherlands, 25 - 30 July 2004.
7. Wastewater of Gaza, Chemistry and Management Approach. Second
Internatuional Conference: Water for Life in the Middle East, Turkey, Antalya, 10-14
October 2004.
XX
Table of Contents
CHAPTER ONE ......................................................................................................... 1
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions ..... 1
ABSTRACT ............................................................................................................. 1
INTRODUCTION ..................................................................................................... 2
MATERIALS AND METHODS ................................................................................. 3
Study Area ............................................................................................................. 3
Criteria of Sampling and Analysis ............................................................................ 4
Groundwater Samples ............................................................................................. 6
Quality Control ...................................................................................................... 7
Meteorology, Geology and Hydrology....................................................................... 8
RESULTS AND DISCUSSION .................................................................................. 9
General Physico-chemical Parameters (pH, EC, DO and salinity) ............................... 9
Ions ......................................................................................................................10
Spatial and Seasonal Variations in the Concentrations of the Parameters Tested .........15
Ion Concentrations and Ratios ................................................................................15
CONCLUSIONS ......................................................................................................16
RECOMMENDATIONS AND ACTIONS TO BE TAKEN..........................................17
CHAPTER TWO....................................................................................................... 18
Fluorides in groundwater, soil and infused-black tea and the occurrence of
dental fluorosis among school children of the Gaza Strip ................................ 18
ABSTRACT ............................................................................................................18
INTRODUCTION ....................................................................................................19
MATERIALS AND METHODS ................................................................................20
The study area .......................................................................................................20
Sampling and analysis............................................................................................21
RESULTS................................................................................................................25
Groundwater .........................................................................................................25
Soil.......................................................................................................................26
Tea.......................................................................................................................27
DFI, CFI and prevalence of caries...........................................................................28
DISCUSSION ..........................................................................................................29
CONCLUSIONS ......................................................................................................31
RECOMMENDATIONS...........................................................................................31
CHAPTER THREE................................................................................................... 32
Potential use of treated wastewater and sludge in the agricultural sector of the
Gaza Strip .............................................................................................................. 32
ABSTRACT ............................................................................................................32
INTRODUCTION ....................................................................................................33
MATERIALS AND METHODS ................................................................................34
The study area .......................................................................................................34
Beit Lahia (Northern) Wastewater Treatment Plant...................................................35
Gaza Wastewater Treatment Plant...........................................................................35
Industries..............................................................................................................35
The sampling and analysis ......................................................................................37
RESULTS AND DISCUSSION .................................................................................39
Domestic Wastewater.............................................................................................39
i
Industrial Wastewater ............................................................................................43
Sludge ..................................................................................................................44
Variation of heavy metal contents in wastewater and sludge.......................................47
CONCLUSIONS ......................................................................................................47
CHAPTER FOUR..................................................................................................... 48
Geochemical characterization of soil and water from a wastewater treatment
plant in Gaza .......................................................................................................... 48
ABSTRACT ............................................................................................................48
INTRODUCTION ....................................................................................................49
METEOROLOGY, GEOLOGY AND HYDROLOGY.................................................50
STUDY AREA, MATERIALS AND METHODS........................................................51
Location of the study area.......................................................................................51
Sampling and analysis............................................................................................51
RESULTS................................................................................................................55
Wastewater ...........................................................................................................55
Sludge ..................................................................................................................56
Soil.......................................................................................................................56
Groundwater .........................................................................................................62
DISCUSSION ..........................................................................................................63
CONCLUSIONS ......................................................................................................65
CHAPTER FIVE ....................................................................................................... 66
Seasonal variations of chemical composition of water and bottom sediments
in the wetland of Wadi Gaza, Gaza Strip ............................................................. 66
ABSTRACT ............................................................................................................66
INTRODUCTION ....................................................................................................67
MATERIALS AND METHODS ................................................................................67
The study area .......................................................................................................67
The sampling and analysis ......................................................................................69
RESULTS AND DISCUSSION .................................................................................71
Water Quality........................................................................................................71
Human inputs in the Wadi Gaza ..............................................................................73
Sediment metal concentration .................................................................................74
CONCLUSIONS ......................................................................................................79
RECOMMENDATIONS AND MANAGEMENT STRATEGIES .................................80
CHAPTER SIX ......................................................................................................... 81
Geochemical Features of Topsoils in the Gaza Strip: Natural Occurrence and
Anthropogenic Inputs ............................................................................................ 81
ABSTRACT ............................................................................................................81
INTRODUCTION ....................................................................................................82
MATERIALS AND METHODS ................................................................................83
Soil Types .............................................................................................................83
Sampling and Sample Preparation...........................................................................84
Analyses ...............................................................................................................85
Quality control ......................................................................................................86
Fertilizers and Fungicides ......................................................................................86
RESULTS................................................................................................................86
Adsorbable Organic Halogens (AOX) ......................................................................92
ii
Phosphorus, Carbon and Sulfur ..............................................................................92
CaCO3, Ca, Mg, Na and K .....................................................................................93
Fe and Mn ............................................................................................................93
Cu, Zn, Cd, Ni, Pb, Cr, Co, As, and Hg ....................................................................93
DISCUSSION ..........................................................................................................94
CONCLUSIONS ......................................................................................................95
CHAPTER SEVEN................................................................................................... 96
Monitoring of pesticides in the groundwater and the topsoil of the Gaza Strip
................................................................................................................................. 96
ABSTRACT ............................................................................................................96
INTRODUCTION ....................................................................................................97
MATERIALS AND METHODS ................................................................................98
The study area .......................................................................................................98
Sampling...............................................................................................................98
Soil extraction .....................................................................................................102
Analytical methods...............................................................................................102
Quality control ....................................................................................................103
RESULTS..............................................................................................................104
Groundwater .......................................................................................................104
Soil.....................................................................................................................104
DISCUSSION ........................................................................................................106
Triazine (atrazine, atrazine-desisopropyl, propazine, simazine and terbutylazine) ......107
DDT, DDE and DDD ...........................................................................................108
CONCLUSIONS ....................................................................................................109
CHAPTER EIGHT .................................................................................................. 110
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip ..................... 110
ABSTRACT ..........................................................................................................110
INTRODUCTION ..................................................................................................111
MATERIALS AND METHODS ..............................................................................112
Study area...........................................................................................................112
Sampling and analysis..........................................................................................112
EMMA-XRF ........................................................................................................113
ICP/OES.............................................................................................................113
Quality control ....................................................................................................113
RESULTS AND DISCUSSION ...............................................................................115
General reading of the results ...............................................................................115
Comments on the field surveys ..............................................................................120
CONCLUSIONS ....................................................................................................121
REFERENCES.................................................................................................... 122
APPENDICES ..................................................................................................... 135
iii
List of Tables
Page
Chap. 1
Table 1
Table 2
Table 3
Table 4
Table 5
Monitored municipal groundwater wells in each area of the Gaza Strip
Analytical methods used in Gaza and Germany
Results of water quality-major parameters (average of three years)
Comparison of the results of major Ions and WHO standards
Examples of trace elements in fifteen municipal wells of the Gaza Strip
6
7
10
10
14
Chap. 2
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
Table 8
Table 9
Average level of fluorides in groundwater of 73 wells of the Gaza Strip
Groundwater quality of five wells in the area of Khan Yunis
Total fluoride contents in soil samples of five regions in the Gaza Strip
Average tea consumption for school children in the Gaza Strip
Fluoride contents in 20 tea liquor samples collected from 20 houses
Fluoride contents in 10 samples infused tea leaves
Averages DFI for each region and age group
Weighted DFI scores and estimated CFI for the Gaza Strip
Prevalence of caries for each age group and region
25
26
27
27
28
28
28
29
29
Standards of heavy metals in wastewater and sludge
Performance of wastewater treatment plants in the Gaza Strip (4-19 July
2001)
Average concentrations of heavy metals in influent and effluent
wastewater
Heavy metals in the effluents of 10 industries in the Gaza Strip (µg/l),
year 2000
Heavy metals in the effluents of 10 industries in the Gaza Strip (µg/l),
year 2001
Heavy metals in the effluents of 11 industries in the Gaza Strip (µg/l),
year 2002
Averages of trace metals and major parameters in sludge of three years
Other elements in sludge produced from Gaza (mg/kg), by using
EMMA
38
Chap. 3
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
Table 8
Chap. 4
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Chemical Characteristics of Wastewater Effluent
Chemical Composition of Five Sludge Samples
Geochemical Characteristics of Sludge Covered Soil Profile under
Wastewater Lagoon
Geochemical Characteristics of Sludge Covered Soil Profile under
Sludge Drying Area
Chemical Composition of Soil for Selected Depths of the Fifth Profile
Groundwater Quality of Five Boreholes
iv
39
40
43
43
44
44
45
55
56
57
57
60
62
Page
Chap. 5
Table 1
Table 2
Table 3
Water Quality of Wadi Gaza
Chemical characteristics of sediments by flame AAS
Chemical characteristics of sediments by EMMA
72
76
78
84
Table 3
Table 4
Table 5
Soil Types, land form and dominant land use of the Gaza Strip
Concentrations of Trace Metals and Other Elements in Selected Soils of
the Gaza Strip
Spearman Correlation Coefficient, N= 170.
Chemistry of Selected Commercial Fertilizers Used in the Gaza Strip
Chemistry of Selected Commercial Fungicides Used in the Gaza Strip
Chap. 7
Table 1
Table 2
Table 3
Table 4
Groundwater wells sampled for 3 years
List of pesticides analyzed and instrument used for analysis
Pesticides detected in groundwater wells
Pesticides detected in soil samples
97
100
102
102
List of 53 collected samples of solid pesticides used in the Gaza Strip
Heavy metals and some elements in 53 pesticide samples collected from
Gaza, results of the EMMA-XRF
Heavy metals and some elements in 53 pesticide samples collected from
Gaza, results of the ICP/OES
Calculated and measured values of some elements
111
Chap. 6
Table 1
Table 2
Chap. 8
Table 1
Table 2
Table 3
Table 4
v
88
91
92
92
113
115
118
List of Figures
Page
Chap. 1
Fig. 1
Fig. 2
Chap. 2
Fig. 1
Fig. 2
Fig. 3
The study area, classification of the Gaza Strip and the location of the
groundwater wells
Average concentrations of major anions in the five regions of the
Gaza Strip
Five regions of the Gaza Strip and location of groundwater wells
Variation of fluoride contents in groundwater of the Gaza Strip
Levels of total fluorides in soil samples of 5 regions of the Gaza Strip
4
12
21
26
27
Chap. 3
Fig. 1
Fig. 2
Chap. 4
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Existing and proposed wastewater treatment plants and sewage outlets
to the sea in the Gaza Strip
Performance of Beit Lahia wastewater treatment plant (BLWWTP)
and Gaza wastewater treatment plant (GWWTP), heavy metals in
influent and effluent wastewater
Location of the Study Area
Some Examples of XRD Results of the Fifth Soil Profile
General Geological Features of the Five Soil Profiles
Examples of Element Profiles
36
42
53
58
59
61
Chap. 5
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Location of the Wadi Gaza and schematic illustration of the sampling
stations
(a)Temp., and DO, (b) Cl and EC, (c) NO3 and SO4, (d) PO4 and F,
(e) Fe and Mn , (f) Ca and Zn in water samples of the Wadi Gaza
Comparison between trace metals in domestic wastewater (WW)
discharged to Wadi Gaza, water of Wadi (W) in two sampling stations
and groundwater (GW) of two wells in the middle (F62) and the
western (G16) areas of Wadi Gaza
(a) P, (b) Ca and CaCO3, (c) Cu and Zn, (d) Ni and Pb, (e) Co and As,
(f) Fe and Mn in the sediment samples of Wadi Gaza
Comparison between the results of AAS and EMMA for sediment
samples of Wadi Gaza for two successive years
68
74
75
77
79
Chap. 6
Fig. 1
Location of the Gaza Strip and Soil Type Distribution
83
Chap. 7
Fig. 1
Five regions of the Gaza Strip and location of groundwater wells
100
vi
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
CHAPTER ONE
Deterioration of Groundwater Quality in the Gaza Strip:
Alarm for Actions (*)
ABSTRACT
A large database is available of dissolved-fraction groundwater concentrations for Ag, Al,
As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Ni, Pb, Sr and Zn in the course of a 3-year
monitoring program in the Gaza Strip. The results show that the trace elements of the
groundwater of the Gaza Strip do not generally pose any health or environmental hazard. In
spite of that, only 10 % of the municipal wells meet the WHO standards. Cl-, NO3- and Fconcentrations exceeded 2-5 times the WHO standards in 90 % of the wells tested with
average concentrations of 750, 75 and 1.6 mg/l, respectively. Several private wells should not
be used for drinking purposes as the average of Zn, Cd, Pb, Fe and As was 58, 30, 270, 468
and 10 µg/l, respectively. A severe water dilemma will appear in the near future from both
quality and quantity aspects.
Key words: Anions, Gaza Strip, Groundwater, Heavy metals.
_________________________________________________________________________________
(*) The study was submitted to an International Journal.
1
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
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INTRODUCTION
The environment in Palestine suffers considerable strain. The shortage and pollution of
resources, coupled with a high population growth and insufficient job opportunities have
created many environmental problems (MEnA, 2000). Shortage of water and deterioration of
water quality constitute limiting factors in the economic development of Palestine (MEnA,
2001). Palestine is experiencing a severe water crisis caused mainly by the lack of control
over the Palestinian water resources.
At present the average per capita water consumption by the Palestinian population is
approximately 55 l/c/d, or 55% of the WHO minimum standard of 100 l/c/d. This means that
the communal water supply for the Palestinian population is substantially inadequate by
international standards. The average per capita water availability in Palestine, which is 105
m3d, is the lowest in the world (Abu Zahra, 2001).
Wise management, development, protection, and allocation of water resources should be
based on sound data regarding the location, quantity, quality, and use of water and how these
characteristics are changing over time. The quantity and quality of available water varies over
space and time, and is influenced by multifaceted natural and man-made factors including
climate, hydrogeology, management practices, pollution, etc. The foundation for water resources decision - making, sound data must be continuous over space and time (PEPA,
1994).
Natural and anthropogenic contamination of groundwater by heavy metals has become a
crucial water quality problem in many parts of the world. Municipal and industrial wastes of
the Gaza Strip represent a real threat to groundwater; they can contaminate groundwater
where infiltering precipitation can carry leached pollutants from dumping sites (Shomar,
1999). The water quality in Gaza is affected by many different water sources including
inflow of groundwater through the 1948 borders, soil/water interaction in the unsaturated
zone due to recharge and return flows, mobilization of deep brines, sea water intrusion or
upconing and disposal of domestic and industrial wastes into the aquifer. The seawater
intrusion and the upconing of brines in some areas may be due to a water imbalance in the
aquifer, since the rate of water extraction exceeds the rate of groundwater replenishment.
Previous reports on the water quality in Gaza have extensively discussed the high levels of
chloride and nitrate in the drinking water, but they did not address their impact on the human
health. Fortunately, recent studies on the health-effects of nitrate in drinking water indicate
that the effects are less severe than assumed before, and that nitrate may even play a
protecting role against gastro-intestinal infections (L”Hirondel and L”Hironedel, 2002). The
high concentrations of nitrates in the groundwater appear to be due to fertilizers and sewage
contamination from within Gaza. Data indicate that levels of nitrate east of Gaza, byond the
1948 borders, are lower than those in Gaza (CAMP, 2001).
Municipal wells are being used for drinking and domestic purposes while private wells are
being used for irrigation. More than 90% of the population in the Gaza Strip is connected to
the municipal drinking water network while the other 10% of the rural areas are dependent on
the private wells.
2
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
In the Gaza Strip, the geology, hydrology, the groundwater flow and aquifer recharge have
been investigated (Shomar et al., 2004b). Little or no information is, however, available with
regard to the content of the trace constituents, hydrocarbons, pesticides, and microbes in the
groundwater of the Gaza Strip. Trace elements are contributed to the groundwater from a
variety of natural and anthropogenic sources. Once elements are taken up by the
groundwater, their distribution is continually reset by complex geochemical processes (e.g.
equilibrium and non-equilibrium water/solid interactions, advection, dispersion, absorption,
precipitation, coprecipitation, chelation, colloidal interaction) and biological processes
(Newcobm and Rimstidt, 2002; Al-Awadi et al., 2003).
During the preparation phase of this study, it became apparent that the chloride and nitrate
contamination of the groundwater in Gaza is not the only threat to the groundwater and
therefore the drinking water. Many of the agricultural wells have large surface openings
(greater than 1m) where oil products, fertilizers, or any other items stored in the well housing
may enter the aquifer by carelessness or accidental spilling of materials into the well. In
general the largest threat to the aquifer from these wells appear to be petroleum based
products or pesticides, since both of these products tend to be stored in the well building.
The objective of this paper was to achieve an understanding of the quality of the groundwater
as it currently exists and to determine if any of the parameters tested pose a threat to human
health in the Gaza Strip. Specific analysis of contaminant such as finger printing of heavy
metals in this scale is being conducted for the first time.
MATERIALS AND METHODS
Study Area
The Gaza Strip, as one of the most densely populated areas in the world (2638/km2; PCBS,
2000), with limited and deteriorated resources, has already started to suffer the outcomes of
environmental quality deterioration. The study area is a part of the coastal zone in the
transitional area between the temperate Mediterranean climate to the east and north and the
arid desert climate of the Negav and Sinai deserts to the east and south (Fig. 1). As a result,
the Gaza Strip has a characteristically semi-arid climate. The hydrogeology of the coastal
aquifer consists of one sedimentary basin, the post-Eocene marine clay (Saqiya), which fills
the bottom of the aquifer.
Groundwater is the most precious natural resource in the Gaza Strip as it is the only source of
water. Ample supplies of high quality water are essential for economic growth, quality of life,
environmental sustainability, and - when considered in the extreme - for survival.
Water quality in Gaza is tested by different agencies for different reasons. The Ministry of
Health tests all of the municipal wells twice a year for the major ions, nitrates, and coliforms
to insure that the drinking water is safe for public consumption. The Ministry of Agriculture
tests more than 340 wells twice a year for chlorides and nitrates and some additional ions to
assess the quality of the irrigation water in Gaza. In addition, the United Nations Welfare
Relief Agency (UNWRA) tests their drinking water wells in the Refugee Camps on a regular
basis.
3
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
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In the Gaza Strip, qualified laboratories for trace element analysis in the groundwater and soil
are virtually absent and the existing ones are private and very expensive. Because of these
reasons trace element monitoring programs in the groundwater and soil are absent and have
received relatively less attention when compared to major anions (Cl, F, NO3 and SO4) and
cations (Ca, Na, K and Mg).
Criteria of Sampling and Analysis
The groundwater sampling campaigns were performed according to many justifications fitted
to Gaza. Previous data, meteorological conditions, natural and anthropogenic factors,
agricultural practices, well ownership, different and interfered factors affecting groundwater
quality, etc. are examples of these justifications. To provide an overall level of information
on the water quality and the health risks, all available municipal wells were sampled.
Additionally, 20 agricultural wells were monitored for the same purpose. Under the above
mentioned factors and for better understanding, the Gaza Strip was classified into 5 regions
according to the governmental system, north, Gaza, middle, Khan Yunis and Rafah. This
classification may help people and decision makers in each region to take actions when
required.
Figure (1) The study area, classification of the Gaza Strip and the location of the groundwater wells.
4
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
Based on the complexity and the political conflict in the region, the sampling started in the
areas far away from political conflicts especially in the north area, Gaza area and middle area,
and then extended to the south where the situation was very difficult. However, some of the
agricultural wells in the south required several visits to obtain samples because the wells were
not running and the owners were not present. The sampling program went smoothly, and all
but 15 of the wells that were initially selected were not sampled because of political conflicts
in the region.
Due to the difficulty and expense of characterizing the groundwater system, the priority was
given to the municipal wells used for drinking and domestic purposes and several private
wells used for irrigation. The private wells were selected to represent the five geographic
areas of the Gaza Strip.
The sampling campaigns were conducted in three different seasons. The first coincided with
the end of the annual summer dry season (October and November 2001). The second was
conducted at the end of the annual winter rainy season (April and May 2002), while the third
program took place during the winter rainy season and rain fell in considerable amounts
during the sampling period (January and February 2003).
Chlorides were measured in all wells as it is the well-known parameter for salinity and
freshness, not only for specialists but also for the public, especially in the last few years as
people started to use home-filters or buy mineral water.
Nitrates are known as a reason of methaemoglobinaemia. It is documented in the files of
children hospitals of the Gaza Strip that there is a strong correlation between the high levels
of nitrate in drinking water and the distribution of methaemoglobinaemia. On the other hand,
this correlation may be indirect; high levels of nitrate are commonly associated with fecal
pollution, and the true cause of methaemoglobinaemia seems to be the intestinal infections;
l”Hirondel and l”Hirondel (op.cit.p.44) state: “to conclude, the hypothesis that well-water
methaemoglobinaemia is caused by nitrate in the feed being reduced to nitrite in the digestive
tract seems unreasonable”. They also report on the (unethical) experiments of Cornblath and
Hartman, who gave small infants artificial well water with 1000 mg NO3-/l and observed no
clinical methaemoglobinaemia.
Fluorides are known as a reason of dental fluorosis; and Shomar et al., (2004d) confirmed the
correlation of the disease among the school children and the high levels of fluoride in the
groundwater.
Heavy metals were measured for the first time in the scale of a three-years monitoring
program to find the wells with high levels of metals and the proposed sources of such metals
in the groundwater.
In order to assure that the sample collected was from the groundwater and not water standing
in the well, it was originally proposed that the well should be pumped for a minimum of one
to two hours prior to the collection of the sample. However, this was not always possible. The
second sampling program occurred at the end of the winter rainy season, and many
agricultural well owners were not using their wells extensively. However, if it is assumed that
the average agricultural well has a 10-meter depth of standing water in a 12-inch diameter
pipe, the standing well volume is approximately 1m3. Therefore one hour of pumping at a
rate between 45 and 70 m3/hr is sufficient to purge at least three standing well volumes; this
principle is a USEPA rule of thumb for well purging.
5
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
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Groundwater Samples
Prior to the field work a one month intensive course was given to the field staff in Germany
to provide them with an understanding of the field techniques to be used, the preparation of
sampling containers, the calibration and the usage of the portable kits, the sample's additives,
the labeling, the preservation procedures and finally the preparation for shipments to
Germany.
All samples were collected in laboratory certified clean bottles and labeled as to the well
location, date and time of sample collection, analyses to be performed, and field preservation
performed, if any. Preservation of samples in the field was done to avoid revisiting the wells
if mistakes occurred while adding the chemicals to the samples.
Figure 1 shows the distribution of the selected groundwater wells in the study area. Samples
were collected from 90 groundwater wells; all were municipal and used for drinking
purposes. They represented all geographic areas: 23 north, 24 Gaza, 9 middle, 9 Khan Yunis
and 4 Rafah. Twenty private wells were selected but some do not have an ID but the location
is known. Table 1 shows the well ID and to which region it belongs. (For the exact locations
of groundwater wells see the attached map in the appendices).
Table (1) Monitored municipal groundwater wells in each area of the Gaza Strip.
Region
Well ID
Region
Well ID
Region
E/156
R/162L
E/4
R/162 L1
E/1
R/162E
Q/40B
R/162B
Middle
E/90
R/162C
Area
D/74
R/162D
North (Jabalia)
E/61
R/162H
E/142
R/162Hnew
D/20
E/154
D/60
E/157
E/11B
D/68
E/11C
D/69
Gaza
E/138
D/70
Khan Yunis
C/128
R/162G
C/20
D/71
North
C/76
D/72
(Beit Hanoun)
C/127
R/254
C/79
R/265
A/185
R/271
E/6
Sh.Ej.5
Rafah
North
D67
R/74
(Beit Lahia)
Attatra
R/25B
A180
R/25A
R/25D
6
Well ID
D/72
G/49
S/71
S/42
J/32
J/146
S/69
K/21
K/20
D/72
G/49
S/71
S/42
J/32
J/146
S/69
K/21
K/20
P/15
P/24
P/145
P/153
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
One-liter samples were collected and placed in a sampling ice-box and transferred to the
laboratory. The sample was divided into two subsamples: the first (500 ml) was filtered in an
acid-washed filter holder and through 0.45 µm pore size membrane filters, the first few
milliliters were used for rinsing, then they were discarded, and the filtrate was transferred to
clean acid-washed polyetheylene bottles and acidified by concentrated nitric acid (Ultrapur,
Merck, v/v), and stored at 4 oC until analyses by ICP/MS (Perkin Elmer-Sciex, Elan 6000).
The total content of Ag, Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Ni, Pb, Sr and Zn was
determined next to the cations of Ca, K, Mg and Na. The other part of the water was filtered
with no additives and stored at 4 oC for anion analyses by Ion Chromatography (IC). Several
parameters were measured in the water samples during the fieldwork: temperature, turbidity,
electric conductivity and pH; other parameters were measured in the laboratory.
Quality Control
For quality control, analytical blanks and two samples with known concentrations of heavy
metals were prepared and analyzed using the same procedures and reagents. For the
groundwater analysis, Standard Reference Materials 1643c and 1643d were used for the
determination of trace elements (NIST, 1991 and 1994). As an independent check of the
major parameters, they were also measured in two laboratories with different methods (Table
2). The results of the analyses were also reviewed in terms of the milli-equivalent balance,
which compares the ionic charges of the major anions and cations (APHA, 1995). Because
water is electrically neutral the charges should balance; however charge balance errors less
than 5% generally are considered to be acceptable (Freeze and Cherry, 1979).
A simple linear regression value of ion concentrations and ratios was used. A correlation
coefficient was determined for the distribution of the major ions in the five geographic areas
of the Gaza Strip. The univariate regression analysis and correlation coefficient were used to
combine results of water chloride concentration with the nitrate contents of the same well.
For the comparison of the results in the five regions, the results of each groundwater well
were averaged then the averages of all wells of each region were averaged. The variance
between the averages of the regions was higher than the variance in the average of the wells
of each region. In other words, the comparison was carried out because the standard deviation
and the f-test for the regions were significant.
Table (2) Analytical methods used in Gaza and Germany.
Test
Method in Gaza*
Temp., pH, EC, DO
Portable field kits
Cl
Ion Selective Electrode (ISE)
NO3
UV Spectrophotometric Screening method
F
Ion Selective Electrode (ISE)
SO4
Turbidimetric method
PO4
Vanadomolybdophosphoric acid colorimetric
HCO3
Tirtimetric method
Ca
EDTA titrimetric method
Na, K, Mg
Flame photometric method
Heavy metals
Not measured
* APHA, 1995.
7
Method in Germany
Not measured
Ion Chromatograph (IC)
IC
IC
IC
IC
Not measured
ICP-OES
ICP-OES
ICP-MS & ICP-OES
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
Meteorology, Geology and Hydrology
To explain the significantly different heavy metal levels in the groundwater and soil of the
Gaza Strip, the different geological settings and actual hydrogeological conditions of the area
must be considered. The geology and geochemistry of soil profiles were described by Shomar
and others (2004b).
The coastal aquifer of the Gaza Strip is part of a regional groundwater system that ranges
from the coastal areas of the Sinai (Egypt) in the south to Haifa in the north. The coastal
aquifer is generally 10-15 km wide, and its thickness ranges from 0 m in the east to about 200
meters (m) at the coastline.
There are two well defined seasons: the wet season, starting in October and extending into
April, and the dry season from May to September. The average daily mean temperature
ranges from 25 °C in summer to 13 °C in winter, with the average daily maximum
temperature ranging from 29 °C to 17 °C, and the minimum temperature ranging from 21°C
to 9 °C, in the summer and winter, respectively. The daily relative humidity fluctuates from
65% in the daytime and 85% at night in the summer and between 60% and 80%, respectively,
in the winter. The mean annual solar radiation is 2200 J/cm2/day. There is a significant
variation in the wind speed during the daytime, and the average maximum wind speed
velocity is about 3.9 m/s. Moreover, storms have been observed in winter with a maximum
wind speed of about 18 m/s. Peak months of rainfall are December and January; the average
annual rainfall is 335 mm/y (26 year average) (CAMP, 2001).
The coastal aquifer consists primarily of Pleistocene age Kurkar Group deposits including
calcareous and silty sandstones, silts, clays, unconsolidated sands, and conglomerates. Near
the coast, coastal clays extend about 2-5 km inland, and divide the aquifer sequence into three
or four sub-aquifers, depending upon the location. Towards the east, the clays pinch out and
the aquifer is largely unconfined (PEPA, 1994).
Within the Gaza Strip, the total thickness of the Kurkar Group is about 100 m at the shore in
the south, and about 200 m near Gaza City. At the eastern Gaza border, the saturated
thickness is about 60-70 m in the north, and only a few meters in the south near Rafah. Local
perched water conditions exist throughout the Gaza Strip due to the presence of shallow clays
(MEnA, 2000).
Under natural conditions, groundwater flow in the Gaza Strip is towards the Mediterranean
Sea, where fresh groundwater discharges into the sea. However, natural flow patterns have
been significantly disturbed by pumping and artificial sources of recharge over the past 40
years. Within the Gaza Strip, large cones of depression have formed over large areas in the
north and south. Water levels are presently below the mean sea level in many places,
inducing a hydraulic gradient from the Mediterranean Sea towards the major pumping centers
and municipal supply wells. From the limited available piezometer data, head differences
between sub-aquifers along the coast are on the order of 0.1-0.5 m, suggesting that
intervening clay layers may be sufficiently impervious in certain places to hydraulically
separate the various sub-aquifers.
8
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
Long term records (>20 years) of water levels are available for more than 100 wells in the
Gaza Strip. Between 1970-1993, water levels dropped 1.6 m on average, mostly in the south.
This is equivalent to a decline of 5 million cubic meters per year (Mm3/y) in overall aquifer
storage on average, using a specific yield of 0.2. The water level declines are most apparent
in the south, and are most likely a reflection of the lower recharge from rainfall in this area.
In the north, most wells exhibit relatively slow declines with partial or complete recovery
following the wetter than usual hydrological year 1991/92 (CAMP, 2001).
RESULTS AND DISCUSSION
Due to the huge amounts of data for the three-year monitoring of more than 20 parameters,
this section will treat the environmentally significant results only. The results exceed the
WHO standards and may have risks on human or environmental health. The average value is
discussed and anomalous ones are rejected. The samples were analyzed by two separate
laboratories for major anions and cations and the results varied. The values were averaged to
provide the figures for this section. The variation in the concentration of the same element for
the three years could be explained by personal or instrumental errors, groundwater sample
collection, preservation, transportation, laboratory analysis and data reporting carry various
levels of uncertainty with them that affect the reported element concentration.
General Physico-chemical Parameters (pH, EC, DO and salinity)
Generally, the depth of the old wells is ranging between 40 and 60 m, however the municipal
wells are deeper than the private ones. The wells dug after the year 1995 have depths of 90 to
120 m. The average temperature of the groundwater was 20 oC in the summer and 24 oC in
the winter. The pH of the groundwater (Table 3) ranges between 6.8 and 7.5 and this small
variation is dependent on the geographical dimension and seasonal variation. Generally, the
electric conductivity (EC) increases from the north to the south (Table 3) with some
exceptions in Rafah area, this means that the water salinity also had the same trend. The best
aquifer -in terms of fresh water- was located in Beit Lahia at the north western corner of the
Gaza Strip; the lowest value was 520 µS/cm and the highest was about 1000 µS/cm. The most
deteriorated and salty water was in the regions of Khan Yunis and Rafah with an average EC
in the municipal groundwater wells of 5000 µs/cm. Within the same region of Gaza, the north
wells have low EC while the south wells have high values. These findings enhance the Gaza
municipality to mix water of north and south wells before supplying the consumers. The
groundwater of the Gaza Strip is oxygenated and the average dissolved oxygen (DO) was 7.8
mgO2/l in summer and 8.2 mgO2/l in winter (Shomar et al., 2004c).
9
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
Table (3) Results of water quality-major parameters (average of three years).
Beit
Beit
Average
Parameter
Jabalia
Gaza Middle
Lahia
Hanoun
North
EC (µS/cm)
769
1867
1057
1231
2156
2778
TDS (mg/l)
395
1183
672
750
1364
1828
pH
7.4
7.4
7.3
7.4
7.3
7.3
Ca (mg/l)
104
104
109
106
86
118
Mg (mg/l)
29
57
44
43
50
97
Na (mg/l)
63
184
65
104
254
340
K (mg/l)
5.0
3.2
4.4
4.6
11.8
6.0
F (mg/l)
0.7
0.4
0.8
0.6
1.1
1.4
Cl (mg/l)
90
375
128
198
431
620
NO3 (mg/l)
58
79
115
99
107
71
SO4 (mg/l)
28
54
52
45
104
226
Alka. (mgCaCO3/l)
218
279
210
236
290
234
Hardn. (mgCaCO3/l)
293
490
379
387
415
399
Khan
Yunis
3278
2040
7.4
88
53
507
5.8
2.0
684
191
278
255
445
Rafah
1838
1194
7.5
55
58
282
6.6
0.8
352
71
127
260
246
Ions
Except for a few wells in the north area of the Gaza Strip, all wells tested showed high to
very high contents of the major ions (Table 4). The anion-cation balance of the results
obtained for each well showed that the majority of cases are below 5% for each laboratory.
However, this does not mean that the laboratories had identical results. In many instances the
results of both laboratories have low charge balance percentages, but the differences between
the results of each parameter are large. An example of this was the wells D/72 and K/21. In
both instances the charge balance error was 2%, however the values were quite variable.
Table (4) Comparison of the results of major Ions and WHO standards.
Parameter
WHO*
% < WHO
% > WHO
TDS (mg/l)
1000
37
63
Cl (mg/l)
250
46
54
NO3 (mg/l)
50
10
90
F (mg/l)
1.5
80
20
SO4 (mg/l)
250
86
14
Ca (mg/l)
50**
11
89
Mg (mg/l)
30*
13
87
Na (mg/l)
200
47
53
K (mg/l)
10**
93
7
Hardness (mgCaCO3/l)
300
30
70
*) WHO, 1998a.
**) ICON, 2001, European Community guide level.
10
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Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
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The differences in the values may be indicative of certain laboratory practices, and therefore
the averages were used also to lower the inter-laboratory variability. The differences in values
were not consistent between parameters. In the examples given the values for chloride,
sulfate and ammonia were quite high, but in other samples it may have been other parameters
that varied. Variability between laboratories testing the same sample can be expected, but
generally it was on the order of 5%. The variability in the laboratory results for this program
was much higher than expected.
Major Anions (NO3, Cl, F, SO4, PO4)
Approximately 85% of the wells sampled showed nitrate levels above the WHO standard (50
mg/l). The highest levels of nitrate were found in the north and the south regions (Table 4);
they were 151 and 191 mg/l, respectively. All private wells, except three, showed nitrate
concentrations 3-7 times higher than the WHO standards. Sources that contribute to high
nitrate concentrations include the infiltration of domestic sewage through cesspits and septic
tanks, solid waste leachate, manure and agriculture fertilizers. The areas which had the
highest concentrations of nitrates do not have a wastewater collection system, and when
present it was implemented recently. Unpublished data confirmed the good correlation
between the high contents of nitrates in drinking water and the occurrence of
methaemoglobinaemia in the areas where babies are not breast fed.
Chloride was the representative and correspondent parameter to the electric conductivity. The
lowest value in the north area was 40 mg/l while the highest value in the eastern parts of
Rafah area was 3000 mg/l. One should mention that some wells have low Cl contents but
high nitrates and vise versa.
Fluorides were studied in an independent investigation (Shomar et al., 2004d). The results
showed that the trend of the fluoride in the groundwater of the Gaza Strip was similar to Cl,
with some exceptions in the middle area. The high fluoride contents in the groundwater (1.8
to 4 mg/l) was the main reason of the dental fluorosis disease for school children of the Gaza
Strip (Shomar et al., 2004d).
The concentration of sulfate in drinking water needs to be addressed not only because of its
effect on public health but also on the municipal well infrastructure. Most of the wells in
Gaza have levels less than the WHO standard (250 mg/l), especially in the north area. The
highest levels of sulfate appear to be in Khan Yunis and the southeast, where it was 380 mg/l.
On the other hand, many popular European waters are gypsum saturated and contain over
1000 mg/l sulfate. Examples are Contrex and Contrexeville in France, Eptinger and Aproz
Cristal in Switzerland, Alp Quell and Obladis in Austria and Fonti di Crodo and Santa
Chianciano in Italy. In view of this, even if the WHO standard is slightly exceeded, this can
hardly count as a public health problem.
Phosphates were not detected in the groundwater of Gaza with the method of
vanadomolybdophosphoric acid, while the average was 1 mg/l by the IC of Germany. The
test of Gaza was carried out few hours after the sampling process.
Figure 2 shows a comparison between the average contents of the major anions in the
different regions.
11
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
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Cl
NO3
F
2
450
2
300
1
150
1
0
0
Middle
Kh Yunis
3
750
2
500
1
250
0
Rafah
0
T/46
S/69
S/42
S/37
Region
CL
NO3
F
3
1250
2.5
1000
750
2
1.5
0.2
0
E/8
E/90
E/90
500
1
250
0
0.5
0
L/87
E/92
L/86a
L/41
L/179 L/178 L/159
CL
Cl, NO3 and F per Well of Gaza
1
500
0.5
250
0
Cl, NO3 (mg/l)
750
F
F (mg/l)
Cl, NO3 (mg/l)
1.5
1000
Q/39
N/22
M/2a
CL
NO3
F
1250
3
1000
2.5
2
750
1.5
500
1
250
0.5
0
0
0
D/68
N/9
Cl, NO3 and F per Well of Rafah
NO3
2
1250
T/44
Well ID
Well ID
1500
CL
NO3
F
1500
0.4
E/154 E/157
G/149 G/178
Cl, NO3 and F per Well of Khan Yunis
Cl, NO3 (mg/l)
300
200
100
0
D/60
J/146
0.8
0.6
D/2
J/32
1
F (mg/l)
Cl, NO3 (mg/l)
600
500
400
C/76
J/35
Well ID
Cl, NO 3 and F per Well of North area
A/135 A/180 C128
S/19
F (mg/l)
Gaza
4
1000
P/15
D/70 R/162d R/162e R/162f R/162g R/25c
F (mg/l)
North
1250
F (mg/l)
3
600
CL
NO3
F
Cl, NO3 and F per Well of Middle Area
Cl, NO 3 (mg/l)
750
F (mg/l)
Cl, NO3 (mg/l)
Average Anions in the Five Regions
P/145
P/144
P/138
P/138old
P/138
P/124
P/10
Well ID
Well ID
Figure (2) Average concentrations of major anions in the five regions of the Gaza Strip.
Major Cations (Na, Ca, Mg, K)
The lowest levels of sodium were in the north, and the highest levels were in the east and the
south. Approximately 65 of the wells tested (>50% of the wells sampled) had sodium levels
higher than the WHO standard (200 mg/l). Sodium had the same trend as Cl for all wells
analyzed (Table 4).
In most of the wells tested for potassium, the value was less than 5 mg/l. However, a small
number of wells have levels in excess of 15 mg/l. The wells with the highest potassium
levels included R/162H, R/162C, J/35, E/154 and F/88. Neither the USEPA nor the WHO has
standards or guidelines for potassium levels in drinking water.
The groundwater of most areas is hard and the average hardness represented in CaCO3 for all
the wells tested was 380 mg/l. The average of Ca was 93 mg/l and there was no significant
difference in the results of the different seasons. The average of magnesium was 48 mg/l. The
Mg/Ca ratio showed almost all points with about a 1:1 ratio. The middle region wells display
the highest levels of both Ca and Mg and the results were 262 and 128 mg/l, respectively. All
wells were below the seawater ratio, about 5:1 Mg to Ca.
12
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
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Metal Contents (Fe, Mn, Cu, Zn, Ag, As, Pb, Cd, Cr, and Co)
Table 5 shows the results for trace elements from selected wells of the five regions. The Fe
concentration was lower than the WHO standard (300 µg/l). The average content of Fe was
10-50 µg/l, although some wells in the north (Jabalia and Gaza) have Fe up to 140 µg/l.
Several wells showed high contents in the year 2002, such as 6200, 1855, 1040 µg/l in wells
C/127, C/76 and R/112, respectively. None of them showed similar results in the other two
years. Agricultural wells showed a 3-5 times higher iron concentration than the municipal
wells.
Manganese had an average of 10 µg/l as the lowest WHO standard is 100 µg/l.
All results of Cu were below the WHO standard (1-2 mg/l).The Cu ranged between 1-50 µg/l.
Wells of the middle and south areas showed higher Cu contents than the north and Gaza.
The range of the Zn concentrations was 1-30 µg/l, while the WHO standard for Zn is 3 mg/l.
A good indication for the quality control is the results of Zn for the well R/162L which
showed similar results for the three years of monitoring (113, 117 and 102 µg/l, respectively).
The results of Ag were below the USEPA standard (100 µg/l). The well R/162E showed the
same results for the years 2001 and 2002 (0.5 µg/l), while the year 2003 was 7 µg/l.
The average of As contents in the wells tested was 1 µg/l, and the highest well had about 4
µg/l; most standards of As in drinking water are 10 µg/l. The results of 2001 showed an
anomalous result (50 µg/l) of the well (L/178).
The range of lead standards in drinking water is 10-50 µg/l, and the results showed that all
wells tested were below these standards. One municipal well (E/4) in the north area of Jabalia
showed high contents of Pb (69 µg/l) in the year 2001 which was 7 times higher than the
WHO standard. The results of the following years for the same well were < 2.5 µg/l.
The different standards (including the WHO) of Cd in drinking water are 3-10 µg/l. All
results were below the limit of detection.
The different standards of Cr in drinking water are 50-100 µg/l and all of analyzed wells
tested had less Cr than these standards. The average contents of Cr in the south area of the
Gaza Strip (40 µg/l) which is higher than that of the north area (10 µg/l). The well R/162E
showed similar results for the first two years (24, 27 µg/l, respectively) while the last year
only showed 344 µg/l.
Although the WHO has no standard for cobalt (Co) in drinking water, the results showed very
low Co contents in the wells tested. In spite of that, the private-agricultural well A/107E
showed 1.5 µg/l in the year 2001 while the results of the other two years were < 0.5 µg/l.
The last group of elements showed very low contents in general. Al, Hg, and Ni were found
to be less than the WHO standards for all wells and for the three years of monitoring. All
wells had Ba less than the WHO (700 µg/l). The B results showed that more than 75 % of the
wells had B>300 µg/l, the middle and the south areas of the Gaza Strip showed an increase in
the B contents. Li results were 5-20 µg/l and few private wells only showed >30 µg/l. Sr is a
typical alkaline earth element; the Sr results were 0.8-6 mg/l for all samples.
13
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
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Table (5) Examples of trace elements in fifteen municipal wells of the Gaza Strip.
WHO (µg/l)
100
200
10
300
700
3
50
1000
LD (µg/l)
0.5
10
4
10
10
1
0.5
1
1
Well ID
Ag
Al
As
B
Ba
Cd
Co
Cr
Cu
E/4
<0.5
<10
<4
111
197
<1
<0.5
7.71
3.6
D/20
<0.5
47
<4
104
251
<1
<0.5
7.26
<1
E/11C
<0.5
43
<4
348
21
<1
<0.5
11.3
1.0
C/127
<0.5
13
<4
135
124
<1
0.5
9.92
<1
D67
<0.5
15
<4
78.9
216
<1
<0.5
10.2
1.1
R/162E
6.34
28
<4
284
219
<1
1
344
1.3
R/162B
<0.5
38
<4
202
316
<1
<0.5
16.5
1.1
R/162H
<0.5
12
<4 1105
78
<1
0.5
25.1
6.1
R/162G
<0.5
28
4.5
608
105
<1
<0.5
16.1
9.3
D/72
0.5
25
5.8
92.7
268
<1
<0.5
10.3
2.9
S/71
<0.5
20
<4
691
63
<1
<0.5
11.5
3.6
K/20
<0.5
29
<4
747
120
<1
<0.5
29.9
<1
L/178
<0.5
113
6
3084
35
<1
<0.5
111
1.9
L/43
0.8
46
<4
951
62
<1
0.7
32
6.0
P/24
<0.5
<10
<4
469
122
<1
<0.5
30.7
<1
14
300
8
Fe
12
28
19
25
19
528
22
29
54
39
25
13
28
66
25
1
2
Hg
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
Li
3.4
5.4
6.5
3.1
2.2
8.1
7.7
19.3
13.4
5.3
11.4
11.0
26.2
20.6
11.7
100
0.5
Mn
1.1
<0.5
0.594
0.692
<0.5
7.04
0.638
1.47
2.34
1.65
0.72
<0.5
1.79
1.4
10.4
20
0.5
Ni
<0.5
<0.5
<0.5
<0.5
<0.5
6.45
<0.5
1.25
<0.5
0.636
0.603
<0.5
<0.5
<0.5
<0.5
10
2.5
Pb
<2.5
<2.5
<2.5
<2.5
2.99
11.6
3.24
<2.5
6.06
<2.5
4.11
<2.5
7.73
8.86
5.5
0.01
Sr
1228
2223
836
854
687
4951
4682
2056
2536
1377
1256
1328
1561
4668
2382
3000
0.5
Zn
6.81
82.8
41
19.4
8.72
24.5
24.4
35.5
50.5
20.9
19.3
10.3
19.3
31.7
12.8
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
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Spatial and Seasonal Variations in the Concentrations of the Parameters Tested
The Gaza Strip has been classified into five regions according to their governmental system
and this classification correlated with the groundwater quality in each region. With some
exceptions, the Gaza Strip could be classified according to the freshness of the municipal
groundwater into: north, Rafah, Gaza, middle and Khan Yunis; the ranking is based on the
increase of the salinity and other major ions. Only nitrates showed another classification, in
which Gaza comes after the middle area in the ranking.
For the same wells which had extremely high Cl and NO3 concentrations, the heavy metal
contents were found to be very low. The variation in the contents of the major ions,
represented by the EC, is due to the variation in the precipitation levels in each area.
However, the Gaza Strip is about 45 km long and each region has a different annual
precipitation; the north has 500 mm/a while the south has only 250 mm/a.
There is evidence that the groundwater table in the area of the Gaza Strip has been drastically
lowered, which would result in a downshift of the salinity (Shomar et al., 2004c). In spite of
that, there was no relationship between the well depth and groundwater quality for the
municipal wells. The story is different for the private wells, the deep wells showed less
salinity and vise versa. Moreover, several private wells (A/40, A/42, F/130, F/160, and N/2)
showed higher concentrations of Zn, Cd, Pb, Fe and As. These wells are located in the
surroundings of heavy agricultural areas, wastewater treatment plants and solid waste
dumping sites.
Ion Concentrations and Ratios
The CAMP (2001) discussed the main sources of major ions in the groundwater of the Gaza
Strip with ion concentrations and ratios. The concentration of total dissolved solids in water
provides the variability of the ion in the water, but it gives no indication of the source of the
ion variability. Ratios of the dissolved constituents are useful in establishing chemical
similarities among waters of a single aquifer (Appelo and Potsma, 1999), such as the coastal
aquifer in the Gaza Strip. Ratios also make it possible to fingerprint the water sample and
hopefully identify the source of ion variability. Reasons for the variability of groundwater in
the Gaza Strip include seawater intrusion, chloride brines, natural water/soil interactions in
the Kurkar Group materials and anthropogenic causes. Many of these causes have
characteristic ratios of ions that can be applied to groundwater sampling results of the region.
For example, groundwater influenced by seawater intrusion may have high levels of sodium
and chloride, but since the source water is mixed with the groundwater the concentrations of
sodium and chloride will be less than seawater concentrations. However, the ratio between
sodium and chloride could be the same for both, therefore identifying seawater as the source.
Seawater is not the only source with characteristic ratios. The ratio of calcium to magnesium
is useful in studying water from limestone and dolomite, while the ratio of chloride to other
ions also may be useful in studies of water contaminated with common salt (NaCl).
15
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
The same approach was used to confirm the findings of the CAMP (2001). The data above
could indicate several things. In general, seawater intrusion does not seem to be the major
source of the ion variability. In most regions, the ionic molar ratios were not consistent with
seawater standards. Instead, ionic ratios more often resembled ratios characteristic of natural
water interactions with subsurface materials. High chloride levels in the east and middle
region wells could be due to brine deposits at the base of the aquifer. High sodium
concentrations were more likely a result of water withdrawal from sodium-rich sedimentary
rocks. Magnesium to calcium ratios resembled dolomite ratios instead of seawater ratios.
Potassium ratios were below seawater standards in most wells.
CONCLUSIONS
The results indicated that water in both municipal and private wells is polluted by one
parameter or another; however, the municipal groundwater wells are less polluted. The results
showed that 80% of the groundwater wells are not suitable for drinking purposes because of
the high contents of nitrates, chlorides and fluorides and some heavy metals which exceed 27 times the WHO standards. Some wells have a permissible limit of nitrates but high amounts
of chloride or fluoride and vice verse. The high nitrates and fluorides in the drinking water of
Gaza have a direct impact on the human health; although recent findings in the medical
literature cast some doubt on the health hazards of high nitrate per se, although high nitrate is
often a strong indication for fecal pollution.
The governmental classification of the Gaza Strip into five regions correlates with the quality
of the groundwater of each region. The salinity and the major ions increase from the north to
the south regions.
The average results of trace elements in the groundwater indicated that they do not generally
pose any health or environmental hazard in the Gaza Strip. In spite of that several private
wells showed concentrations of Zn, Pb, As and Cd of more than the WHO standards. These
wells should not be used for drinking purposes. These wells are exposed to the contaminants
of the leachate of solid waste, wastewater and manure.
The well depth does not affect its water quality, while the location does. The ion ratios
indicated that the high levels of chloride and other ions do not appear to be due to seawater
intrusion into the aquifer only, but other water sources, including through flow from Israel,
and natural chemical changes due to soil/water interactions may cause the majority of the ion
variability in the aquifer.
The results of the study and the archive of groundwater geochemistry additional to the ion
ratios revealed that the reasons of the anomalous-elevated levels of Cl and other ions are the
anthropogenic factors, the lateral groundwater flow and the natural chemical changes and to a
lesser extent the seawater intrusion.
16
Chapter One
Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions
__________________________________________________________________________________________
RECOMMENDATIONS AND ACTIONS TO BE TAKEN
The results of the study showed that the pollution of the groundwater is a major problem in
the Gaza Strip. Not only there are numerous sources of pollution, but also the aquifer is
highly vulnerable to pollution. The increasing chloride, nitrate and fluoride contents in most
of municipal wells and the high contents of several heavy metals in several private wells
illustrate the pollution problem.
Several studies should be conducted mainly on the health risk assessment and water
toxicology. Examples of these studies are the methaemoglobinaemia as a result of high
nitrates, the dental fluorosis as a result of high fluorides and the cancers as a result of high
levels of carcinogenic pesticides.
To improve our understanding of water quality in the aquifer an integrated monitoring
program should be conducted. The municipal wells should be sampled 2-4 times a year for
the analysis of anions, cations, heavy metals and pesticides. The data of the groundwater
quality should be centralized in a data bank or a water archive.
The risk of deterioration of water quality is an urgent theme. The objective of the Palestinian
water institutions should be how to safeguard the water resources system from pollution. The
protection of water quality and the reduction of the risk contamination are of great
importance to a reliable and sustainable water supply. Several initiatives could be taken such
as wastewater management through full collection and treatment, solid waste management to
prevent leaching and infiltration into the groundwater aquifer, setting up a management
system for use of pesticides and fertilizers through proper handling, storage measures and
safe application, setting up groundwater protection zones in the vulnerable areas to pollution,
and finally setting up an early warning and emergency response system, that will enable to
take appropriate actions.
17
Chapter Two
Fluoride Study
__________________________________________________________________________________________
CHAPTER TWO
Fluorides in groundwater, soil and infused-black tea and the occurrence
of dental fluorosis among school children of the Gaza Strip (*)
ABSTRACT
The purpose of this study was to determine the fluoride levels in water, soil and tea, and to
identify the major fluoride minerals in soil that supply water with fluoride ions. Another aim
was to study the prevalence of dental fluorosis in permanent dentition of the school children
of the Gaza Strip.
Monitoring of fluoride levels in 73 groundwater wells and 20 topsoil samples for the last
three years revealed a general trend of increasing from north to south of the Gaza Strip. A
linear regression analysis found a correlation coefficient of r = 0.93 between the fluoride
concentrations in groundwater and soil for the same geographic areas. However, the X-ray
diffraction technique (XRD) results showed that none of the four major fluoride minerals
were detected in the tested soil samples; the PHREEQC model showed that fluorite (CaF2)
was the main donating mineral of fluoride ions to groundwater.
A high positive correlation was found between fluoride concentrations in groundwater and
occurrence of dental fluorosis. Among 353 school children of the five geographic areas of the
Gaza Strip the prevalence of dental fluorosis was 60% and 40% had no signs of fluorosis in
their permanent dentitions. The highest occurrence, 94%, was in Khan Yunis, followed by
82% in Rafah, 68% in the middle area, 29% in Gaza and the lowest occurrence of 9% was in
the northern area. These percentages were directly proportional to the average contents of
fluoride in groundwater of each area: 2.6, 0.9, 1.7, 1.2, and 0.7 ppm, respectively. The
exception was Rafah where people drank from new groundwater wells that have been dug in
the last 10 years.
The occurrence of the disease was due to intake of high amounts of fluorides in drinking
water, tea and fish. Communication with population indicated a heavy intake of tea starting
from a very young ages; not uncommonly tea is put in nursing bottles. No significant
correlation was found between prevalence figures and gender or age groups. This high
prevalence indicates a need to examine other sources of F including diet.
Key words: Dental fluorosis, Gaza Strip, Soil fluoride, Tea, Water fluoride
_________________________________________________________________________________
(*) The study was published in the Journal of Water and Health as:
Shomar B. Müller G. Yahya A. Askar S. Sansur R. (2004) Fluorides in groundwater, soil and infusedblack tea and the occurrence of dental fluorosis among school children of the Gaza Strip. Journal of
Water and Health, 2(1), 23-36.
18
Chapter Two
Fluoride Study
__________________________________________________________________________________________
INTRODUCTION
The fate of fluoride in soil environment and groundwater is of concern for several reasons. It
is generally accepted that fluoride stimulates bone formation (Richards et al., 1994), and
small concentrations of fluorides have beneficial effects on the teeth by hardening the enamel
and reducing the incidence of caries (Fung et al., 1999). McDonagh et al., (2000) described in
great details the role of fluoride in the prevention of dental fluorosis. At low levels (< 2 ppm)
soluble fluoride in the drinking water may cause mottled enamel during the formation of the
teeth, but at higher levels other toxic effects may be observed (Weast and Lide, 1990).
Excessive intake of fluorides results in skeletal and dental fluorosis (Czarnowski et al., 1999).
Severe symptoms lead to death when fluoride doses reach 250-450 ppm (Luther et al., 1995).
It is found that the IQ of the children in the high fluoride areas (drinking water fluoride 3.15
ppm) was significantly low (Lu et al., 2000).
Fluorides enter the human diet mainly through the intake of water and, to a lesser extent
foods. Among the foods rich in fluorides are fish, tea, and certain drugs (EPA, 1997).
Ingested fluorides are quickly absorbed in the gastrointestinal tract, 35-48% is retained by the
body, mostly in skeletal and calcified tissues and the balance is excreted largely in the urine.
Chronic ingestion of fluoride-rich fodder and water in endemic areas leads to development of
fluorosis in animals e.g. dental discoloration, difficulty in mastication, bony lesions,
lameness, debility and mortality (Patra et al., 2000).
Children drink about one liter of water per day depending on the ambient temperature, and
because water consumption is higher in areas with higher ambient temperatures, it is
proposed that the recommended fluoride level in water in arid and semiarid areas would be
0.7 ppm (EPA, 1997), instead of 1.5 ppm which is the guidelines of the WHO (WHO,
1998a). Children may show dental fluorosis at an early age while skeletal fluorosis may
appear at an older age (Choubisa, 2001).
Naturally occurring fluorides in groundwater are a result of the dissolution of fluoridecontaining rock minerals by water (Kabata and Pendias, 1984) while artificially high soil F
levels can occur through contamination by application of phosphate fertilizers or sewage
sludges, or from pesticides (EPA, 1997). The F compounds added to soils by pollution are
usually readily soluble. Fluorine is a typical lithophile element under terrestrial conditions,
and there are not many stable F minerals; the most common are topaz (Al2(F,OH)2SiO4) and
fluorite (CaF2). F reveals an affinity to replace hydroxyl groups in minerals, and these
reactions have resulted in fluoroapatite (Ca10(PO4)6F2), the most common F mineral, and have
also been responsible for increased amounts of F in amphiboles and micaceous minerals
(Kabata and Pendias, 1984). The mobility of F in soils is complex and that the predominant
factors controlling the level of this ion in the soil solution are the amount of clay minerals, the
soil pH, and the concentration of Ca and P in soils. The greatest adsorption of F by soil
mineral components is at about pH 6 to 7. The range for most normal soils seems to be from
150 to 400 ppm (Turekian and Wedepohl, 1961), but the overall variation is much broader,
and in some heavy soils F levels above 1000 ppm have been found (Kabata and Pendias
1984). Much higher levels of F in uncontaminated soils are reported for provinces of endemic
fluorosis.
19
Chapter Two
Fluoride Study
__________________________________________________________________________________________
Beside the health effects, dental fluorosis may have social and psychological consequences.
There has been an escalation in daily fluoride intake via the total human food and beverage
chain, with the likelihood that this escalation will continue in the future (Marier, 1977).
Carbonated soft drinks have considerable amounts of fluorides (Heilman, 1999). Beers
brewed in locations with high fluoride water levels may contribute significantly to the daily
fluoride intake (Warnakulasuriya et al., 2002), and sweetened iced teas contain significant
amounts of fluoride (Behrendt et al., 2002). A single serving of chicken sticks alone would
provide about half of a child's upper limit of safety for fluoride (Fein and Cerklewski, 2001).
Children's ingestion of fluoride from juices and juice-flavored drinks can be substantial and a
factor in the development of fluorosis (Kiritsy et al., 1996; Whitford, 1989).
Tea is the most popular beverage in the Gaza Strip. It is well known that fluorine accumulates
mainly in the leaves of the tea plants, especially in fallen leaves (Fung et al., 1999). There is
one very common method of infusing tea in Gaza, by infusing tea leaves (about 10 g) for few
minutes in about one liter of boiling water. People of Gaza, including babies at very early
ages, consume strong and sweet tea.
The main objectives of this study were: (1) to determine the average levels of fluoride in
groundwater and top soils of the Gaza Strip; (2) to determine the levels of fluoride in the
prepared tea and tea leaves used in Gaza; (3) to identify the major fluoride minerals in soil
that may supply groundwater with fluoride ions; and (4) to determine the dental fluorosis
index (DFI) for school children of both sexes in the age range 5-16 years, and then the
community fluorosis index (CFI) followed by the number of teeth with caries.
MATERIALS AND METHODS
The study area
The Gaza Strip, as one of the most densely populated areas in the world (2638/km2; PCBS,
2000), with limited and declining resources, has already started to suffer the outcomes of
environmental quality deterioration. The study area is a part of the coastal zone in the
transitional area between the temperate Mediterranean climate to the east and north and the
arid desert climate of the Negav and Sinai deserts to the east and south. As a result, the Gaza
Strip has a characteristically semi-arid climate and the hydrogeology of the coastal aquifer
consists of one sedimentary basin, the post-Eocene marine clay (Saqiya), which fills the
bottom of the aquifer.
Groundwater is the most precious natural resource in the Gaza Strip as it is the only source of
water. Ample supplies of high quality water are essential for economic growth, quality of life,
environmental sustainability and, when considered in the extreme, for survival.
Wise management, development, protection, and allocation of water resources are based on
sound data regarding the location, quantity, quality, and use of water and how these
characteristics are changing over time. The quantity and quality of available water varies over
space and time, and is influenced by multifaceted natural and man-made factors including
climate, hydrogeology, management practices, pollution, etc. As the foundation for water
resources decision-making, sound data must be continuous over space and time.
20
Chapter Two
Fluoride Study
__________________________________________________________________________________________
Previous reports on the water quality in Gaza have discussed extensively the high levels of
chloride and nitrate in the drinking water (PEPA, 1994). The water quality in Gaza is affected
by many different water sources including inflow of groundwater from Israel, soil- water
interaction in the unsaturated zone due to recharge and return flows, mobilization of deep
brines, seawater intrusion or upconing, and disposal of domestic and industrial wastes into
the aquifer. The seawater intrusion and the upconing of brines in some areas may be due to
water imbalance in the aquifer, since the rate of water extraction exceeds the rate of
groundwater replenishment. The high concentrations of nitrates in the groundwater appear to
be due to fertilizers and sewage contamination from within Gaza. Data indicate that levels of
nitrate east of Gaza, in Israel, are lower than those in Gaza.
North
Gaza
Middle
Khan
Yunis
Location of Groundwater Wells
Rafah
Figure (1) Five regions of the Gaza Strip and location of groundwater wells.
Sampling and analysis
The study area (Fig. 1) is divided into five geographic regions, the northern area, Gaza, the
middle area, Khan Yunis and Rafah which represent the main five governorates of the Gaza
Strip; moreover, the groundwater quality in terms of both salinity and nitrate contents
deteriorates from north to south. Three sampling campaigns have been conducted in three
years over the periods: 20 November-12 December 2000, 26 June-17 July 2001 and 25 April
-17 May 2002. Soil and tea samples were collected in the last sampling campaign.
21
Chapter Two
Fluoride Study
__________________________________________________________________________________________
Water samples
Under the water quality testing program about 73 municipal wells and a few private wells in
the Gaza Strip were sampled. The municipal wells represent groundwater in the five
geographic areas of the Gaza Strip. At the municipal wells, samples were collected from a tap
along the water distribution line. Prior to sampling, the injection of chlorine or sodium
hypochlorite into the system was discontinued so the additive would not interfere with the
analysis. In addition to the general locations of wells, Table 1 shows the ID of each well. The
wells in the table are ordered from north to south where 17, 26, 7, 16, and 7 wells are chosen
from the north, Gaza, the middle, Khan Yunis and Rafah regions, respectively.
In order to assure that the sample collected was from groundwater and not water standing in
the well, it was originally proposed that the well should be pumped for a minimum of 1-2 h
prior to the collection of the sample; however this was not always possible. The third
sampling programme occurred at the end of the winter rainy season, and many private well
owners were not using their wells extensively. However if it is assumed that the average
private well has a 10-m depth of standing water in a 30-cm diameter pipe, the standing well
volume is approximately 1 m3. Therefore 1 h of pumping at a rate of between 45 and 70 m3/h
is sufficient to purge at least three standing well volumes; this principle is a USEPA rule of
thumb for well purging.
Samples were collected from 73 groundwater wells; all are municipal and being used for
drinking purposes. They represented all geographic areas: 17 in the north, 26 in Gaza, 8 in the
middle, 15 in Khan Yunis and 7 in Rafah. Preservation of samples in the field was done to
avoid revisiting the wells if mistakes occurred while adding the chemicals to the samples.
About 250 ml water was taken in laboratory certified clean bottles and labelled as to the
sample location, date and time of sample collection. The sample was placed in a sampling
ice-box and transferred to a laboratory, then the sample was filtered through 0.45 µm
(Sartorius) filter; the first few ml were used for rinsing, then they were discarded, and the
filtrate was transferred to clean polyethylene bottles and stored at 4 oC. The sample was
divided into two sub-samples: the first 100 ml was analyzed in Gaza using an ion selective
electrode (ISE) according to APHA (1995), and the other 150 ml was shipped to Germany
where fluoride was analyzed by ion chromatography (IC DIONEX DX-120) with minor
modifications (Yin et al., 2001). As a part of a parallel research, the same groundwater wells
were sampled and analyzed for major anions and cations (see Table 2 for results from five
wells in Khan Yunis).
Soil samples
Twenty composite soil samples were collected from the five regions (Table 3) from the
surroundings of 20 wells. They were collected using a stainless steel dredge; approximately
0.5 kg was put in polyethylene cups and stored at 4 oC during its transport to laboratories
where the soil was dried in an oven at 50 oC until it reached a constant weight. Then the
samples were shipped to Germany in plastic sampling bags. The samples were sieved through
a 20-µm sieve, then ground to a very soft powder by using a sand mill (FRITSCH-Labor
Planeten Mühle, pulverisette 5). Approximately 50 mg of sample was placed in a nickel
crucible, then 2 g of 1:1 Na2CO3-K2CO3 (anhydrous dried at 110 oC overnight) was added to
the sample in the crucible. The crucibles were placed in a muffle furnace at 800 oC for 15
min.
22
Chapter Two
Fluoride Study
__________________________________________________________________________________________
After cooling, 15 ml of 1 M citric acid was added to the crucible and the mixture was allowed
to digest until CO2 evolution was no longer detected (3-4 h, or preferably overnight). Then 25
ml of sodium citrate buffer (1M) was added to the contents of the crucible. Finally, the
mixture was transferred to a 100-ml polypropylene volumetric flask where it was diluted to
the mark by deionized H2O. The total fluoride in the soil extract was analyzed by the ISE
(APHA, 1995).
The semi-quantitative X-ray diffraction technique (XR Diffractometer-SIEMENS) was used
to identify the major fluoride minerals in soil samples; the four major fluoride minerals were
investigated (topaz: Al2(F,OH)2SiO4; fluorite: CaF2; fluoroapatite: Ca10(PO4)6F2; cryolite:
Na3AlF6). Moreover, PHREEQC (a small program for speciation, batch-reaction, onedimensional transport, and inverse geochemical calculations) was applied to achieve the same
purpose by using groundwater data of five wells in the area of Khan Yunis where the fluoride
level is high.
Tea samples and tea consumption
To determine if the tea consumed in Gaza may have influenced the observed dental fluorosis,
tea samples were collected both as a liquid and as tea leaves. Twenty teacups were collected
from 20 different houses in the area of Khan Yunis. The houses were selected according to a
statistical base; the first house of every ten houses was chosen in the area of Khan Yunis and
eastern villages of Abasan, Bani Suhaila and Khoza'a. Tea leaves were bought from the main
10 markets of the area and infused in the laboratory by using Milli-Q water in the same
manner as normally done by the Gaza population (about 10 g of tea leaves with one liter
water) and it was strong and sweet. Both tea types were analyzed by the ISE.
The tea consumption was calculated from the direct answers of the tested children and from
the answers given to the questionnaire distributed to the children.
Quality control
For quality control, analytical blanks and the same groundwater samples were analyzed in
Gaza and Germany. The fluoride ion selective electrode and potentiometer was an ORION
868 type, USA. The calibration curve was plotted against a standard NaF solution (1000 ppm
Merck-Darmstadt, Germany) containing 0.1, 0.5, 1.0, 5 and 10 mg F/l and a total ionic
strength adjustment buffer was used. The mV readings were linear against the logarithm of
mg/l F concentration.
Dental fluorosis index (DFI), community fluorosis index (CFI) and dental caries
The examinations were performed by two dentists and three assistants. Prior to the field work
the assistants attended a one week intensive course to provide them with an understanding of
the required literature and the field procedures to be used, as well as the preparation and the
distribution of the questionnaires. Mouth mirrors, pliers, and dental probes were used under
natural light. Key issues were taken into consideration; the examiners should note the
distribution pattern of any defects and decide if they are typical of fluorosis. Considerable
care should be taken to diagnose tooth-colored fillings, which may be extremely difficult to
detect.
23
Chapter Two
Fluoride Study
__________________________________________________________________________________________
From 24 elementary and preparatory schools, 353 pupils were involved in the study. The
schools represent the five regions of the Gaza Strip according to the population density and
gender. There were six schools from the northern area, six from Gaza, four from the middle
area, four from Khan Yunis and four from Rafah. The number of males and females was
almost the same. All the 353 school children of the age group 5-16 years were examined
clinically. The age group (5-16) is recommended: 5 years for primary teeth and >12 years for
permanent teeth. Age -and sex- matched children of the Gaza Strip consuming water having
fluoride levels within the 1.5 ppm permissible limit, according to WHO (1998a), were used
as controls.
The survey of the schoolchildren in order to examine the symptoms of dental fluorosis is the
first and most important step that can decide the presence or absence of fluorosis. Only when
presence of dental fluorosis is confirmed in the survey, it is necessary to study further the
magnitude and severity of the problem. According to the results of the dental fluorosis index
(DFI), the next step is to establish the percentage incidence of fluorosis as well as the
community fluorosis index (CFI).
Dental fluorosis is the most sensitive and specific index in the diagnosis of fluorosis (Jin et
al., 2000). It has been classified in a number of ways. One of the most universally accepted
classifications was developed by Dean (1942). In using Dean's fluorosis index, each tooth
present in an individual's mouth is rated according to the fluorosis index. The index classified
individuals into 5 categories, depending on the degree of enamel alteration. The recording of
the DFI is made on the basis of the two teeth that are most affected. If the two teeth are not
equally affected, the score for the less affected of the two should be recorded. When teeth are
scored, the examiner should start at the higher end of the index, i.e. "severe", and eliminate
each score until he arrives at the condition present. If there is any doubt, the lower score
should be given. The DFI was determined for the permanent teeth only after brushing with
toothpaste so as to reduce errors arising from dental plaque.
The dental fluorosis index was estimated according to Dean's standard method (Dean, 1942).
Dean's classification index indicated that dental fluorosis comprises opaque white patches
which cover less than 50% of the enamel surface. The more severe grades, 3 and 4, can
involve dark brown staining and pitting of the fluorosed enamel. A cross-sectional survey
was used to determine the prevalence of dental fluorosis. The dental caries was determined
for each tooth. Multiple caries per tooth were considered as one.
The CFI can be calculated from the DFI. Based on the symptoms, dental fluorosis is
classified into normal, questionable, very mild, mild, moderate and severe and each of these
five classifications is given a numerical weight such as 0, 1, 2, 3, 4, and 5, respectively. The
number of people in each category is multiplied by the corresponding numerical weight, the
products thus obtained for the various categories are added up and the sum of the total
divided by the total number of people surveyed, gives the community fluorosis index (CFI).
Only when the CFI value is greater than 0.6, fluorosis is considered to be a public health
problem in the area. Based on this procedure, the following formula was used:
CFI = No. of individuals in each region x Statistical weight
Total No. of Individuals tested
24
Chapter Two
Fluoride Study
__________________________________________________________________________________________
A simple linear regression value of soil/water fluoride was used. Twenty groundwater wells
(of the 73) were selected to represent wells of each region where the 20 soil samples were
taken. The univariate regression analysis and correlation coefficient were used to combine
results of water fluoride concentration with the prevalence of dental fluorosis and community
fluorosis index.
RESULTS
Groundwater
Table 1 shows the average concentration of fluoride in groundwater of 73 wells while Figure
2 shows the variation in fluoride contents from north to south, indicating that the highest
contents were found in the Khan Yunis area (4.4 mg/l).
Drinking water that had two to three times higher than the WHO standard for fluoride (1.5
mg F/l) was found in the Khan Yunis area where dental fluorosis was easily recognized.
Table (1) Average level of fluorides in groundwater of 73 wells of the Gaza Strip.
Region
Well
F
Well
F
σ
σ
Region
Region
ID
(mg/l)
ID
(mg/l)
D/67
0.5
0.20
R/162La 0.8
0.24
D/73
0.9
0.71
R/162Ha 1.1
0.12 Middle
D/74
0.5
0.02
R/162H
1.0
0.14
E/06
0.2
0.11
R/162G
1.0
0.24
E/10
0.4
0.06
R/162F
0.8
0.08
E/11A
0.8
0.28
R/162E
1.0
0.18
E/11B
0.7
0.16
R/162C
1.1
1.16
E/11C
0.7
0.08
R/162B
0.8
0.11
North
E/138
0.9
0.51
D/71
1.6
0.06
E/148
0.6
0.06 Gaza
D/72
1.1
0.46
Khan
E/156
0.9
0.17
R/25a
1.5
0.25
Yunis
E/4
0.8
0.19
R/25b
0.9
0.21
E/61
0.6
0.51
R/25c
1.5
0.16
E/8
2.0
0.05
R/25d
1.8
0.31
E/90
0.6
0.18
R/112
1.6
0.24
E/92
0.7
0.06
R/254
1.7
0.29
Q/40b
0.8
0.12
R/265
1.1
0.10
E/154
0.9
0.12
R/74
1.7
0.70
E/157
1.0
0.28
R/75
1.7
0.70
D/68
1.0
0.19
G1/178
2
0.06
D/69
0.9
0.27
J 146
1.8
0.34
Gaza
D/70
1.3
0.06
J 32
1.3
0.41 Rafah
Middle
Q/39
0.2
0.06
J 35
1.4
0.35
R/162L 0.9
0.17
S 19
1.2
0.14
25
Well
ID
S 42
S 69
T 46
L 127
L 159
L 176
L 178A
L 179
L 41
L 43
L 86
L 86A
L 87
M 2A
M 2B
N 22
N9
T 44
P 10
P 124
P 138
P 138 old
P 139
P 144
P 15
F
(mg/l)
1.4
1.7
2.5
1.3
1.2
2.0
4.4
4.4
3.0
1.5
1.5
4.0
1.7
3.0
3.2
2.6
3.1
2.0
1.3
0.8
0.9
0.8
0.8
0.9
0.9
σ
0.31
0.37
0.55
0.15
0.08
0.24
1.13
1.09
0.53
0.16
0.38
1.47
0.16
0.32
0.52
0.21
0.25
0.27
0.21
0.11
0.10
0.10
0.01
0.08
0.12
Chapter Two
Fluoride Study
__________________________________________________________________________________________
P 15
P 10
P 138 old
N 22
L 87
L 43
L 178A
S 42
L 127
J 32
R/75
R/254
D/72
R/25c
R/162C
R/162G
R/162La
D/70
E/92
E/157
E/61
E/148
E/11B
WHO Drinking Water
Standard for Fluoride = 1.5 mg/l
E/06
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
D/67
F (mg/l)
Fluoride contents in groundwater of the Gaza Strip
Well ID
Figure (2) Variation of fluoride contents in groundwater of the Gaza Strip.
To identify the fluoride minerals supplying groundwater with fluoride ions, five groundwater
wells were selected in the area of Khan Yunis. Major anions and cations were analyzed and
the average of three year readings is shown in Table 2. PHREEQC was applied. It was found
that the main donating fluoride mineral is fluorite (CaF2).
Table (2) Groundwater quality of five wells in the area of Khan Yunis.
Parameter
L 178A
L 179
L 86A
pH
7.9
8.2
7.9
DO (mg/l)
7.4
7.5
7.7
NO3 (mg/l)
70
126
180
SO4 (mg/l)
604
250
250
Cl (mg/l)
1240
597
958
F (mg/l)
4.4
4.4
4
HCO3 (mg/l)
322
240
315
Ca (mg/l)
93
70
182
Mg (mg/l)
56
46
52
Na (mg/l)
980
406
595
K (mg/l)
8.7
4.7
6.9
Fe (µg/l)
44
70
79
Al (µg/l)
72
73
53
M 2A
7.7
7.2
190
650
1288
3
308
126
56
1058
9.7
113
56
N22
7.5
7.6
95
568
1135
2.6
215
67
42
873
6.8
52
34
Soil
The results of total fluoride in soil samples are shown in Table 3 and the trend from north to
south is shown in Figure 3. The figure shows the same trend of fluoride contents as the water
samples, increasing in the area of Khan Yunis.
26
Chapter Two
Fluoride Study
__________________________________________________________________________________________
Table (3) Total fluoride contents in soil samples of five regions in the Gaza Strip.
Location
Sample code
mg/kg
Location
Sample code
North
Middle area
N1
178
M2
North
Middle
area
N2
100
M3
North
Middle area
N3
150
M4
North
Middle area
N4
144
M5
North
Khan
Yunis
N5
144
Kh1
Gaza
Khan Yunis
G1
177
Kh2
Gaza
Khan Yunis
G2
183
Kh3
Gaza
Rafah
G3
137
R1
Gaza
Rafah
G4
156
R2
Middle area
Rafah
M1
236
R3
mg/kg
200
243
253
224
475
438
309
163
178
139
R3
R2
R1
Kh3
Kh2
Kh1
M5
M4
M3
M2
M1
G4
G3
G2
G1
N5
N4
N3
N2
N1
Total fluoride (mg/kg)
Total fluoride in soils of the Gaza Strip
500
450
400
350
300
250
200
150
100
50
0
Soil sam ple
Figure (3) Levels of total fluorides in soil samples of 5 regions of the Gaza Strip.
Tea
Table 4 shows the average tea consumption during the field survey. The average number of
cups drank per person per day is indicated, the highest, 3.19 cups, being in Rafah and the
lowest, 2.50 cups, in Khan Yunis. For all regions of the Gaza Strip, the average number of
cups drunk per day is approximately 3.
Table (4) Average tea consumption for school children in the Gaza Strip.
Region
Average number of tea cups per person per day
North
2.8
Gaza
3.21
Middle
2.60
Khan Yunis
2.50
Rafah
3.19
27
Chapter Two
Fluoride Study
__________________________________________________________________________________________
The average fluoride content in tea as a beverage, as brewed in Gaza and calculated by us,
was about 4.7 ppm (Table 5). The fluoride content in the tea leaves is given in Table 6, the
average is 2.7 ppm. The survey indicated an average consumption of tea of about 3 cups
(each 100-120 ml) per day (Table 4).
Table (5) Fluoride contents in 20 tea liquor samples collected from 20 houses.
House No.
F (mg/l)
House No.
F (mg/l)
1
3.7
11
4.8
2
4.2
12
4.7
3
4.5
13
5.1
4
4.6
14
5.2
5
4.1
15
5.5
6
3.9
16
5.3
7
4.9
17
5.5
8
5.1
18
4.9
9
5.2
19
4.8
10
5.5
20
4.4
Table (6) Fluoride contents in 10 samples infused tea leaves.
Sample No.
F (mg/l)
1
2.2
2
2.4
3
2.1
4
2.5
5
3.0
6
3.1
7
2.8
8
2.7
9
2.9
10
3.1
DFI, CFI and prevalence of caries
The dental fluorosis index was not affected by sex or age and the results are shown in Table
7. Overall, the DFI increased going from north to south as the lowest value being in the
northern area of Jabalia, 2.85, and the highest value, 4.39, in eastern villages of Khan Yunis.
Table (7) Averages DFI for each region and age group.
Region
North
Gaza
Middle
Khan Yunis
Rafah
5-7
3.13
3.49
3.41
3.83
3.50
8-10
3.20
3.29
3.11
4.11
3.20
DFI and age groups
11-13
2.67
3.77
3.9
4.08
3.37
28
14-16
2.84
3.72
3.60
4.42
4.21
All ages
2.85
3.80
3.90
4.39
3.50
Chapter Two
Fluoride Study
__________________________________________________________________________________________
The DFI score was weighted and a CFI was calculated. The results are presented in Table 8
where the CFI for the Gaza Strip as a whole was calculated as 2.42.
Table (8) Weighted DFI scores and estimated CFI for the Gaza Strip.
Region
Weighted DFI Score
North
1.85
Gaza
2.76
Middle
2.82
Khan Yunis
3.15
Rafah
2.45
No. Individuals
62
48
117
67
59
CFI = 2.42
Prevalence of caries for each age group and region, presented as the number of permanent
teeth with caries is given in Table 9. The number of teeth with caries ranged from 0 in the age
group 5-7 to a maximum of 1.33, while it reached a maximum of 7 for the age group 14-16.
Table (9) Prevalence of caries for each age group and region.
No. of permanent teeth with caries Age groups
Region
5-7
8-10
11-13
14-16
North
1.00
0.75
3.34
1.14
Gaza
0.00
3.64
4.00
Middle
1.00
2.00
2.55
7.00
Khan Yunis
1.33
3.50
5.50
Rafah
0.67
4.05
6.00
DISCUSSION
The concentration of fluoride in groundwater increases from north to south, as do other
parameters such as salinity and nitrate. The results showed a very good agreement between
the ISE and IC results, especially for the samples which have fluoride contents exceeding 0.5
mg/l, while the IC showed more accurate results for the fluoride values less than 0.5 mg/l.
Overall, there was no significant difference between the fluoride readings of winter and
summer, however, in several wells there was a 5-10% increase in summer due to the
overexploitation of groundwater and absence of recharge; the same percentage was found for
the majority of tested anions and cations in a recent-parallel study.
Due to our knowledge of the region we suspected other factors to be involved in the
development of dental fluorosis. These factors revolve around the intake of fluoride from
other dietary sources such as the consumption of fish and tea. Fish also constitute a major
source of dietary fluorides. Fish consumption is considered to be high (verbal
communications and unpublished data from local sources). The other factor, tea, was also
considered. Communication with the population indicated a heavy intake of tea starting from
a very young age. Not uncommonly, tea is put in nursing bottles. Tea is made strong and
sweet. The average fluoride content in tea as a beverage, as brewed in Gaza and as calculated
by us was about 3 ppm. Our survey indicated an average consumption of tea of about 3 cups
per day. We believe this to be on the low side and double that quantity may be more
reasonable. The respondents to our survey feared a penalty from indicating the correct
29
Chapter Two
Fluoride Study
__________________________________________________________________________________________
amount of tea drunk. In spite of that we believe that tea consumption is heavy in Gaza and is
a contributing factor in the total dietary intake of fluorides.
The sources of fluorides in the groundwater of Gaza Strip are believed to be natural bedrock
that supplies the fluoride ions to the water. The results of soil samples showed good
correlation with the groundwater results, as the same general increase of fluoride is shown
from north to south. However, the total fluoride contents of all tested soil samples are lower
than the natural background of total fluoride in top soils (611 mg/kg) according to Turekian
and Wedepohl (1961). For the soil samples and the wells nearby, the correlation coefficient r
of soil/water fluoride was 0.93. None of the four fluoride minerals screened by the XRD
were found in the tested soil samples. The semi-quantitative analysis and the limit of
detection of the XRD showed that there were no distinguished peaks for the four major
fluoride minerals tested. In spite of that the computer model suggested fluorite (CaF2) as a
donating fluoride mineral to groundwater.
DFI showed a slight increasing trend going from north to south. Linear regression analysis
found a correlation (r = 0.72) between the level of fluorides in drinking water and the DFI. If
we exclude Khan Yunis and Rafah the correlation coefficient will be 0.93. The average level
of fluorides in Khan Yunis was 2.8 ppm and the DFI was found to be 4.39. In Rafah, the level
of fluorides was 0.73 ppm while the DFI was 3.45. It must be noted here that dental fluorosis
was formed during the tooth development period and years before the water was analyzed,
suggesting that water resources have recently been altered.
It is an established fact that, in the Gaza Strip, new water wells are dug on a periodic basis to
replace others where the salinity becomes high or they become contaminated as a result of
human activity.
The CFI for Gaza as a whole was calculated to be 2.42. According to Dean (1942) if the CFI
rises above 0.6, it begins to constitute a public health problem warranting increasing
consideration. Even if the score used in the formula to calculate CFI is halved, the index will
still remain far above the 0.6 figure recommended by Dean.
The number of teeth exhibiting caries was low for the Gaza population, especially in the
younger age groups. It is believed that two factors are involved in that, the high DFI and the
low consumption of candied products. It is a known fact that fluorides help reduce dental
caries, in addition the population is of low economic status such that candied food products
are a luxury and not affordable by many.
An epidemiological study of Rugg-Gunn et al., (1997) suggested that the prevalence of dental
fluorosis was high among children suffering from malnutrition. Some correlation between
drinking water type fluorosis and the population's socio-economic condition and nutritional
status is indicated. Fluorosis prevalence increases through the agricultural towns of Khan
Yunis to urban regions.
30
Chapter Two
Fluoride Study
__________________________________________________________________________________________
CONCLUSIONS
The levels of fluorides found in groundwater and topsoil showed a general increasing trend
from northern to southern areas of the Gaza Strip. Dental fluorosis occurred in many areas
especially in Khan Yunis (south and south-east) where the average level of fluoride for all
tested wells was 2.6 mg F/l. The sources of fluorides in groundwater are believed to be
natural bedrock that supply fluoride ions to the groundwater; however the XRD results
showed that none of the major fluoride minerals tested in soil samples were detected, the
computer model-PHREEQC revealed that fluorite (CaF2) was the donating mineral of
fluoride ions to the groundwater. The dental fluorosis index (DFI) showed an increasing trend
going from north to south and the community fluorosis index (CFI) for the Gaza Strip as a
whole was 2.42 which represents a public health problem warranting increasing
consideration. Many factors were involved in the development of dental fluorosis in the area,
these factors revolved around the intake of fluoride from other dietary sources such as the
consumption of tea and fish; the tea is heavily consumed as sweet and strong and being
consumed from a very young age where it is put in nursing bottles.
RECOMMENDATIONS
The situation in which fluorides play an important factor in public health must be addressed
on an urgent basis to avoid an environmental health catastrophe. One of the recommendations
we suggest is integrating the water supply for Gaza as a whole. There are a number of wells
in the northern area that are low both in fluoride and salinity which when mixed with other
wells will result in water of acceptable quality. This option seems to be the only feasible
solution for the foreseeable future. Parents, caregivers, water quality experts and health care
professionals should judiciously monitor use of all fluoride-containing dental products by
children under age 5 as is the case with any therapeutic product.
31
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
CHAPTER THREE
Potential use of treated wastewater and sludge in the agricultural sector
of the Gaza Strip (*)
ABSTRACT
Twelve elements (Ag, Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were analyzed in 120
composite samples of influent and effluent wastewater; the results revealed that domestic
wastewater influent contains considerable amounts of heavy metals and the partially
functional treatment plants of Gaza are able to remove 40-70% of most metals during the
treatment process. Heavy metals in 31 industrial wastewater effluents are within the ranges of
international standards. All industries of Gaza are light; although they have no treatment
facilities, their effluents are being discharged to municipal sewerage system and the existing
treatment plants are capable of absorbing the industrial effluents with no significant impact
on treatment bioprocesses.
Thirty parameters were determined in 35 sludge samples: P, AOX, C, S, CaCO3, Mg, Ca, Na,
K, Li, Cu, Zn, Ni, Pb, Mn, Fe, Cr, Co, Cd, As, Hg, Ti, Se, Br, Rb, Th, Sr, Y, U, and Zr.
Although there are no treatment facilities for sludge within the treatment plants, the results
indicated that sludge in general is clean of heavy metals. Only zinc and AOX showed
anomalous concentrations; more than 85% of sludge samples showed that averages of zinc
and AOX are 2,000 mg/kg and 550 mg Cl/kg, respectively, which exceed the standards of all
industrial countries for sludge to be used in land application.
Key words: Heavy metals, Reuse, Sludge, Wastewater treatment plants
___________________________________________________________________________
(*) The study was published in the Journal of Clean Technologies and Environmental Policy as:
Shomar B. Müller G. Yahya A. (2004) Potential use of treated wastewater and sludge in the
agricultural sector of the Gaza Strip. Journal of Clean Technologies and Environmental Policy, 6(2),
128-137.
32
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
INTRODUCTION
The arid and semi-arid nature of the region renders it to be a water scarce region. Population
growth and agricultural and industrial development have put more pressure on the existing
scarce resources. They are currently being exploited to their maximum capacity to meet the
desired development. As a result, a lot of environmental problems have started to arise at all
places and levels. Such problems will be more acute in the near future if the current resource
utilization patterns continue. Therefore there is an essential need to start looking at the
different options and mechanisms that will help overcome these escalating environmental
problems.
Lack of wastewater management has a direct impact on problems related to public health,
marine and coastal pollution, deterioration of nature and biodiversity, as well as landscape
and aesthetic distortion in the Gaza Strip (MEnA, 2000). Currently, about 60-80% of the
domestic wastewater is discharged into the environment without treatment, either directly at
the source, after collection from cesspits, or through the effluent of the sewer system or the
overloaded treatment plants (MEnA, 2001). Assuming that 60% of the water used for
domestic usage comes back as wastewater, Gaza produces about 13 MCM annually (CAMP,
2001). About 40% (50,000 m3/day) of the wastewater that is generated in Gaza is currently
discharged into the sea; a minor part infiltrates into the soil and contaminates the
groundwater.
Compared to the neighboring countries, the industrial sector in Palestine is presently rather
underdeveloped. Most industries are concentrated in the city of Gaza and in the northern
areas, grouped in two main industrial estates, Gaza Industrial Estate (GIE) and smaller Beit
Hanoun Industrial Estate (BIE). Several industries are scattered among residential areas. The
industries of greatest concern are the food industry, chemical industry, tanning industry,
textile industry, and the electroplating and metal finishing industry. Industries in Gaza are
light and each has 5 to 100 individuals (Shomar, 1999). Heavy metals may inhibit the
activities of microorganisms within the treatment process. Regulated metals include barium,
cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, zinc and arsenic
(Edwards, 1995). Industrial wastewater requires onsite pretreatment before it can be disposed
into the municipal sewage network to guarantee the stability of domestic wastewater
treatment plants (Safi, 1999). Because heavy metals can not be degraded in the wastewater
treatment plant, either they end up in the treatment plant sludge or they pass through the plant
and leave with the effluent.
Up to now there has been very little production of sludge as all existing wastewater treatment
plants are deficient and operating with old technologies. The construction of new wastewater
treatment plants or the rehabilitation of the existing ones in Gaza will produce a regular daily
volume of sludge that will need to be disposed in landfill sites, incinerated, ocean dumped,
composted or applied in agricultural lands (PEPA, 1994). Sludge treatment facilities are
almost absent and the produced sludge is removed from the ponds and left to be dried,
partially depending on the season and the available area close to the treatment plant (PWA,
1999). Sludge production is a function of the biological oxygen demand (BOD5) removal rate
(EPA, 1999). It is assumed that the minimum sludge production should correspond to a BOD
removal rate of 95% (effluent at 30 mg O2/l) for some treatment plants in Gaza. Next to the
available data of the PWA, the field visits confirmed that the amount of sludge Gaza
wastewater treatment plants produce is low.
33
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
The solids content is within the range of 16 and 22% which categorize the Gaza sludge as a
dewatered sludge, although dewatered sludges have as much as 40% solids.
To guarantee and safeguard hygienic standards and have no adverse effects on the human
health, environmental quality must be given the highest priority. Although opponents of
sludge use have many reservations, one of their main concerns is the long-term buildup of
heavy metals in the soil (Zufiaurre et al., 1998). Over time, metals such as cadmium, zinc,
and copper could build up to levels high enough to damage agricultural soils (EPA, 1999).
Although the use of sludge on agricultural land is largely dictated by nutrient content (N and
P), the accumulation of potentially toxic elements in sewage sludge is an important aspect of
sludge quality, which should be considered in terms of long-term sustainable use of sludge on
land (Burica et al., 1996). The most important nutrients in the sludge are nitrogen,
phosphorus, and potassium. Other nutrients that may be present include calcium, magnesium,
sulfur and they add copper even though it is considered as a heavy metal (Alloway and
Jackson, 1991). According to the American standards of sludge used in agriculture, the
average concentration of N and P in dry weight is 2% and <1% respectively; while the total
solids are 3.4% (EPA, 2002). Although sludge is a valuable source of plant nutrients, the
nutrient concentrations are significantly lower than most commercial fertilizers (Sterritt and
Lester, 1980). It has been suggested that determination of adsorbable organic halogens
(AOX) be used as an indicator for these priority substances. Moreover, AOX determination is
a relatively easy technique to use. Because AOX is an analytical parameter and represents a
wide range of substances, differing not only in their chemical structure but also in their
toxicological profile, a description of relevant toxicological endpoints cannot be given
(Planquart et al., 1999).
The main objective of this study is to introduce the concentration of trace metals and some
major parameters in domestic, industrial wastewater and sludge for the first time. Moreover,
it tries to highlight the various options that aim to reuse the treated wastewater and sludge in
the Gaza Strip in a manner that will ensure agriculturally sustainable development.
MATERIALS AND METHODS
The study area
There are, at the present time, four wastewater treatment plants that are either being planned,
under construction or in operation. The main two operating treatment plants are: the Beit
Lahia Wastewater Treatment Plant in the northern area of Gaza and the Gaza Wastewater
Treatment Plant in the region of Gaza City (Fig. 1), but none is working properly. The
monitoring program on wastewater of the two treatment plants is conducted by the
Palestinian Water Authority (PWA) and only a few parameters (pH, solids, BOD, and COD)
are recorded in a regular basis.
34
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Beit Lahia (Northern) Wastewater Treatment Plant
The Beit Lahia Wastewater Treatment Plant, located some 1.5 km east of the town of Beit
Lahia in the northern part of the Gaza Strip, was erected in stages, commencing in 1976. It
serves the town of Jabalia, as well as the nearby refugee camp and the communities of Beit
Lahia and Beit Hanoun. The population in the area amounts to about 150,000 people today.
But, depending on an exceptionally high natural rate of growth, the population could rise to
260,000 in the year 2010 and reach over 350,000 people in the year 2020, according to the
official forecasts. That means a doubling of the population in a period of 20 years (PCBS,
2000). The existing plant consists of several ponds disposed in two lines, the first two ponds
of each line being aerated, and with possibilities of interconnection. The plant has no
pretreatment facilities and it is designed for a peak flow of 2,600 m3/h. The plant is located in
a depression without natural outlet to the sea, although it does not lie so far (4.5 km) from it.
The effluent merely overflows from the last pond of the works, spreading in a large sand
dune area in the immediate vicinity of the plant, where it infiltrates to groundwater. The plant
faces major operation problems, such as: no preliminary treatment; presence of sand; BOD
of over 600 mg O2/l; an overflow of used water; and the pumping station is out of operation.
The average sludge production at the Beit Lahia WWTP can be estimated to be on average
8.5 tons total solids per day in the year 2010, i.e. approximately 28 m3/day.
Gaza Wastewater Treatment Plant
This plant was originally constructed in 1977 as a two-pond treatment system. In 1986, it was
expanded to a capacity of 12,000 m3/day with the construction of two additional ponds. A
project in 1994 rehabilitated the plant without capacity increase. In 1999, with USAID
funding, the plant was expanded to a capacity of 32,000 m3/day and consisted of anaerobic
ponds, an aerated pond, biotowers, an effluent polishing pond, disinfection, effluent pump
station/force main and sludge drying beds. The current flow to the plant is about 42,000
m3/day from Gaza City and parts of Jabalia. The sludge produced in this plant is exposed to
the sun and then accumulated and transferred to dumping sites. The plant is close to less
urbanized areas and closer to agricultural areas to facilitate the distribution of reused water to
farmers.
Industries
The major industries were selected to represent all industrial activities in the Gaza Strip
(Tables 4, 5 and 6). Among 31 industries, 20 are located in the two major industrial estates,
Gaza, and Beit Hanoun. The other 11 industries are scattered among residential areas
especially in Gaza, Jabalia and few in Khan Yunis.
35
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Fig. 1. Existing and proposed wastewater treatment plants and sewage outlets to the sea in the Gaza Strip.
36
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
The sampling and analysis
Domestic wastewater
The continuous presence of a trained guard in each wastewater treatment plant made the
sampling campaigns easier, especially because his mandates are to protect the plant and to
collect samples for the routine monitoring program of the PWA. Three sampling campaigns
have been conducted in 3 years (20 influent and 20 effluent samples each year) in the periods
20 November-12 December 2000, 26 June-17 July 2001 and 25 April -17 May 2002.
A series of grab samples (8-10) were taken over 1 day (1l per 2h), starting from 6:00 am, and
combined in a container to form a composite sample. Finally, 1 l of the mixture was taken in
an acid-washed bottle and transferred to the laboratory, and was then filtered in an acidwashed filter holder and through a 0.45-µm Sartorius filter. The first few milliliters were used
for rinsing, then they were discarded, and the filtrate was transferred to clean acid-washed
polyetheylene bottles and acidified with concentrated nitric acid (Ultrapur, Merck, v/v), and
stored at 4 oC until analyses by the ICP/MS (Perkin Elmer-Sciex, Elan 6000) were
performed; the other part of wastewater was filtered with no additives and stored at 4 oC for
anion analyses by Ion Chromatography (IC DIONEX DX-120). Several parameters were
measured during the fieldwork: temperature, electrical conductivity and pH, other parameters
(SS, TSS, TDS, COD and BOD5) were measured a few hours later according to the American
standard methods (APHA, 1995).
Industrial wastewater
The samples were taken from the effluent wastewater of the existing operating industries in
Gaza, and they were collected in the same periods as the domestic wastewater. Although the
situation in Gaza was very difficult, the sampling program went smoothly, and all but three of
the industries that were initially selected were sampled, as listed in Tables 4, 5 and 6. In
coordination with the staff of monitoring and inspection of the Palestinian Ministry of
Environment, 31 composite samples were collected (10 in the first year, 21 in the following
two years). They had the same treatment and analysis as the domestic wastewater samples.
Sludge
Thirty-five sewage sludge samples were collected during the campaigns, 5, 20 and 10 in the 3
years. Samples of sludge were collected in polyethylene containers from the different drying
lagoons of the two treatment plants and from the accumulated piles in the surrounding areas.
After collection, samples were freeze-dried until complete dryness; then they were ground
and homogenized in an agate mortar and sieved through a mesh of 0.63-mm pore size.
About 0.5 to 1.0 g of the homogenized sample were dissolved in 10.5 ml of concentrated
hydrochloric acid (37% p.a.) and 3.5 ml of concentrated nitric acid (65% p.a.) in 50 ml
retorts. The samples were allowed to degas (12 h). Then all samples were heated to 160 °C
on a sand bath until a complete extraction had taken place (3 h). After cooling, the solutions
were diluted with distilled water in 50-ml volumetric flasks and kept in 100-ml polyethylene
bottles for analysis.
37
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Heavy metals were analyzed by two different techniques: flame atomic absorption
spectrometry (AAS vario 6- analytikjena) was used for determination of Mg, Li, Ca, K, Na,
Cu, Zn, Ni, Pb, Mn, Fe, Cr, Co, Cd and As. An energy-dispersive miniprobe multielement
analyzer (EMMA) for direct analysis was used for K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se,
Br, Rb, Sr, Y, Zr, Pb, Th and U in sludge (Cheburkin and Shotyk, 1996). The distribution of
total phosphorus represented as (PO4) was measured for all sampling stations (APHA, 1995).
Mercury concentrations were determined using atomic absorption spectroscopy after thermal
combustion of the freeze dried samples (50-100 mg) and Hg pre-concentration on a single
gold trap by means of an advanced mercury analyzer (AMA) 254 solid phase Hg-Analyzer
(LECO). The total carbon and sulfur were determined directly in dried samples by using a
carbon-sulfur determinator (Leco CS-225). Carbonates were measured directly via a
carbonate bomb (Müller and Gastner, 1971). The TOC can be calculated by the subtraction of
inorganic carbon from total carbon. AOX was determined using a Euroglas Organic Halogen
Analyzery- Netherlands according to the DIN 38414 S18 Deutsche Einheitsverfahren zur
Wasser, Abwasser und Schlammuntersuchung, Sludge and Sediment (Group S)
Determination of AOX (DIN, 1989).
Table (1) Standards of heavy metals in wastewater and sludge.
Domestic wastewatera
Industrial wastewaterb
Sewage sludgec (mg/kg)
(mg/l)
(mg/l)
Element
Ayers &
China2
WHO4
Jordan5
USA6 Germany7
France8
EPA1
Westcot3
Ag
0.03
1
Al
5
As
0.05
0.05
0.1
0.05
41
Cd
20
0.005
0.01
0.01
39
1.5
2
Co
2
0.05
Cr
5
0.1
0.1
5
0.05
1200
100
150
Cu
0.2
1
0.2
1
1
1500
60
100
Fe
5
Mn
10
0.2
1
Ni
0.2
0.2
1
0.1
420
50
50
Pb
0.05
0.1
5
0.1
0.1
300
100
100
Zn
2
2
2
5
15
2800
200
300
Hg
0.001
0.001
17
1
1
a
: Standards for reuse.
b
: Standards for discharging into municipal sewerage system and to the environment.
c
: Limit values for heavy metals in sludge for use in agriculture.
1
: EPA, 1999.
2
: China National Regulations for Agricultural Irrigation, 1992.
3
: Ayres and Westcot, 1985.
4
: WHO, 1998b: Concentration of heavy metals inhibiting aerobic biological treatment processes.
5
: Ministry of Municipal and Rural Affairs & the Environment-Jordan, 1991.
6
: EPA, 2002: pollutant concentration limit (mg/kg) for Land Application in the United States, Dry Weight
Basis.
7
: ICON, 2001: Standards for agricultural application and McGrath, 1995.
8
: McGrath, 1995.
38
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Quality control
For quality control, analytical blanks and two samples with known concentrations of heavy
metals were prepared and analyzed using the same procedures and reagents. For wastewater
analysis, Standard Reference Material 1643c was used for determination of trace elements
(NIST, 1991). For sludge samples, the accuracy was evaluated by two Sewage Sludge
Standard Reference Materials (DIN, 1997). As an independent check on the trace element
measurements of the sludge, these were also measured in solid samples using the energydispersive miniprobe multielement analyzer EMMA-XRF. As a boundary and a reference of
the expected results, about nine international standards of heavy metals in domestic
wastewater, industrial wastewater and sludge were chosen (Table 1).
RESULTS AND DISCUSSION
Domestic Wastewater
In a 2-week monitoring of general parameters, the performance of the two plants was
recorded (Table 2), while the performance of the plants with respect to the heavy metals in 3
years is shown in Table 3. The general parameters indicated that the two plants under the
existing treatment facilities were working well and they were able to remove >92%, >88%,
>60% of BOD5, COD and both total P and total N, respectively.
Table (2) Performance of wastewater treatment plants in the Gaza Strip (4-19 July 2001).
Beit
Gaza
Beit Lahia
Lahia
Removal
German
Parameter*
WWTP
WWTP**
WWTP
(%)
standards
Influent
Influent
Effluent
pH
7.04
7.43
-6
7.5
Temperature (oC)
22.3
22.3
0
25.5
Settleable Solids SS (Ml/l)
6
0.1
98
9
Total Dissolved Solids (TDS) mg/l
895
1007
-13
1470
Total Suspended Solids (TSS) mg/l
1288
1024
20
440
Chloride (mg/l)
270
250
555
Fluoride (mg/l)
0.6
0.6
1.2
Sulfate (mg/l)
242
250
314
Total P (mg/l)
2
15
6
60
23
Total N (mg/l)
18
17
6
65
19
NO2 (mg/l)
63
16
75
71
NH4-N (mg/l)
10
64.4
61.4
5
62
COD (mg O2/l)
110
884
108
88
940
BOD5 (mg O2/l)
25
420
35
92
520
* Average value of each parameter.
** WWTP: Wastewater Treatment Plant
39
Gaza
WWTP
Effluent
7.7
26
0.1
1536
20
480
1.4
320
9
7
20
60
89
25
Removal
(%)
-3
-2
99
-4
95
61
63
72
3
91
95
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
The heavy metal removal was not constant due to the many factors affecting the treatment
process. A good example was the shortage in aerator performance, and this affected the
oxygen contents in the aeration lagoons and the latter affected the form of the metals and
their solubility; this could explain the maximum and minimum variations of some parameters
sensitive to dissolved oxygen such as Fe, Mn and As.
Table (3) Average concentrations of heavy metals in influent and effluent wastewater.
Beit Lahia Wastewater Treatment Plant
LDa
Inf 2000
Eff 2000
Inf 2001
Eff 2001
Inf 2002
Ag µg/l
0.5
0.7
0.6
NMb
NM
7.3
Al µg/l
25
73
39
NM
NM
138
As µg/l
5
5.6
5.1
0.7
0.6
5.5
Cd µg/l
0.5
< 0.5
0.8
0.1
< 0.5
< 0.5
Co µg/l
0.3
0.3
0.8
NM
NM
0.6
Cr µg/l
2.5
38.9
7.6
25.3
2.9
25.2
Cu µg/l
1
6.0
6.7
2.5
2.7
8.5
Fe µg/l
15
373
114
344
76
356
Mn µg/l
1
120
96
116
47
142
Ni µg/l
0.5
21.9
11.8
NM
NM
13.1
Pb µg/l
2.5
2.6
< 2.5
2.9
< 2.5
2.7
Zn µg/l
10
120
35
105
29
87
Gaza Wastewater Treatment Plant
Inf 2000
Eff 2000
Inf 2001
Eff 2001
Inf 2002
Ag µg/l
0.5
0.8
0.8
NM
NM
0.7
Al µg/l
25
71
61
NM
NM
89
As µg/l
5
6.6
7.0
0.4
1.1
7.8
Cd µg/l
0.5
0.5
< 0.5
0.1
0.1
0.5
Co µg/l
0.3
0.4
0.7
NM
NM
0.5
Cr µg/l
2.5
11.3
4.8
7.0
2.6
11.3
Cu µg/l
1
7.0
7.0
4.3
3.2
6.9
Fe µg/l
15
137
132
163
121
198
Mn µg/l
1
76
68
303
103
70
Ni µg/l
0.5
5.5
6.8
NM
NM
5.4
Pb µg/l
2.5
2.6
2.6
2.5
< 2.5
3.3
Zn µg/l
10
75
54
61
41
92
a
Limit of detection
b
NM: not measured
Eff 2002
1.3
44
5.4
1.3
0.8
8.4
5.1
347
139
12.1
< 2.5
59
Eff 2002
1.0
278
8.4
< 0.5
0.9
5.9
7.5
202
52
7.1
< 2.5
56
The results indicated that the concentrations of major anions (Cl, F, NO3 and SO4) and major
cations (Na, Ca, Mg and K) in wastewater were similar to their values in the groundwater of
the area of each treatment plant. Many metals have a high affinity to react with anions and
this affects their mobility within the treatment process and their final contents in effluent and
sludge. Anomalous results of some elements indicated that their concentrations in the effluent
were higher than those in the influent; despite the fact that there is no clear explanation, it is
assumed that the accumulation of these elements in water has occurred in the final
sedimentation lagoons of each plant. There was no steady state behavior of each element in
the 3 years of monitoring; the same phenomenon appeared independently for each treatment
plant. On the other hand; major indicating parameters (BOD5, COD and TSS) were removed
to the maximum and all tested heavy metals in the effluent complied with different standards.
40
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
All tested elements showed similar concentrations in the influent in the 3 years monitored and
no significant difference was observed between the values of both treatment plants; the
effluents showed a similar situation; only Ag showed anomalous results in the influent of
2000 and 2002 for the Beit Lahia treatment plant. The wastewater effluent had good
characteristics close to the guidelines and standards of many developed countries (Table 1),
and in general the results revealed that there was no significant difference between the
performances of the two treatment plants in terms of heavy metal removal (Fig. 2). Moreover,
the wastewater effluent of the two treatment plants was suitable for all purposes and
applications such as agriculture and industry. Generally the results showed that heavy metals
in the effluent are low and they comply with the standards of reused wastewater in
agriculture.
41
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Performance of GWWTP (2001)
Performance of BLWWTP (2001)
400
350
350
300
300
250
influent
200
effluent
(µg/l)
(µg/l)
250
150
200
influent
150
effluent
100
100
50
50
0
0
Fe
Zn
Fe
Mn
Performance of BLWWTP (2001)
Zn
Mn
Performance of GWWTP (2001)
25
8
7
6
5
15
influent
effluent
10
(µg/l)
(µg/l)
20
influent
4
effluent
3
2
5
1
0
0
Cu
Cr
Pb
As
Cu
Cd
Performance of BLWWTP (2002)
Cr
Pb
As
Cd
Performance of GWWTP (2002)
14
9
12
8
7
6
8
influent
6
effluent
(µg/l)
(µg/l)
10
5
influent
4
effluent
3
4
2
2
1
0
0
Ag
As
Cu
Ni
Ag
Pb
Performance of BLWWTP (2002)
As
Cu
Ni
Pb
Performance of GWWTP (2002)
300
400
350
250
200
250
influent
200
effluent
(µg/l)
(µg/l)
300
150
influent
150
effluent
100
100
50
50
0
0
Al
Fe
Mn
Zn
Cr
Al
Performance of BLWWTP (2002)
Fe
Mn
Zn
Cr
Performance of GWWTP (2002)
1.4
0.9
1.2
0.8
0.7
0.6
0.8
influent
0.6
effluent
(µg/l)
(µg/l)
1
0.5
influent
0.4
effluent
0.3
0.4
0.2
0.2
0.1
0
0
Cd
Co
Cd
Co
Fig. 2. Performance of Beit Lahia wastewater treatment plant (BLWWTP) and Gaza wastewater
treatment plant (GWWTP), heavy metals in influent and effluent wastewater.
42
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Industrial Wastewater
From the field surveys, it was found that the industrial wastewater was disposed of to the
municipal sewage system when the latter was present, or to septic tanks constructed for each
industry, or directly to the surrounding areas which are in some cases wadies. Treatment
processes were almost absent, and in the best case they were very simple, represented by
sediment tanks. There was no periodic inspection, and if present there were no scientific rules
regarding the discharge standards or quality control. Tables 4, 5, and 6 show the heavy metals
in the effluent of 31 industries. The tables confirmed important conclusions: unlike the
domestic wastewaters, it is very difficult to generalize about the industrial wastewaters; the
characteristics of the industrial wastes vary not only with the type of industry, but also from
plant to plant, due to differences in manufacturing processes and, to a lesser degree, the
quality of the original raw water used. Under the worst-case scenario of the industrial
wastewater production in terms of quality and quantity, the treatment plants are able to
absorb all amounts of pollutants and the final effluent is considered clean for agriculture and
other reuse applications.
Table (4) Heavy metals in the effluents of 10 industries in the Gaza Strip (µg/l), year 2000.
Industry
Fe
Zn
Cu
Mn
As
Pb
Pharmaceutical Industry
97
259
2.68
40
0.92
<2.5
Cosmetics Industry
127
109
4.262
45
0.36
4.1
Jeans washing
775
1369
500
124
1.2
6.61
Electroplating Factory
5450
29500
4000
219
3.58
102
Galvanic Factory
2900
3096
14.95
26
2.36
10.3
Detergent Factory
1619
1730
1
71
7.77
110
Cloth Washing Factory
277
503
500
57
1.9
6.52
Ice Cream Factory
222
251
100
26
1.44
<2.5
Soft Drinks Factory
825
143
400
64
1.34
4.25
Car Washing Machine
1308
212
100
75
2.12
27.3
Cr
<2.5
5.52
16.43
15859
797
1073
50.65
50.95
22.32
23.13
Table (5) Heavy metals in the effluents of 10 industries in the Gaza Strip (µg/l), year 2001.
Industry
Fe
Zn
Cu
Mn
As
Pb
Cr
Pharmaceutical Industry
97
259
2.68
40
0.92
<2.5
1.89
Cosmetics Industry
127
109
4.26
45
0.36
4.10
5.52
Jeans washing
775
1369
500
124
1.20
6.61
16.43
Electroplating Factory
5450
29500
4000
219
3.58
102
15859
Galvanic Factory
2900
3096
14.95
26
2.36
10.3
797
Detergent Factory
1619
1730
0.67
71
7.77
110
1073
Cloth Washing Factory
277
503
500
57
1.9
6.52
50.65
Ice Cream Factory
222
251
100
26
1.44
<2.5
50.95
Soft Drinks Factory
825
143
400
64
1.34
4.25
22.32
Car Washing Machine
1308
212
100
75
2.12
27.30 23.13
43
Cd
<0.5
<0.5
<0.5
70.15
9.40
8.65
<0.5
0.86
<0.5
<0.5
Cd
0.06
0.09
0.03
70.15
9.40
8.65
0.28
0.86
0.19
0.44
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Table (6) Heavy metals in the effluents of 11 industries in the Gaza Strip (µg/l), year 2002.
Industry
Ag
Al
As
Cd
Co
Cr
Cu
Fe
Industry of Detergents (1)
2.79
925
31
0.7
2.2
103.5
174
645
Industry of Detergents (2)
35.05 1010
29
2.3
2.3
281.0
48
375
Metal coating – Galvanization 21.55 104
8
< 0.5 3.4
71.5
385
565
Jeans-Washing Industry
8.9
59
5
0.6
0.8
7.6
39
380
Pharmaceuticals
1
313
14
0.8
3.5
102.5
54
3200
Cosmetics and perfumes
0.5
33
8
< 0.5 0.5
11.4
11
379
Jeans-Washing Industry
1.755
38
10
< 0.5 0.5
34.1
25
281
Paintings
< 0.5 1440
15
0.5
2.2
8.7
51
585
Soft Drinks
2.05
466
14
0.8
1.0
27.3
32
1330
Industry for Plastics
< 0.5
920
5
< 0.5 0.3
6.9
10
395
Metal Electroplating
0.94
143
<5
0.7
3.6
48050 1585 1270
Mn
12
16
3
111
221
42
32
45
21
22
80
Ni
27
5
5
5
22
5
13
6
14
2
74
Pb
10.7
7.9
< 2,5
< 2,5
53.0
< 2,5
< 2,5
453.0
84.5
17.2
7.0
Sludge
Table 7 summarizes the statistical analysis of sludge quality and the average value is
considered to represent each parameter, bearing in mind that the median value is very close to
the average.
Table (7) Averages of trace metals and major parameters in sludge of three years.
Gaza WWTP
BLWWTP Gaza WWTP BLWWTP Gaza WWTP
Parameter
2000
2001
2001
2002
2002
Mean
Mean
Mean
Mean
Mean
PO4 [g/Kg]
10
10
21
13
25
AOX [mg/kg]
490
467
523
480
495
C [%]
15
31
31
34
24
S [%]
0.5
2.0
2.0
3.8
2.6
CaCO3 [%]
23
17
23
17
22
Mg [%]
0.9
1.2
1.3
1.0
1.0
Ca [%]
7
4
4
8
11
Na [mg/Kg]
2230
1257
3076
4145
7095
K [mg/Kg]
2425
1158
1447
1890
1746
Li [mg/kg]
3.3
3
3
3.1
2.9
Cu [mg/Kg]
110
200
251
257
276
Zn [mg/Kg]
897
1646
1909
2000
2281
Ni [mg/Kg]
24
60
25
46
25
Pb [mg/Kg]
49
77
121
92
140
Mn [mg/Kg]
206
148
235
158
244
Fe [%]
1.1
1.7
1.2
1.4
1.4
Cr [mg/Kg]
50
120
82
98
93
Co [mg/Kg]
4.1
6.5
5.3
2.8
2.5
Cd [mg/Kg]
0.9
2.4
1.3
2.0
1.8
As [mg/Kg]
18.2
35.0
21.2
6.4
4.1
Hg [mg/Kg]
3.1
2.0
2.6
2.4
3.3
44
Zn
269
174
10200
940
605
426
102
173
63
53
1085
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Heavy metals
According to the results of the wastewater, the majority of metals transfer to sewage sludge,
although 20% may be lost in the treated effluent, depending on the solubility and this may be
as high as 40%-60% for the most soluble metal, Ni. It is important to mention that the quality
of the wastewater effluent has a direct relationship with the quality of the sludge produced
from the same plant. This means that when the total solids in the effluent are high the sludge
has low solid contents and the treatment process is not efficient and vise versa.
In addition to the common metals analyzed (Table 7) in sludge samples in many parts of the
world, an extra nine elements were determined (Table 8) and, although these elements are of
lesser importance, seven of them have low concentrations and only titanium (Ti) and
strontium (Sr) as an alkaline earth metal showed considerable amounts in the tested samples.
Table (8) Other elements in sludge produced from Gaza (mg/kg), by using EMMA.
Sludge quality of Beit Lahia WWTP, April 2002 Sludge quality of Gaza WWTP, April 2002
Parameter LD*
max
min
mean median
σ
max
min
mean median
σ
Ti
3336
2457 2835
2846
328
3213 2276 2719
2854
416
Se
0.6
2
1
1.2
1.0
0.5
5
3
3
3
1.0
Br
0.7
20
18
19.2
19
0.7
27
17
23
23
3.9
Rb
0.7
13
8
10.5
11
2.1
12
8
10
10
1
Sr
0.8
363
335
349
352
11.5
984
540
709
651
168
Y
1.0
9
6
8.0
9
1.2
8
6
7
7
1.0
Zr
0.5
86
59
71.0
69
10.5
185
96
129
103
42
Zn
1.0
1597
1383 1495
1472
98
1642 1107 1341
1261
239
Th
2.5
9
5
7
7
1.8
3
0
2
2
1.4
U
2.5
5
3
4
4.3
0.8
11
6
9
9
2.0
*) Limit of Detection
The results of Zn in more than 90% of sludge samples revealed that this metal is present in
high amounts and this is a very serious fact. Zinc in sludge of Gaza exceeds that of all
standards of developed and industrial countries (Table 1). This raises the question about the
main sources of Zn in sludge. Based on the field surveys, the Zn sources are expected to be
domestic and commercial in origin. Domestic sources of Zn are corrosion and leaching of
plumbing, water-proofing products, anti-pest products, wood preservatives, deodorants and
cosmetics, medicines and ointments, paints and pigments, printing inks and coloring agents.
The commercial sources are galvanization processes, brass and bronze alloy production, tires,
batteries, paints, plastics, rubber, fungicides, paper, textiles, taxidermy, building materials,
special cements, and also cosmetics and pharmaceuticals.
As mentioned above, the effluent wastewater showed low contents of Zn and the average of
Zn removal in the treatment process was 55%; this ratio finds its way to the sludge and this
may explain the high contents of Zn in sludge. For further quality assurance, the same
samples were analyzed by the EMMA, and the Zn average was 1400 mg/kg which is the
same as the American standard. Under the best-case scenario of Zn contents in sludge and
taking the EMMA reading, it is recommended not to apply this sludge on agricultural land
before detailed investigations.
45
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
A brief comparison between the sludge of the two plants revealed that Mg, Ca, Li, Cu, Zn,
Fe, Cr, Co and As have similar concentrations and no significant changes occurred during the
3 years of monitoring; however the results for As and Zn were 2-3 times higher in the years
2001 and 2002, respectively. Nickel was 2-3 times higher in Beit Lahia WWTP while Mn
and Pb were 2 times higher in the sludge of Gaza WWTP; the reason is expected to be the
fluctuation of industrial activities and the irregular production load of these elements in the
industrial wastewater. The high concentrations of Na in the sludge of Gaza (2-3 times) may
be connected to the same ratio of Na in groundwater and wastewater for the two areas.
Nutrients (N and P)
The averages of calculated total organic carbon TOC (total carbon – inorganic carbon) for
sludge are 17-22 % for Beit Lahai and Gaza, respectively, while the results of nitrogen for the
two plants showed averages that are less than 2% (the American standards); nitrogen in Beit
Lahia WWTP was 1.35% while it was 1.6 in Gaza WWTP. This range puts the sludge of
Gaza in an acceptable ranking for land application.
The average of phosphorus in the sludge of Gaza plant was 0.7% while it was only 0.4% in
the sludge of the Beit Lahia plant. Both results are less than the standards of the USA (1%)
and other developed countries. All other values of K, Ca, Mg etc. are shown in Table 7 and
they are all within the international standards.
Adsorbable organic halogens (AOX)
In this survey of contamination levels of sludge of Gaza, it was found that concentration of
AOX is in the range of 200-600 mg Cl/kg, while the German and EU standard is 500 mg
Cl/kg. AOX is not a measure for toxicity, and according to the site visits the main sources are
expected to be paper pulp industry. Even though the wastewater effluent of the paper
industries was not examined, it is proposed that the main source of AOX in sludge was the 26
paper industries distributed in Gaza and the northern area. These industries were using old
technologies and they represented the largest consumer of chlorine and the greatest source of
toxic organochlorine discharges directly into waterways. Large quantities of toxic
organochlorine byproducts, including dioxin and thousands of other substances, were being
discharged into the municipal sewage system. Many organochlorines resist natural
breakdown processes, so they build up over time in the sludge, and this explains the high
AOX ratio in the sludge of Gaza. Based on the results of the heavy metals and of the other
major parameters obtained in this study, the application of sludge should comply with the soil
physical, chemical and biological characteristics. Protection of soil organisms and
microbially mediated soil processes is important. Regular monitoring systems for sludge and
soil should be implemented and risk assessment programs should be adopted prior to and
after sludge application.
46
Chapter Three
Potential Reuse of Treated Wastewater
__________________________________________________________________________________________
Variation of heavy metal contents in wastewater and sludge
The fluctuation of heavy metal contents in wastewater and sludge could be explained as
follows: firstly, the majority of industries in Gaza are connected to the treatment plants and
they represent a major source of heavy metals in wastewater; these industries work neither to
a regular time schedule nor in a steady state of wastewater production; secondly, around 35%
of population and industries in Gaza are not connected to the wastewater collection network
and they use septic tanks for wastewater disposal, these septic tanks have different sizes and
they used to be emptied into the treatment plants by special tankers, the quantity and the
quality of the transported wastewater is not stable; and thirdly, Gaza is located in a semi-arid
zone where the rainy season is very short (4-5 months) and the seasonal variation plays an
important role in the variation of wastewater characteristics. The three sampling campaigns
were conducted in three different seasons; the weather and the rain intensity were varying
even from day to day and this affects the concentration of heavy metals in both influent and
effluent wastewater. Moreover, the wastewater treatment plants are open lagoons and they
directly receive rain water on the rainy days and this affects the quality of wastewater and
sludge.
CONCLUSIONS
1. The existing wastewater treatment plants in Gaza show a similar performance, and
although they are partially functional, the heavy metal contents of the effluent are less than
that of the standards of neighboring countries, and the treated wastewater could be used in
agriculture with respect to heavy metals.
2. The industries in Gaza are light and they have no treatment facilities. Some individual
industries produce high amounts of heavy metals in their effluents but the wastewater
treatment plants have the capability to absorb the industrial effluents with no significant
impact on the treatment bioprocesses.
3. The existing plants produce small amounts of sludge with low contents of all tested heavy
metals except Zn, which exceeds the standards of all industrial countries. This is additional to
the AOX which is found to be more than 500mg Cl/kg in some sludge samples of Gaza
treatment plant while more than 85% of the samples have less than 500mg Cl/kg.
4. In addition to total metal concentrations the determination of specific chemical forms of
heavy metals and their mode of binding in soil is very important in order to estimate their
mobility, bioavailability and related ecotoxicity. Education, information, and training of
farmers also play an important role in promoting sensible reuse practices.
5. Gaza Strip is a good example for similar studies in all neighboring countries which have
similar conditions of metrology and climate, environment and natural resources, population
growth, water scarcity, wastewater management problems and finally socio-economic
situations. The findings and conclusions of wastewater reuse and sludge application could be
imitated in these similar areas not only in the region but also in many developing countries.
6. By the reuse of treated wastewater, Gaza can not only reduce the pollution load of the
Mediterranean Sea by wastewater contaminants but also consider wastewater as a precious
source of water which could be used in agriculture.
47
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
CHAPTER FOUR
Geochemical characterization of soil and water from a wastewater
treatment plant in Gaza (*)
ABSTRACT
The aim of the study was to determine the interaction between the natural geochemistry and
the anthropogenic effects through trace element profiles in one of the environmentally
significant areas of the Gaza Strip. Five boreholes were dug in the area of the Gaza
wastewater treatment plant. The geology, mineralogy, and geochemistry of the soil profiles
were studied; and the geochemistry of wastewater, sludge, soil, and groundwater was
identified by several analytical techniques. The study introduced the environmental baselines
and the infrastructure needed for further research for the first time: the natural infiltration
potential, the artificial recharge, and the agricultural activities of water and wastewater. The
results of the geochemical investigations confirmed that the upper 40 cm of soil was found to
be the affected zone by wastewater and sludge. Among 26 elements analyzed, only a few
metals: As, Cd, Cr, Hg, Zn, and to a lesser extent Pb showed relevance from the human
health point of view. The metal accumulations in the soils were characterized by a large
spatial variability, with some ‘hot spots’ of Cu and Zn reaching topsoil concentrations of up
to 240 and 2005 mg/kg, respectively. In spite of that, the results of the groundwater revealed
that none of them was detected at concentrations that exceeded the WHO (World Health
Organization) standards. Moreover, it was shown that both anthropogenic activities as well as
seawater intrusion caused the high levels of nitrate and salinity.
Key words: Gaza, Geochemistry, Soil profile, Wastewater treatment plant
_________________________________________________________________________________
(*) The study was accepted in the Soil and Sediment Contamination: an International Journal as:
Shomar B. Müller G. Yahya A. (2004) Geochemical characterization of soil and water from a
wastewater treatment plant in Gaza. Soil and Sediment Contamination: an International Journal, in
press.
48
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
INTRODUCTION
Groundwater is the most precious natural resource in the Gaza Strip as it is the only source of
water. The groundwater aquifer of Gaza is extremely susceptible to surface-derived
contamination because of its largely unconfined nature and highly permeable sands and
gravels. In the past decade, the aquifer has become the focus of experts and public concern.
This concern has resulted from widespread salinity, nitrate and fluoride; from the detection of
agricultural pesticides and fertilizers; and from increased pressures for urban development
above the aquifer. As a first step to determine the reference levels of contaminants, it is
necessary to know their contents in various environmental compartments. A few studies have
been conducted in the area of wastewater and sludge but none in soil and groundwater.
Studies of the interaction between environmental components of Gaza are completely
lacking. Soils are one of the most precious natural resources of Gaza and they are prone to
contamination from atmospheric and hydrological sources, but direct waste disposal causes a
major impact on this limited natural resource, posing serious environmental concerns.
Information on the soil macro- and micronutrient levels and trace elements could be of great
interest for agricultural usage and artificial recharge of the groundwater aquifer (McBride et
al., 1997; Roemkens and Salomons, 1998; Wilcke et al., 1998; Whittle et al., 2002).
Metal mobility in soils depends on two main factors: (1) water transfer through the soil and
(2) physicochemistry or biogeochemistry of the trace metals with the solid phase of the soil
(sorption/desorption, precipitation/dissolution, complexation by the organic matter). Water
transfer and chemical reactions depend on the chemical, mineralogical, and
physical/hydrological properties of the different soil horizons (Cornu et al., 2001; Abrahams,
2002). As a matter of fact, pollution problems may arise if toxic metals are mobilized into the
soil solution and are either taken up by plants or transported to the groundwater (Planquart et
al., 1999). The concentrations of several potentially harmful contaminants, such as metals
commonly found in sludges, limit their application on land. The high contents of Zn and
Adsorbable Organic Halogen (AOX) in the sludges of Gaza are examples of such
contaminants (Shomar et al., 2004e). By spreading sewage sludge on fields, the metal content
of the soil drastically increases (Smith et al., 1996), inducing a potential risk of groundwater
pollution, increased toxic metal mobility (e.g. organic complexing of the transition metals),
plant toxicity, and metal contamination through the food chain (Mikac et al., 1998; Cornu et
al., 2001). Many investigations on the distribution of metals in relation to depth in the profiles
of sludged soils have shown that, in the short term, relatively little downward movement of
metals occurs below the depth of cultivation or of sludge application (Alloway and Jackson,
1991). Increases in metal concentrations below the depth of 30 cm did not appear to be
significant compared to background values, suggesting that the movement of metals
downward in the soil profile was minimal. However, several authors have reported a more
pronounced movement of metals within the profiles of amended soils.
Darwish and Ahmad (1997) have shown that sludge-borne Zn, Cu, Cd, and Pb moved down
to a depth of 40 cm in soils referred to as saline, non-saline, sodic, and calcareous (except Zn
in the calcareous soil). Although several trace metals have clearly migrated within the
profiles, and therefore must have been in a soluble form at some time, their present
concentrations in the leachates are very low. This indicates that after migration they have
become fixed in more stable and insoluble forms (Planquart et al., 1999; Cornu et al., 2001;
Hoffmann et al., 2002).
49
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
The main goals of this study were: (1) to introduce all relevant information from the study
area on hydrogeology, geochemistry, and geology; and (2) to study the geochemical
characteristics of an on site column of wastewater, sludge, soil, and groundwater in the area
of the Gaza central wastewater treatment plant.
METEOROLOGY, GEOLOGY AND HYDROLOGY
There are two well-defined seasons: the wet season, starting in October and extending into
April, and the dry season from May to September. The average daily mean temperature
ranges from 25 °C in summer to 13 °C in winter, with the average daily maximum
temperature ranging from 29 °C to 17 °C, and the minimum temperature ranging from 21°C
to 9 °C, in the summer and winter, respectively. The daily relative humidity fluctuates from
65% in the daytime to 85% at night in the summer and between 60% and 80%, respectively,
in the winter. The mean annual solar radiation is 2200 J/cm2/day (MEnA, 2000). There is a
significant variation in the wind speed during the daytime, and the average maximum wind
speed velocity is about 3.9 m/s. Moreover, storms have been observed in the winter with a
maximum wind speed of about 18 m/s. Peak months of rainfall are December and January;
the average annual rainfall is 335 mm/y (26 year average) (CAMP, 2001).
The coastal aquifer consists primarily of Pleistocene age Kurkar Group deposits, including
calcareous and silty sandstones, silts, clays, unconsolidated sands, and conglomerates. Near
the coast, coastal clays extend about 2-5 km inland, and divide the aquifer sequence into three
or four sub-aquifers, depending upon the location. Towards the east, the clays pinch out and
the aquifer is largely unconfined (PEPA, 1994). Within the Gaza Strip, the total thickness of
the Kurkar Group is about 100 m at the shore in the south, and about 200 m near Gaza City.
At the eastern Gaza border, the saturated thickness is about 60-70 m in the north, and only a
few meters in the south near Rafah. Local perched water conditions exist throughout the
Gaza Strip due to the presence of shallow clays (MEnA, 2000).
From the results of pump tests carried out in the Gaza Strip, aquifer transmissivity values
range between 700 and 5,000 square meters per day (m2/d). Corresponding values of
hydraulic conductivity are mostly within a relatively narrow range, 20-80 meters per day
(m/d). Most of the wells that have been tested are municipal wells screened across more than
one subaquifer. Hence, little is known about any differences in hydraulic properties between
these sub-aquifers. Specific yield values are estimated to be about 15-30% while specific
storativity is about 10-4 from tests conducted in Gaza (CAMP, 2001).
Under natural conditions, groundwater flow in the Gaza Strip is towards the Mediterranean
Sea, where fresh groundwater discharges into the sea. However, natural flow patterns have
been significantly disturbed by pumping and artificial sources of recharge over the past 40
years. Within the Gaza Strip, large cones of depression have formed over large areas in the
north and south. Water levels are presently below mean sea level in many places, inducing a
hydraulic gradient from the Mediterranean Sea towards the major pumping centers and
municipal supply wells (PEPA, 1994). Between 1970-1993, water levels dropped 1.6 m on
average, mostly in the south. This is equivalent to 5 million cubic meters per year (Mm3/y)
decline in overall aquifer storage on average, using a specific yield of 0.2 (CAMP, 2001).
50
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
It is estimated from available data that less than 10% of the Gaza’s aquifer resource contains
groundwater that meets the WHO drinking water standard for chloride (250 mg/l); primarily
in the north and along the coastal sand dune areas of the Mawasi (southwest). The major
documented water quality problems in the Gaza Strip are elevated salinity and nitrate
concentrations in the aquifer. Depending on location, rates of salinization may be gradual or
sudden. In Gaza City/Jabalia, chloride values are increasing at rates up to 10 mg/l per year in
several wells. The lateral inflow of brackish water across the 1948 borders (chloride
concentrations varying from 800 to 2000 mg/l) affects the water quality of a significant
portion of the Gaza coastal aquifer, and is of a natural origin. Nitrate in 90% of the
groundwater wells is more than 50 mg/l (CAMP, 2001).
Rates of aquifer replenishment are one of the most difficult parameters to derive. There is no
simple method that can be applied to estimate recharge from rainfall in the Gaza Strip. This is
primarily a function of the extreme climatological variability observed between rainfall
stations and numerous influencing factors, such as soil types and irrigation practices. A
pragmatic approach has been used for the Gaza regional model, which translates supporting
information from other similar areas to the Gaza situation, and is guided by groundwater
modeling (CAMP, 2001; MEnA, 2000).
STUDY AREA, MATERIALS AND METHODS
Location of the study area
The study area is the central wastewater treatment plant of the Gaza Strip which lies to the
southwest of Gaza City. The specific location within the plant is the drying lagoons which are
being used as filtration basins. Treated wastewater and produced sludge are disposed to open
areas a few meters beside the plant itself. The plant is close to less urbanized and agricultural
areas. Figure 1 shows the location of the Gaza Strip and a schematic illustration of the
wastewater treatment plant as well as the five boreholes. The area has a long history of
exposure to wastewater and sludge. Large areas have been used for the disposal of raw
sewage effluents and untreated sludge from 1977 up to date. Due to the lack of functional and
effective wastewater treatment plants associated with the absence of a wastewater
management system, the area of 50 ha was converted to a pure sewage disposal field and
receives up to 10,000 m3/day of untreated or partially treated wastewater.
Sampling and analysis
Sampling considerations
As an independent project, 13 test borings were drilled at specified locations determined by
an approved surveyor. The sampling locations were selected according to many justifications
fitted to Gaza. The aquifer system, groundwater flow, available geological data,
meteorological conditions, natural and anthropogenic factors, etc., are examples of these
justifications. Because of the high cost of transportation and analysis, five test borings were
chosen for this specific study to represent all locations Figure 1.
51
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
The five boreholes were selected to be: one borehole inside the existing treated wastewater
pond, one borehole inside an old sludge drying pond, and three boreholes from the
surrounding area. Each borehole is considered as a vertical study area starting from the
surface, which is in some cases treated wastewater followed by sludge, then soil and finally
groundwater. The ground surface at the site is covered with sand dunes of yellowish, fine
sand.
Wastewater samples
The sampling campaign was conducted in the period of 10 October-25 December, 2002. The
average depth of wastewater in the sampling site was 30 cm. A series of grab samples (8-10)
were taken from two lagoons 1-2 days before the drilling process. The grab samples were
combined in a container to form a composite sample. Finally, one liter of the mixture was
taken in an acid-washed bottle and transferred to the laboratory, where it was filtered in an
acid-washed filter holder and through 0.45 µm pore size Sartorius membrane filters; the first
few milliliters were used for rinsing, then discarded, and the filtrate was transferred to clean
acid-washed polyethylene bottles and acidified by concentrated nitric acid (Ultrapur, Merck,
v/v) to pH <2 and stored at 4 oC until analyses by the inductive coupled plasma mass
spectrometer (ICP/MS - Perkin Elmer-Sciex, Elan 6000) were performed. The other part of
the wastewater was filtered with no additives and stored at 4 oC for anion analyses by ion
chromatography (IC DIONEX DX-120). Several parameters were measured during the
fieldwork: temperature, electric conductivity, and pH; other parameters (settleable solids SS,
total suspended solids TSS, total dissolved solids TDS, chemical oxygen demand COD, and
biochemical oxygen demand BOD5) were measured a few hours later according to the
American standard methods (APHA, 1995).
Sludge samples
A continuous layer of sludge (15-25 cm depth) was found directly under the wastewater
column of one site. The other four samples were collected from the neighboring sludge
drying areas. Samples were collected in polyethylene containers. After collection, samples
were freeze-dried to complete dryness; then they were ground and homogenized in an agate
mortar and sieved through a mesh of 63-mm pore size. About 0.5 to 1.0 grams of the
homogenized sample were dissolved in 10.5 ml concentrated hydrochloric acid (37%) and 3.5
ml concentrated nitric acid (65%) in 50 ml retorts. The samples were degassed (12 hours),
then heated to 160 °C for 3 h. After cooling to room temperature, the solutions were diluted
with distilled water in 50 ml volumetric flasks and kept in 100 ml polyethylene bottles for
analysis.
52
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
Mediterranean
Sea
# Beit Hanun
Beit Lahia
#
Jabalia
Beit Hanoun
ed
ite
rra
ne
an
Se
a
Gaza
#
al-Mograga
an-Nusirat
M
ash-Shija'iye
#
al-Montar
Johr al_Diek
al-Burij
az-Zawida
al-Maghazi
al-Msadar
Deir al-Balah
Salga
#
al-Qarara
Khan Younis
al-Qarara
Bani
Abasan
Suhaila al-Sagira
Abasan
al-kabira
Legend
Entry Points
#
Sea Line
Treatment Plant
Existing
Proposed
Delimiting Line
Roads Network
Regional
Main
Local
Municipal Boundaries
Built-up Area
Airport
Yellow Area
Colony's Built-up Area
Military Installation Area
Mediterranean Sea
Ga'a al-Grain
Khuza'a
al-Fukhari
al-Bayuk
Rafah
#
al-Shoka
al-Matar
al-'Awda #
#
5
0
5 Kilometers
1:200000
N
Sources:
- MOPIC
- MEnA
Gaza Governorates
Date: August, 2000
© 2000 MEnA
Location of Wastewater Treatment Plants
Ministry of Environmental Affairs, Palestine
Figure (1) Location of the Study Area.
Elements were analyzed by different instruments; a flame atomic absorption (AAS vario 6Analytik Jena) for determination of Ca, Cu, K, Li, Mg, and Na; an ICP/OES (VARIAN,
VISTA-MPX) for determination of As, Cd, Co, Cr, Fe, Mn, Ni, Pb, Sr, and Zn; and an
energy-dispersive miniprobe multielement analyzer (EMMA-XRF) (Cheburkin and Shotyk,
1996) for determination of Br, Rb, Se, Th, U, Y and Zr. Mercury concentrations were
determined using atomic absorption spectroscopy after thermal combustion of freeze-dried
samples (50-100 mg) and Hg pre-concentration on a single gold trap by means of an AMA
254 solid phase Hg-Analyzer (LECO).
53
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
Total carbon and sulfur were determined directly in dried samples by using a carbon-sulfur
determinator (LECO CS-225); and finally carbonates were measured directly by a carbonate
bomb (Müller and Gastner, 1971). The total organic carbon (TOC) was calculated by the
subtraction of inorganic carbon from total carbon. Adsorbable organic halogen (AOX) was
determined by a Euroglas organic halogen analyzer- The Netherlands according to the DIN
38414 S18 Deutsche Einheitsverfahren zur Wasser, Abwasser und Schlammuntersuchung,
Sludge and Sediment (Group S) Determination of AOX (DIN, 1989).
Soil samples
Soil samples were obtained continuously from the five boreholes throughout the drilled
depth. Three-inch size split spoon sampling tubes (3" diameter x 24" long) were used to
collect the samples. The samples were examined, described, and classified by geologists and
geotechnical engineers. Natural beeswax was used to cap the ends of the sample tubes, as
requested. The samples were properly labeled and placed in waterproof plastic bags before
being placed in wooden boxes. Approximately 0.5 kg of soil was put in polyethylene cups
and stored at 4 oC during transport to laboratories where soil was dried in an oven at 50 oC
until constant weight. Then they were shipped to Germany in plastic sampling bags. The
samples were sieved through a 20-µm sieve and ground to a very fine powder by using a sand
mill (FRITSCH-Labor Planeten Mühle, pulverisette 5). Approximately 1-2 grams of the
homogenized sample were dissolved with 10.5 ml of concentrated hydrochloric acid (37%)
and 3.5 ml of concentrated nitric acid (65%) in 50 ml retorts. The digestion process of the
soil samples was the same as the above-mentioned process for sludge samples. Al and Ba
were analyzed by inductively coupled plasma optical emission spectroscopy (ICP/OES).
AOX was analyzed by the same method as the sludge samples. In order to determine soil
mineralogy, a semi-quantitative X-ray Diffraction technique (XR Diffractometer, SIEMENS)
(Moore and Reynolds, 1989) was used.
Groundwater samples
Groundwater depth measurements were taken whenever groundwater was encountered in the
boreholes, using a water-level indicator instrument. Groundwater samples were collected
from the boreholes at the specified depths; they were sampled about one meter below the
groundwater surface. Five groundwater samples were collected from the five boreholes. Oneliter samples were collected and treated as the wastewater samples above. Several parameters
were measured during the fieldwork: temperature, turbidity, electric conductivity, and pH.
Elemental analysis was measured in the lab.
Quality control
For quality control, analytical blanks and two standard reference materials with known
concentrations of metals were prepared and analyzed using the same procedures and reagents.
Precision for the results of soil and sludge samples was estimated using the reproducibility
between the duplicates, and a coefficient of variation of less than 5% was found. The
accuracy was evaluated using 20 aliquots of two river sediment standard reference materialsRS1 and RS3-Deutsche Industrie Norm (DIN, 1989, 1997). As an independent check of the
trace element measurements of the soil and sludge, these were also measured in solid samples
using the energy-dispersive miniprobe multielement analyzer (EMMA-XRF). A deviation of
54
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
less than 5% from the certified values was found. The coefficient of variation for triplicates
(2 samples and one standard) was less than 2% for all parameters. For the wastewater and
groundwater analysis, standard reference materials 1643c and 1643d were used for the
determination of trace elements (NIST, 1991, 1994) and SPS-WW2, wastewater level 2 (SPS,
2002).
RESULTS
Wastewater
Table 1 shows the average values of parameters of the wastewater effluent. The general
parameters indicate that the treatment plant was able to remove >92%, >88%, >60% of
BOD5, COD, and both total P and total N, respectively, under the existing treatment facilities.
The table shows the metal content of the collected five composite wastewater samples, and
these results agree with the findings of a three-year monitoring program conducted by
Shomar et al. (2004e).
Table (1) Chemical Characteristics of Wastewater Effluent.
Parameter
pH
Temperature (oC)
Settleable Solids SS (ml/l)
Total Dissolved Solids (TDS) mg/l
Total Suspended Solids (TSS) mg/l
Chloride (mg/l)
Fluoride (mg/l)
Sulfate (mg/l)
Total P (mg/l)
NO3 (mg/l)
COD (mgO2/l)
BOD5 (mgO2/l)
Ag (µg/l)
Al (µg/l)
As (µg/l)
Cd (µg/l)
Co (µg/l)
Cr (µg/l)
Cu (µg/l)
Fe (µg/l)
Mn (µg/l)
Ni (µg/l)
Pb (µg/l)
Zn (µg/l)
* Average value of each parameter.
55
Average
SD (σ)
7.7
26
0.1
1536
20
480
1.4
320
9
20
89
25
0.7
52
8
< 0.5
0.8
5
7
163
48
6
< 2.5
42
0.3
1.7
0.03
62
2.6
50
0.1
26
0.3
6.1
7.7
1.3
0.0
2.9
1.3
0.1
0.4
1.0
0.8
3.2
4.2
1.7
0.2
12
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
Sludge
In addition to the common metals analyzed in the sludge samples in many parts of the world,
an additional eight elements were determined (Table 2). Seven of them had low
concentrations and only strontium (Sr) showed considerable amounts in the tested samples.
Zinc in the sludge of Gaza (> 2100 mg/kg) exceeds that of all standards of developed and
industrialized countries for land application. As a very general parameter, the average AOX
in the tested samples reached the mean value of 550 mg Cl/kg.
Table (2) Average Chemical Composition of Five Sludge Samples (n=3).
Element
Sample 1
Sample 2
Sample 3
Sample 4
AOX (mg Cl/kg)
610 ± 68
600 ± 55
530 ± 62
510 ± 44
As (ppm)
5.5 ± 0.8
2.1 ± 0.8
3.5 ± 0.7
5.4 ± 0.8
Cr (ppm)
89 ± 6
68 ± 5
89 ± 7
111 ± 6
C (%)
27 ± 0.7
19 ± 0.5
27 ± 0.8
26 ± 0.8
Ca (%)
12.7 ± 0.3
9.0 ± 0.2
13.3 ± 1
10.5 ± 0.8
Cd (ppm)
2.2 ± 0.8
1.5 ± 0.7
1.7 ± 0.3
2.0 ± 0.1
Co (ppm)
3.3 ± 0.3
3.6 ± 0.2
0.9 ± 0.1
2.5 ± 0.2
Cr (ppm)
89 ± 7
68 ± 5
89 ± 6
111 ± 11
Cu (ppm)
304 ± 11
220 ± 8
288 ± 13
286 ± 14
Fe (%)
1.5 ± 0.1
1.2 ± 0.1
1.3 ± 0.1
1.5 ± 0.2
Hg (ppm)
3.5 ± 0.5
2.6 ± 0.5
4.5 ± 1
3.2 ± 0.6
K (ppm)
1836 ± 36
1808 ± 42
1673 ± 40
1810 ± 37
Li (ppm)
3.0 ± 0.2
2.5 ± 0.2
2.6 ± 0.2
3.4 ± 0.3
Mg (%)
1.1 ± 0.3
0.9 ± 0.2
1.0 ± 0.1
1.0 ± 0.1
Mn (ppm)
227 ± 8
188 ± 5
270 ± 7
261 ± 8
Na (ppm)
9894 ± 26
10312 ± 42
7720 ± 35
3191 ± 22
Ni (ppm)
28 ± 5
21 ± 4
24 ± 5
26 ± 6
Pb (ppm)
154 ± 5
111 ± 6
140 ± 11
156 ± 9
Rb (ppm)
10.6 ± 0.7
11.5 ± 1
9.0 ± 0.5
9.9 ± 0.8
S (%)
3.0 ± 0.3
2.1 ± 0.4
2.8 ± 0.2
3.1 ± 0.3
Se (ppm)
2.6 ± 0.2
2.6 ± 0.2
5.0 ± 0.4
3.2 ± 0.4
Sr (ppm)
651 ± 7
540 ± 9
984 ± 15
643 ± 32
Th (ppm)
3.1 ± 0.2
0.0 ± 0
2.0 ± 0.2
2.4 ± 0.1
U (ppm)
8.8 ± 0.6
5.7 ± 0.5
10.7 ± 1
10.5 ± 2
Y (ppm)
7.1 ± 0.4
8.3 ± 0.5
5.8 ± 0.2
6.9 ± 0.3
Zn (ppm)
2443 ± 46
1820 ± 66
2230 ± 84
2527 ± 72
Zr (ppm)
185 ± 5
164 ± 11
96 ± 9
103 ± 7
Sample 5
495 ± 52
4.3 ± 0.6
108 ± 11
22 ± 1
11.5 ± 0.4
1.8 ± 0.3
2.4 ± 0.2
108 ± 8
281 ± 12
1.3 ± 0.1
2.8 ± 0.5
1605 ± 38
3.2 ± 0.3
0.9 ± 0.1
273 ± 10
4359 ± 25
25 ± 5
136 ± 8
8.2 ± 1
2.1 ± 0.1
3.0 ± 0.5
730 ± 62
0.0 ± 0
8.5 ± 0.4
8.1 ± 0.4
2385 ± 78
98 ± 11
Soil
Due to the large set data obtained from the analysis of 160 soil samples, each having 26
parameters, this section will cover mostly the fifth soil profile which represent the five
profiles. The upper 40-50 cm represent a mixture of sludge and fine sand and its color starts
from dark black in the surface layer up to very light dark downward. A well-distinguished
soil appears from 20 cm depth and more.
56
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
The four examples of X-ray diffractograms (Fig. 2) show that the soil mineralogy is mainly
composed, in order of abundance, of quartz, calcite, kaolinite, and some feldspars. The soil
texture, including the major components of each layer, is shown in Figure 3.
Table (3) Geochemical Characteristics of Sludge Covered Soil Profile under Wastewater Lagoon.
0
5
10
15
20
25
30
35
40
45
Parameter
cm
cm
cm
cm
cm
cm
cm
cm
cm
cm
Org. C (%)
26.1
26.1
23.7
21.6
20.8
20.1
1.6
1.9
1
1.2
Ca (%)
12.8
10.0
10.1
13.4
12.5
10.0
11.9
1.4
0.59
0.5
Cu (mg/kg)
237
237
157
120
77
45
18
12.7
5.3
1.3
Fe (%)
1.3
1.6
1.8
0.4
0.2
0.4
0.3
0.3
0.4
0.2
Ni (mg/kg)
41
38
34
13
11
6.0
3.2
2.3
2.3
2.2
Pb (mg/kg)
114
76
58
33
8
3
2.0
0.8
0.6
0.1
Zn (mg/kg)
2197
1276
999
217
10.7
8
7.2
3.5
2.7
4.8
Table (4) Geochemical Characteristics of Sludge Covered Soil Profile under Sludge Drying Area.
0
5
10
15
20
25
30
35
40
45
Parameter
cm
cm
cm
cm
cm
cm
cm
cm
cm
cm
Org. C (%)
25.7
25
21
20.2
20
19.2
1.9
2
0.9
1.3
Ca (%)
12.1
12.8
10.0
13.5
11.5
3.19
2
0.59
0.7
0.5
Cu (mg/kg)
240
210
180
132
95
52
20
17
6
2
Fe (%)
1.7
1.5
1.7
0.5
0.3
0.4
0.3
0.4
0.3
0.3
Ni (mg/kg)
42
39
28
14
10
6.0
3.2
2.3
1.8
2.9
Pb (mg/kg)
115
82
60
27
11
2.5
1.8
0.9
0.7
0.2
Zn (mg/kg)
2005
1700
1102
350
42
22
9
5.2
3.4
2.6
57
50
cm
0.4
0.45
1.8
0.2
1.9
0.5
5.1
50
cm
0.5
0.8
1.2
0.2
2.5
03
2.5
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
Figure (2) Some Examples of XRD Results of the Fifth Soil Profile.
58
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
Soil Surface
5
4
3
2
30 m
1
Borehole numbers
20 m
N
10 m
0 Sea Level
-10 m
Legend
Sand
Silty clay with trace gravel
Clay
-20 m
Silty sand with trace gravel
Sand with trace gravel
Silty
-30 m
Sand and gravel
Clayey sand with trace gravel
Groundwater table
Figure (3) General Geological Features of the Five Soil Profiles.
The soil-wastewater/sludge interaction and the trend of major parameters could be found in
two profiles (1 and 2). The first is under the treated wastewater lagoon (Table 3) and the
second is under the sludge old drying area (Table 4). Selected depths of soil profile and their
metal contents are shown in Table 5 and Figure 4.
59
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
The organic content of the soil decreased with depth from 26% organic carbon by weight in
the surface sludge to less than 0.05% of 55 m depth, while the AOX in general is very low in
the deep layers (less than 5 mg Cl/kg). The soil at the study plot was neutral to basic (pH 7.28 in 0.4-60 m), while the upper 40 cm of the sludge-covered soil was acidic (pH 4.8) due to
high inputs of nitrate and sulfate loads from wastewater and sludge which increase the acidity
through the intensive mineralization and nitrification processes.
Table (5) Chemical Composition of Soil for Selected Depths of the Fifth Profile (Aver.± SD).
Element
UC*
LC**
0.6 m
7.5 m
24.5 m
Al (%)
7.74
8.21
0.3 ± 0.1
1.7 ± 0.2
1.0 ± 0.1
As (mg/kg)
2
1.3
2.8 ± 0.2
2.1 ± 0.3
0.8 ± 0.1
Ba (mg/kg)
668
568
32 ± 4
79 ± 16
67 ± 11
Br (mg/kg)
1.6
0.28
0.0 ± 0
4.3 ± 0.8
1.4 ± 0.1
C (%)
0.32
0.06
0.9 ± 0.2
2.4 ± 0.4
0.8 ± 0.1
Ca (%)
2.95
4.86
3.2 ± 0.4
7.4 ± 1
2.2 ± 0.2
Cd (mg/kg)
0.102
0.101
0.06 ± 0
0.07 ± 0
0.04 ± 0
Co (mg/kg)
11.6
38
2.7 ± 1
9.8 ± 2
6.9 ± 2
Cr (mg/kg)
35
228
8±1
34 ± 7
11 ± 3
Cu (mg/kg)
14.3
37.4
2.5 ± 0.6
26.1 ± 7
8.5 ± 3
Fe (%)
3.1
5.7
0.4 ± 0.1
1.7 ± 0.2
0.8 ± 0.2
Hg (µg/kg)
56
21
2.0 ± 0.4
2.0 ± 0.2
2.0 ± 0.2
K (%)
2.86
1.31
0.07 ± 0
0.17 ± 0.1
0.14 ± 0
Li (mg/kg)
22
13
1 ± 0.2
4.8 ± 1
3.9 ± 0.3
Mg (%)
1.35
3.15
0.1 ± 0.1
0.6 ± 0.1
0.4 ± 0.1
Mn (mg/kg)
527
929
94 ± 11
251 ± 34
219 ± 80
Na (%)
2.57
2.12
0.12 ± 0
0.05 ± 0
0.05 ± 0
Ni (mg/kg)
18.6
99
6 ± 0.2
17 ± 4
13 ± 2
Pb (mg/kg)
17
12.5
0.8 ± 0.1
2.8 ± 0.3
1.7 ± 0.4
Rb (mg/kg)
110
41
10 ± 2
20 ± 4
20 ± 5
S (%)
0.95
0.41
0.01 ± 0
0.01 ± 0
0.01 ± 0
Sr (mg/kg)
316
352
95 ± 12
133 ± 41
95 ± 24
Th (mg/kg)
10.3
6.6
0.0 ± 0
2.5 ± 0.8
0.0 ± 0
Y (mg/kg)
20.7
27.2
9±2
21 ± 6
32 ± 8
Zn (mg/kg)
52
79
8±2
26 ± 8
26 ± 7
Zr (mg/kg)
237
165
342 ± 44
254 ± 51
354 ± 58
(*) Upper Crust, and (**) Lower Crust: Turekian and Wedepohl, 1961.
60
35 m
0.7 ± 0.1
3.6 ± 0.2
66 ± 12
1.2 ± 0.3
1.6 ± 0.2
4.6 ± 0.8
0.08 ± 0
4.3 ± 0.4
12 ± 3
3.6 ± 1
0.7 ± 0.1
2.0 ± 0.1
0.07 ± 0
2.1 ± 0.2
0.3 ± 0.1
148 ± 47
0.04 ± 0
7±1
1.1 ± 0.4
17 ± 4
0.01 ± 0
63 ± 13
2.7 ± 0.7
14 ± 3
14 ± 4
188 ± 46
55 m
0.1 ± 0.1
4.7 ± 0.4
12 ± 2
1.0 ± 0.1
1.3 ± 0.1
4.2 ± 0.7
0.1 ± 0
1.3 ± 0.1
4±1
4.6 ± 2
0.3 ± 0.1
1.0 ± 0.1
0.02 ± 0
0.5 ± 0.1
0.1 ± 0
64 ± 14
0.03 ± 0
2±1
0.6 ± 0.2
7±2
0.01 ± 0
77 ± 9
0.0 ± 0
8±1
13 ± 4
107 ± 28
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
As (ppm )
Al (%)
0.0
0.5
1.0
0.0
1.5
2.0
2.0
4.0
C (%)
6.0
0
0
0
10
10
20
20
1
2
3
0
10
30
Depth (m)
Depth (m)
30
40
50
50
50
60
60
60
Cd (ppm )
0.00
0.05
0.10
Hg (m g/kg)
0.15
0.20
0
20
40
Pb (ppm )
60
0
0
0
0
10
10
10
20
20
20
30
Depth (m)
Depth (m)
30
40
40
Depth (m)
Depth (m)
20
30
30
40
40
40
50
50
50
60
60
60
Figure (4) Examples of Element Profiles.
61
1
2
3
4
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
Groundwater
Table 6 shows the concentration of the major anions and cations in the five groundwater
samples. The average total dissolved solids (TDS) of groundwater is 1800 mg/l; and major
ions of Cl, F, NO3, SO4, CO3, PO4, Na, Ca, Mg, and K are high. Tested groundwater of the
area showed sulfate averages of 190 mg/l (Shomar et al., 2004c). Although it is assumed that
fluoride is a natural constitutional of the groundwater of the Gaza Strip (Shomar et al.,
2004d), F averages of the tested wells are 1.8 mg/l. The results of the fluoride contents by
using IC are consistent with the results of the ISE. Phosphates were below the detection limit
of the vanadate molybdate spectrophotometric method. Groundwater is oxygenated and Fe
and Mn are in the oxidized soluble forms. The average dissolved oxygen (DO) was 6.7
mgO2/l. Previous studies of the groundwater quality in the surrounding area revealed that
many parameters (EC, TDS, Cl, NO3, SO4, F, Ca, Mg, and Na) are affected by seasonal
variation; they are 30-60% higher in the summer (Shomar et al., 2004c).
Table (6) Groundwater Quality of Five Boreholes (Average ± SD σ).
Parameter
Sample 1
Sample 2
Sample 3
Sample 4
Sample 5
Temp. (oC)
22 ± 0.5
22 ± 0.6
23 ± 0.4
pH
6.7 ± 0.2 6.8 ± 0.3 7.1 ± 0.2
DO mgO2/l
6.4 ± 0.2 6.3 ± 0.2 6.9 ± 0.2
EC mS/cm
2.65 ± 0.1 2.59 ± 0.2 2.6 ± 0.1
Cl (mg/l)
560 ± 32 590 ± 35 505 ± 28
NO3 (mg/l)
77 ± 7
85 ± 11
76 ± 9
SO4 (mg/l)
135 ± 14 140 ± 17 160 ± 16
F (mg/l)
1.7 ± 0.1 1.8 ± 0.2 1.7 ± 0.1
PO4 (mg/l)
< 1 ± 0.0 < 1 ± 0.1 < 1 ± 0.1
Na (mg/l)
320 ± 22 201 ± 24 370 ± 29
Mg (mg/l)
90 ± 14
87 ± 9
110 ± 7
Ca (mg/l)
128 ± 19 140 ± 20 133 ± 22
Ag (µg/l)
< 0.5 ± 0.1 < 0.5 ± 0.1 < 0.5 ± 0
Al (µg/l)
28 ± 4
34 ± 7
27 ± 6
As (µg/l)
5±1
10 ± 1
9±2
Cd (µg/l)
0.7 ± 0.1 < 0.5 ± 0 < 0.5 ± 0.1
Co (µg/l)
<0.3 ± 0
<0.3 ± 0 <0.3 ± 0.1
Cr (µg/l)
11 ± 2
29 ± 3
45 ± 3
Cu (µg/l)
< 1 ± 0.1
9±1
3 ± 0.5
Fe (µg/l)
26 ± 4 1855 ± 245 28 ± 4
Mn (µg/l)
< 1 ± 0.1
15 ± 3
< 1 ± 0.1
Ni (µg/l)
3 ± 0.2
6 ± 0.2
4 ± 0.1
Pb (µg/l)
< 2. 5 ± 0.2 2.6 ± 0.2 < 2.5 ± 0.3
Zn (µg/l)
< 10 ± 2
12 ± 2
< 10 ± 1
* WHO: World Health Organization Guidelines.
** LD: Limit of Detection by the ICP/MS in (µg/l).
24 ± 0.7
6.9 ± 0.2
6.7 ± 0.3
2.61 ± 0.2
602 ± 34
89 ± 14
110 ± 9
2.0 ± 0.1
<1±0
198 ± 18
106 ± 10
122 ± 19
< 0.5 ± 0.1
< 25 ± 4
7±1
< 0.5 ± 0
<0.3 ± 0.1
23 ± 2
4 ± 0.2
16 ± 2
<1±0
3 ± 0.4
< 2.5 ± 0.3
12 ± 2
21 ± 0.4
6.7 ± 0.2 6.5-8.5
7.1 ± 0.4
2.65 ± 0.2
595 ± 33
250
64 ± 7
50
123 ± 11
250
1.9 ± 0.2
1.5
< 1 ± 0.1
231 ± 27
200
119 ± 10
143 ± 23
< 0.5 ± 0
29 ± 7
200
7±2
10
< 0.5 ± 0
3
<0.3 ± 0
30 ± 3
50
2 ± 0.1
2000
26 ± 3
300
< 1 ± 0.1
500
2 ± 0.2
20
< 2.5 ± 0.5
10
23 ± 3
3000
62
WHO*
LD**
(µg/l)
0.5
25
2.5
0.5
0.3
2.5
1
1
0.5
2.5
10
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
The results for the metals indicate that all of them are within the WHO drinking water
standards. Arsenic and iron for borehole number 2 are high; As is the same as the tentative
new WHO standard (10 µg/l), while Fe is 1855 µg/l which is about 6 times higher than the
WHO standard (300 µg/l).
DISCUSSION
The wastewater treatment plant was able to remove >92%, >88%, >60% of BOD5, COD, and
both total P and total N, respectively. This indicates that the majority of the metals have been
transferred from the wastewater to the sewage sludge where Zn, Pb, Cu, and Cr in the sludge
were 2100, 125, 240, and 75 mg/kg, respectively. The new results agree with the findings of
Shomar et al., (2004e), however, 20% may be lost in the treated effluent, depending on the
solubility, and this may be as high as 40-60% for the most soluble metal, Ni (Scancar et al.,
2000). The average of Zn removal in the treatment process was 55%; this ratio finds its way
to the sludge and this may explain the high contents of Zn in the sludge (>2100 mg/kg).
The most affected zone by wastewater and sludge is the upper 40-50 cm of the soil profile
and the metal content decreased with depth. Element mobility sequence was Ni>Ca>Cu>>Fe
where the concentrations in the upper 5 cm were 40 mg/kg, 10%, 240 mg/kg, and 1.5% and
in the lower 40 cm were 2, 0.5, 5, and 0.3, respectively. This result agrees with that of Legret
(1993) and Cornu (2001). Nickel is the most soluble metal in sludge, and thus the most
mobile (Henry and Harrison, 1992). The general trend of the total Ni concentrations in each
soil profile was a slight increase with depth. The distribution of Ni in a soil profile is related
to the clay fractions; the higher the clay content, the greater the accumulation of Ni. The
percent clay in the soil profiles increased due to the claylenses in the 6.3 and 9.3 m depth, as
did the total Ni concentrations. This could be supported by the explanation of the EPA (1995)
that stated that Ni tends to accumulate in arid and semiarid soils as well. The sludge-covered
soils were exposed to rainfall over the course of the study which may have resulted in the
leaching of Ni to the lower depths. It has been shown that soils with higher pHs have higher
potentials for fixing Ni in less soluble forms than in soils with lower pHs (Abdel-Sabour,
1991). A mean comparison of total trace element concentrations in the upper 40 cm depth
indicated that the uncovered soil had significantly lower Cu and Ni concentrations than the
sludge-covered soils. In addition, the comparison of means from each soil profile indicated
there were no significant differences among the mean of most tested elements.
In soil, Ca is the most mobile, while Fe is the least mobile element (Sparks, 2002). The pH of
the upper 40 cm for the sludge-covered soils increased slightly with depth. The results of the
upper 40 cm of the soil profile were anticipated as the sludges that covered the soil surface
contained low concentrations of the tested elements. The trend showed a definite increase in
Cu within the upper 40 cm of all sludge-covered soils. This could be explained by the fact
that the organic compounds of the sludge increased the solubility of Cu (Kabata-Pendias and
Pendias, 1992). Total soil Cu concentrations were somewhat variable in the individual
profiles.
63
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
The solubility, mobility and concentration of Pb and Zn are controlled by several mechanisms
like organic matter, pH and soil structure (Sims and Patrick, 1978; Pepper et al., 1983; Milner
and Barker, 1989). The total Pb concentrations of the soil were basically uniform throughout
the soil profiles. The heavy precipitation, in combination with the acidic environment of the
upper sludge layer of pH 4.8 and the high contents of organic matter (26%) enhances the
solubility and leaching processes of Pb from sludge. Pb concentration is high in the upper
layers and decreases with depth. Even although the pH of the sandy layers was high, the
concentrations of Pb and Zn were low due to the lack of organic matter and the effect of the
downward water flow. Pb reached its minimum concentration (2.7 mg/kg) in the sandy soil at
a depth of 40 cm. The leached Pb accumulated in the deep layers of clay at a depth of 5.5 and
25 m, where its concentrations are 4.2 and 3.6 mg/kg, respectively. The Pb profile in soil is
similar to the Fe profile as well as to the organic matter profile. In comparison with Zn,
organic matter is relatively more important in adsorbing Pb, but clay minerals are relatively
more important in adsorbing Zn. Zn showed similar trend as Pb.
It was found that the soil metal content was affected by soil structure. Clay layers showed
higher contents of major elements than soil layers. In clay layers Cd, Cr, Fe, Mn, Ni, Pb, and
Zn were 0.1 mg/kg, 23 mg/kg, 6%, 930 mg/kg, 100 mg/kg, 13 mg/kg, and 80 mg/kg,
respectively while they were 0.04, 10, 0.7, 70, 8, 1, and 13, respectively in other soil
structures. Generally speaking, a trend of increase of most elements was observed from fine
sand, sandstone, loose sandstone, sand clay, and clay. This conclusion agrees with the
findings of several studies (Premovic et al., 2001; Navas and Machin, 2002; Pearson et al.,
2002; USGS, 2004). Except for the upper half-meter of the soil profile which is directly
affected by sludge, the lateral distribution of elements was dependent on the physicochemical
characteristics of the soil and not on depth.
The total contents of studied elements indicate that the concentrations of Zn, Mn, Cu, Fe, and
partly As and Pb correlate with the clay content in the individual soil profile. The total
content of Mn, Fe, Zn, and Cu in the individual soil horizons is proportional to their clay
content (Martinek et al., 1999). The trend showed that the layer of 6.3-9.3 m deep had high
contents of Al, Ca, Cr, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Sr, Th, Y, Zn, and Zr, and to a lesser
extent of Cd, Co, and Hg. Also, the soil samples of 35-55 m depth showed an increase in the
contents of most elements. The Al figure shows the same trend of Ba, Co, Cr, Cu, Fe, Li, Mg,
Mn, Ni, Sr, Th, Y, and Zn. The figure of Cd shows the trend of Rb. The Pb figure shows the
same trend of S and Zr.
There is no significant difference between the mineralogy of the different depths of the fifth
profile. Although the five boreholes were dug in around a 1 km2 area, the layers were not
continuous and this could be explained by the irregular deposition, sedimentation, and
weathering rates. The stability rate under weathering conditions in the study area is
gravel>sand>clay, where the clay layer is impermeable.
However, the results of groundwater revealed that it is highly polluted and all major
parameters exceed regional and international standards, it was hard to judge that the major
source of pollution is the leaching of these pollutants from the upper surface to the aquifer.
64
Chapter Four
Geochemical Characterization of Soil and Water
__________________________________________________________________________________________
It is believed that the high concentrations of nitrate (>75 mg/l) in the area is caused by
leaching of nitrate from wastewater to the aquifer (CAMP, 2001; Shomar et al., 2004e). The
results for the metals indicate that all of them are within the WHO drinking water standards
(1998a). Arsenic and iron for borehole number 2 are high; As is the same as the tentative new
WHO standard (10 µg/l), while Fe is 1855 µg/l which is about 6 times higher than the WHO
standard (300 µg/l).
CONCLUSIONS
A very good agreement was observed between soil physical characteristics and the vertical
distribution of metals. The trend of most elements was: clay>sandclay>loose
sandstone>sandstone>fine sand. The trend showed that the clay layer of 6-9 m depth had high
contents of Al, Ca, Cr, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Sr, Th, Y, Zn, and Zr, and to a lesser
extent of Cd, Co, and Hg.
Except for the upper half-meter of the soil profile which is directly affected by waster and
sludge, the lateral distribution of elements was dependent on the physical characteristics of
the soil and not on the depth.
The treated wastewater is a promising water resource for agriculture, and regular monitoring
systems on soil, crops and groundwater should be adopted. Sludges, on the other hand, have
high Zn (>2000 mg/kg) and AOX (>500mg Cl/kg) concentrations, which exceed the
standards of all industrialized countries for land application.
Although the groundwater samples were collected from the aquifer below the wastewater
treatment plant, no anomalous concentrations were found with respect to metals. However,
several studies showed that elevated salinity, nitrate, chloride, and sulfate are believed to be a
result of both anthropogenic and natural sources.
65
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
CHAPTER FIVE
Seasonal variations of chemical composition of water and bottom
sediments in the wetland of Wadi Gaza, Gaza Strip (*)
ABSTRACT
Water and sediment samples were collected from 18 sampling stations in Wadi Gaza for two
successive years in order to: (1) Establish a baseline condition of the geochemistry of surface
water and sediments; (2) assess the impact of seasonal variation on distribution of heavy
metals and major ions; and (3) identify possible natural and anthropogenic sources of
pollution. The heavy metal concentrations in the sediments of the lake (downstream) were
higher than those of the eastern eight stations (upstream) where the water was shallower. The
discharge of olive oil mill wastewater was recorded in the Ca, Na, Mg, K and P
concentrations in sediments of one of the sampling stations.
Water in shallower areas showed greater temporal variation than deeper areas. Several
elements (P, Fe, Mn and As) showed the greatest temporal variability. For example, in the
winter rainy season these elements decreased 2-10 times compared to their values in summer.
Moreover, Ca, Na, Cl, PO4, and NO3 decreased 3, 3, 5, 2, 4 times, respectively. Some of the
trace metals were more abundant in these waters compared to the domestic wastewaters of
the study area. The averages of Cd and Co were 6 and 43 µg/l, respectively and they were 50
times higher than the domestic wastewater results.
Key words: Heavy metals, Seasonal variation, Wadi Gaza, Water and sediment quality.
___________________________________________________________________________
(*) The study was published in the Journal of Wetlands Ecology and Management as:
Shomar B. Müller G. Yahya A. (2004) Seasonal variations of chemical composition of water and
bottom sediments in the wetland of Wadi Gaza, Gaza Strip. Journal of Wetlands Ecology and
Management, in press.
66
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
INTRODUCTION
The Gaza Strip is one of the most densely populated areas in the world (2638 People/km2;
PCBS, 2000). With limited and deteriorated resources, it has already started to suffer the
outcomes of environmental quality deterioration. The shortage and pollution of resources,
coupled with high population growth and insufficient job opportunities have created many
environmental hazards. The shortage of water and the deterioration of water quality constitute
a limiting factor in the economic development of Palestine (MEnA, 2000). Because of these
problems, the Wadi Gaza is under threat (MEnA, 2000). Moreover, the Wadi is closed from
both upper (inlet) and lower (outlet) streams. There is urgent need to obtain background
geochemical data for this site, as no data are currently available.
The capacity of sediment to accumulate contaminants makes them one of the most important
tools to assess environmental impact on aquatic ecosystems (Silva and Rezende, 2002). In
fact, lake sediments can serve as an information archive of environmental changes through
time (Haworth and Lund, 1984). Chemical speciation studies have shown that heavy metals
display different degrees of affinity for either organic or inorganic compounds and that this is
an important factor influencing metal distribution (Lu et al., 1983). In aquatic ecosystems
research, the role of sediments in the cycling of chemical elements has often been
underestimated, and the exchange of elements (especially nutrients) between sediment and
water is a crucial topic (Alloway and Ayres, 1997; Kelderman et al., 2000). Seasonal
variation may also affect the exchange process directly and indirectly. Anaerobic conditions
in summer period were shown to cause a rapid phosphorus release from the sediment to the
hypolimion of the water body. This mechanism is still one of the key examples of sedimentwater interaction (Kelderman, 1985). Many factors affect the sediment-water exchange of
nutrients such as sediment type and grain size, aerobic and anaerobic conditions, temperature
and pH (Rippey, 1977; Holdren and Armstrong, 1980; Nixon et al., 1980; Kelderman, 1996).
The main goal of this paper was to establish a baseline study of water and sediment quality of
the Wadi Gaza. A secondary objective was to identify the extent to which the relevant water
and sediment quality parameters vary seasonally.
MATERIALS AND METHODS
The study area
Wadi Gaza* is the only major watercourse in the Gaza Strip (Fig.1). Its catchment covers
3,500 km2 most of which is in the Israeli territory, with only the last 7 km of its course in the
Gaza Strip (MEnA, 2002a). The Gaza section, which lies some 7-8 km south of Gaza City, is
a sandy valley 20-50 m wide, with steep cliffs 6-8 m high. The river flow has eroded the
Wadi banks, expanding to a permanent, brackish, water body several hundred meters wide
(forming a lake) shortly before it reaches the Mediterranean Sea. No data are available on
flood-flow frequency, height or volume; yet it is evident that occasional or regular flash
floods sweep down the Wadi bed, although their frequency may be reduced by the suspected
presence of small dams, or diversion schemes, in the catchment.
___________________________________________________________________________
* The part of the Wadi located in the Gaza Strip.
67
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
The study area is a part of the coastal zone of the Gaza Strip and the hydrogeology of the
coastal aquifer consists of one sedimentary basin, the post-Eocene marine clay (Saqiya),
which fills the bottom of the aquifer. Wadi Gaza as well as the whole Gaza Strip area is
located in the transitional zone between the temperate Mediterranean climate to the East and
North and the arid desert climate of the Negav and Sinai deserts to the East and South. As a
result, the Wadi Gaza area has a characteristically semi-arid climate. There are two well
defined seasons: the wet season starting in October and extending into April, and the dry
season from May to September.
Mediterranean
Sea
Well
F62
Refugee-Middle Camps
Well
G16
Olive Oil
Mill
Fig. 1. Location of the Wadi Gaza and schematic illustration of the sampling stations.
68
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
The average daily mean temperature ranges from 25 °C in summer to 13 °C in winter, with
the average daily maximum temperature ranges from 29 °C to 17 °C, and the minimum
temperature range from 21 °C to 9 °C in the summer and winter respectively. The daily
relative humidity fluctuates between 65% in the daytime and 85% at night in the summer and
between 60% and 80% respectively in the winter. The mean annual solar radiation is 2200
J/cm2/day. There is a significant variation in the wind speed during the daytime, and the
average maximum wind speed velocity is about 3.9 m/s. Moreover, storms have been
observed in winter with a maximum wind speed of about 18 m/s. Peak months of rainfall are
December and January; the average annual rainfall is 335 mm/y (26-year average). There is a
constant flow of untreated domestic sewage water and agricultural runoff into the Wadi from
the Refugee–Middle Camps with the main outlet at the southern bank of the Wadi under
Salahedden Bridge (Fig. 1). This maintains a trickle of water in the Wadi bed, and feeds the
permanent stagnant pool that covers several hectares at the mouth of Wadi Gaza, hence
maintaining an extensive water body during the dry season (CAMP, 2001). Fish are known to
occur in this pool, although it is dominated by dense algal growth in summer season. No
surface water quality data are available, but several wells around the Wadi appear to have
unacceptable levels of bacterial contamination, indicating that the pollution is extending to
the groundwater in this area (MEnA, 2002a). Three bridges cross the Wadi (two roads and
one rail) and numerous dry season tracks criss-cross the Wadi bed where it widens near the
refugee camps. At the southern side of the Wadi there is a three stage olive mill which
disposes the wastewater and the marc directly to the Wadi. On either side of the Wadi,
farmland extends with olives, vines, fruits and vegetables, some of which are probably
flooded during major storm events. At the eastern road bridge, farmers dam the river in
summer using earth, and pump the water for irrigation; this water is affected by algal blooms
and has a bright green color. The vegetation in the Wadi is dominated by Tamarix growing
on the dunes and sand deposits in and around the Wadi bed. The wetter areas have stands of
Typha which also fringe the water body near the outlet to the sea (Issac et al., 1997). Around
125 hectares of saltmarshes recorded in the Gaza Environmental Profile of 1994 have
disappeared following construction of the new bridge at the Wadi Gaza outflow in 1996. This
has disrupted the outlet, affected windblown sand deposition, improved access to the public
and generally modified the ecology and geomorphology of Wadi Gaza estuary. Local staff
reports indicated that the foundations of the bridge have also blocked the river course and
therefore raised the level of the pond. While this may be the case, it is evident that sand
accumulation, either brought down by the Wadi Gaza in recent floods, or deposited during
sea storm events is another proximate cause of the blockage (MEnA, 2002b). During westerly
storms, seawater may be pushed over the sand barrier into the Wadi, maintaining brackish
conditions in the downstream part of the system.
The sampling and analysis
The study area (Fig. 1) is divided into nine parts, each about 1-km long, numbered from east
to west (K1 to K7). The eighth part (En 8) represents the entrance of the Wadi to the lake and
the ninth is the lake. The lake is divided into 10 areas (W1 to W10). During the sampling
period, the water depth varied between 0.4 and 1.5 m due to change in the total wastewater
discharged to the Wadi; the topographic depression of wetland has an average depth of 1.8 m.
The two sampling campaigns were conducted at the end of summer dry season 2001 and at
the end of winter rainy season 2002.
69
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
Water samples
A total of 17 composite water samples were collected in late summer (November, 2001) and
18 in late winter (April, 2002). Water samples were collected from the six eastern parts
(Stations 2-7): the first Station was dry in summer, and another sample from Station 8 which
represents the entrance of the Wadi to the lake. Ten water samples were collected from the
lake. One-liter samples were collected, then divided into two subsamples, the first (500 ml)
was filtered in acid-washed filter holder and through 0.45 µm pore size membrane filters, the
first few milliliters were used to rinse then they were discarded, and the filtrate was
transferred to clean acid-washed polyetheylene bottles and acidified by concentrated nitric
acid (Ultrapur, Merck, v/v), and stored at 4 oC until analyses of total metal contents by
ICP/MS (Perkin Elmer-Sciex, Elan 6000) were performed; the other part of water was filtered
with no additives and stored at 4 oC for anion analyses by Ion Chromatography (IC). Several
parameters were measured in the water samples during the fieldwork: temperature, turbidity,
electric conductivity and pH, other parameters were measured in the lab. As excessive
fluoride concentrations are known to be problematic in this area, fluorides were measured
also, using Ion Selective Electrode (ISE) according to the American standard methods
(APHA, 1995). One wastewater composite sample was collected from the open canal directly
before entering the Wadi and two groundwater samples were collected from the wells F62
and G16 which are located 50-100 m away from the Wadi.
Sediment samples
Thirty six sediment samples were collected from the same stations in the two sampling
campaigns. They were collected using a stainless steel dredge; approximately 0.5 kg was put
in polyethylene cups and stored at 4 oC during its transport to laboratories. Sediments were
sieved through a 20-µm sieve with deionized water, and then were dried in an oven at 50 oC
until constant weight. Samples were ground in an agate mortar. Approximately 1-2 grams of
the homogenized sample were dissolved with 10.5 ml of concentrated hydrochloric acid
(37% p.a.) and 3.5 ml of concentrated nitric acid (65% p.a.) in 50 ml retorts. The samples
were allowed to degas (12 hours). Then all samples were heated to 160 °C on a sand bath
until complete extraction (3 hours). After cooling, the solutions were diluted with distilled
water in 50 ml volumetric flasks and kept in 100 ml polyethylene bottles for analysis. Trace
metals were analyzed using a Flame Atomic Absorption (AAS vario 6- Analytik Jena). The
distribution of phosphorus as (P2O5) was measured for all sampling stations (APHA, 1995).
Mercury concentrations were determined using atomic absorption spectroscopy after thermal
combustion of freeze dried samples (50-100 mg) and Hg pre-concentration on a single gold
trap by means of an AMA 254 solid phase Hg-Analyzer (LECO). Total carbon and sulfur
were determined directly in dried samples by using a Carbon-Sulfur Determinator (Leco CS225). Carbonates were measured directly by a carbonate bomb (Müller & Gastner, 1971).
70
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
Quality control
For quality control, analytical blanks and two samples with known concentrations of heavy
metals were prepared and analyzed using the same procedures and reagents (Avila-Perez et
al., 1999). For the surface water, groundwater and wastewater analyses, Standard Reference
Materials 1643c and 1643d were used for the determination of trace elements (National
Institute of Standards and Technology NIST, Gaithersburg, 1991 and 1994) and SPS-WW2,
Wastewater Level 2 (SPS, 2002).
Precision was estimated evaluating the reproducibility between the duplicates and a
coefficient variation of lower than 5% was found. The accuracy was evaluated by two River
Sediment Standard Reference Materials-RS1 and RS3-Deutsche Industrie Norm (DIN, 1997,
1989). As an independent check on the trace element measurements of the sediments, these
were also measured in solid samples using the Energy-dispersive Miniprobe Multielement
Analyzer EMMA-X-Ray Fluorescence Spectrometry (Cheburkin and Shotyk, 1996).
The EMMA was calibrated and standardized for trace elements in sediments using a variety
of certified, standard reference materials. These materials were used in the AAS
measurements. A rigorous quality control program was implemented to check the results
obtained from the two methods (AAS and EMMA). From the statistical point of view, a
simple comparison (in percentage) was calculated between the results for the same parameter
of the two methods.
RESULTS AND DISCUSSION
Many parameters were not detected in any of the water samples, while other parameters (Hg
and Cd) in the sediments were found to be less than the background. Consequently data from
these elements are not presented in figures 2 and 4.
Water Quality
Table 1 shows the results of all water samples from all stations in summer and winter and
Figure 2 indicates the trend of each parameter along the Wadi.
Temperature, pH, Electric Conductivity and Dissolved Oxygen
Both Table 1 and Figure 2 show the seasonal variation of water temperature, pH, DO and EC.
The latter has the same trend of Cl. The rainy winter season reduced EC and Cl by diluting
the waters of the Wadi.
Major ions
The average total dissolved solids (TDS) in groundwater, wastewater and Wadi's water was
1800 mg/l and major ions of Cl, F, NO3, SO4, CO3, PO4, Na, Ca, Mg, K were higher than
their concentrations in several surface water bodies in the world (Song and Müller, 1999).
The western stations of the wetland are exposed to the sea waves especially in summer and
this resulted in the high concentrations of Cl, Na, Ca, Mg, SO4 in area 10 of the lake.
71
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
In the winter, the concentrations of these ions were influenced by rainwater and wastewater;
while in summer their concentrations were influenced only by wastewater. In the winter,
rainwater inputs decreased NO3 concentrations; moreover the lake was eutrophic in summer
and not in winter. Groundwater concentrations of sulfate averaged between 240 and 190 mg/l
in summer and winter, respectively and SO4 contents were not affected by seasonal variation
(Fig. 2c). Although it was assumed that fluoride is a natural constitute of the groundwater of
the Gaza Strip (Shomar et al., 2004d), F decreased to the half in winter. The results of
fluoride analysis using IC were consistent with the results of the ISE and only few samples
showed a difference of around 5%. Phosphates in the same figure fluctuated along the Wadi
due to the different factors affecting the existence of phosphate in the river. Phosphate
contents in the groundwater of the area were very low, while they were much higher in
domestic wastewater (25 mgPO4/l).
Table (1) Water Quality of Wadi Gaza.
Summer, November 2001
Temp. (oC)
pH
DO mgO2/l
EC mS/cm
Cl (mg/l)
NO3 (mg/l)
SO4 (mg/l)
F (mg/l)
PO4 (mg/l)
Na (mg/l)
Mg (mg/l)
Ca (mg/l)
Fe (µg/l)
Zn (µg/l)
Cu (µg/l)
Mn (µg/l)
As (µg/l)
Pb (µg/l)
Cr (µg/l)
Cd (µg/l)
Co (µg/l)
Max
24
9
7
4.8
1142
21
2536
31
85
8233
303
348
776
206
10
580
9.4
30
139
12
70
Min
21
6.5
3.9
2.9
450
2
14
1
5
19
53
68
192
1
1
320
0.5
1
3
1
15
Mean
23
7.6
5.3
4.2
924
8
236
4.4
49
678
89
136
382
82
4
423
1.7
12
65
6
43
σ
0.8
0.5
0.8
0.8
296
5.3
614
7.9
19.2
2015
60.4
62.8
174.1
45.1
2.9
64.9
2.1
10
38.3
3.4
19.6
Winter, April 2002
Max
17
8.6
9.6
2.8
700
31
305
3.2
42
160
95
124
6600
1560
123
385
27.6
135
130
3.4
8.1
Min
15
8
4.3
1.7
320
17
80
0.8
12
102
42
67
223
13.6
5.5
38.3
7.6
5.1
4.6
0.5
1.1
Mean
16
8.3
8.4
2.18
478
22.7
184
1.8
24.7
124
65.7
102
909
148
16.4
266
12.7
40.8
20.6
1.6
2.3
σ
0.7
0.2
1.3
0.3
107
4.2
82
0.6
11.4
15.9
15.9
16.8
1666
408
30
85
4.6
63
34
1.3
1.7
FreshDomestic
LD***
water* Wastewater** (µg/l)
25.5
7.5
3
650
0. 22
11.1
0.1
0.06
6
4
15
500
15
3
8
0. 5
3
1
0.1
0.2
1.2
25
380
36
43
200
100
6
300
0.4
2
7
0.5
0.3
15
10
1
1
5
2.5
2.5
0.5
0.3
* Elemental composition of freshwater (Bowen, 1979).
** Elemental composition of domestic wastewater discharged to the Wadi.
*** LD: Limit of Detection by the ICP/MS in (µg/l).
Fe and Mn
Water of Wadi Gaza was oxygenated and the Fe and Mn were in the oxidized soluble forms.
The measurement of DO of water samples collected from Wadi Gaza showed an average of
9.6 mgO2/l, keeping in mind that the sampling program was carried out under windy
conditions in winter. Groundwater wells in the same area had lower Fe and Mn contents than
the Wadi Gaza samples. Figure 2e shows stability of Mn concentrations in the eastern
stations of the Wadi, while there was a gradual increase of Mn in the lake from east to west.
Fe, on the other hand, decreased from east to west, remained constant in 8 stations of the
wetland, and only Station 6 had higher Fe compared with other stations.
72
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
Trace elements (Zn, As, Pb, Cr, Co, Cd, and Cu)
These elements come to the Wadi from the wastewater and generally were high in summer
and low in winter. Groundwater samples of wells F62 and G16 have considerable amounts of
these elements (Fig. 3). The impact of seasonal variation was recorded for As and Cd and
they showed opposite behavior, while Pb, Co, and Cu were not significantly affected.
Human inputs in the Wadi Gaza
Figure 3 shows the comparison between wastewater, water of sampling stations 7 and area 3
of the lake and groundwater of the two wells nearby. Untreated wastewater is directly
discharged to the Wadi and has high amounts of microorganisms, which during summer
increase the biodegradation activity, reduce DO and pH, and affect the redox processes of Fe,
Mn, As and P. In summer, wastewaters also expressed an increase in NO3, SO4, F, Cu, Al, Ni,
Zn, Pb, Cr and Cd concentrations in Wadi Gaza. Some industrial wastes of detergents and
fertilizers increase P contents, while metallic wastes and construction materials in the area
increase Ca, Na, Mg, Fe and Mn concentrations. The three stage olive oil extraction mill
generates oil and two by-products: wastewater and marc (solid waste formed by olive stone
and pulp wastes). The amount of waste generated ranges between 0.5 and 1.4 l/kg of
processed olive. The wastes of the olive oil mill reduced the pH of surface water in summer
and increased the Na, Mg, Ca and P concentrations in station 7. The groundwater in the area
showed high amounts of Cl and NO3, especially in summer. Well F62 had 989 mg Cl/l and
117 mg NO3/l and well G16 had 890 and 110 mg/l of the same anions.
73
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
d)
8
80
10
15
6
10
4
5
2
0
0
6
9
W
W
8
7
6
W
W
4
5
W
2
3
W
W
8
1
W
Sampling Stations
Fe-sum
Fe-w int
Mn-sum
Mn-w int
Seasonal Variation of Fe and Mn
e)
7000
700
5
6000
600
800
4
5000
500
4000
400
600
3
3000
300
400
2
2000
200
200
1
1000
100
0
0
Fe (µg/l)
EC (m S/cm )
6
1000
10
9
8
W
W
W
6
W
W
7
5
4
W
W
2
3
W
8
1
10
W
9
8
W
W
7
6
W
W
4
5
W
W
3
2
W
W
1
W
En
8
K
9
W
7
8
W
6
W
W
5
W
3
4
W
2
W
W
8
7
1
W
En
K
6
K
5
K
4
K
3
K
1
2
K
W
0
6
0
1
0
Zn-sum
Zn-w int
Ca-sum
Ca-w int
50
0
7
20
K
50
100
50
K
40
5
60
150
100
K
100
200
150
4
80
250
200
K
150
Ca (m g/l)
100
SO 4 (m g/l)
120
200
250
3
140
K
160
250
Seasonal Variation of Ca and Zn
f)
2
300
SO4-sum
SO4-w int
NO3-sum
NO3-w int
K
Seasonal Variation of NO3 and SO4
K
W
Sampling Stations
Sampling Stations
c)
En
7
6
K
K
2
5
K
K
K
K
K
W
W
9
8
7
W
W
6
5
4
W
W
2
3
W
W
8
1
W
En
7
K
6
K
5
K
3
4
K
K
2
1
K
K
4
0
3
0
1
Cl (m g/l)
1200
Mn (µg/l)
Cl-sum
Cl-w int
EC-sum
EC-w int
Seasonal Variation of Cl and EC
Zn (µg/l)
b)
W
6
7
En
K
K
4
K
K
K
K
5
0
3
2
0
2
4
20
1
40
K
D O (m gO 2/l)
10
9
8
60
W
W
W
7
W
5
W
W
W
W
3
2
1
W
W
7
En
6
K
K
5
4
3
K
K
2
K
K
K
P O 4 (m g/l)
12
20
8
14
100
6
120
10
4
12
25
8
30
Sampling Stations
N O3 (m g/l)
PO4-sum
PO4-w int
F-sum
F-w int
Seasonal Variation of PO4 and F
F (m g/l)
Tem.sum
Tem.w int
DO.sum
DO.w int
Seasonal Variation of Temp., & DO
1
Tem p. (C o )
a)
Sampling Stations
Sampling Stations
Fig. 2. (a) Temp., and DO, (b) Cl and EC, (c) NO3 and SO4, (d) PO4 and F, (e) Fe and Mn ,
(f) Ca and Zn in water samples of the Wadi Gaza.
Sediment metal concentration
The coefficient of variation for two independently prepared aliquots of the same sample was
less than 2% for all parameters. The agreement between the certified and experimentally
established concentrations in Standard Reference Materials was less than 2% for all
parameters except for Cd which was more than 6%. The difference between the Standard
Reference Materials (RS1 and RS3) supplied by DIN was used to estimate the accuracy of
the
method
analyzed.
The
difference
rates
(%)
were: CaCO3=0.9, Mg=0.44, Ca=1.05, Cu=0.7, Zn=0.72, Ni=0.77, Pb=0.65, Mn=0.73,
Fe=0.67, Cr=1.26, Cd=6.7 and As=0.66.
74
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
wastewater, Wadi and groundwater, Middle
wastewater, Wadi and groundwater, West
16
10
14
12
WW
6
Wadi
4
GW
(µg/l)
(µg/l)
8
10
WW
8
Wadi
6
GW
4
2
2
0
0
Ag
Cd
Co
As
Ni
Cr
wastewater, Wadi and groundwater, Middle
Cu
Pb
wastewater, Wadi and groundwater, West
10
40
35
8
25
WW
20
Wadi
15
GW
(µg/l)
(µg/l)
30
10
Wadi
4
GW
2
5
0
0
Cr
Cu
Pb
Ag
wastewater, Wadi and groundwater, Middle
Cd
Co
As
Ni
wastewater, Wadi and groundwater, West
400
400
350
350
300
300
250
WW
200
Wadi
150
GW
(µg/l)
(µg/l)
WW
6
250
WW
200
Wadi
150
GW
100
100
50
50
0
0
Mn
Al
Zn
Fe
Mn
Al
Zn
Fe
Fig. 3. Comparison between trace metals in domestic wastewater (WW) discharged to Wadi
Gaza, water of Wadi (W) in two sampling stations and groundwater (GW) of two wells in the
middle (F62) and the western (G16) areas of Wadi Gaza.
Phosphorus
Phosphorus in sediment followed an opposite trend to P in water; P in sediment was high in
winter and low in summer. Figure 4a shows the trend of P along the Wadi. The eastern
stations were shallow and the P content in the lake was higher than its values in these
stations. Moreover, the water flow in summer was very slow, eutrophication phenomena
appeared in the western lake, and limited algal blooms appeared in the eastern stations. The
major source of phosphorus in the area is wastewater, containing detergents and fertilizers
applied in the surrounding agricultural areas. The relationship between P and Fe is discussed
under the results of Fe in water and sediments. Table 2 and Figure 4a show the variation of P
in summer and winter. Generally P increased by a factor of 2 in winter compared with
summer in the western lake. The decay of water plants in winter may have increased the P in
sediment and decreased the P in water. Moreover, the sediments release P to water in summer
and sorb it in winter (Kelderman, 1996).
75
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
Table (2) Chemical characteristics of sediments by flame AAS.
Summer, November 2001
*Backgro
und
Winter, April 2002
Parameter
Mi
Mean
n
P g/Kg
1.6
0.3
1.0
C[%]
9.7
0.6
4.0
S[%]
1.2
0.0
0.5
CaCO3 [%]
32.0
7.0
24.6
Mg [%]
2.1
0.2
1.4
Ca [%]
12.9
3.0
10.1
Na mg/Kg
28714 196 6586
K mg/Kg
10964 624 7370
Cu mg/Kg
28.0
4.0
20.5
Zn mg/Kg
104.0 7.0
70.4
Ni mg/Kg
48.0
1.0
30.4
Pb mg/Kg
16.0
4.0
11.6
Mn mg/Kg
739
85
502
Fe [%]
7.5
0.6
4.3
Cr mg/Kg
59.0
6.0
35.8
Co mg/Kg
18.0
2.0
11.4
Cd mg/Kg
0.4
0.0
0.2
As mg/Kg
10.1
1.8
5.9
Hg mg/Kg
0.9
0.0
0.1
* Turekian & Wedepohl, 1961.
Max
σ
Max
Min
Mean
σ
0.4
2.4
0.4
7.8
0.7
2.8
7302
3597
8.7
30.2
17.3
3.6
228
2.5
17.8
4.9
0.1
2.2
0.2
2.3
5.1
1.92
28
2.0
13.1
43072
9207
28.6
101.1
47.4
17.7
671.0
3.9
62.5
16.5
0.4
4.6
0.1
0.2
1.2
0.0
7
0.3
3.4
81
655
3.8
13.9
3.5
0.1
88.2
0.4
5.1
0.9
0.0
0.5
0.004
1.3
3.56
0.78
19.3
1.34
9.40
11762
5336
20.88
74.77
31.14
10.91
483.7
2.53
37.28
11.43
0.21
2.62
0.05
0.7
1.3
0.6
7.0
0.6
3.4
13814
3348
8.7
31.0
15.8
5.8
217.2
1.3
20.6
5.3
0.1
1.3
0.03
45
95
68
20
850
4.7
90
19
0.3
0.4
Carbon and Sulfur
The field survey indicated that the sources of carbon in the Wadi Gaza include not only
natural sources but also different construction materials dumped to the Wadi. There was no
significant difference in the contents of C and S in summer and winter and only two sampling
stations showed sudden increases in C summer samples.
CaCO3, Ca, Mg and Na
Figure 4b shows the trend of CaCO3 and Ca in the summer and winter. Sampling station 6
has a sudden increase in the Ca contents in the summer presumably from the accumulated
wastewater produced from the olive oil mill opposite to this station. The wastewater was very
rich in Ca and may have percolated to the sediment of that area. The CaCO3 showed the same
trend as Ca. Generally, seasonal variation affected the contents of CaCO3 and it was higher in
summer than winter. The results of Mg and Na in summer and winter were similar, especially
in the eastern sampling stations, and the reason of the fluctuation of Na in 3 stations within
the lake was not clear. The lake showed higher Na in winter than summer, while the Mg
remained the same in all stations.
Cu, Zn, Cr, Ni, Pb, Co, As, Hg and Cd
The analysis of Cu and Zn in sediments of the Wadi Gaza showed similar values in summer
and winter with no major difference. The two metals displayed the same trend in summer and
winter and also in all sampling stations (Fig. 4c). Cu started low in the east and increased
gradually in the west.
76
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
The concentration of each metal remained the same within the lake's 10 areas. Chromium had
the same trend in summer and winter; it started in the eastern sampling stations then
increased in the lake. As shown in Figure 4d, the concentrations of Ni and Pb
were the same in summer and winter.
Only sampling Station 6 showed an increase in Ni in winter while the others remained the
same. Cobalt fluctuated in summer and winter but both results had the same range (Fig. 4e).
As, on the other hand, was two times higher in summer than in winter especially in the lake
where the water depth was about 1.8 m; the eastern stations showed less difference as the
water was shallow (30-60 cm depth).
a)
P in summer and winter
P-sum
d)
Ni and Pb in summer and winter
2.50
60
2.00
50
Ni and Pb (mg/kg)
1.50
1.00
0.50
30
20
10
5
6
K
7
En
8
W
1
W
2
W
3
W
4
W
5
W
6
W
7
W
8
W
W 9
10
K
2
4
K
K
1
K
K
Sampling stations
Sampling stations
e)
Co and As in summer and winter
6
K
7
En
8
W
1
W
2
W
3
W
4
W
5
W
6
W
7
W
8
W
W 9
10
K
1
K
K
7
En
8
W
1
W
2
W
3
W
4
W
5
W
6
W
7
W
8
W
W 9
10
Sampling stations
Sampling stations
f)
4
300
3
200
2
100
1
0
0
K
1
K
7
En
8
W
1
W
2
W
3
W
4
W
5
W
6
W
7
W
8
W
W 9
10
6
K
5
K
3
4
K
K
1
K
K
2
0
Sampling stations
6
5
400
5
6
500
K
30
7
600
K
60
8
700
4
90
Mn-sum
Mnw int
Fe-sum
Fe-w int
800
K
Mn (mg/kg)
120
3
150
Fe and Mn in summer and winter
K
Cu-sum
Cu-w int
Zn-sum
Zn-w int
2
Cu and Zn in summer and winter
K
c)
Fe (%)
6
K
5
K
4
3
K
2
K
K
K
1
0
5
5
K
10
4
15
K
20
2
25
Co-sum
Co-w int
As-sum
As-w int
20
18
16
14
12
10
8
6
4
2
0
30
Co and As (mg/kg)
Ca and CaO3 (%)
35
3
CaCO3-sum
CaCO3-w int
Ca-sum
Ca-w int
K
Ca and CaO3 in summer and winter
K
b)
K
7
En
8
W
1
W
2
W
3
W
4
W
5
W
6
W
7
W
8
W
9
W
10
6
5
4
3
2
7
En
8
W
1
W
2
W
3
W
4
W
5
W
6
W
7
W
8
W
9
W
10
K
K
K
K
K
1
K
K
3
0
0.00
Cu and Zn (mg/kg)
Ni-sum
Ni-w int
Pb-sum
Pb-w int
40
K
P (g/kg)
P-wint
Sampling stations
Fig. 4. (a) P, (b) Ca and CaCO3, (c) Cu and Zn, (d) Ni and Pb, (e) Co and As, (f) Fe and Mn in
the sediment samples of Wadi Gaza.
77
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
During the summer sampling, some medical wastes were found in the area, as a result of the
disposal activities by local clinics. The recent observations agreed with the findings of
Zoarob (1997) who identified Wadi Gaza as a disposal site of medical wastes. This is
probably the main source of Hg in the area. Mercury values were not affected by seasonal
variation. They remained low and two anomalous readings only appeared in Station 1 and
area 5 (W5) of the lake in summer sediments. Hg levels were still below the German and the
European standards for sediments (Oka-Elbe Project, 2000). Cadmium was low but
fluctuated in all sediment samples with no significant differences along the Wadi.
Fe and Mn
Fe and Mn represented the major metals in sediment samples of Wadi Gaza. Fe and Mn in the
sediments were also much higher than the Fe and Mn contents in the soils of the other areas
in the Gaza Strip. As mentioned before, most of the metallic solid wastes dumped into Wadi
had high amounts of Fe. The results showed that both Fe and Mn followed similar trends
(Fig. 4f). The summer season had many impacts on water and sediment and the sedimentwater exchange of P was much dependent on the season. In the summer the sediment released
P whereas in the winter, a P accumulation took place. In the summer season this phosphorus
was used as a main source of nutrients needed for water plants covering the Wadi. Higher
temperatures could lead to anoxic conditions in sediment resulting in Fe and P release. In
winter the sediments are oxygen-rich, and Fe is in the Fe(III) form, which forms an insoluble
bond with phosphate. Under anaerobic conditions of summer (to be more specific, at redox
potentials below 150 mV), the Fe(III) was reduced to Fe(II). Since Fe(II)-phosphates are 100
times more soluble than Fe(III)-phosphates, this gave rise to a P release from Fe-P bondings.
Table (3) Chemical characteristics of sediments by EMMA.
Summer, November 2001
Winter, April 2002
Parameter
Max
Min
Mean
σ
Max
Min
Mean
K [%]
2.4
0.6
1.8
0.6
2.6
0.9
2.0
Ca [%]
12.0
4.4
10.2
1.8
12.9
5.8
10.3
Ti [%]
0.6
0.4
0.5
0.1
0.8
0.3
0.5
Cr mg/Kg
117.1
32.3
76.1
25.4
117.2 32.1
85.8
Mn mg/Kg
672.8 122.9 475.1 171.3 597.7 145.5 465.1
Fe [%]
4.1
0.8
3.0
1.1
4.2
1.0
3.1
Ni mg/Kg
59.9
4.5
35.5
17.2
52.0
7.7
34.1
Cu mg/Kg
566.1
4.7
50.9
128.8
34.3
6.7
24.2
Zn mg/Kg
140.4
14.7
81.0
30.4
118.5 18.0
86.5
Ga mg/Kg
13.9
2.3
10.0
3.7
15.4
2.1
10.8
As mg/Kg
7.6
0.0
3.8
2.6
6.1
0.0
3.7
Se mg/Kg
0.9
0.0
0.1
0.3
0.0
0.0
0.0
Br mg/Kg
84.1
2.4
23.2
22.3
168.3
1.6
36.7
Rb mg/Kg
45.6
11.0
34.4
12.9
46.2
10.3
34.4
Sr mg/Kg
385.3 140.6 284.6
64.9
455.6 106.0 285.4
Y mg/Kg
26.4
8.0
20.3
7.0
25.9
5.6
19.0
Zr mg/Kg
511.3 144.6 246.9 130.0 330.9 103.3 175.1
Pb mg/Kg
193.3
2.5
21.1
43.1
18.8
3.8
12.5
Th mg/Kg
8.1
0.0
4.2
2.2
6.3
0.0
3.9
78
σ
0.6
2.1
0.1
26.6
147.4
1.2
14.2
9.0
34.0
4.6
2.0
0.0
43.7
13.6
93.2
7.2
67.5
3.8
2.4
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
AAS and EMMA
Tables 2 and 3 and Figure 5 show the results obtained from the flame AAS and the EMMA.
The agreement between the two methods was generally good and was compatible with the
findings of Cheburkin and Shotyk (1996). The shared parameters between the two methods
were Ca, Fe, Mn, Cu, Zn, Ni, Pb, Cr, As and K. The flame AAS showed levels 5% and 10 %
higher than the EMMA for Ca and As respectively and 6-8% higher than the Mn
concentrations. Both systems have a difference of 5% for Cu, Zn and Pb. They showed < 2 %
difference for Fe. The Cr and Ni were 40 and 20% higher in the EMMA to the AAS results,
respectively, probably because of an incomplete dissolution of the soil samples during the
digestion process by acids. Additional metals were measured by the EMMA and Table 3
showed the contents of these metals (Ti, Ga, Se, Br, Rb, Sr, Y, Zr and Th) in summer and
winter.
Comparison between FAAS and EMMA-2002
14
12
10
8
6
4
2
0
500
400
EMMA
AAS
ppm
ppm
Comparison between FAAS and EMMA-2002
300
100
0
K%
Ca %
Fe %
As
Cr
Pb
Comparison between FAAS and EMMA-2001
Cu
Ni
Zn
Mn
Comparison between FAAS and EMMA-2001
25
600
20
500
400
15
EMMA
AAS
10
ppm
ppm
EMMA
AAS
200
EMMA
AAS
300
200
5
100
0
0
K%
Ca %
Fe %
As
Cr
Pb
Cu
Ni
Zn
Mn
Fig. 5. Comparison between the results of AAS and EMMA for sediment samples of Wadi Gaza
for two successive years.
CONCLUSIONS
1) The results obtained served to increase our knowledge of the geochemistry of water and
sediment of the Wadi Gaza. In spite of this, the study has highlighted the need for further
research, by increasing sampling density and regularity to better characterize the geochemical
conditions of the Wadi.
2) Excluding Station 7, no major contamination of Fe, Zn, Cu, Mn, As, Pb, Cr, Cd, and Co
was found in water at most of the stations. Sediments in only two stations had high Hg, Cd, Fe
and Zn compared to background values of Turekian & Wedepohl (1961). Heavy metal
contents in sediment samples were low in the eastern stations and higher in the lake.
79
Chapter Five
Seasonal variations of chemical composition of water and sediments of Wadi Gaza
__________________________________________________________________________________________
3) The various anthropogenic inputs may lead to the enrichment of many metals in the
sediments of Wadi Gaza. Pollution of several sites was found to be considerably high for Hg,
Cd, Fe and Zn and to a somewhat lesser extent for As, Pb, Ni, Cu and Co, whereas
anthropogenic input of Ga, Se and Th seems to be less important.
4) The chemical composition of water and sediments exhibited seasonal variation. The human
inputs affect the concentrations of the tested parameters in summer; while the precipitation
inputs in winter diluted pollutants to minimum levels.
RECOMMENDATIONS AND MANAGEMENT STRATEGIES
Wadi Gaza is the only wetland in the Gaza Strip and its unique habitat and species warrant
careful management. The opportunity exists to apply measures which can bring both
ecological and socio-economic benefits. Measures to clean up and restore the wetland would
bring ecological, landscape and visual improvements. This may improve the health and the
environmental conditions for local people, bring new opportunities in education, recreation,
tourism and research, as well as maintain a range of cultural, social and historical heritage
values.
The main pressures should be reduced in short, medium and long term measures. These
pressures include overgrazing, pollution from the untreated wastewater, discharge of oils and
pesticides, cutting and burning of natural vegetation, building roads, agricultural
encroachment, hunting and poaching. By reduction of these pressures, the ecosystem
functions and productivity will be restored. Examples of short term measures would be to
open the mouth of the Wadi to the Mediterranean Sea and to stop the use of oil and pesticides
for combating mosquitoes. Examples of medium and long term measures would be to stop
the discharge of raw wastewater to the Wadi and to cooperate with the upstream regions in
management of the Wadi water resources. Because the Wadi is subject to many jurisdictions,
local, governmental, and nongovernmental institutions should all play a role in protecting and
conserving the Wadi. The efforts should aim to support the conservation of the wetland by
implementing activities such as: (1) cleaning campaigns, (2) removal of construction debris,
(3) development of recreational areas, (4) building of bridges of culverts, hiking trails,
observation towers, and water retention structures and (5) planting of trees in the site.
80
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
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CHAPTER SIX
Geochemical Features of Topsoils in the Gaza Strip: Natural Occurrence
and Anthropogenic Inputs (*)
ABSTRACT
The aims of this study were to establish the current contents of trace metals and major
elements in agricultural soils of the Gaza Strip, and to identify the main anthropogenic inputs
affecting trace metal contents. An extensive soil survey was conducted in agricultural and nonagricultural areas. One hundred seventy sites were selected which represent a broad range of
soil types and locations. The results revealed that soils fall within the range of the
uncontaminated to slightly contaminated category. Up to 90% of the tested soils had trace
metal contents representing the international background values. 10% showed slight
contamination mainly by Zn, Cu, As and Pb due to anthropogenic inputs, and their mean
concentrations were 180, 45, 13 and 190 mg/kg, respectively. The trace metal contents vary
with the highest contents detected in the southern regions (clay soil and low precipitation) and
the lowest in the northern areas (sandy soil and high precipitation). The soil geochemistry is
dependent on soil type and location and to a lesser extent on crop pattern and fertilizer and
fungicide application. Anthropogenic inputs lead to the enrichment of Zn, Pb, Cu and Cd in
the agricultural soils. Pollution of several investigated sites was found to be most severe for
Zn, Pb, Cu and Cd and to a somewhat lesser extent for As, whereas anthropogenic input of Hg,
Ni and Co seem to be less important. The application of Cd-containing phosphate fertilizers
coupled with Cu-containing fungicides may be important sources of Cd and Cu in several
soils. High Zn levels (1000 ppm) in several soils may be caused by sewage sludge that has an
average Zn content of 2000 ppm. Saline-sodic soils were found in the central and southern
regions where the soils are characterized by high contents of Na and salty groundwater.
Elevated Cl, Na, Zn and Pb contents in some areas need further investigation for their
ecological and health implications.
Key words: Anthropogenic inputs, Gaza Strip, Soil pollution, Trace elements.
_________________________________________________________________________________
(*) The study was published in the Journal of Environmental Research as:
Shomar B. Müller G. Yahya A. (2004) Geochemical Features of Topsoils in the Gaza Strip: Natural
Occurrence and Anthropogenic Inputs. Journal of Environmental Research, in press.
81
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
INTRODUCTION
Due to the scarcity of land and rapid urbanization in the Gaza Strip, most agricultural areas are
located near industrial areas and the environmental hotspots of wastewater treatment plants
and solid waste dumping sites. The soils of these agricultural areas are subject to potential
pollution from various sources (Abrahams, 2002). Soils are prone to contamination from
atmospheric and hydrological sources, but direct waste disposal causes a major impact on this
natural resource, posing serious environmental concern (Navas and Machin, 2002). At current
rates of atmospheric deposition concentrations of potentially toxic trace metals in soils of
several countries worldwide may already be close to exceeding their critical capacity for
pollution (Nriagu, 1990). Most trace metal contamination in the surface environment is
associated with a cocktail of contaminants rather than one metal (Jung, 2001). It has been
noted that roadside soils near heavy traffic and urban soils are polluted by Cd, Cu, Pb and Zn
and other metals (Li et al., 2001). In the polluted soil, the trace metal concentrations in crop
plants were found to vary between plant species (Lee et al., 2001). Balances between removed
and supplied quantities of trace elements indicate slow depletion of the micro nutrients Zn, Cu
and Mn in farming based on cash crops and conventional fertilization. The soil levels of Cd,
Hg and Pb are slowly increasing due to additions of commercial fertilizers (Andersson, 1992;
Bowen, 1979).
Soil salinity and sodicity can have a major effect on the structure of soils. Soil structure, or the
arrangement of soil particles, is critical in affecting permeability and infiltration (Sparks,
1995). Saline irrigation water, low soil permeability, inadequate drainage, low rainfall, high
potential evapo-transpiration and poor irrigation management all cause salts to accumulate in
several soils of Gaza, which deleteriously affects crop growth and yields (Sparks, 1995).
In the Gaza Strip, there is not enough water to leach soluble salts from soil. Consequently, the
soluble salts accumulate, resulting in salt-affected soils. The major cations and anions of
concern in saline soils and waters are Na+, Ca2+, Mg2+ and K+ and the primary anions are Cl-,
SO42-, HCO3-, CO32- and NO3-. Carbonate ions are normally found only at pH≥ 9.5.
Crop rotation and fertilization vary between different regions depending on climate and soil
conditions, and, similarly, there is a variation in the rate of precipitation from south (250
mm/a) to north (400 mm/a) over the Gaza Strip.
The main goal of this study was to establish the topsoil geochemistry in the Gaza Strip. A
secondary objective was to identify the major anthropogenic inputs affecting soil
geochemistry.
82
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
MATERIALS AND METHODS
Soil Types
The Gaza Strip is 360 km2, has several major soil types (Fig. 1). Arenosolic, Calcaric,
Rhegosolic and Calcaric Fluvisolic soils are examples of these soils (Table 1). Arenosolic
(Sandy) soils of dune accumulations are Regosols without a marked profile. The soils are
moderately calcareous (5-8% CaCO3), with low organic matter, physically suitable for
intensive horticulture.
Mediterranean
Sea
Fig. 1. Location of the Gaza Strip and Soil Type Distribution.
83
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Calcaric Arenosols (Loessy sandy soils) can be found some 5 km inland in the central and
southern part of the Strip, in a zone along Khan Yunis towards Rafah, parallel to the coast.
This belt forms a transitional zone between the Arenosolic soils and the Calcaric (Loess) soils.
Typical Calcaric soils are found in the area between the city of Gaza and the Wadi Gaza and
they contain 8-12% CaCO3. Arenosolic Calcaric (Sandy loess) soils are transitional soils,
characterized by a lighter texture. These soils can be found in the depression between the
Calcareous (Kurkar) ridges of Deir El Balah. Apparently, windblown sands have been mixed
with Calcareous deposits. Deposition of these two types of windblown materials originating
from different sources has occurred over time and more or less simultaneously. These soils
have a rather uniform texture. Another transitional form is the Arenosols over Calcaric soils.
These are loess or loessial soils (sandy clay loam), which have been covered by a layer (0.20 –
0.50 m) of dune sand. These soils can be found east of Rafah and Khan Yunis.
Table (1) Soil Types, land form and dominant land use of the Gaza Strip.
Soil Type
Land Form
Dominant Land Use
Irrigated horticulture in greenhouses
Active steep dunes
Irrigated horticulture in tunnels and open fields
Arenosolic Rhegosols
Undulating stabilized dunes
El Mawasy rainfed vegetables/fruit
Calcareous ridges
Rainfed grapes
Calcaric Arenosols
Flat/rolling interdune areas
Open horticulture, tunnels
Dates
Flat/rolling plains
Citrus plantation
Arenosolic Calcaric Soils
or depressions
Some irrigated vegetables, fieldcrops
Calcaric Soils
Rolling plains
Citrus plantations
Rainfed fieldcrops
Arenosolic Calcaric over Calcaric Soils Gently rolling plains
Almonds, olives
Some irrigated vegetables
Citrus orchards
Ancient alluvial valleys
Luvisols, Xerosols
Rainfed fieldcrops
Depressions and slopes
Non-rainfed vegetables
Fluvisols (Alluvial) and Vertisols (Grumosolic), dominated by loamy clay textures are found
on the slopes of the northern depressions between Beit Hanoun and Wadi Gaza. Borings east
of El Montar ridge have revealed that alluvial deposits of about 25 m in thickness occur. At
some depth, calcareous concentrations are present. The CaCO3 content can be approximately
15 – 20%. Some of the soils have been strongly eroded and the reddish brown subsoils may be
exposed on top of ridges and along the slopes. The alluvial sediments are underlain by a
calcareous layer.
Sampling and Sample Preparation
The soil sampling campaigns were conducted according to the European soil sampling
guidelines (Theocharopoulos et al., 2001). The criteria for the sampling area, specific site, and
point selection were mainly based on pedology, land use and geology. The depth of sampling
varied between 0-10 cm for the open and grass soils; 20 cm for the vegetable soils; and up to
30 cm for the ploughed soils.
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Chapter Six
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___________________________________________________________________________________________
One hundred seventy soil samples were collected in October/November 2001, April/May
2002, and January/February 2003: 35 samples from the green houses (vegetables) of three
different geographic areas, 25 from fruit farms (olive, peach, guava), 25 from citrus farms of
northern and southern areas, 20 from open vegetable farms, 15 from strawberry farms, 20 from
the vegetable farms near wastewater treatment plants, 20 from the vegetable farms near solid
waste dumping sites and 10 from non-agricultural isolated areas representing local reference
sites.
At each sampling station, a circle of 2-5-m diameter was identified and 10 sub-samples were
collected within the perimeter and mixed to form a composite sample. Samples (0.5 kg) were
collected and placed into polyethylene cups and stored at 4 oC. The soils were dried in an oven
at 45 oC until constant weight. They were then shipped to Germany in plastic sample bags.
Analyses
Samples were freeze-dried until complete drynessm and sieved through a 2-mm sieve and
ground to a powder by using a ring mill (FRITSCH-Labor Planeten Mühle, pulverisette 5).
Approximately 0.5 to 1.0 g of each homogenized sample was dissolved in 10.5 ml of
concentrated HCl (37% p.a.) and 3.5 ml of concentrated HNO3 (65% p.a.) in 50 ml retorts.
The samples were degassed (12 h) then heated to 160 °C on a sand bath until a complete
extraction had taken place (3 h). After cooling, the solutions were diluted with distilled water
in 50 ml volumetric flasks and kept in 100 ml polyethylene bottles for analysis.
Samples were analyzed by ICP/OES (VISTA-MPX, VARIAN) for alkali and alkaline-earth
elements Mg, Li, Ca, K, and Na, heavy metals Cu, Zn, Ni, Pb, Mn, Fe, Cr, Co, Cd, and the
metalloid As. Energy-dispersive miniprobe multielement analyzer-X-ray fluorescence
(EMMA-XRF) was used for K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, Pb,
Th and U (Cheburkin and Shotyk, 1996). The distribution of total P represented as (PO4) was
measured according to APHA (1995). Mercury concentrations were determined using atomic
absorption spectroscopy after thermal combustion of the freeze dried samples (50-100 mg) by
an advanced mercury analyzer (AMA) 254 solid phase Hg-Analyzer (LECO). The total C and
S contents were determined in dried samples by using a Carbon-Sulfur Determinator (Leco
CS-225). Carbonates were measured via a carbonate bomb (Müller and Gastner, 1971). The
TOC was calculated by the subtraction of inorganic C from total C.
The adsorbable organic halogens (AOX) were determined using a Euroglas Organic Halogen
Analyzer. Analytical procedures DIN 38414 S18 followed that in the "Deutsche
Einheitsverfahren zur Wasser, Abwasser und Schlammuntersuchung, Sludge and Sediment
(Group S) Determination of AOX" (DIN, 1989). The AOX in soil was analyzed according to
Asplund et al., (1994). Ten to 50 mg milled soil sample was added to an acidic nitrate solution
(20 ml, 0.2 M KNO3, 0.02 M HNO3) and shaken on a rotary shaker (200 rpm) for at least 1 h.
The suspension was filtered through a 0.45 m polycarbonate filter. The filter with the filter
cake were then combusted under a stream of O2 at 1000 °C in an Euroglas AOX-analyser
(model 1200) in which the formed hydrogen halides were determined by microcoulombmetric
titration with Ag ions. Each sample was analyzed in duplicate. Blanks were analyzed
according to the same procedure but without addition of soil.
85
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Quality control
Analytical blanks and two Standard Reference Materials with known concentrations of heavy
metals were prepared and analyzed using the same procedures and reagents (Avila-Perez et al.,
1999). Precision for the results of soil samples was estimated using the reproducibility
between the duplicates, and a coefficient of variation of less than 5% was found. The accuracy
was evaluated using 20 aliquots of two River Sediment Standard Reference Materials-RS1 and
RS3-Deutsche Industrie Norm (DIN, 1997, 1989). Geochemical reference materials were also
analyzed by EMMA techniques. A deviation of less than 5% from the certified values was
found. The coefficient of variation for triplicates (2 samples and one standard) was less than
2% for all parameters except for Cd which had a coefficient of variation higher than 6%. The
difference between the Standard Reference Materials (RS1 and RS3) supplied by DIN was
used to estimate the accuracy of the analytical method (ICP/OES) and the data accuracy rates
came within: CaCO3 0.9%, Mg 0.44%, Ca 1.05%, Cu 0.7%, Zn 0.72%, Ni 0.77%, Pb 0.65%,
Mn 0.73%, Fe 0.67%, Cr 1.26%, Cd 6.7% and As 0.66%. The accuracy rates with EMMA
were: Cu 1.1%, Zn, Ni, Pb, Mn and Cd1%, and As, Fe, Cr 0.9%.
Fertilizers and Fungicides
Samples of commonly used fertilizers and fungicides were collected from private stores in
Gaza. They were freeze-dried and ground to powder. Fertilizer and fungicide samples were
measured using EMMA-XRF for K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr and Pb.
The analyzer used monochromatic excitation with an energy of 19.6 keV. The software
includes a possibility to normalize the peak area of each element by the intensity of incoherent
scattering radiation. This feature allows the elimination of the matrix effect for samples with a
different matrix. However, with the extremely wide range of matrices for fungicide samples
even such normalizing does not work well. Several fungicide samples have a very heavy
matrix due to the presence of high concentration of Mn, Cu, Zn and Br.
The EMMA-XRF analyzer was calibrated using different Standard Reference Materials.
The analytical data for trace elements in the fungicides are semi-quantitative and may have a
relative error up to 30%. As the results of the EMMA-XRF were semi-quantitative, a
quantitative determination was carried out after a full digestion procedure by using the
ICP/OES (VISTA-MPX, VARIAN) instrument for analyzing Al, Ba, Cd, Co, Cr, Cu, Fe, Mn,
Ni, Pb, Sc, Sr and Zn. The detection limit of the ICP/OES was estimated as 10% less than the
lowest measurable standard used for calibration.
RESULTS
Due to the large data set obtained from the analysis of 170 soil samples, each having 26
parameters, this section will cover mostly elements that are environmentally significant in
Gaza. Mercury was detected in 56 samples while Sb was only detected in 8 of them. The
levels of Ti, Br, Rb, Sr, Y and Zr were low to very low and consequently data from these
elements are not presented in Table 2. The statistical median of similar soils was considered
and 11 soil categories were used to represent all samples (Table 2).
86
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Among a total of 27 elements analyzed, only a few trace elements showed environmental
relevance in Gaza: As, Cd, Cr, Hg and to a lesser extent Pb. The trace metal accumulations in
the soils affected by sludge were characterized by a large spatial variability, with some ‘hot
spots’ of Cu and Zn with concentrations of up to 45, 1800 mg/kg, respectively (Shomar et al.,
2004a).
Non-parametric Spearman correlation coefficient was calculated for the raw data of 170 soil
samples and the results are presented in Table 3.
Fertilizers are expected to be another source of trace elements apart from the natural
occurrence. Table 4 shows the contents of some trace metals in selected commercial fertilizers
commonly used in the Gaza Strip. The results of Ni, As, Se, Rb, Y and Zr were below the
detection limit of the analytical procedure and, consequently they are not included in Table 4.
Table 5 shows examples of the fungicides used in Gaza and their content of trace metals.
87
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Table (2) Concentrations of Trace Metals and Other Elements in Selected Soils of the Gaza Strip
C
AOX
P
Mg
Ca
Na
Fe
Mn
Cr
Soil taken from
%
mg/kg g/kg mg/kg
%
mg/kg
%
mg/kg mg/kg
DL* 0.05
0.5
0.001
0.01
0.01
0.01
0.01
0.01
1
Reference areas (n=10)
Minimum
0.2
<0.5
0.1
260
0.3
89
0.2
30
2.0
Maximum
0.4
<0.5
0.2
560
2.0
115
0.7
44
5.4
Mean
0.3
<0.5
0.2
346
0.9
107
0.3
37
2.8
Median
0.2
<0.5
0.1
330
0.7
110
0.2
37
2.4
St. dev. (s)
0.1
0.0
0.0
82
0.5
9
0.1
5
1.0
Citrus farms (1) (n=12)
Minimum
0.9
7.0
0.4
699
1.6
360
0.3
96
17
Maximum
2.9
10.0
1.3
11093
7.1
792
2.0
420
130
Mean
2.0
8.2
0.8
2273
3.0
524
1.4
319
85
Median
2.0
8.0
0.9
1530
2.9
497
1.3
349
97
St. dev. (s)
0.6
1.1
0.3
2601
1.4
110
0.6
88
32
Citrus farms (2) (n=13)
Minimum
0.7
6.0
0.2
1100
1.2
105
0.5
74
12
Maximum
2.2
11.0
1.2
3128
3.1
473
2.0
393
130
Mean
1.4
7.7
0.7
1679
2.3
260
1.0
189
66
Median
1.3
7.0
0.6
1760
2.5
240
0.9
188
65
St. dev. (s)
0.5
1.5
0.3
634
0.6
133
0.5
94
46
Greenhouses (1) (n=12)
Minimum
2.2
4.0
0.1
677
1.9
119
0.4
165
10
Maximum
2.5
8.0
2.0
3903
4.4
765
1.3
289
110
Mean
2.4
5.3
0.8
2204
2.9
321
0.9
238
54
Median
2.4
5.0
0.5
2030
3.0
206
1
256
65
St. dev. (s)
0.1
1.2
0.7
1126
0.6
244
0.3
44
29
Greenhouses (2) (n=13)
Minimum
1.7
5.0
0.3
324
2.4
222
0.3
132
12
Maximum
2.4
14.0
2.9
4562
4.6
765
1.5
198
72
Mean
2.2
10.8
1.2
1848
3.0
394
0.9
162
49
Median
2.3
12.0
0.8
1800
2.7
366
1.0
160
60
St. dev. (s)
0.2
2.4
0.8
1150
0.6
169
0.4
22
23
88
Cd
µg/kg
10
Pb
mg/kg
10
Ni
mg/kg
2
Cu
mg/kg
5
Zn
mg/kg
1
Co
mg/kg
2
Hg
µg/kg
2
As
mg/kg
1
<10
15
<10
<10
6
<10
<10
<10
<10
0.3
<2
4.1
2.3
<2
1.0
<5
11.3
5.0
<5
3.4
3.2
8.8
5.3
5.0
1.9
<2
3.4
1.9
<2
0.9
<5
<5
<5
<5
0.0
<1
<1
<1
<1
0.4
<10
105
43
43
23
<10
23.0
18.8
19.5
3.4
2
23
7
6
5
15
50
35
40
10
3.0
67.4
39.1
40.0
14.5
2.0
16.9
7.5
6.3
4.6
3.2
10.3
6.4
6.1
2.0
1.2
4.1
3.0
3.0
0.7
<10
220
83
70
73
<10
22
14
14
4
3
23
11
7
6
5
28
16
19
7
18
72
44
46
17
3.3
16.9
7.5
5.0
5.1
<5
10.3
7.2
7.0
1.9
<1
3.9
2.1
2.4
1.3
<10
432
119
49
146
<10
20
14
17
6
<2
12
6
5
3
5
25
17
19
6
7
76
29
19
25
<2
9.4
5.2
5.7
3.4
<5
21
7
8
5
<1
12
4
5
4
<10
187
53
46
52
11
20
15
15
3
6
12
9
9
2
8
17
12
13
2
11
78
43
47
22
<2
9.4
3.9
3.0
2.4
8
14
10
10
2
5
12
8
8
2
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Table (2) Continued.
Soil taken from
DL*
Greenhouses (3) (n=10)
Minimum
Maximum
Mean
Median
St. dev. (s)
Strawberry farm (n=15)
Minimum
Maximum
Mean
Median
St. dev. (s)
Open farms (n=20)
Minimum
Maximum
Mean
Median
St. dev. (s)
Fruit farms (n=25)
Minimum
Maximum
Mean
Median
St. dev. (s)
Nearby WWTP (n=20)
Minimum
Maximum
Mean
Median
St. dev. (s)
C
%
0.05
AOX
mg/kg
0.5
0.001
Mg
mg/kg
0.01
Ca
%
0.01
Na
mg/kg
0.01
Fe
%
0.01
Mn
mg/kg
0.01
Cr
mg/kg
1
Cd
µg/kg
10
Pb
mg/kg
10
Ni
mg/kg
2
Cu
mg/kg
5
Zn
mg/kg
1
Co
mg/kg
2
Hg
µg/kg
2
As
mg/kg
1
1.7
2.9
2.3
2.4
0.4
5.0
13.0
8.3
9.0
2.7
0.5
2.1
1.1
1.1
0.5
422
13958
3434
2211
3271
2.2
7.0
4.0
3.7
1.7
156
888
580
588
204
0.6
2.9
1.5
1.3
0.7
309
598
474
518
90
32
130
86
80
29
<10
227
80
58
73
<10
57
25
21
14
5
81
22
12
24
8
23
16
17
3
4
90
50
52
27
3
11
5
5
2
4
12
8
9
2
<1
9
3
3
3
0.5
4.0
2.4
2.3
0.95
15
350
115
23
126
0.3
0.9
0.6
0.6
0.19
795
6771
3287
3225
2085
0.1
5.5
3.8
4.3
1.6
50
351
194
189
75
0.2
1.0
0.6
0.4
0.29
42
210
126
106
59
5
274
133
120
102
<10
67
26
16
29
<10
200
61
14
82
2
33
14
7
12
6
59
25
18
18
4
60
30
18
22
<2
10
3
3
3
6
33
15
10
10
<1
14
5
4
4
0.7
2.9
1.8
1.8
0.7
4.0
7.0
5.6
5.5
0.8
0.3
1.3
0.9
1.1
0.3
1633
13958
3118
2075
2710
1.3
7.0
3.9
3.2
1.8
156
887
404
347
225
0.5
2.9
2.2
2.6
0.8
140
531
430
505
136
5
130
83
120
54
<10
177
52
57
43
<10
57
30
29
17
4
88
57
80
31
5
23
12
13
3
14
71
50
60
17
2
11
4
3
2
5
14
9
10
2
<1
4
1
1
1
0.8
21.0
1.9
2.01
0.5
12
21
15
15
2
0.2
1.2
0.6
0.6
0.2
213
8389
4470
5789
2693
0.8
920
4.0
3.8
2.1
119
920
537
564
190
0.3
410
1.5
1.7
0.6
110
410
307
301
70
5
472
61
84
46
<10
472
256
360
212
<10
170
82
130
62
<2
170
70
16
65
<5
187
10
11
5
4
187
111
165
75
<2
28
8
10
3
<2
28
17
21
9
<1
18
10
12
6
0.2
4.0
2.3
3.0
1.1
33
410
225
250
110
0.1
1.5
0.6
0.6
0.4
212
4913
2318
2108
1363
0.1
3.4
2.0
2.7
1.3
50
765
370
350
225
0.2
1.7
0.7
0.4
0.5
26
239
117
106
65
5
278
193
260
112
<10
1495
236
33
465
<10
210
110
114
84
<2
40
25
30
11
5
59
36
40
13
10
300
70
31
89
<2
13
7
9
3
<2
42
24
30
13
<1
15
8
11
5
P g/kg
89
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Table (2) Continued.
Soil taken from
C
%
0.05
AOX
mg/kg
0.5
DL*
Nearby SWDS (n=20)
Minimum
0.3
33
Maximum
3.2
356
Mean
2.3
175
Median
3.0
178
St. dev. (s)
0.9
105
*) DL: detection limit
WWTP: Wastewater Treatment Plant
SWDS: Solid Waste Dumping Site
P
g/kg
0.001
Mg
mg/kg
0.01
Ca
%
0.01
Na
mg/kg
0.01
Fe
%
0.01
Mn
mg/kg
0.01
Cr
mg/kg
1
Cd
µg/kg
10
Pb
mg/kg
10
Ni
mg/kg
2
Cu
mg/kg
5
Zn
mg/kg
1
Co
mg/kg
2
Hg
µg/kg
2
As
mg/kg
1
0.6
8.0
1.2
0.9
1.6
213
6914
2910
2395
1636
0.8
3.5
2.7
3.1
0.8
50
765
341
372
207
0.1
1.7
0.5
0.2
0.6
26
239
83
41
68
2
280
168
244
119
22
66
41
41
8
146
210
185
186
17
<2
35
21
26
9
<5
50
38
44
13
28
190
149
172
44
2
11
7
8
2
27
36
31
32
2
<1
19
10
12
4
90
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Table (3) Spearman Correlation Coefficient, N= 170.
C%
AOX
P
Mg
Ca
mg/kg g/Kg mg/kg %
C
Cor. Coef.
1.00
0.29
0.31 0.17 0.31
Sig. (2-tailed)
0.00
0.00 0.02 0.00
AOX Cor. Coef.
0.29
1.00
0.07 0.30 0.11
Sig. (2-tailed) 0.00
0.34 0.00 0.13
P
Cor. Coef.
0.31
0.07
1.00 0.06 0.13
Sig. (2-tailed) 0.00
0.34
0.40 0.07
Mg Cor. Coef.
0.17
0.30
0.06 1.00 0.33
Sig. (2-tailed) 0.02
0.00
0.40
0.00
Ca Cor. Coef.
0.31
0.11
0.13 0.33 1.00
Sig. (2-tailed) 0.00
0.13
0.07 0.00
Na Cor. Coef.
0.23
0.07
0.27 0.17 0.19
Sig. (2-tailed) 0.00
0.30
0.00 0.02 0.01
Fe Cor. Coef.
-0.02
-0.25
0.11 0.24 0.18
Sig. (2-tailed) 0.78
0.00
0.13 0.00 0.01
Mn Cor. Coef.
0.05
-0.33
0.21 0.18 0.27
Sig. (2-tailed) 0.47
0.00
0.00 0.01 0.00
Cr Cor. Coef.
0.26
0.41
0.14 0.20 0.18
Sig. (2-tailed) 0.00
0.00
0.05 0.00 0.01
Cd Cor. Coef.
0.00
0.00
0.11 0.06 0.05
Sig. (2-tailed) 0.90
0.91
0.14 0.43 0.46
Pb Cor. Coef.
0.41
0.42
0.27 0.17 0.07
Sig. (2-tailed) 0.00
0.00
0.00 0.02 0.31
Ni Cor. Coef.
0.18
0.30
0.23 0.20 0.19
Sig. (2-tailed) 0.01
0.00
0.00 0.00 0.01
Cu Cor. Coef.
0.31
0.41
0.18 0.07 0.00
Sig. (2-tailed) 0.00
0.00
0.01 0.36 0.97
Zn Cor. Coef.
0.14
0.32
0.25 0.18 0.05
Sig. (2-tailed) 0.06
0.00
0.00 0.01 0.49
Co Cor. Coef.
0.16
0.32
0.09 0.17 0.04
Sig. (2-tailed) 0.03
0.00
0.20 0.02 0.54
Hg Cor. Coef.
0.31
0.56
0.25 0.26 0.14
Sig. (2-tailed) 0.00
0.00
0.00 0.00 0.05
As Cor. Coef.
0.29
0.50
0.12 0.13 0.11
Sig. (2-tailed) 0.00
0.00
0.12 0.07 0.15
Na
mg/kg
0.23
0.00
0.07
0.30
0.27
0.00
0.17
0.02
0.19
0.01
1.00
0.50
0.00
0.48
0.00
0.14
0.06
0.23
0.00
0.31
0.00
0.29
0.00
0.07
0.35
0.31
0.00
0.33
0.00
0.22
0.00
0.20
0.00
Fe
%
-0.02
0.78
-0.25
0.00
0.11
0.13
0.24
0.00
0.18
0.01
0.50
0.00
1.00
0.81
0.00
0.03
0.69
0.22
0.00
0.08
0.27
0.22
0.00
-0.13
0.08
0.10
0.16
0.20
0.00
0.01
0.86
-0.11
0.15
Mn
mg/kg
0.05
0.47
-0.33
0.00
0.21
0.00
0.18
0.01
0.27
0.00
0.48
0.00
0.81
0.00
1.00
0.01
0.82
0.29
0.00
-0.01
0.87
0.19
0.01
-0.15
0.04
0.09
0.24
0.13
0.07
-0.09
0.24
-0.14
0.05
Cr
Cd
Pb
Ni
Cu
Zn
Co
Hg
As
mg/kg µg/kg mg/kg mg/kg mg/kg mg/kg mg/kg µg/kg mg/kg
0.26 0.00 0.41 0.18 0.31 0.14 0.16 0.31 0.29
0.00 0.90 0.00 0.01 0.00 0.06 0.03 0.00 0.00
0.41 -0.00 0.42 0.30 0.41 0.32 0.32 0.56 0.50
0.00 0.91 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0.14 0.11 0.27 0.23 0.18 0.25 0.09 0.25 0.12
0.05 0.14 0.00 0.00 0.01 0.00 0.20 0.00 0.12
0.20 0.06 0.17 0.20 0.07 0.18 0.178 0.26 0.13
0.00 0.43 0.02 0.00 0.36 0.01 0.02 0.00 0.07
0.18 0.05 0.07 0.19 -0.00 0.05 0.04 0.14 0.11
0.01 0.46 0.31 0.01 0.97 0.49 0.54 0.05 0.15
0.14 0.23 0.31 0.29 0.07 0.31 0.33 0.22 0.20
0.06 0.00 0.00 0.00 0.35 0.00 0.00 0.00 0.00
0.03 0.22 0.08 0.22 -0.13 0.10 0.20 0.01 -0.11
0.69 0.00 0.27 0.00 0.08 0.16 0.00 0.86 0.15
0.01 0.29 -0.01 0.19 -0.15 0.09 0.13 -0.09 -0.14
0.82 0.00 0.87 0.01 0.04 0.24 0.07 0.24 0.05
1.00 0.11 0.27 0.22 0.32 0.21 0.12 0.26 0.07
0.14 0.00 0.00 0.00 0.00 0.10 0.00 0.35
0.11 1.00 0.10 0.26 -0.08 0.74 0.14 0.07 0.19
0.14
0.17 0.00 0.29 0.00 0.06 0.31 0.01
0.27 0.10 1.00 0.42 0.30 0.43 0.37 0.53 0.35
0.00 0.17
0.00 0.00 0.00 0.00 0.00 0.00
0.22 0.26 0.42 1.00 0.00 0.50 0.28 0.45 0.28
0.00 0.00 0.00
0.99 0.00 0.00 0.00 0.00
0.32 -0.08 0.30 0.00 1.00 0.11 0.16 0.27 0.22
0.00 0.29 0.00 0.99
0.15 0.03 0.00 0.00
0.21 0.74 0.43 0.50 0.11 1.00 0.28 0.42 0.40
0.00 0.00 0.00 0.00 0.15
0.00 0.00 0.00
0.12 0.14 0.37 0.28 0.16 0.28 1.00 0.25 0.28
0.10 0.06 0.00 0.00 0.03 0.00
0.00 0.00
0.26 0.07 0.53 0.45 0.27 0.42 0.25 1.00 0.49
0.00 0.31 0.00 0.00 0.00 0.00 0.00
0.00
0.07 0.19 0.35 0.28 0.22 0.40 0.28 0.49 1.00
0.35 0.01 0.00 0.00 0.00 0.00 0.00 0.00
91
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Table (4) Chemistry of Selected Commercial Fertilizers Used in the Gaza Strip
K
Ca
Ti
Cr
Mn
Fe
Cu
Zn
(%)
(%) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)
DL*
0.05
0.05
30
20
10
10
1.5
1
Gibberellic acid
<0.05 <0.05 <30
<20
13
25
<1.5
11
<0.05 <30
<20
Fe-EDDHA
5
<10
58028
4
24
<20
NO2, Fe, Mn
>10% <0.05 <30
140
360
27
45
<1
Thiabendazole
<0.05
1
1142 <20
45
10475 <1.5
<0.05
<30
<1.5
<1
Clindune
4
7794
<10
204
<20
Cu, Fe fertilizer
<0.05 <0.05 <30
19987 47890 10583 4999
<20
N+P2O5+KO
>10%
3
44
387
949
21
16
*) DL: detection limit
Table (5) Chemistry of Selected Commercial Fungicides Used in the Gaza Strip
K
Ca
Ti
Mn
Fe
Cu
Zn
Br
Fungicide
%
%
ppm
ppm
ppm
ppm
ppm
ppm
Benony
<0.05 <0.05
<1
<0.7
<30
23
22
7
Fosethyl Aluminum
<0.05 <0.05
<1.5
<0.7
388
<10
642
7
Chlor thalonil
<0.05
<1.5
1.0
425
76
1327
6
3
Propineb
<0.05 <0.05 <30
884
3768 <1.5
>10%
260
Mncozeb
<0.05 <0.05 <30
<1.5
>10%
<10
17500 <0.7
Maneb
<0.05
2.0
10911 19980 11474
23
923
6
Manganes
<0.05
<1.5
4.0
<30
>10%
<10
1875 <0.7
Foscthyl-Aluminum
<0.05 <0.05
<10
<1.5
440
843
8
3
Copper Chloride
<0.05 <0.05 <30
<10
<1
<0.7
4000 >10%
Cyger Sulfate
<0.05 <0.05 <30
<10
<1
<0.7
5977 >10%
Metalaxyl
<0.05 <0.05 <30
<1.5
>10%
<10
20927
73
Simzin
<0.05 >10% <30
<1.5
<10
116
<1
10
Captan
<0.05 <0.05 2155
16
3072
306
14
72
Mineozab
<0.05 <0.05
<1.5
<30
>10% <10
10288 <0.7
Br
(ppm)
0.7
<0.7
<0.7
19
45
38
11
6
Rb
ppm
<0.7
8
37
18
<0.7
20
<0.7
7
<0.7
<0.7
12
<0.7
22
<0.7
Rb
(ppm)
0.7
<0.7
8
19
4
18
<0.7
11
Sr
ppm
<0.8
3
127
<0.8
<0.8
322
56
4
<0.8
<0.8
<0.8
70
20
<0.8
Sr
(ppm)
0.8
<0.8
2
<0.8
5
4
18
2079
Pb
(ppm)
0.6
<0.6
<0.6
<0.6
<0.6
<0.6
9
<0.6
Pb
ppm
<0.6
5
18
<0.6
<0.6
17
<0.6
8
<0.6
<0.6
<0.6
11
30
<0.6
Adsorbable Organic Halogens (AOX)
The AOX in the soils of Gaza was very low and it ranged between the detection limit (0.5) and
20 mgCl/kg. A few sites showed high AOX values of 250 mgCl/kg due to their location near
the sludge disposal areas and solid waste dumping sites.
Phosphorus, Carbon and Sulfur
The total P concentration in the top soil varies between about 0.4 and 1.2 gP/kg which is
suitable for agricultural purposes.
Total C in soils of the Gaza Strip was between 0.5-3%. The lowest percentage of S in the soils
of the Gaza Strip was 0.016% while the highest was 0.07%. It is important to mention that the
irrigation water in the southern areas of the Gaza Strip has high contents of SO4 (380 mg/L)
and this leads to more soil acidity (Shomar et al., 2004b).
92
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
CaCO3, Ca, Mg, Na and K
The results showed great variation (1.6-19%) of CaCO3 contents in soils of Gaza. Calcium in
the tested soils was between 0.7 and 5.4%. Several of the residual soils in Gaza are relatively
low in Mg (0.03%). Sodium contents in soils were 110-825 mg/kg. The high Na content of
household products for laundry, kitchen, bath and cleaning are a primary source of Na in soil.
Addition of water softener wastes or the Na content in the local water supply also contributes
to the problem. Soils showed suitable amounts of K with respect to agricultural requirements.
The lowest and the highest K averages were 330 and 4500 mg/kg, respectively.
Fe and Mn
The contents of Fe in the soils of Gaza ranging between 0.2 and 2% were less than the value
listed by Turekian and Wedepohl (1961) of 4.72% in the upper crust. The highest Fe levels
were found in the middle area and Khan Yunis. Manganese showed a similar trend to Fe.
Generally, Mn levels were low and the range was between 37 to 542 mg/kg. The correlations
between Fe and Mn for the same soil types showed that both had the same source and
behaviour (r =0.9).
Cu, Zn, Cd, Ni, Pb, Cr, Co, As, and Hg
The median of Cu in soils of the Gaza Strip was 10 mg/kg. The highest (45 mg/kg) was found
in the greenhouses and the lowest (2 mg/kg) in the open sandy farms. Zinc seems to be
distributed uniformly. The lowest Zn (2 mg/kg) was found in the local reference samples, with
the highest (1800 mg/kg) being found in the soils exposed directly to domestic sludge. The Cd
unit in µg/kg reflects its low level in soils. More than 75% of the soil samples showed results
below the detection limit (10 µg/kg). Several greenhouses had 430 µg/kg of Cd in their soils.
One site beside the wastewater treatment plant showed a level of 1500 µgCd/kg. The
correlation coefficients between Zn and Cd in the different soils was 0.85 for the soils of the
greenhouses of the southern regions, while it was only 0.53 for the northern regions.
Nickel was low with an average of 28 mg/kg and no significant difference was found in the Ni
levels of each area. Only one guava farm showed a high level of Pb (145 mg/kg) while the rest
of the soils showed an average of 30 mg/kg. The correlation between Pb and organic C was
good (r =0.8). This could explain the behavior of Pb in the clay soils as it attaches to the
organic matter. An anomalous result for Cr (472 mg/kg) was found in the area of Beit Hanoun.
The site was 10 m from the industrial estate. The same soil from Beit Hanoun showed Co to be
29 mg/kg, while the average for all soils was 6 mg/kg. The average of As was 2.2 mg/kg,
while the site near the solid waste dumping site reached 19 mg/kg. Finally, the average of Hg
in the soils of Gaza was 10 µg/kg with many samples being below the detection limit of the
analytical method.
93
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
DISCUSSION
The Palestinian environmental strategy (MEnA, 2000) has established that several threats
cause the deterioration of soil quality in the Gaza Strip. Accumulation of solid and hazardous
wastes, discharge of untreated wastewater, extensive use of fertilizers and fungicides,
overgrazing, soil salinization, urbanization, vegetation removal, and soil erosion are examples
of these threats. The agricultural areas are exposed to one or more of these threats.
The average contents of AOX in the sludge of Gaza was (550 mgCl/kg), which exceeds the
standards of industrial countries (Shomar et al., 2004a). In spite of that the AOX in the tested
soils was very low and the highest was 24 mgCl/kg. Moreover, the presence of AOX in soil
may be due to the effect of living organisms during natural abiogenic processes (Müller,
2003).
The results revealed that the occurrence of trace metals in the different soils of the Gaza Strip
was dependent not only on the soil type but also on the location of the soil, the vegetation
cover and the agricultural activities. It showed that the levels of trace metals of the soils
planted with the same crop were similar when the soil type, the irrigation water and the
fertilizers used were the same. Five soils from open lands in the different geographic regions
of the Gaza Strip were almost the same.
Soils covered by wastewater during some of the flooding episodes of the winter season
showed high contents of trace elements. The owners used them for agricultural purposes for
the rest of the year and insufficient care was taken to avoid contamination. Moreover, these
soils were found to have Zn and Cu enrichments and this may be due to recycling by
microorganisms (Blaser et al., 2000).
The soils exposed to the solid wastes showed high levels of trace metals. The wastes were
disposed to the tested soils for long periods before they were transferred to the central
dumping site. During the period of accumulation of the solid wastes, leachates may percolate
through soil increasing levels of trace metals.
The greenhouses showed a clear variation in the contents of trace metals. The field surveys
indicated that the average age of a greenhouse in Gaza is 5 years. They are used for vegetables
such as tomatoes, cucumber, eggplants and others; with some exceptions in the area of Beit
Lahia (North) where flowers and strawberries are planted beside the vegetables. The farmers
use large amounts of fertilizers and fungicides. More than 200-250 t of formulated fungicides
are applied annually in the Gaza Strip (Safi, 2002) and the majority is used in the greenhouses
without monitoring. The analyses of trace metals in the most common fertilizers and
fungicides revealed that they contain considerable amounts of several metals such as Fe, Mn,
Cu, Zn and Cr and as a consequence these elements may increase in the soils of the
greenhouses. The greenhouses of the Khan Yunis area showed higher levels of several trace
metals and other elements. Fe, Zn, Cu, Ni, Pb, and Cr were higher than those in the
greenhouses of the north area of Beit Lahia being 12.4%, 84, 17, 10, 19 and 74 mg/kg,
respectively. The reason of variation could be the soil structure where it is sandy in the north
and clay in Khan Yunis (South). In addition, the soil of Khan Yunis is affected by traffic
contamination. The greenhouses of Khan Yunis were 10 m away from the main highway of
Gaza. These results agree with findings from other authors (Manta et al., 2002; Navas and
Machin, 2002; Fakayode and Owolabi, 2003).
94
Chapter Six
Geochemical Features of Topsoils in the Gaza Strip
___________________________________________________________________________________________
Variations in the amounts of rainfall strongly influence the crops grown in Gaza. The
groundwater quality deteriorates from north (Cl = 40 mg/L) to south (Cl = 3000 mg/L)
(Shomar et al., 2004b). Consequently, strawberries and flowers are planted only in Beit Lahia
while rain fed agriculture is located in the south eastern parts of Gaza. Presence of
considerable amounts of CaCO3 in soils because potential evapo-transpiration exceeds the
rainfall in Gaza. On the other hand, in soils with a higher rate of precipitation in the north area,
which leads to a higher rate of percolation, carbonates are easily dissolved and leached out.
The amount and particle size of CaCO3 minerals can increase the precipitation of calcium
phosphate minerals on the surface (Sparks, 1995). This could explain the low levels of P in the
north areas of Gaza where soils are sandy and the annual precipitation is higher than in the
southern clay soils. In addition, high P levels were found in the greenhouses where Pfertilizers were commonly used. It is assumed that in neutral and calcareous soils of Gaza,
inorganic P in the soil solution precipitates as calcium phosphate minerals. The low contents
of Ca in several soils of Gaza could be explained as a result of soil erosion, urbanization and
vegetation removal (Sparks, 1995).
CONCLUSIONS
1. The soil types, crop patterns, and specific location factors largely control the distribution of
trace metals (Pb, Cu, Zn, Cd and Mn) in soils. Linear regression analysis found a correlation
coefficient of r =0.85 between Zn and Cd concentrations in soils and the presence of highways
nearby.
2. The irrigation water, the applied fertilizers and fungicides, and the sludge and wastewater
nearby have played a major role and contributed significantly the enrichment of several soils
with Zn, Pb, Cu and Fe. Affected soils by sludge, solid wastes and wastewater showed similar
contents of trace metals.
3. With respect to the global comparison, it may be noted that the values for the trace metals in
the different soils of the Gaza Strip were well within the worldwide soil average values. These
levels were still low and probably harmless to the soil ecosystem. However, the distribution
pattern for Zn, Cd, and Cu in several soils clearly indicated that their contamination due to
anthropogenic factors were on the rise and may become alarming if mitigation measures are
not taken.
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CHAPTER SEVEN
Monitoring of pesticides in the groundwater and the topsoil of the
Gaza Strip (*)
ABSTRACT
Agricultural activities in the Gaza Strip have associated with excessive and
uncontrolled use of dozens of pesticides. Accordingly, groundwater and soil are
potentially contaminated causing severe threat to the crowded population. The present
study describes in a 3-year monitoring program types and level of contamination by
various pesticides used in Gaza. Two analytical instruments (GC/MS and HPLC/MS)
were applied to achieve this objective.
More than 92% of targeted pesticides in groundwater were much lower than their
allowable limit of the World Health Organization. However, the municipal
groundwater wells showed better quality as they are located in the residential areas
than the private wells in the agricultural regions. Atrazine, atrazine-desisopropyl,
propazine, simazine were detected in water samples with average concentrations of
3.5, 1.2, 1.5 and 2.3 µg/l, respectively. A linear correlation was found between the
chloride concentrations in groundwater and atrazine for the same geographic areas.
Generally speaking, shallow aquifers of low annual precipitation in the southern areas
of Gaza showed detectable concentrations of pesticides. In soil, pesticides presence
was found to depend on type of soils. Clay soils for instance, showed 3-4 times more
than sandy soils for the same pesticide species.
A linear regression analysis found a correlation coefficient of r = 0.87 between the
strawberry greenhouses and the occurrence of propazine, sebutylazine, terbutylazine,
4,4’-DDT, 4,4’-DDE, and 4,4’-DDD in soil. The averages of propazine, sebutylazine
and terbutylazine were 19, 13 and 39 µg/kg, respectively. One soil sample showed
contents of 4,4'-DDE and 4,4'-DDT up to 1104 and 793 µg/kg , respectively.
Key words: Gaza, Groundwater, Pesticides, Soil.
_________________________________________________________________________________
(*) The study was submitted to an International Journal.
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INTRODUCTION
Pesticides are considered priority pollutants in Gaza and, with the expanding use of
greenhouses; Palestinian agriculture is becoming increasingly dependent on chemical
pesticides and fertilizers. According to Safi (2002), Gaza Strip consumed more than
393.3 t of pesticides in 1999. Pesticides are often misused by the non-professional,
inexperienced farmers, who do not take into consideration the "safe period", which is
identified as the period between spraying and gathering of crops, specified according
to the type of pesticide (Abu Middain, 1994). Pesticides affect humans, either
immediately or in the long run (Carbonell et al., 1995; Bain and LeBlanc, 1996; Ribas
et al., 1997; Richer and Safi, 1997). As an example, methyl bromide, which is used
extensively in Gaza, causes fetus deformations, eye infections and dermatitis (Safi,
2002). Organochlorine pesticides used in Gaza cause breast cancer (Aronson et al.,
2000). Another study conducted by Safi (2002) showed that heavy misuse of
pesticides in the Gaza environment correlated with the growing incidence of cancer.
It is ironic that pesticides that are banned or restricted in many countries are being
marketed and used in Gaza because of lack proper assessment and monitoring
programs (SCF, 1991; Haapala, 1993; UNRWA, 1993; Abu Middain, 1994; Richter
and Safi, 1997; IARC, 1999). Also lack of awareness among shop owners, farmers
and public increased the level of soil and water contamination across Gaza (Hulshof,
1991; Issa, 2000).
Contamination resulting from leaching of pesticides is a common and growing
problem in major agricultural regions (Flury, 1996; DaSilva et al., 2003).
The method and rate of pesticide application, the use of tillage systems that modify
soil conditions, and the amount and quality of water can also influence pesticide
leaching (Hebb and Wheeler, 1978; Kolpin, 1997; Tomlin, 1997; Kubilius and
Bushway, 1998; USGS, 1998).
Groundwater is the most precious natural resource in the Gaza Strip as it is the only
source of water. Therefore groundwater contamination will be of catastrophic
consequences to the around populated areas. The groundwater aquifer of Gaza is
extremely susceptible to surface-derived contamination because of its largely
unconfined nature and highly permeable sands and gravels. In the past decade, the
aquifer has become the focus of experts and public concern. This concern has resulted
from widespread salinity, nitrate and fluoride; from the detection of agricultural
pesticides and fertilizers; and from increased pressures for urban development above
the aquifer.
The objective of the present baseline study is to identify and quantify the
concentration of pesticides in the groundwater and the topsoil of the Gaza Strip.
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MATERIALS AND METHODS
The study area
The Gaza Strip, as one of the most densely populated areas in the world (2638
people/km2; PCBS, 2000), with limited and declining resources, has already started to
suffer the outcomes of environmental quality deterioration. The study area is a part of
the coastal zone in the transitional area between the temperate Mediterranean climate
to the north east and the arid desert climate of the Negav and Sinai deserts to the south
east. As a result, the Gaza Strip has a characteristically semi-arid climate and the
hydrogeology of the coastal aquifer consists of one sedimentary basin, the postEocene marine clay (Saqiya), which fills the bottom of the aquifer.
The quantity and quality of available water varies over space and time, and is
influenced by multifaceted natural and man-made factors including climate,
hydrogeology, management practices, pollution, etc.
Two thirds of the Gaza Strip (total 365 km2) is an agricultural area (PCBS, 2000).
Approximately 393.3 t of pesticides and more than 900 t of methyl bromide are used
annually to protect the major crops, including vegetables, citrus, olives and grapes
(Safi, 2002).
Recently, several pesticides were detected in the major vegetables consumed in Gaza.
α and β-endosulfan, chlorpyrifos, carbofuran, chlorfluazuron, triadimenol I and II,
penconazole, coptafolmetabolite, pyrimethanil and iprodione were detected and
confirmed on some samples of cucumber, tomatoes and strawberries (Safi et al.,
2002); however, they were low and below the maximum residue limits.
Sampling
The study area (Fig. 1) is divided into five geographic regions, the northern area,
Gaza, the middle area, Khan Yunis and Rafah which represent the main five
governorates of the Gaza Strip. Three sampling campaigns have been conducted in
three years over the periods: 20 November-12 December 2000, 26 June-17 July 2001
and 25 January -17 March 2002. Soil samples were collected in the last sampling
campaign.
Under the water quality testing program about 73 municipal wells and 21 private
wells in the Gaza Strip were sampled. At the municipal wells, samples were collected
from a tap along the water distribution line. Prior to sampling, the injection of
chlorine or sodium hypochlorite into the water system was discontinued so the
additive would not interfere with the analysis. In addition to the general locations of
wells, Table 1 shows the ID of each well. The wells in the table are ordered from
north to south where 17, 26, 8, 15, and 7 wells are chosen from the north, Gaza, the
middle, Khan Yunis and Rafah regions, respectively.
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In order to assure that the sample collected was from groundwater and not water
standing in the well, it was originally proposed that the well should be pumped for a
minimum of 1-2 h prior to the collection of the sample; however this was not always
possible. The third sampling programme occurred at the end of the winter rainy
season, and many private well owners were not using their wells extensively. The
average private well has a 10-m depth of standing water in a 30-cm diameter pipe
representing a volume of approximately 1 m3. Therefore 1 h of pumping at a rate
ranging between 45 and 70 m3/h was sufficient to purge at least three standing well
volumes. Water samples were collected from municipal groundwater wells (Table 1)
used for drinking representing all geographic areas: 17 in the north, 26 in Gaza, 8 in
the middle, 15 in Khan Yunis and 7 in Rafah.
For general screening of pesticides in the groundwater of Gaza, 4 water samples were
collected in the preparation phase of the study and one month before the actual
sampling campaigns. One liter of 4 groundwater wells was collected in glass bottles; 2
from municipal wells and 2 from private wells. The wells were selected according to
the agricultural activities in the area. The 4 liters were transported and analyzed in
Germany by using the high performance liquid chromatography (HPLC/MS).
In the case of soil, sampling was conducted according to the European soil sampling
guidelines (Theocharopoulos et al., 2001). Fifty seven sites were selected to represent
all soils of Gaza. The depth of sampling varied between 0-10 cm for the open and
grass soils; 20 cm for the vegetable soils; and up to 30 cm for the ploughed soils.
Fifteen soil samples from the greenhouses (vegetables) of three different geographic
areas, 6 from fruit farms (olive, peach, guava, citrus), 5 from open vegetable farms, 8
from strawberry farms, and 5 from non-agricultural isolated areas representing local
reference sites. At each sampling station, a circle of 2-5-m diameter was identified
and 10 sub-samples were collected within the perimeter and mixed to form a
composite sample. Samples (0.5 kg) were collected and placed into dark polyethylene
cups and stored at 4 oC until extraction and analysis.
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North
Gaza
Middle
Khan
Yunis
Location of Groundwater Wells
Rafah
Figure (1) Five regions of the Gaza Strip and location of groundwater wells.
Table (1) Groundwater wells sampled for 3 years.
Region
Well
Well
ID
ID
D/67
E/157
D/73
D/68
D/74
D/69
Gaza
E/06
D/70
E/10
Q/39
E/11A
R/162L
E/11B
R/162La
E/11C
R/162Ha
North
E/138
R/162H
Gaza
E/148
R/162G
E/156
R/162F
Middle
E/45
R/162E
E/61
R/162C
E/8
R/162B
E/90
D/71
E/92
D/72
Khan
Q/40b
R/25a
Yunis
E/154
Gaza
R/25b
100
Well
ID
R/25c
R/25d
R/112
R/254
R/265
R/74
R/75
G1/178
J 146
J 32
J 35
S 19
S 42
S 69
T 46
L 127
L 159
L 176
Khan
Yunis
Rafah
Well
ID
L 178A
L 179
L 41
L 43
L 86
L 86A
L 87
M 2A
M 2B
N 22
N9
T 44
P 10
P 124
P 138
P 138 old
P 139
P 144
P 15
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Solvents, chemicals and standards
Aacetone, ethylacetate, methanol, ethanol, acetonitril, n-hexane, cyclohexane,
petroleum ether, diethylether, isooctane, toluene, sulfuric acid 95-97% and
Phosphoric acid 85% were obtained from Merck (Darmstadt, Germany). Silver nitrate
was from Aldrich (Buchs, Switzerland); dodecane and Methyl-t-Butyl-Ether (MTBE)
was obtained from Fluka (Buchs, Switzerland). All reagents were tested fusing gas
chromatography coupled with mass spectrometer (MS). NaCl, KOH were obtained
from Merck and made free of water by heating at 550 °C for 2 h. Silica gel 60 A, 100200 mesh, was obtained from Merck was activated by previously heating at 300 °C
for 12 h, then allowed to cool in a dessicator and later stored in a brown boronsilicate
bottle in a dry place.
Pesticide standards: Triclopyr, Picloram, Dicamba, Dichloroprop, 2,4 DB, Mecoprop,
Fenoprop, MCPA, MCPB, 2,4-D, 2,4,5-T all from Dr. Ehrensdorfer, Augsburg,
Germany and calibration solutions (5 µg/ml) were prepared by dilution of the
respective stock solution in methanol; Phenol Kit 27 (standard mix in methanol) is
from SUPELCO.INC. Solid reagents were heated at 400 oC for 5 hours to free them
from the interfering organic substances (Stan, 1995). Diazomethane was prepared
adapted to de Boer and Baker (1954; see appendices).
Water extraction
Water was collected in 1-liter glass bottle and treated with 5 ml phosphoric acid
(85%, analytical grade) followed by 100 µl internal standard solution (5 µg/ml) of
2,4-dichlorophenoxyacetic acid (Ring 13C6) in methanol. The bottles were thoroughly
shaken and placed in an ice cooling box and later extracted using a solid phase
extraction (SPE-cartridge type: Oasis HLB, 200 mg, 6 ccm, 30 µm grain size)
technique as described by Stan (1995). The SPE was rinsed with 3 ml ethyl acetate
(analytical grade) followed by 3 ml Milli-Q water. The water sample was extracted
through the SPE with fixed filtration flow rate of 10 ml/min. At the end of the
extraction step, the SPE was washed with 5 ml Milli-Q water and some air was
sucked through the cartridge for several seconds. The SPE cartridges were wrapped in
aluminum foils in order to protect them from contamination and were kept frozen
until they have been sent to Germany for analysis.
For the final preparation of water samples, the solid phase extractors were cleaned by
6 ml methanol/ tert-butyl- methyl ether (TBME), 20:80 (v:v). Then 100 µl of internal
standard mix 33 (5 µg/ml) was added. The final volume was reduced to 0.5 ml by a
gentle stream of N2 where it was transferred into measuring vials. 100 µl
diazomethane solution were added and the vials were degassed and kept at 4 oC.
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Soil extraction
Soil samples were freeze-dried for 48 h until complete dryness and sieved through a
2-mm sieve. Approximately 10 to 20 g was placed in a Soxhelt extraction-cartridge
and extracted over night (12 h) with 75 ml n-hexane/ethylacetate (100:2 v/v). To the
extract, 100 µl of the internal standard for the GC/MS (Ehrenstorfer internal standard
mix 33, (5µ/ml) was added followed by 1 g anhydrous Na2SO4. The samples were
evaporated to about 6 ml through a rotary evaporator, then to 1 ml by a gentle stream
of N2. About 0.8 g home made silica gel/AgNO3 (100:5 wt:wt ) was poured into the
SPE followed by few drops absolute methanol for activation. The SPE cartridges were
conditioned by 6 ml n-hexane/ethylacetate. The extract was cleaned by 6 ml nhexane/ethylacetate where they were received in glass tubes and reduced by a gentle
stream of N2 to 0.5 ml, so an enrichment factor of 20 was reached.
Analytical methods
Table 2 shows the instrument used for the analysis of target pesticides.
GC/MS
Organochlorine pesticides were determined using a gas chromatograph (Agilent GC
6890 N series, Waldbronn, Germany), equipped with cold injection system - CIS
(Gerstel, Mülheim, Germany). The detector was mass spectrometer MS-Agilent: 5973
(Waldbronn, Germany). Chromatographic parameters: oven: initial temperature 40 oC
and initial time 1 min; oven ramp level 1: rate 20 oC/min, final temperature 100 oC
and final time 0.0 min; oven ramp level 2: rate 10 oC/min, final temperature 310 oC
and final time 3.2 min; oven ramp level 3: rate 100 oC/min, final temperature 340 oC
and final time 5.0 min; total time 33.5 min. Column parameters: The column was
Macherey-Nagel. (30 m x 0.25 mm i.d., 0.25 µm film thickness) mode constant flow;
initial flow 1 ml/min; initial pressure 7.04 pound/inch2 (psi); gas type helium in
average velocity 36 cm/sec. MS was in single ion monitoring SIM-Mode.
The application of one internal standard during gas chromatographic analysis is
recommended to minimize systematic errors. The internal standard used in this work
was 2,4,5-trichlorobiphenyl (TCB), which has physicochemical properties similar to
those of the analyzed substances and separated well from all analyzed organochlorine
pesticides.
HPLC/MS
HPLC was Agilent System 1100 (Waldbronn, Germany), and the conditions were as
follows: PreColumn: Security Guard, SYNERGI Max-RP 4 x 2.0 mm (Phenomenex).
Column was SYNERGI Max-RP: 150 mm x 2 mm i.d., 4 µm, 80 Å (Phenomenex),
temperature: 30 °C, flow: 0.2 ml/min. Eluents: mobile phase A: 950 ml water,
adjusted to pH 2.6 with dropwise addition of formic acid, ad 1000 ml: acetonitrile;
degassed. Mobile phase B: methanol, degassed, gradient: linear: 0 until 8 min from
50 to 70% B, 8 until 12 min from 70 to 95% B, 12 until 20 min 95% B.
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The detection of the analytes was conducted with MS (Applied Biosystems, API 2000
triple quad system, Langen, Germany). Ionization mode was atmospheric pressure
chemical ionization (APCI) and the scan type was multiple reaction monitoring
(+MRM). Identification of compounds was performed by comparing their retention
times with standards and by their fragment mass ions. Quantification was done using
internal quantification. Linearity was identified by using 5 determinations of standard
solution in the concentration range of 5 µg/l to 200 µg/l. Software used was Applied
Biosystems “Analyst”.
Table (2) List of pesticides analyzed and instrument used for analysis.
Pesticide
Analysis
LD* (µg/l) Pesticide
Alachlor
HPLC/MS 0.025
Monolinuron
Atrazine
HPLC/MS 0.025
Monuron
Atrazine-desethyl
HPLC/MS 0.05
Pendimethalin
Atrazine-desisopropyl HPLC/MS 0.055
Propazine
Azinphos-ethyl
HPLC/MS 0.05
Propiconazol
Benfluralin
HPLC/MS 0.05
Sebutylazine
Bromacil
HPLC/MS 0.025
Simazin
Carbofuran
HPLC/MS 0.05
Terbutryn
Chlorbromuron
HPLC/MS 0.05
Terbutylazin
Chlorfenvinphos
HPLC/MS 0.05
Terbutylazin-desethyl
Chlortoluron
HPLC/MS 0.05
Triadimenol
Cycloat
HPLC/MS 0.05
Triallat
Desmetryn
HPLC/MS 0.035
Trifluralin
Diuron
HPLC/MS 0.03
Aldrin
Etrimfos
HPLC/MS 0.05
Chlordan
Fenuron
HPLC/MS 0.025
4,4'-DDD
Fluometuron
HPLC/MS 0.05
4,4'-DDE
Hexazinon
HPLC/MS 0.05
4,4'-DDT
Isoproturon
HPLC/MS 0.05
Dieldrin
Linuron
HPLC/MS 0.05
Endrin
Metazachlor
HPLC/MS 0.05
Heptachlor
Methabenzthiazuron
HPLC/MS 0.025
Heptachlorepoxid
Metobromuron
HPLC/MS 0.05
Hexachlorbenzol
Metolachlor
HPLC/MS 0.05
Lindan
Metoxuron
HPLC/MS 0.025
Methoxychlor
Metribuzin
HPLC/MS 0.05
Mirex
LD* is limit of detection.
Analysis
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
HPLC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
GC/MS
LD (µg/l)
0.05
0.025
0.025
0.025
0.05
0.025
0.025
0.025
0.025
0.05
0.05
0.05
0.025
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
Quality control
Analytical blanks and standards with known concentrations of pesticides were
prepared and analyzed using the same procedure and reagents. The extraction
efficiencies of pesticides with the SPE cartridges for the target compounds were
determined by passing 1000 ml of Milli-Q water spiked with 0.1 µg of each target
compound through the cartridges. As a kind of internal quality control, 250-500 µl of
same extracted water and soil samples were analyzed in the laboratories of
Department of Water Hygiene/Chemistry in the Institute for Hygiene and Public
Health at the University of Bonn.
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RESULTS
Despite the fact that more than 52 different pesticides were applied across agricultural
farmlands in Gaza, only few pesticides were detected in the soils of Gaza and many
were found in the groundwater. Generally, no significant difference was observed
between the results of same wells for the successive 3 years. The results of same
samples analyzed in two laboratories showed ±5% difference. The most important
finding of this study was the detection of 12 pesticides in the groundwater (Table 3)
and 6 pesticides in the topsoils (Table 4).
Groundwater
The HPLC/MS and GC/MS results showed that 92% of target pesticides in the
groundwater were less than the instrumental detection limit.
Also, the results of the analysis indicated low levels of pesticides in 13 of the 94 wells
tested. Of the 13 wells, 5 were agricultural wells, and the remaining were municipal
wells. The wells are mostly in the areas of Khan Yunis and Rafah.
Bromacil was 0.5 µg/l in Safa 1 and Atrazine-desisopropyl was 0.1 µg/l in Safa 2
(R/25a). Most results of the GC/MS of other target pesticides were generally less than
the detection limit. Several private wells in Rafah area showed traces of endrin,
heptachlorepoxide, DDT, DDE, and DDD.
Atrazine was detected in 47% of groundwater samples, while atrazine-desisopropyl,
propazine, simazine were detected in 40%, 24%, and 13% of water samples,
respectively. All showed results above the instrumental detection limit. Two water
samples showed 5 µg/l of triadimenol, the wells are private and located in the area of
Gaza wastewater treatment plant.
Soil
Several soil samples of strawberry greenhouses in Beit Lahia showed detectable
values of propazine, sebutylazine, terbutylazine, 4,4’-DDT, 4,4’-DDE, and 4,4’-DDD.
The averages of propazine, sebutylazine and terbutylazine were 19, 13 and 39 µg/kg,
respectively. A linear regression r = 0.87 was obtained between the occurrence of
detected pesticides and soils of strawberry greenhouses.
The results showed that one soil sample had high contents of 4,4'-DDE and 4,4'-DDT
which were 1104 and 793 µg/kg, respectively. This sample was collected from the
northern area of Beit Lahia in a vegetable farm.
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Table (3) Concentration (µg/l, n=3) of various pesticides detected in groundwater wells.
Well
Pesticide
Conc.
Well ID
Pesticide
ID
E/6
Atrazine
1 ± 0.1
L/43
Terbutryn
E/6
Atrazine-desisopropyl
1 ± 0.1
L/43
Terbutylazin
E/6
Propazine
1 ± 0.2
L/87
Atrazine
E/4
Atrazine
2 ± 0.3
L/47
4,4’DDT
E/4
Atrazine-desisopropyl
1 ± 0.1
R/162C Atrazine
E/1
Atrazine
2 ± 0.4
R/162L Atrazine
E/1
Atrazine-desisopropyl
1 ± 0.2
R/162L Atrazine-desisopropyl
E/11b
Atrazine
5 ± 0.3
R/162C Atrazinedesisopropyl
E/11b
Atrazine-desisopropyl
1 ± 0.1
R/162C Propazine
D/20
Atrazine
20 ± 3
R/25
bromacil
D/20
Atrazine-desisopropyl
8 ± 0.9
P/101
endrin
D/20
Simazine
4 ± 0.1
P/101
dieldren
D/20
Propazine
3 ± 0.1
P/101
4,4’DDT
D/72
Atrazine
1 ± 0.1
P/15
Atrazine
D/68
Atrazine-desisopropyl
1 ± 0.1
P/15
Atrazine-desisopropyl
D/68
Simazine
1 ± 0.2
P/15
4,4’DDT
D/68
Propazine
1 ± 0.2
P/24
Atrazine
D/74
Atrazine
3 ± 0.3
P/24
Atrazine-desisopropyl
D/74
Atrazine-desisopropyl
2 ± 0.1
P/139
4,4’DDT
D/74
Propazine
1 ± 0.1
P/144
4,4’DDT
A/185
Atrazine
4 ± 0.2
P/10
4,4’DDT
A/185
Atrazine-desisopropyl
1 ± 0.1
F/191
endrin
A/185
Simazine
2 ± 0.2
F/191
4,4’DDT
A/185
Propazine
1 ± 0.3
F/191
4,4’DDE
A/107
Atrazine
1 ± 0.4
F/191
4,4’DDD
A/107
Atrazine-desisopropyl
1 ± 0.2
S/15
4,4’DDT
A/180
Atrazine
2 ± 0.5
S/15
heptachlor epoxide
A/180
Atrazine-desisopropyl
1 ± 0.3
G/49
Atrazine
A/180
Simazine
1 ± 0.4
K/21
Atrazine
A/180
Propazine
1 ± 0.1
Priv. 1
Simazine
L/43
Atrazine
5 ± 0.4
Priv. 2
Triadimenol
L/43
Atrazine-desisopropyl
2 ± 0.3
Priv. 3
Triadimenol
L/43
Propazine
1 ± 0.3
Conc.
1 ± 0.1
1 ± 0.3
1 ± 0.1
0.008 ± 0.001
14 ± 2
5±1
1 ± 0.2
7±2
8±2
0.5 ± 0.02
6±1
5±1
0.021 ± 0.001
6±1
6±2
0.002 ± 0.001
8±1
8±1
0.002 ± 0.001
0.002 ± 0.001
0.002 ± 0.001
0.1 ± 0.01
0.002 ± 0.001
0.006 ± 0.002
0.006 ± 0.002
0.002 ± 0.001
0.003 ± 0.001
1 ± 0.2
1 ± 0.1
6±1
5 ± 0.7
5 ± 0.6
Table (4) Pesticides detected in soil samples.
Soil
Pesticide
Strawberry greenhouses farms (n=8)
Fruit farms (n=6)
Open vegetable farms (n=8)
Strawberry greenhouses farms (n=8)
Vegetable greenhouse farms (n=7)
Open vegetable farms (n=8)
Propazine
Sebutylazine
Terbutylazine
4,4’DDT
4,4’DDE
4,4’DDD
Min.
(µg/kg)
18
13
385
795
1110
750
105
Max.
(µg/kg)
20
16
410
823
1150
795
Aver.
(µg/kg)
19
15
397
806
1129
779
Median
(µg/kg)
19
15
398
803
1130
786
Stdev.
0.9
1.2
10
10
17
16
Chapter Seven
Monitoring of Pesticides in Groundwater and Soil
___________________________________________________________________________________
DISCUSSION
The levels of pesticides found in 92% of the tested wells were below the WHO
allowable drinking water standards. Approximately half of the wells, in which
pesticides were detected, were below the detection limit for the pesticide in question,
and therefore should be used with caution, since at these low levels, the results may
not be repeatable; wells P/10 and P/10a are examples of these wells. Some private
wells showed a sum of detected pesticides more than the EC standards (1998) and the
German legislation (Trinkwasserverordnung, 2001). The later sets a limit of 0.1 µg/l
of individual pesticide (for aldrin, dieldrin, heptachlor and heptachlor epoxide the
limit is even lower at 0.03 µg/l) and a maximum of 0.5 µg/l for the sum of detected
pesticides in drinking water.
The higher detection of pesticides in the groundwater of the southern areas may be
due to the presence of large number of greenhouses, which possibly use large
quantities of pesticides. The area in the north near well E/45 is also heavily
agricultural, with strawberries being a main crop.
The differences in the results of the 3 consecutive years for the same well was
insignificant while there was a significant variation in pesticide concentrations for the
well depth and location. The deeper the water table, the less likely that pesticides
reach groundwater. Most of groundwater wells that showed detectable pesticides have
25-50 m depth. A deep aquifer of municipal wells provides more opportunities and
time than does a shallow aquifer of private wells for pesticide adsorption, degradation
and other processes to occur. The recharge of rainwater and agricultural activities can
carry pesticides down to the aquifer.
There was a correlation between the occurrence of some pesticides in groundwater
such as atrazine and water salinity (r = 0.64) and this conclusion agrees with Gascon
et al. (1998). Most of agricultural wells of the southern area have average Cl
concentrations of 1200 mg/l and the highest values of atrazine range between 6-20
µg/l. Wells D20 and E11b in the northern area showed anomalous results as they are
old and were used for decades as private wells before they became municipal.
The field surveys revealed that the potential sources of pesticide contamination of
private wells include sites used for pesticide storage mainly in the well building,
mixing, loading, disposal, or application. Most of private wells are located inside the
farm and surrounded by intensive agriculture.
Although many pesticides have been found in the groundwater, few of them were
detected in soil samples. They were more abundant in clay soils of the northern area
than they were in the southern area where the annual precipitation is lower and the
soil is sandy. 4,4'-DDE and 4,4'-DDT, propazine, sebutylazine and terbutylazine were
almost the same in the soils of the greenhouses of several areas in the Gaza Strip
where they have same vegetables and same loamy soils (sand, silt and clay). These
results agree with the findings of Jansma and Linders, 1995; Hatzinger and
Alexander, 1997; Chung and Alexander, 1998, 2002; Kolpin, 1998a; Navas and
Machin, 2002; Worrall et al., 2002.
106
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Monitoring of Pesticides in Groundwater and Soil
___________________________________________________________________________________
Detected pesticides were found in clay soils while none of them was detected in sandy
soils. Clay soils -which have higher organic matter- have both a low leaching
potential and a high sorption potential. Mobility is always correlated with soil organic
carbon content where higher organic carbon contents in the upper soil layer slow
down dislocation of pesticides to deeper layers (Burnside et al. 1969; Huang and
Frink 1989).
Triazine (atrazine, atrazine-desisopropyl, propazine, simazine and terbutylazine)
Some of the triazine derivatives including atrazine, atrazine-desisopropyl, propazine,
and simazine were detected in some wells. Triazines are known to be somewhat
persistent in water and mobile in soil (Tchounwou, et al., 2000). In many agricultural
areas, triazine metabolites and transformation products such as desethylatrazine and
deisopropylatrazine are also commonly found in groundwater, together with their
parent compounds (Kolpin et al., 1998b). It has been found that metabolite
concentrations in groundwater often exceed parent compound concentrations for
triazine herbicides (Kolpin et al., 2000). None of atrazine, atrazine-desisopropyl,
propazine and simazine was detected in soil samples; however results of water
samples showed that 47%, 40%, 24% and 13%, respectively of these pesticides were
>1µg/l in the monitored groundwater wells. The USEPA maximum contaminant level
(MCL) drinking water standard for atrazine is 3.0 µg/l (USEPA, 1994).
Atrazine was the only herbicide found in 90% of groundwater samples; however it
was not detected in soil samples. Katz et al. (2000) reported that atrazine in soil could
be degraded by denitrifying bacteria. Atrazine has the potential to move rapidly in
sandy soils with low organic matter content, especially when these soils are irrigated
(Chung and Alexander, 2002). This agrees with the findings of atrazine in the
southern areas of Gaza where the soil is sandy with very low contents of organic
matter (0.5%).
Until its prohibition in many countries including Gaza in 1991, atrazine was
substituted mainly by terbutylazine in Germany. Nevertheless, atrazine and its
metabolite desethylatrazine are by far the most abundant herbicides detected in
shallow groundwater (Tappe et al., 2002). Atrazine is applied with water, liquid
fertilizer, or impregnated on dry bulk fertilizer to the soil either as a preplant on the
soil surface, pre-plant incorporated, or as a pre-emergence treatment. Atrazine is not
approved for fall application but may be applied up to 45 days before planting. It can
also be applied after crop emergence.
It is found that farmers of Gaza use atrazine more than any other pesticide because it
is highly effective and less expensive compared to other herbicide options currently
available. One of the reasons why all atrazine containing products are classified as
restricted use pesticides is that atrazine is relatively mobile and can move with water
or sediment, through runoff or leaching (USNRCS, 2004).
Although atrazine desisopropyl is a biotic degradation product of atrazine and it was
detected in several wells where atrazine was not detected. Bromacil is mainly used on
citrus of Gaza and it is easily lost from soil by leaching. However bromacil uptake is
mainly via the roots of the plants, it was not detected in any soil sample.
107
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___________________________________________________________________________________
Farmers of Gaza use simazine on many crops especially citrus. However, high
amounts of simazine are applied in Gaza; it was not detected in any soil sample but
only in groundwater. Several articles (Snedeker and Clark, 1998; DaSilva et al., 2003)
indicated that simazine is easily lost from soil by leaching and has a moderate
potential for loss due to surface adsorption and surface solution. Furthermore, it is
expected that the half-life of simazine in soil of Gaza is short and has been expected
to be in the range of few days. This is based on several studies showed that the halflife of simazine is short when: soil in general is sandy to loamy, low organic matter
content, pH is neutral to basic, high temperature, low moisture content (Chen et al.,
1983; Rahman and Holland, 1985; USEPA, 1994; Redondo, 1997). Consequently,
simazine was not detected in any of soil samples. Use of an efficient irrigation
management technique could have enhanced simazine’s performance through a
decreased leaching of residues.
Terbutylazine belongs to triazines where they are intensively applied in the
agriculture of Gaza over the past decades. Terbutylazine was detected in several soil
samples of fruit trees, citrus and open vegetable farms. However, atrazine was
substituted mainly by terbutylazine in many countries; the later was not detected in
groundwater but only in soil samples.
Propazine was found in 24% of groundwater wells and was the major detected
pesticide in several soil sites. Propazine has a high potential to leach into
groundwater. It was detected in 90% of soils of greenhouses. Propazine is moderately
persistent to degradation under aerobic soil conditions, degrading with half-lives of 12
to 24 weeks in nonsterile loamy sand and 8-12 weeks in sterile loamy sand soils.
DDT, DDE and DDD
DDT was banned in several countries, but is still used in Gaza. Traces of DDT and its
breakdown products DDE and DDD were detected in several soils of Gaza as well as
in several groundwater wells of Khan Yunis and Rafah areas.
DDT adsorbs strongly to soil (Fischer et al., 1993; Thompson et al., 1999; Bacchetta
et al., 2001; Binelli and Provini, 2003); breaks down slowly to DDE and DDD by
light and microorganisms (Spencer et al., 1996; Morrison et al., 2000). Half life of the
DDT in soil is 2-15 years, depending on the type of soil (Wiberg et al., 2001). Due to
strong adsorption to soil, only a small amount of DDT migrates through the soil into
groundwater (Hung and Thiemann, 2002). Consequently, few wells in Rafah area,
where the soil is sandy; showed some DDT and its breakdown products.
108
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Monitoring of Pesticides in Groundwater and Soil
___________________________________________________________________________________
CONCLUSIONS
1. Several pesticides were detected in the groundwater of Gaza and the minority has
concentrations exceeded their respective WHO maximum contaminant levels or
health advisory levels for drinking water.
2. Private groundwater wells showed higher contents of pesticides than the municipal
wells. The levels of pesticides found in the municipal wells were at levels well below
the water quality guidelines, and many were at levels close to the detection limit for
the method and should therefore be used with caution.
3. Several factors affecting the occurrence of pesticides in the groundwater of Gaza;
soil type, aquifer characteristics and meteorological conditions, well location, well
depth and groundwater quality.
109
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Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
CHAPTER EIGHT
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip (*)
ABSTRACT
Two different techniques were used to determine different elements in pesticides; a semiquantitative EMMA-XRF technique followed by ICP/OES were used to test the
concentrations of Al, As, Ba, Br, Ca, Cd, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, Rb, Sc, Se, Sr Ti and
Zn in the most used 53 different species of solid pesticides collected from many markets of
the Gaza Strip. The results revealed that the tested pesticides contain considerable amounts of
heavy metals and they do not comply with the expected-theoretical structure of each species;
moreover, they don't reflect the actual constituents mentioned in the trade labels. Interviews
with market owners and field surveys confirmed that pesticides were not pure and they have
been mixed in local markets with minor inorganic species without a scientific basis; or they
have been smuggled to Gaza with different impurities. The results propose that pesticides
should be considered as a source of certain heavy metals (Cu, Mn, and Zn) and other
elements (Br, Sr and Ti) that may affect their mass balances in soil and groundwater as well
as plant uptake; and different scenarios and calculation models of heavy metal transport in
soil and groundwater of the Gaza Strip should include pesticides as an additional source of
certain heavy metals.
Key words: Gaza Strip, Heavy metals, Pesticides.
_________________________________________________________________________________
(*) The study was submitted to an International Journal.
110
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
INTRODUCTION
Researchers on pesticides focus on the organic dimension while the inorganic field has been
neglected or has been less investigated. This could explain the shortage in the literature about
the existence of heavy metals in pesticides as it is assumed that the chemical structure of
pesticides is well known, labeled or documented. But this is not the case in many countries,
especially in the developing countries. Pesticides have greatly improved the agricultural
production world-wide and have shown to be very effective to control vector-borne diseases.
However, their indiscriminate use and improper application raise great concern because of
the hazards and risks they pose to human beings and the environment (Abu Middain, 1994).
They represent a variety of different chemical characteristics (Stan, 1995); they can be bound
in different ways such as metal complexes.
Pesticides including their heavy metal constituents have been found in contaminated
groundwater and soil. Contamination resulting from leaching of pesticides is a common and
growing problem in major agricultural regions (Flury, 1996; Roberts, 1996). For example,
bromacil and hexazinone are often detected in groundwater in the areas that they are used
(Hebb and Wheeler, 1978; Kubilius and Bushway, 1998; USGS, 1998). Pesticides that have
heavy metals in their chemical structure (fosetyl-aluminum, propineb, mancozeb, maneb and
copper oxychloride) were detected in groundwater of many regions in the world. A recent
study categorized a wide range of pesticides as ‘‘leachers’’ or ‘‘non-leachers’’ for a specific
Hawaii hydrogeological setting (Li et al., 2001b). In the United States, a considerable body of
work exists relating to the occurrence of both parent compound pesticides and their
metabolites in groundwater aquifers (Baker et al., 1993; Lawrence et al., 1993; Kolpin et al.,
2000a,b). The US Geological Survey (USGS) has conducted extensive sampling of
groundwater for pesticides throughout the Midwestern United States. The findings of this
work have been reported extensively. The study used results from 100 monitoring wells
sampled by the USGS. These wells were a subset of a study of 303 wells originally sampled
in 1991, the subset being chosen by a stratified random design based on geography and
aquifer class. The data from this subset were chosen for this study rather than that from the
larger initial survey because they were analysed over a period of 2 years. The compounds
analyzed were: alachlor, ametryn, atrazine, cyanazine, metolachlor, metribuzin, prometon,
prometryn, propazine, simazine and terbutryn (Kolpin, 1997; Kolpin et al., 1995, 1998a,b;
Kolpin et al., 2000a,b). Moreover, occurrence of pesticides in soil was reported in many
locations of the USA and Canada (Wiberg et al., 2001).
The main goal of this paper is to introduce a general method for determination of heavy
metals in solid pesticides; and to reveal the heavy metal contents and some elements in 53
pesticides which are intensively being used in Gaza. A secondary objective is to prove that
even pesticides originally with no heavy metals in their chemical structure have impurities of
such metals that have been added by local markets.
111
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
MATERIALS AND METHODS
Study area
Pesticides are considered priority pollutants in Gaza and, with the expanding use of
greenhouses; Palestinian agriculture is becoming increasingly dependent on chemical
pesticides and fertilizers. In the Gaza Strip, a few reports have identified some of
malpractices of pesticides use by shop owners, farmers and agricultural workers. Similarly,
the use of extremely toxic pesticides that are banned or restricted in many countries are being
used in Gaza (Haapala, 1993). Nevertheless, poor medical records, absence of health
surveillance and monitoring systems and absence of legislation and control systems, have
resulted in a lack of awareness among shop owners, farmers and the public (Hulshof, 1991).
Consequently, farmers continue to use pesticides excessively without being aware of the
hazards they cause to their own health, that of the consumers, and the environment (Issa,
2000). Moreover, there is no monitoring of pesticide residues in agricultural crops that
endanger the health of the whole population (UNRWA, 1993). More than 200-250 metric
tons of formulated pesticides are used annually in the Gaza Strip, and about 90% is imported
from Israel while the other 10% is manufactured locally. Since there is no restriction on the
sale and use of pesticides, farmers have easy access to all of them including the banned, the
highly toxic and the restricted species, and they do not have to show a special permit or
require special training before buying them (Happala, 1993; Hulshof, 1991; Issa, 2000).
There are around 55 pesticide shops in the Gaza Strip and there are no wholesalers; all
pesticides come from Israel through Israeli Arab wholesalers, who usually get most of their
products from Israeli pesticide companies and sometimes from agents for imported chemicals
(UNRWA, 1993; SCF, 1991). Since there is no monitoring either on the sale of pesticides, or
on their chemical composition (there are neither laboratories nor facilities for this purpose),
adulteration and fraudulent sale of pesticides are common practices (Abu Middain, 1994;
Hulshof, 1991).
There are about 400 officially registered pesticides in Israel, some of which are banned for
use in industrialized countries due to their high toxicity, low biodegradability, and mutagenic
or carcinogenic potential. In addition there are pesticides registered in Israel that have not
been registered in the countries of origin.
Sampling and analysis
Fifty-three solid samples of pesticides were collected between March and May 2002.
Samples were collected from 5 private stores in Gaza, and they were bought in the same
storage containers, the majority of which are commercial plastic, some other are made of
polyethylene and few are metallic containers. Table 1 shows the pesticide samples and the
chemical formula of each one as well as its use. It was found that same pesticides have
different names not only in different shops but also sometimes in the same shop; they were
treated independently in the analysis procedure. Table 1 also shows the similarities between
numbers 3, 31; 9, 30; 12, 13; 20, 52 and 35, 50.
Samples were freeze-dried until complete dryness then the non-powder species were ground
until they were very soft.
112
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
EMMA-XRF
As a rough estimating technique, pesticide samples were measured using the Energydispersive Miniprobe Multielement Analyzer-X Ray Fluorescence (EMMA-XRF)
(Cheburkin, and Shotyk, 1996). Direct analyses were conducted for K, Ca, Ti, Cr, Mn, Fe,
Ni, Cu, Zn, As, Se, Br, Rb, Sr and Pb. The EMMA-XRF analyzer was designed for trace
element analysis of plant soil and rock samples. The analyzer used monochromatic excitation
with the energy of 19.6 keV. The software includes a possibility to normalize the peak area of
each element by intensity of incoherent scattering radiation. This feature allows the
elimination of the matrix effect for samples with a different matrix. However, with the
extremely wide range of matrices for pesticide samples even such normalizing does not work
well. Some of pesticide samples have a very heavy matrix due to the presence of high
concentration of Mn, Cu, Zn and Br.
The EMMA-XRF analyzer has been calibrated using different Standard Reference Materials
(SRM) like: NIST 1575 (Pine needles); 1632b (Coal); 1635 (Coal); G-2 (Granite); BCR60
(Olive leaves); BCR62 (Aquatic plants); MAG-1(Marine mud); W-1 (Diabase). The SRMs
are made by the National Institute of Standards & Technology, NIST USA. The CRB
Standards have been produced by Community Bureau of Reference, Commission of the
European Communities. One of the problems is that these SRMs have very different matrices
from those of many pesticide samples and this means that it was not easy to make a precise
calculation of trace elements in some pesticide samples. Generally, the analytical data for
trace elements in such pesticides are semi-quantitative and may have a relative error up to
30%.
ICP/OES
As the results of the EMMA-XRF are semi-quantitative and showed a signal to go for
detailed quantitative determination, full digestion procedure and ICP instrument was used.
The samples were handled with great care, under a hood, and about 0.5 to 1.0 grams of the
homogenized sample were dissolved with 10 ml of concentrated nitric acid (Merck 65% p.a.)
in 50 ml retorts. The samples were allowed to degas (24 h), and then they were heated on a
sand bath to 50 oC for 30 minutes then to 160 °C for 3 hours. After cooling, the solutions
were diluted with Milli-Q water in 50 ml volumetric flasks, then filtered through 0.45 µm
pore size membrane filters and transferred in 100 ml polyethylene bottles for analysis.
Elements (Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sc, Sr and Zn) were analyzed by ICP/OES
(VISTA-MPX, VARIAN). The detection limit of the ICP/OES was estimated 10% less than
the lowest standard used for calibration.
Quality control
For quality control, analytical blanks and 2 reference materials with known concentrations of
heavy metals were prepared and analyzed using the same procedures and reagents. The
reference materials were pine needles (American National Bureau of Standards, Washington,
D.C. 20234, 1976). Precision was estimated evaluating the reproducibility between the
duplicates and a coefficient variation of lower than 5%.
113
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
Table (1) List of 53 collected samples of solid pesticides used in the Gaza Strip.
No.
Common Name
Chemical Formula*
1
Methomyl
C5H10N2O2S
2
Benomyl
C14H18N4O3
3
Fosetyl-aluminum
C6H18AlO9P3
4
Chlorothalonil
C8Cl4N2
5
Propineb
(C5H8N2S4Zn)x
6
Mancozeb
[-SCSNHCH2CH2NHCSSMn-]x (Zn)y
7
Aluminum Phosphide
AlP
8
Carbaryl
C12H11NO2
9
Sulphur 704
Sx
10
Sulphur 904
Sx
11
Chinomethionat
C10H6N2OS2
12
Maneb
C4H6MnN2S4
13
Aldicarb
C7H14N2O2S
14
Permethrin
C21H20Cl2O3
15
Warfarin
C19H16O4
16
Bromacil
C9H13BrN2O2
17
Bromadiolone
C30H23BrO4
18
Dicofol
C14H9Cl5O
19
Pyrethroid
C21H20Cl2O3
20
Manage-imibenconazole
C17H13Cl3N4S
21
Aminotriazole
C2H4N4
22
Chlorobenzilate
C16H14Cl2O3
23
Trichlorfon
C4H8Cl3O4P
24
Azinphos-methyl
C10H12N3O3PS2
25
Carbaryl
C12H11NO2
26
Foscthyl-Aluminum
C6H18AlO9P3
27
Copper Oxychloride
ClCu2H3O3
28
Copper Sulfate
CuH10O9S
29
Metalaxyl
C15H21NO4
30
Simazine
C7H12ClN5
31
Metaldehyde
C8H16O4
32
DDT
C14H9Cl5
33
Fenbuconazole
C19H17ClN4
34
Terbutryne
C10H19N5S
35
Etaconazole
C14H15Cl2N3O2
36
Amitrole
C2H4N4
37
Bromadialone
C30H23BrO4
38
Trifluralin
C13H16F3N3O4
39
Metiram
(C16H33N11S16Zn3)x
40
Dichlofluanild
C9H11Cl2FN2O2S2
41
Simazin
C7H12ClN5
42
Terbutryne Ametryne
C10H19N5S
43
Bromacil
C9H13BrN2O2
44
Linuron
C9H10Cl2N2O2
45
Triazine
C7H12ClN5
46
Zineb
C4H6N2S4Zn
47
Dimethoate
C5H12NO3PS2
48
Baycor
C20H23N3O3
49
Captan
C9H8Cl3NO2S
50
Chinomethionet
C10H6N2OS2
*) From the Pesticide Manual (PCPC), 1997.
114
Type
Insecticide
Fungicide
Fungicide
Fungicide
Fungicide
Fungicide
Pesticide
Insecticide
Insecticide
Insecticide
Insecticide
Fungicide
Insecticide
Insecticide
Rodenticide
Herbicide
Herbicide
Acaricide
Insecticide
Fungicide
Herbicide
Acaricide
Insecticide
Insecticide
Insecticide
Fungicide
Fungicide
Fungicide
Fungicide
Fungicide
Molluscicide
Insecticide
Fungicide
Herbicide
Fungicide
Herbicide
Rodenticide
Herbicide
Fungicide
Herbicide
Herbicide
Herbicide
Herbicide
Herbicide
Herbicide
Fungicide
Insecticide
Fungicide
Fungicide
Fungicide
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
RESULTS AND DISCUSSION
General reading of the results
Tables 2 and 3 show the results of EMMA-XRF and ICP/OES keeping in mind that the final
calculations (Table 4) are obtained from the ICP/OES results except for Br. Generally, tested
elements were not only found in the corresponding first 14 pesticides shown in table 4, but
some heavy metals were also found with high amounts in other pesticides which do not have
these metals in their structure table 1 and 3. Based on the results, the collected samples can be
classified into two categories: the ones that have one or more of the tested elements in their
structures and showed positive results; and the ones that have none of the collected elements
in the structure but showed them in the analysis. Fourteen samples only have one or more of
the tested elements in their structures and the concentration of the corresponding element is
measured and calculated to compare the measured and the calculated values (Table 4). The
calculated value of each element was obtained from the percentage it represents in the
chemical formula of the relevant pesticide. Ten samples also showed the highest
concentrations of the tested elements, and although they have none of the tested elements in
their chemical structure they showed anomalous contents of corresponding element (Table 4).
For the first category of the tested pesticides, the calculated value of each element is much
higher than the measured value (Table 4). Al, for example, in fosetyl-aluminum was 4 times
higher than the measured value and it was 3 times higher in the second sample of the same
pesticide; Zn was 11, 6, 1 and 12 in propineb, mancozeb, metiram, and zineb respectively;
Mn was 4 and 9 times higher than the measured value in mancozeb and maneb respectively;
Br 3 times higher in the two samples of bromacil; while it is 6895 and 9480 times higher in
the two samples of bromadiolone; and finally Cu was 2 times higher in both copper
oxychloride and copper sulfate.
The second category of pesticides represents the species that have none of the tested elements
in their structure but they showed high amounts of them. The last 10 pesticides in table 4
clearly showed the amounts in mg/kg dry weight.
Some pesticides of the first category showed high amounts not only of the metal present in
their structure but also other metals not present in their structure; a good example is copper
oxychloride which has high amounts of Pb; copper sulfate showed high amounts of Ni; and
maneb showed high amounts of Fe beside the Mn as well.
115
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
Table (2) Heavy metals and some elements in 54 pesticide samples collected from Gaza, results of the EMMA-XRF.
LD
0.05
0.05
30
20
20
10
2.5
1.5
1
1.5
Element
K
Ca
Ti
Cr
Mn
Fe
Ni
Cu
Zn
As
Unit
%
%
ppm
ppm
Ppm
ppm
ppm
ppm
ppm
ppm
1
0.0
0.0
0
0
10
0
0
0
0
33
2
0.0
0.0
0
0
23
0
7
0
0
22
3
0.0
0.0
388
0
0
0
0
7
0
642
4
1.0
0.0
425
0
76
0
0
6
0
1327
5
0.0
0.0
0
0
884
0
0
>10.0%
0
3768
6
0.0
0.0
0
0
>10.0%
0
0
0
17500
0
7
0.0
0.0
0
0
0
0
6
6
50
1211
8
0.0
0.0
0
0
15
0
22
9
0
304
9
0.0
0.0
4072
0
0
0
7
9
0
4295
10
0.0
0.0
118
0
28
0
10
7
0
229
11
0.0
0.0
184
0
560
0
0
14
0
373
12
0.0
2.0
10012
0
19011
36
32
940
4
10939
13
0.0
2.0
10911
0
19980
0
23
923
0
11474
14
0.0
6.0
456
0
110
0
0
12
0
4514
15
1.0
0.0
1052
0
67
45
10
63
0
5639
16
0.0
3.0
19
0
22
0
0
7
0
103
17
0.0
0.0
0
0
0
0
0
0
0
0
18
0.0
0.0
189
0
0
0
0
0
0
164
19
0.0
1.0
831
0
72
23
8
540
11
4513
20
0.0
0.0
12025
0
20
21
18
13
0
9623
21
0.0
4.0
0
0
>10.0%
0
0
1875
0
22
0.0
0.0
0
0
179
0
12
0
214
23
0.0
>10.0%
5853
81
81
42
17
210
13
7790
24
0.0
5.0
8126
57
32
22
10
102
3
8901
116
0.6
Se
ppm
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
3
0
0.7
Br
ppm
0
0
0
3
260
0
7
0
4
0
2
5
6
9
81
3
>10.0%
22
473
9
0
195
32
18
0.7
Rb
ppm
0
0
8
37
18
0
0
23
2
0
0
19
20
0
21
9
0
0
73
6
0
0
9
6
0.8
Sr
ppm
0
0
3
127
0
0
8
0
96
6
7
303
322
452
45
12
0
0
54
173
56
0
1261
723
0.6
Pb
ppm
7
0
5
18
0
0
0
0
11
0
0
18
17
4
3
0
0
0
0
31
0
0
7
14
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
Table (2) continued
Element
K
Ca
Unit
%
%
25
0.0
4.0
26
0.0
0.0
27
0.0
0.0
28
0.0
0.0
29
0.0
0.0
30
0.0
0.0
31
0.0
>10.0%
32
1.0
2.0
33
0.0
>10.0%
34
2.0
0.0
35
0.0
9.0
36
0.0
0.0
37
0.0
4.0
38
0.0
0.0
39
0.0
0.0
40
0.0
0.0
41
0.0
0.0
42
0.0
>10.0%
43
0.0
0.0
44
0.0
0.0
45
5.0
7.0
46
0.0
>10.0%
47
0.0
0.0
48
0.0
0.0
49
0.0
0.0
50
2.0
0.0
51
0.0
0.0
52
0.0
0.0
53
0.0
0.0
54
0.0
0.0
Ti
ppm
5833
5063
440
0
0
0
0
0
4032
1205
532
1991
7694
0
0
0
0
0
0
0
974
66
158
0
0
1116
871
2155
0
0
Cr
ppm
48
26
0
0
0
0
0
0
35
0
0
0
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Mn
Ppm
31
187
0
0
0
>10.0%
0
208
41
0
313
62
38
47
121
6885
0
97
64
0
0
42
589
>10.0%
106
49
0
16
>10.0%
219
Fe
ppm
7444
8029
843
4000
5977
0
116
126
5153
7463
4550
2748
7959
72
512
553
419
83
3014
0
6143
1318
2684
0
315
7004
3747
3072
0
3697
Ni
ppm
14
17
0
0
0
0
0
0
32
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Cu
ppm
36
2318
0
>10.0%
>10.0%
0
0
178
29
7
8
0
15
19
7
0
41
0
6
0
445
18
37
0
0
0
28
306
0
16
117
Zn
ppm
83
3748
8
0
0
20927
0
69
245
25
46
16
95
33
18
>10.0%
7
10
44
0
37
13
92
17819
8
22
0
14
10288
89
As
ppm
0
3
0
0
0
0
0
0
3
4
0
0
0
0
0
0
0
0
0
0
14
0
5
0
0
4
4
0
0
13
Se
ppm
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Br
ppm
48
26
3
0
0
73
10
9
21
5
23
70
0
16
28
32
13
11
151
>10.0%
6
3
6
0
0
5
3
72
0
15
Rb
ppm
13
13
7
0
0
12
0
5
0
133
16
23
8
3
24
11
25
0
15
0
171
4
176
0
0
126
16
22
0
176
Sr
ppm
188
105
4
0
0
0
70
9
1323
57
57
15
647
4
15
21
11
72
10
0
1359
446
51
0
8
50
21
20
0
124
Pb
ppm
13
20
8
0
0
0
11
0
16
9
4
0
18
0
12
0
0
9
0
0
0
7
8
0
0
10
12
30
0
16
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
Table (3) Heavy metals and some elements in 50 pesticide samples collected from Gaza, results of the ICP/OES.
Mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
Sample
Al
Ba
Cd
Co
Cr
Cu
Fe
Mn
1
47
5.5
0.1
BDL
0.4
0.4
17
2
2
1
0.8
0.1
BDL
BDL
1.4
BDL
5
3
65140
8.0
0.3
BDL
1.6
4.0
250
3
4
4428
193.0
4.3
42.0
1.1
1.7
802
56
5
1255
2.6
0.5
BDL
1.7
2.4
584
102
6
381
2.2
0.1
BDL
BDL
9.4
414
4634
7
233475
8.3
0.1
0.2
3.5
8.8
1398
284
8
1269
9.4
0.1
BDL
0.0
42.4
171
24
9
2542
4.5
1.3
4.8
9.9
16.0
3275
6
10
5
1.5
2.7
10.4
BDL
11.1
248
5
11
23364
33.8
0.1
0.3
40.7
40.2
5123
22536
12
25560
35.1
2.9
0.8
42.7
28.0
5183
23339
13
2509
28.2
0.5
BDL
5.8
2.8
2386
106
14
3927
40.0
0.2
BDL
17.9
8.4
2657
24
15
6074
27.5
0.1
BDL
BDL
1.1
159
38
16
1038
5.2
2.0
0.6
2.4
1.4
374
28
17
256
15.5
0.5
BDL
BDL
1.8
27
3
18
8475
44.1
1.8
8.0
19.8
14.6
2389
77
19
6881
32.6
0.1
BDL
33.5
19.3
4671
5
20
4465
3.0
27.8
0.1
BDL
2.0
323
14059
21
60
1.9
5.0
BDL
BDL
0.8
46
208
22
28670
80.3
0.3
BDL
125.0
26.9
5891
15
23
32785
71.0
0.4
BDL
74.8
22.7
5543
15
118
mg/kg
Ni
7.3
5.1
5.6
8.5
4.0
58.6
8.7
4.9
3.9
6.0
20.5
21.2
11.8
28.3
6.0
9.2
16.8
35.1
9.5
26.9
8.0
33.1
24.5
mg/kg
Pb
BDL
BDL
1.4
5.5
0.3
15.5
BDL
1.4
2.6
0.2
10.5
10.5
0.6
0.2
1.0
BDL
BDL
3.9
5.4
14.3
BDL
7.1
9.3
mg/kg
Sc
28
43
36
55
29
28
29
35
28
50
48
48
55
44
49
60
137
91
71
78
61
49
82
mg/kg
Sr
2
2
4
12
3
5
6
10
22
17
150
156
482
20
12
11
8
33
47
49
3
823
457
mg/kg
Zn
1
3
7
9
20277
10913
63
18
5
7
1224
1316
12
66
35
125
8
713
5
2997
34
316
152
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
Table (3) continued
Mg/kg
Sample
Al
24
11661
25
6838
26
74735
27
1395
28
81
29
33
30
708
31
33
32
66897
33
2345
34
4479
35
5432
36
37451
37
8
38
1276
39
606
40
1669
41
566
42
5281
43
328
44
4256
45
594
46
208
47
42
48
5510
49
6923
50
8132
mg/kg
Ba
30.7
26.9
11.9
23.5
2.6
2.0
56.1
23.8
216.6
46.6
86.5
12.5
83.1
2.4
19.3
11.1
14.8
57.4
13.2
5.1
56.4
225.4
3.8
6.3
12.6
18.2
146.2
mg/kg
Cd
0.4
0.3
0.4
0.3
17.2
1.7
0.3
0.4
0.7
0.2
7.9
0.3
0.2
11.7
0.3
0.3
0.8
0.5
0.2
0.3
2.9
0.3
0.4
0.6
0.4
0.4
0.5
mg/kg
Co
BDL
BDL
BDL
BDL
28.7
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
BDL
26.6
BDL
BDL
BDL
BDL
BDL
BDL
mg/kg
Cr
23.9
13.0
0.5
12.9
BDL
BDL
4.3
BDL
252.1
0.8
12.0
2.7
80.8
43.0
BDL
BDL
BDL
0.5
19.5
BDL
BDL
2.9
BDL
BDL
10.8
4.1
0.1
mg/kg
Cu
37.7
2471.5
5.0
169791.7
135129.7
104.1
28.7
284.5
102.7
5.9
3.2
3.0
35.2
16.2
6.4
5.3
66.4
1.1
17.3
2.6
622.0
29.6
13.3
1.5
19.2
335.7
16.9
119
mg/kg
Fe
4239
2897
280
1822
108
280
99
88
9150
958
1804
273
5663
56
111
174
171
79
2765
295
159
725
423
191
1618
373
1039
mg/kg
Mn
30
97
6
19
11
21021
46
280
25
15
431
73
36
35
141
2996
15
82
123
208
15
95
22760
15
23
19
190
mg/kg
Ni
26.8
21.6
15.2
88.5
1742.8
21.3
16.0
24.3
70.6
10.3
17.9
18.0
26.4
12.1
13.3
13.8
15.6
11.0
18.9
14.3
14.3
20.7
82.4
13.5
17.7
19.0
20.0
mg/kg
Pb
1.5
10.6
1.9
2790.9
BDL
15.7
7.8
BDL
16.1
0.9
BDL
3.9
10.6
BDL
11.2
40.7
0.5
8.3
BDL
1.8
0.9
5.0
16.7
BDL
4.2
9.2
9.1
mg/kg
Sc
139
154
110
101
120
116
113
149
139
68
116
137
92
77
106
94
119
83
100
99
117
125
128
101
129
141
155
mg/kg
Sr
76
44
7
19
4
4
42
16
1958
8
35
11
473
7
13
18
16
40
10
19
1119
396
8
11
8
20
66
mg/kg
Zn
95
3603
8
1149
338
20852
9
95
870
10
68
16
144
31
23
52715
62
20
193
36
7
24
20114
5
6
129
99
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
Comments on the field surveys
A very serious situation exists with respect to pesticide use, due to the exceedingly large
volumes used and the lack of information available in Arabic, to wholesalers, farmers and
others dealing with pesticides. Gaza is suffering of absence of legislations, limited
experience, shortage in the qualified individuals, in addition to the key point that pesticides
are present in unspecialized shops and they are handled and sold by low or uneducated
persons. The absence of governmental monitoring and inspection systems coupled with
limited awareness among pesticide users allow the later group to store pesticides under bad
conditions. Because pesticides are very expensive, some shop owners mix different pesticides
without scientific rules and the field visits revealed some of this practice. During the
application of pesticides, farmers spray, eat and smoke at the same time, disregarding the
general instructions of spraying. Around 24 chemical pesticides that have been prohibited or
restricted worldwide are still being used in the Gaza Strip; examples of such pesticides are
Lindane, Dorspan, DDT, Tamaron and others.
Leniency in laws against irresponsible use of pesticides and lack of government and social
awareness programs allow toxic and dangerous pesticides to easily reach the hands of the
people.
Malpractices include sales of pesticides that have passed their expiration date; internationally
wrong labeling containers to sell cheap products at high prices; and sale of organic and
inorganic chemicals instead of pesticides. Another dangerous problem is the labels of the
pesticide's containers. As the wholesalers import pesticides in big containers, they divide big
size containers into small ones (mostly made of plastic) as the final containers have the
commercial name in the best cases and only numbers in the majority. Although farmers of
Gaza are very professional, they do not have the access either to information on pesticide
application, safety and storage measure or to pesticides adverse effects on human health and
environment.
120
Chapter Eight
Heavy Metals in Major Solid-Pesticides Used in the Gaza Strip
__________________________________________________________________________________________
Table (4) Calculated and measured values of some elements.
Pesticide
Chemical Structure
Fosetyl-aluminum
Propineb
Mancozeb
Maneb
Aluminum phosphide
Bromacil
Bromadiolone
Foscthyl-Aluminum
Copper Oxychloride
Copper Sulfate
Bromadialone
Metiram
Bromacil
Zineb
Triazine
Manage-imibenconazole
Terbutryne
Amitrole
Linuron
Maneb
Chinomethionat
Copper Sulfate
Copper Oxychloride
Carbaryl
DDT
Manage-imibenconazole
*) Theoretical monomer
**) Pentahydrate
C6H18AlO9P3
(C5H8N2S4Zn)x*
[-SCSNHCH2CH2NHCSSMn-]x (Zn)y
C4H6MnN2S4
AlP
C9H13BrN2O2
C30H23BrO4
C6H18AlO9P3
ClCu2H3O3
CuH10O9S**
C30H23BrO4
(C16H33N11S16Zn3)x
C9H13BrN2O2
C4H6N2S4Zn
C7H12ClN5
C17H13Cl3N4S
C10H19N5S
C2H4N4
C9H10Cl2N2O2
C4H6MnN2S4
C10H6N2OS2
CuH10O9S
ClCu2H3O3
C12H11NO2
C14H9Cl5
C17H13Cl3N4S
Tested
Element
Al
Zn
Mn, Zn
Mn
Al
Br
Br
Al
Cu
Cu
Br
Zn
Br
Zn
Ba
Cd
Co
Cr
Cu
Fe
Mn
Ni
Pb
Sc
Sr
Zn
Calculated
value (mg/kg)
245455
224293
25500, 200000
207312
224000
>30%
151688
245455
299625
256308
151688
59704
306396
235678
0
0
0
0
0
0
0
0
0
0
0
0
Measured
value (mg/kg)
65140
20277
4634, 10913
23339
233475
>10%
22
74735
169792
135130
16
52715
>10%
20114
225
28
42
125
622
5183
22536
59
2791
154
1958
2997
CONCLUSIONS
1. Tested pesticides have considerable amounts of heavy metals and there is no agreement
between measured and calculated values; the calculated values are much higher.
2. The same pesticides have different names in the same shop and in different shops, as well
as different amounts of the same heavy metals.
3. Many tested pesticides have no heavy metals in their chemical structure in the pure form
but they have them in the marketed forms in Gaza.
4. The field surveys revealed that the contamination of pesticides by heavy metals may occur
due to bad procedures of storage and preservation; mixing of some pesticides in the market
itself without scientific rules; and finally the absence of legislations and governmental
inspection programs.
5. Pesticides should be considered as a source of some heavy metals in soil and groundwater
of the Gaza Strip and they should be included in mass balance and geochemical cycle of
some heavy metals.
121
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Whitford, G. 1989. The Metabolism and Toxicity of Fluoride. Monogr. Oral Sci. 13, 1-160.
Whittle, A. J., Dyson, A. J. 2002. The fate of heavy metals in green waste composting.
Environmentalist 22, 13-21.
WHO. 1998a. Guidelines for Drinking Water Quality Addendum to Volume 2, Second
Edition, Health Criteria and Other Supporting Information (WHO/EOS/98.1), World Health
Organization, Geneva.
WHO. 1998b. Industrial Wastewater in the Mediterranean Area, Environmental Health 8,
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Wiberg, K., Harner, T., Wideman J. L., Bidleman, T. 2001. Chiral analysis of organochlorine
pesticides in Alabama soils. Chemosphere 45, 843-848.
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134
APPENDICES
Preparation and digestion of soil, sediment and sludge samples
Soil, sediment and sludge samples could be found as:
* Dry samples or
* Wet samples.
Collection and preparation:
- Open and grass soils: 0-10 cm deep.
- Vegetable soils: 20 cm deep.
- Ploughed soils: 30 cm deep.
At each sampling station, a circle of 2-5-m diameter to be identified and 10 sub-samples to be
collected within the perimeter and mixed to form a composite sample. Remove all plant
tissues and large stones. Samples (0.5 kg) to be collected using a stainless steel dredge,
placed into polyethylene cups and stored at 4 oC. Approximately 0.5 kg of soil was put in
polyethylene cups and stored at 4 oC during transport to laboratories where soil was dried in
an oven at 50 oC until constant weight. Then they were shipped to Germany in plastic
sampling bags. The samples were sieved through a 20-µm sieve and ground to a very soft
powder. The sample could be used for all cations including heavy metals, C, N, S, B, F and P.
For organic parameters samples should be dry-frozen for 48 hours.
Preservation:
Keep the samples in dark and dry conditions or in the refrigerator at 4 oC.
Digestion of soil, sediment and sludge samples for heavy metal and P analysis
1. In glass beakers, weight 0.5 or 1 to 2 g of each sample in duplicates (depending on the
expected range of heavy metals and phosphate; for sludge samples 0.5 g is enough, for
soil 1-2 g).
2. Under a hood, add 3.3 ml HNO3 (65%), shake gently. Add 9.9 ml HCl (37%), shake gently
by using a glass rod. The ratio is 1 conc. HNO3: 3 conc. HCl.
3. Use acids only as blanks, and known Standard Reference Materials (SRM) as a
reference. Blanks and SRF should be treated as samples and digested together.
3. Cover the beakers by glass-watches.
4. Leave at room temperature for 1 to 2 days for dissolving and degassing.
5. Place the samples in a sand bath at 160 oC for 3 to 4 hours, increase the temperature
gradually and avoid boiling by shaking the beakers from time to time.
6. Transfer beaker contents to a 50-ml volumetric flask including all sample residues, mix
well and complete the total volume up to 50 ml by dH2O.
7. Filter the samples by using normal filter paper into plastic containers 100 ml.
8. Keep at room temperature until analysis.
1
Determination of soil pH
1. Take about 10 g of dry soft soil.
2. Add 20 ml of CaCl2 (0.01 N).
3. Wait for about 1 hour.
4. Measure by the pH electrode.
Determination of total fluorides in soil samples
Sample preparation:
1. Take about 50 mg dry-sieved sample in a nickel crucible.
2. Add 2 g 1:1 Na2CO3-K2CO3 (anhydrous dried at 110 oC overnight).
3. Place in the oven (a muffle furnace) at 800 oC for 15 minutes.
4. After cooling, add 15 ml of 1 M citric acid to the crucible and allow the mixture to digest
until CO2 evolution is no longer detected (3-4 hours, or preferably overnight). (1M citric acid
prepared by dissolving 210.15 g citric acid monohydrate in 1 liter dH2O).
5. Add 25 ml of sodium citrate buffer (1M) to the contents of the crucible.
(Prepared by dissolving 294 g Sodium citrate dihydrate in about 800 ml dH2O, adjust the pH
to 6 with 6N HCl and finally dilute the solution up to 1 liter).
6. Transfer the mixture to a 100-ml polypropylene beaker.
7. Carefully rinse the crucible with dH2O.
8. Dilute the sample solution to 100 ml by dH2O.
Reagents:
Stock fluoride solution:
- Dissolve 2.21 g anhydrous (dried at 110 oC overnight) sodium fluoride (NaF) in distilled
water and dilute to 1 liter, 1000 mg/l is produced. (or use the MERCK stock 1000 ppm).
Sodium hydroxide (NaOH) 6 N:
- Dissolve 60 g NaOH in 250 ml dH2O.
Fluoride buffer solution:
- Place about 500 ml dH2O in a 1-liter beaker.
- Add 57 ml glacial acetic acid.
- Add 58 g NaCl.
- Add 4 g 1,2 cyclohexylenediamineteteraacetic acid (CDTA = trans-1,2Diaminocyclohexane-N,N,N,N-tetraacetic acid.).
Note: CDTA can be replaced by EDTA.
- Stir to dissolve, place beaker in a cold water bath and add slowly 6 N NaOH (about 125 ml)
with stirring until pH is between 5.3 and 5.5.
- Transfer to a 1-L volumetric flask and complete the volume up to 1 liter by dH2O.
2
Determination of inorganic carbon in soil samples using a carbonate bomb to
measure total inorganic carbon as % CaCO3
Procedure:
1. Weight exactly 0.74 g of dry-sieved soil sample.
2. Place the wt. in the measuring bottle.
3. Add 25% HCl (6N) into the internal chamber of the bomb head, up to the mark.
4. Close the bottle vertically very tight.
5. Let the acid flow to the sample in the bottle, shake very well (don’t touch the bottle but
only the head).
6. Wait until you have constant reading which represents % CaCO3.
NOTES:
a) When the sample has high amounts of CaCO3, the reading will appear very fast, but when
it has high MgCO3 then you have to wait up to 15 minutes.
b) Use a reference material (Calcite CaCO3 which gives 99.2% CaCO3) each 15-20 samples.
When the reference material gives less than 99.2% then include a correction factor in the final
results.
c) The meter can minimally read 5% and more, when the sample gives less than 5% then you
can use (X) 0.74 g sample.
E.g. 2*0.74 = 1.48 g or even 3*0.74 = 2.22 g.
The final reading should be divided by X
e.g. 1.48 g sample gives 8% CaCO3, so the final CaCO3 is 8/2 = 4%
How to prepare 6N of HCl?
1. When you have a concentrated acid of 12 N (in the label), take acid to water v/v (1:1).
2. When the normality or the molarity is not labeled:
Density = 1.19 g/ml.
Purity = 37%.
M.wt. = 36.5 g.
Needed volume to be prepared = 1000 ml (1liter).
Molarity = No. moles/liter
No. moles = weight (g)/M.wt(g)
Weight = Density * volume (ml) * purity %
100
Molarity = 1.19 * 1000 * 37
= 12.06 M (or N).
36.5 * 100
Note: Molarity of HCl 35% = 11.4 M
3
Preparation of Diazomethane
Important:
Diazomethane was prepared using the method of de Boer and Baker (1954). Every step of
this reaction has to be performed under a hood with a security glass pane. Diazomethane is
poisonous, carcinogenic and mutagenic.
Preparation:
- Dissolve 8 g KOH in 20 ml ethanol/water (90:10 v/v) in a 250 ml double-necked round
bottom flask.
- The flask is equipped with a magnetic stirrer and mounted on a heating bath (filled with
water or glycerol).
- Dissolve in a separate vessel 5 g N-methyl-N-nitroso-p-toluenesulfonamide in 50 ml
diethylether under stirring or shaking.
- Place a dropping funnel containing the ethereal solution on top of the two-necked flask. Connect a distillation bridge with a Vigreux coloumn to the flask. The receiving flask for the
distillate is cooled in an ice bath.
- Heat the reaction flask to about 50-60 °C.
- Now add slowly under stirring the ethereal solution drop by drop.
- Collect about 30 ml of the distilled yellow diazomethane solution in ether.
- Pipette it into three 10 ml tubes (screw cap with Teflon liners).
- Store them at -18 °C.
Finally neutralize the alkaline reaction mixture with HCl. Decontaminate all glassware,
which has been in contact with diazomethane which dilute acetic acid.
Caution! Diazomethane is highly volatile, toxic and carcinogenic. Work under a hood and
apply the usual precaution measures carefully! A suitable destroying agent against spilled
Diazomethane solution is acetic acid.
Reference:
de Boer T J, Baker H J. (1954) A new method for the preparation of Diazomethane. Recl.
Trav. Chim. Pay-Bas 73, 229-234.
4
Extraction procedure and sample preparation for the combined GC/MS
Analysis of PAHs, PCBs, Chlorobenzenes and non-polar chloropesticides in
soil and similar materials
Chemicals and reagents:
1. Extraction solvent of cyclohexane/ethylacetate (100:2) (only if present)
- mix 1000 ml cyclohexane + 20 ml ethylacetate.
2. Extraction solvent of n-hexane/ethylacetate (100:2)
- mix 1000 ml n-hexane + 20 ml ethylacetate.
3. Silica gel/ AgNO3 (100:5 wt:wt): to adsorb all polar groups during the extraction process:
- Dissolve 50 g AgNO3 in about 30 to 50 ml dH2O.
- Weight 1 kg of commercial silica gel.
- Mix the AgNO3 and the silica gel very well, divide the mixture into 3 glass bottles
(each 1 l volume) about 2/3 of each.
- Place in the rotating shaker for about 24 hours.
- Dry and mix all bottles to form homogenous mixture.
4. Anhydrous sodium sulfate (Na2SO4) as a dehydrating agent.
5. Internal standard: (Ehrenstorfer internal standard mix 33, diluted by cyclohexane to a
concentration of 5µg/ml.
Sample preservation and preparation for the Extraction:
1. Freeze-dry the samples for 48-72 hours depending on the water content.
2. Sieve the samples through < 2 mm.
3. Store in cool and dark (about -18 oC stand for years).
Extraction procedure:
First: Soxhlet Extraction (12 hours)
1. In a beaker, take about 10-15 g dry soil sample.
2. Transfer to the filter thimble by a plastic funnel.
3. Place the filter thimble in the Soxhlet extraction assembly.
4. Take 75 ml of n-hexane/ethylacetate (100:2) in a 100 ml spherical flask.
5. Connect the upper end of the Soxhlet extraction assembly to the cooler by using a
Teflon ring seal, be sure the system is tight.
6. Connect the lower end of the Soxhlet extraction assembly to the spherical flask.
7. Adjust the water current of the cooler.
8. Adjust the temperature to the boiling point of the solvent (about 50 oC), level 2.
9. Leave it overnight (about 12 hours).
Notes:
*The filter thimbles may be reused by drying them under the hood and emptying them.
* Do not use grease for the glassware, but use Teflon rings only.
5
Second: Rotating Evaporation:
1. After the extraction, remove the filter thimble and leave to dry under the hood.
2. To the extraction, add 100 µl of internal standard for the GC/MS (Ehrenstorfer internal
standard mix 33, (5µ/ml).
3. Add 1 spatula (1-2 g) anhydrous Na2SO4, shake and leave to settle down.
4. Transfer all contents (without Na2SO4 ppt.) to a pear-shaped (special spherical) flask
with graduated centrifuge tube at the bottom.
5. Use a Teflon ring and connect the pear-shaped flask to a rotating evaporator and use a
plastic ligament to connect the upper part of the flask to the cooling system.
6. Keeping the following conditions: the pressure is adjusted at 260 mbar, the speed is
between 3-4 rpm, and the water temperature is between 40-50 oC. Close the cooling glass
helix upper valve during evaporation.
7. Reduce the total volume into 2-3 ml.
Switch the system off (the thermostat, the pressure and the instrument, open the helix
valve gently).
Third: Volume Reduction and SPE System:
1. Under a gentle current of N2 gas, reduce the volume into 1-2 ml only. The probe inside
the flask bottom should not touch the extract.
2. Use a 6-ml SPE florisil cartridge (a magnesium silicate), (filled with a combination of
several absorbents). Fix it to the extraction beaker. Inside the beaker, place a plastic
centrifuge-tube in the corresponding position to the cartridge.
3. Add few drops (about 1 ml) of absolute methanol to the SPE to activate its content.
4. Fill the cartridge with about 2 ml solvent (n-hexane/ethylacetate).
5. By using a dry funnel, pour in SPE ca. 0.8 g home made silica gel/AgNO3.
6. Condition and clean with 4 ml solvent.
7. As soon as the liquid level has reached the solid phase surface, close the small tap and
discard the 5-6 ml solvent of the tube (from the beaker) into the wastes.
8. During this step the column should remain wet, transfer the concentrated extract (about
1 ml) gently to the column.
9. Add 6 ml solvent above the sample extract, open the small tap and leave to percolate to
the surface of solid phase. (Add 2 ml solvent in 3 steps).
10. The collected liquid is about 5-6 ml (in the centrifuge tube inside the beaker).
11. Reduce the extract into 1 ml under a gentle current of nitrogen gas.
12. Transfer to the autosampler vials (glass cells), close well, label and keep in the
refrigerator (4 oC) for analysis (can stand for few years).
Notes:
1. If there are impurities in the column, you can use a vacuum to achieve flow rate of
filtrate (1-2 ml/minute).
2. Clean the extraction SPE-system (small taps you used), by fixing an empty cartridge,
then add about few mls acetone (or ethylacetate) for rinsing (allow to leave then close the
tap), followed by 4 ml solvent.
3. The empty cartridge are dried under the hood and been used again.
4. Used cartridge: let them dry under the hood and collect the silver-containing upper
phase in a special container of wastes for recycling.
6
Fourth: Preparation of Blank
Use only an empty filter thimble and do the exact procedure of extraction.
Fifth: Preparation of Reference Standard (identify extraction procedure)
1. Use a clean sample (soil or sediment), after 12 hours Soxhlet extraction, dry the filter
thimble under the hood. Take the clean sample and weigh few grams (or take the entire
amount available).
2. Use 75 ml Cyclohexane, and connect the flask to the Soxhlet extractor.
3. Place the filter thimble inside the Soxhlet and by a long pipette:
4. Add 1 ml of PAHs standard (500 ng/ml).
5. Add 1 ml of PCBs and Pesticides standard (500 ng/ml).
6. Do the rest as usual.
Sixth: Efficiency of Cleaning Procedure
1. In a centrifuge tube, place 1 ml of PAHs standard (500 ng/ml) and 1 ml of PCBs and
Pesticides standard (500 ng/ml).
2. Add 100 µl of the internal standard for the GC/MS (Ehrenstorfer internal standard mix
33, (5µ/ml).
3. Reduce the volume by N2 gas into 1 ml.
4. Continue the SPE procedure as usual.
Important:
Determination of PAHs, PCBs, Chlorobenzenes and non-polar chloropesticides in
groundwater by Using HPLC/MS.
The prepared vials could be used for HPLC by minor modifications in the solvent used.
Modification Procedure:
- Transfer 500 µl of the old vials to new clean vials (Keep the rest for the GC/MS analyses
later).
- Under N2 gentle current, dry the contents of the vials to complete dryness or to very minute
droplet.
- Add 1 ml (absolute methanol: dH2O) 1:1 v/v. to each vial.
- Shake, leave for few minutes and close well.
- Label the new vials of water and soil samples.
7
Water extraction for polar and medium-polar compounds
Reagents and solvents:
1) Absolute methanol.
2) 1,3,5-trimethoxybenzene (ready in the refrigerator).
Internal Standard Solution:
1) 2,4-D (Ring 13C6) with concentration of 5 µg/ml. Store the standard solution cool, if
possible, and in the dark. Tightly close the bottle immediately after every use.
2) Ethyl acetate (analytical grade).
3) Acetonitril (analytical grade).
4) Phosphoric acid (85 %, analytical grade).
5) Internal standard: (Ehrenstorfer internal standard mix 33, diluted by cyclohexane to a
concentration of 5µg/ml.
6) PAHs standard (500 ng/ml).
7) PCBs and Pesticides standard (500 ng/ml).
8) Explosives standard (2000 ng/ml = 2µg/ml).
9) Diazomethane solution (in deep freezer).
10) Major Pesticides:
- Triclopyr (5 µg/ml) = (5 mg/l).
- Picloram (5 µg/ml).
- Dicamba (5 µg/ml).
- Dichloroprop (5 µg/ml).
- 2,4 DB (5 µg/ml).
- Mecoprop (5 µg/ml).
- MCPA (5 µg/ml).
- MCPB (5 µg/ml).
- 2,4-D (5 µg/ml).
- 2,4,5-T (5 µg/ml)
11) Methanol/ Tert-Butyl- Methyl Ether (TBME), 20:80 (v:v).
(take 20 ml Methanol and 80 ml MTBE and mix).
Extraction procedure:
1. In a glass-container cleaned and dried in an oven over night at 120 oC, and later on
washed many times by methanol, collect 1 liter of the groundwater sample.
2. Add 5 ml phosphoric acid (85 %, analytical grade)
3. Add 100 µ l internal Standard solution 2,4-D (Ring 13C6).
4. Add 100 µl of 1,3,5-trimethoxybenzene.
5. Add 100 ml absolute methanol.
6. Shake thoroughly
7. As standard sample, add 100 µl of each of the following standards:
- Triclopyr (5 µg/ml).
- Picloram (5 µg/ml).
- Dicamba (5 µg/ml).
- Dichloroprop (5 µg/ml).
- 2,4 DB (5 µg/ml).
- Mecoprop (5 µg/ml).
8
- Fenoprop (5 µg/ml) (if present).
- MCPA (5 µg/ml).
- MCPB (5 µg/ml).
- 2,4-D (5 µg/ml).
- 2,4,5-T (5 µg/ml)
Add 1 ml of PAHs standard (500 ng/ml) and1 ml of PCBs and Pesticides standard
(500 ng/ml) and 100 µl of Explosives standard (2000 ng/ml = 2µg/ml).
8. Shake very well.
9. As Blank sample, use 1 liter of Milli-Q dH2O (add every thing except the standards).
10. Use a fresh SPE-cartridge type: Oasis HLB, 200 mg, 6 ccm, 30 µm grain size.
11. Condition the SPE as shown in the figure.
12. Rinse the SPE with 3 ml Ethyl acetate (analytical grade), then rinse again with 3 ml dwater.
13. Discard the received 6 ml as waste.
14. Connect the assembly as shown in step (3) extraction and adjust the flow rate at ca.
10-20 ml/min
15. At the end of the extraction step, suck some air through the cartridge for several
seconds. Freeze or - if possible - freeze-dry the cartridge. Wrap it in aluminum foil in
order to protect it from contamination. Keep frozen or - if freeze-dried - store cool in the
dark in a closed container. In this state it can be maintained virtually for an unlimited
duration.
16. For final preparation and for measurements, rinse the SPE by 6 ml methanol/TBME
solvent.
17. Add 100 µl of internal standard mix 33 (5 µg/ml).
18. Reduce the final volume into ca. 500 µl by a gentle current of N2.
19. Transfer to measuring vials, add 100 µl Diazomethane solution, N2 gas is librated
from the vials, cover them and leave for one hour at room temperature to allow all N2 to
liberate and finally, close the vials very well, keep in the refrigerator at 4 oC.
IMPORTANT:
a) One standard is used to chick the accuracy and the performance of the enrichment step,
do not do steps 3 and 4 and add 100 µ l internal Standard solution 2,4-D (Ring 13C6) then
100 µl of 1,3,5-trimethoxybenzene to the extract after step 16 above .
b) For Comparison, you can try 6 ml ethylacetate, or 6 ml acetonitril in new SPEs). Use
another two solvents, do not use methanol in step 16 and to the first standard add 6 ml
ethylacetate, and to the second add 6 ml acetonitril.
9
Solid phase extraction (SPE) procedure for water samples using commercial
SPE Cartridges
Used SPE-cartridge type: Oasis HLB, 200 mg, 6 ccm, 30 µm grain size.
Steps
1
Conditioning
1. rinse with 3 ml Ethyl acetate (analytical grade)
2. rinse with 3 ml water
SPE cartridge
vacuum pump
2
Sample preparation
1. add 5 ml phosphoric acid (85 %, analytical grade)
2. add 100 µl internal standard solution (ring 13C6) (*)
3. shake thoroughly
(*) contains 500 ng 2,4-D (ring 13C6).
This step may be omitted, if the standard is
not available at the sampling site. In this case
the internal standard must be added in the
laboratory later during SPE re-extraction.
1 liter collected
Water sample
Note: Function of phosphoric acid (H3PO4) is to donate protons.
10
3
Extraction
PTFE tubing
flow rate:
ca. 10 - 20 ml/min
vacuum pump
waste
4
Storing conditions
At the end of the extraction step, wash with 5 ml distilled water (analytical grade) and
suck some air through the cartridge for several seconds. Freeze or - if possible freeze-dry the cartridge. Wrap it in aluminium foil in order to protect it from
contamination. Keep frozen or - if freeze-dried - store cool in the dark in a closed
container. In this state it can be maintained virtually for an unlimited duration.
Internal Standard Solution
The internal standard is:
2,4-dichlorophenoxyacetic acid (ring 13C6) in Methanol.
Conc. = 5 µg/ml.
5
Re-extraction and final preparation
1. Place the SPEs in the freeze-dryer for 48 hours (open the Al-foil but don't remove).
2. Add 100 µl internal standard solution (ring 13C6) directly to SPE.
3. Re-extract the SPE with 6 ml TBME (Tert. Butyl methylether) solvent.
4. To the receiving tube, add 0.4 g anhydrous Na2SO4. (to adsorb water and moisture).
5. Stir and leave the tubes for about 30 minutes.
6. Transfer the solvent (avoid the ppt of Na2SO4) to new tubes.
7. Reduce the final volume into ca. 500 µl by a gentle current of N2.
8. Transfer to measuring vials, add 100 µl Diazomethane solution, N2 gas is librated from the
vials, cover them and leave for one hour at room temperature to allow all N2 to liberate and
finally, close the vials very well, keep in the refrigerator at 4 oC.
11
Preparation of standards used for determination of polar and medium-polar
compounds in water samples
We are searching for three groups of compounds:
1) Phenoxy acetic acid (e.g. 11 standards herbicides).
2) PAHs and PCBs (including chloropesticides).
3) Phenols. (Phenol kit 27. (Standard mix in Methanol) is from SUPELCO.INC under Cat. No. 44570).
Standards are prepared in the same procedure of water samples
1. In 3 clean- dry 1000 ml sampling bottles (in an oven over night at 120 oC, and later on washed
many times by methanol), collect 1000 ml Elga-water (Milli-Q Water).
2. Add 5 ml phosphoric acid (85 %, analytical grade)
3. Add 100 µ l internal Standard solution 2,4-D (Ring 13C6).
4. Add 5 ml absolute methanol. Shake thoroughly.
5. Bottle (a) Standards of Phenoxy acetic acid:
Add 100 µl of each of the following standards:
1) Triclopyr (5 µg/ml).
2) Picloram (5 µg/ml).
3) Dicamba (5 µg/ml).
4) Dichloroprop (5 µg/ml).
5) 2,4 DB (5 µg/ml).
6) Mecoprop (5 µg/ml).
7) Fenoprop (5 µg/ml) (if present).
8) MCPA (5 µg/ml).
9) MCPB (5 µg/ml).
10) 2,4-D (5 µg/ml).
11) 2,4,5-T (5 µg/ml.
6. Bottle (b) Standards of PAHs and PCBs:
Add the mixture of following standards:
- In a centrifuge tube, Mix 1 ml PAHs standard (500 ng/ml) and 1 ml of PCBs and Pesticides
standard (500 ng/ml) and also: 100 µl Internal standard: (Ehrenstorfer internal standard mix
33 diluted by cyclohexane to a concentration of 5µg/ml) in a tube.
- Reduce the volume under N2 gas to dryness (leave only one small drop).
- Add 3 ml acetonitril.
- For complete dissolution, put into ultrasonicator (u.s bath) for about 5 minutes.
- Add the mixture to the sampling bottle.
(Note: the mixing step and the complete dissolution of the standards with this solvent is
important to water samples. The solvent changes cyclohexane into water miscible Acetonitril).
7. Bottle (c) Standards of Phenols:
Add 0.5 ml of phenol kit 27 (1-50, conc. = 10mg/100ml).
8. Shake the three bottles very well.
9. Use a fresh SPE-cartridge type: Oasis HLB, 200 mg, 6 ccm, 30 µm grain size. Condition the
SPE (Step 3) as shown in the figure and extract (Step 5 from point 3 to 8).
12
Coordinates of municipal wells in the Gaza Strip used in this study
Name
ID
(X)
(Y)
(Z)
Indus. Area Iriz
A/135
109560
107460
40
Ghabn
A/180
102458.9 107032.7 24.071
Al Mashrooa'
A/185
102530 106252.3 40.629
Al Majlis
A/32
102583.8 106270.5 40.015
Assalatin-old
D/67
101715.9 107217.9 22.902
Assalatin-new
D/73
101036.5 106827.4 22.902
Al Izba
C127
104777.6 106153.9 57.238
Abu Ghazala
C128
106476.9 104891.2 66.019
Industrial estate
C/76
104667.1 104337.1 41.098
Awqaf
C/79
105349.3 105095.3 42.45
Abu Sharkh-East
D/2
101379.3 105027.6 40.23
Abu Sharkh-West
D/60
101286 105111.8 35.978
Aamer
D/74
100503.7 106104.1 39.986
Ashshwa
E/6
103013.3 105334.3 35.165
Al Alami
E/10
102522.5 105106
38.162
UNRWA-1
E/11a
101845.1 104418.8 35.8161
UNRWA-2
E/11b
102164.8 105095 28.4091
UNRWA-3
E/11c
101970.5 105190.4 33.8914
Abu Rashid
E/138
102719.8 104398.4 41.34
Ashanti
E/142
99980
105260
Abu Talal
E/156
102066.9 104589.4 27.207
Al Bahtimi
E/4
103034 105064.1 37.885
Murad
E/61
99737.38 106339.3 44.753
Atturk
E/8
102740
104910
40
Al Khazzan
E/90
101277.9 104582.7 46.205
Al Majlis
E/92
100910
104230
Nammar
Q/40b
102769 103963.3 55.001
Abu Haseera
E1
13
Coordinates of municipal wells in the Gaza Strip…..continued
Name
ID
(X)
(Y)
Sheikh Radwan 8
E/154
99330.04 105052.3
Sheikh Radwan 9
E/157
100155.9 104669.8
Sheikh Radwan 10
D/68
100513.6 105179.3
Sheikh Radwan 7
R/162h
99054.74 103698.8
Sheikh Radwan 7a
R/162ha
99049.88 103698.8
Sheikh Radwan 1a
R/162La
98480.54 104045.3
Sheikh Radwan 1
R/162L
98441.98 104037.2
Sheikh Radwan 11
D/69
100834.7 105466
Asalia
Q/39
103040
109300
Sheikh Radwan 12
D/70
101439.9 105833.2
Sheikh Radwan 12
D/72
101739.3 106462.4
Sheikh Radwan 3
R/162b
98725.4 104402.2
Sheikh Radwan 4
R/162c
98866.31 104595.4
Sheikh Radwan 5
R/162d
98638.31 104989.9
Sheikh Radwan 2
R/162e
98247.77 104479.3
Sheikh Radwan 6
R/162f
98480.54 104045.3
Sheikh Radwan 13
R/162g
99165.91 103952.4
Ashija'ea 4
R/66b
Ashija'ea 2
R/75
100417.2 101298.9
Ashija'ea 3
R/74
100661.2 101542.9
Sheikh Ejleen 3
R265/
95809.39 101707.6
Sheikh Ejleen 4
R/113
96558.03 102588.6
Sheikh Ejleen 2
R/254
96542.39 102055.5
Sheikh Ejleen 1
R/112
96061.2 102650.2
Assafa 4
R/25d
100819.9 102495.9
Assafa 3
R/25c
100774.7 102456
Assafa 1
R/25b
100778.7 102527.2
Assafa 2
R/25a
100758.5 102581.4
Sheikh Radwan 15
D/71
101458 106192.9
Sheikh Radwan 2
R/162E
98247.77 104479.3
Deir Balah-East
T/46
91983.82 90272.48
Deir Balah-2
S/69
91767.68 90702.94
Deir. B. Abu Bashir
G/178
89227.91 92534.58
Al Maghazi-Bin Said
S/42
93032.33 91934.48
Al Maghazi-Municipality
S/37
92220.31 92755.94
Al Bureij
S/19
93660
93660
Deir Balah-3
J/35
88270
92040
Desalination Plant
J/32
88304.06 91767.2
Deir Balah-1
J/146
91200.34 90460.38
Al Maghazi
G/149
91516.8 92948.4
14
(Z)
43.634
26.235
22.848
33.049
34.45
57.796
56.88
27.499
53.5
24.894
21.591
53.504
50.544
39.853
40.033
35.715
42.053
44.657
39.099
40.96
36.055
20.712
34.456
34.44
33.108
32.269
27.969
40.033
78.541
67.685
24.01
74.81
42.871
94910
13.79
28.257
60.98
26.536
Coordinates of municipal wells in the Gaza Strip…..continued
Name
ID
(X)
(Y)
Assa'da
L/87
83040.16 84200.69
UNRWA-new
L/86a
82235.27 84662.68
UNRWA-new
L/86
82244.33 84658.55
Ayya
L/43
83062.92 83461.37
Municiaplity-East
L/41
84345.8 83160.51
Qarara-new
L/179
85570.28 87462.72
Assatar
L/178
84366.49 86366.49
Municiaplity-South
L/176
82186.59 83276.65
Al Amal-new
L/159a
82677.99 85081.92
Al Amal-old
L/159
82604.9 85047.02
Al Ahrash
L/127
82850.87 83935.06
Qarara
K/19
86461.66 88591.6
Tawfeek Al Kurd
T/44
89230.79 87641.99
Abasan Kabeera
N/9
87833.14 81623.57
Abasan Kabeera
N/22
88050
81820
Bani Suhail-East
M/2b
85766.62 83686.87
Bani Suhail
M/2a
85554.73 83908.8
Rafah-East
P/124
77598.02 79413.99
UNRWA
P/10
78612.96 77038.7
Zo'rob
P/153
Canada
P/144
78301.93 80376.27
Al Hashash
P/145
79368.62 79856.37
Municipality-new
P/138
78772.7 79764.8
Municipality
P/139
77166.57 82010.52
Municipality
P/15
77926.76 78904.24
15
(Z)
52.698
47.982
47.72
59.907
61.624
28.545
22.835
38.386
45.12
42.815
52.96
24.09
86.542
76.42
79.967
87.369
67.447
24.152
81.72
32.159
48.206
47.8
9.815
21.967
#
Q/39
D/67 A/180
D/73 #
#
#
E/61
##
#
#
#
A/135
#
#
C127
A/32
#
#
Beit Hanun
North Area
D/74
D/70 E/6
#
#
#
#
## #
R/162d# E/154
##
#
#
# E/4
#
R/162e #
#
#
# #
#
# E/8
E/157 #
##
#
#
R/162E
E/92
R/162g
#
Q/40b
R/162L
R/162h
R/112
R/25a R/25d
# # R/113
#
#
C/79
#
#
#
C128
C/76
##
#
R265/
#
#
R/25c
R/254
#
#
R/74
Se
a
R/75
Gaza
er
ra
ne
an
#
ash-Shija'iye
#
M
ed
it
al-Montar
Middle Area
S/19
#
G/149
G/178
#
#
J/35
#
#
S/37
#
S/42
#
J/32
S/69
J/146 # T/46
#
#
K/19
#
T/44
L/179
#
#
#
L/178
al-Qarara
#
Khan Yunis
L/159a
L/159 ##
L/87
L/86 #
L/127#
#
L/176
M/2a
#
#
#
L/43
L/41
#
#
M/2b
P/139
N/22
#
N/9 #
#
P/144
#
P/145
#
#
#
P/138
#
P/15
Rafah
P/10
#
#
al-'Awda
al-Matar
#
Legend
#
#
N
#
5
0
5 Kilometers
Municipal Wells
Entry Points
Governorate Border
Delimiting Line
Sea
Sources:
- MOPIC
- EQA
1:200000
Location of Monitoring Municipal Wells in the Gaza Strip
16
Date: November, 2003
© 2003 EQA
Curriculum Vitae
Basem Hasan Shomar
0049 6221 655526 (Home-Germany).
0049 178 3577180 (Mobile-Germany).
Email:
[email protected]
[email protected]
Nationality: Palestinian.
Date of Birth: February 6th, 1968.
Place of Birth: Gaza, Palestine.
Marital Status: Married.
Name:
Phone:
Education:
1983 – 1986
General Secondary School, Scientific Branch, Gaza Strip-Palestine.
Grade: Excellent, 91%
1986 – 1994
BSc. Biology and Biochemistry, Birzeit University, West Bank-Palestine.
Grade: Excellent, 88%.
1997 – 1999
MSc. Environmental and Water Quality, UNESCO-IHE - Institute for
Water Education, Delft, The Netherlands.
2001-2005
PhD. Environmental Geochemistry, University of Heidelberg, Germany.
(Expected: February 2005).
Research Experience:
1992–1993
Research
Assistant,
Chemical
composition
of
snail’s
saliva,
Department of Biology and Biochemistry, Birzeit Uiversity, Ramaalah,
West Bank. (Dr. Adimar Zogheier).
1993-1994 Research Assistant, Male fertility in relation to Glycogen contents of rat testes,
Biology & Biochemistry Department, Birzeit University, Ramaalah, West
Bank. (Prof. Nabeel Nahhas).
1993-1994
Advanced research in Genetics, Modes of heredity in Dorosophilla, Biology
& Biochemistry Department, Birzeit University, Ramaalah, West Bank. (Dr.
Ahed Abdulkhaliq)
1993-1994
Research on the Health Aspects of Black Yeasts, Mycology, Biology &
Biochemistry Department, Birzeit University, Ramaalah, West Bank. (Dr.
Mo’nes Abou Asab).
1993-1994
Graduation Project, Regulation of Inflammation by Lipocortin 1,
Immunology, Biology & Biochemistry Department, Birzeit University,
Ramaalah, West Bank. (Dr. Tamer Issawi).
1993-1995
Teacher Assistant, Biology & Biochemistry Department, Birzeit University,
Ramaalah, West Bank.
1994-1997
Researcher, Environmental sciences, Center for Environmental and
Occupational Health Sciences, Birzeit University, Ramaalah, West Bank.
1995-1997
Teacher Assistant, Biology & Biochemistry Department, Al Azhar
University, Gaza Strip (Part-Time Job).
17
Job Experience:
1994 – 1997
Director of Birzeit University- Center for Environmental & Occupational
Health Sciences-Branch Gaza.
Coordinator of four projects concerning water and wastewater management in the Gaza
Strip:
¾ Dutch Project: Monitoring of groundwater quality surrounding the solid waste
dumping site of Gaza. April 95 to October 1996. My mandates were: the evaluation
of the project in terms of selection of the monitoring wells, management of
groundwater quality in the area, coordination with municipalities and reporting to the
Dutch team leader.
¾ Italian Project: Desalination Plants in Khan Yunis area. My mandates were: Project
management, assessment of water quality in the area, evaluation of desalination
plants performance, and reporting. July to November 1995.
¾ Japanese Project: Wastewater treatment plant in Khan Yunis area. My mandates
were: Evaluation of wastewater situation, communication with different stakeholders
and policymakers also public representatives. Monitoring of groundwater quality of
five wells surrounding the proposed plant. Reporting to the Japanese Team.
September to November 1996 and August to October 1997.
¾ USAID project: Wastewater Treatment Plant of Gaza area. My mandates were:
Implementation of sampling schemes, sample analysis, adopting financial issues, and
reporting to the team leader. July 96 to October 1997.
1999- 2001
¾
¾
¾
¾
¾
¾
¾
¾
UNDP Consultant for the Ministry of the Environmental Affairs (MEnA),
Gaza, Palestine (Participation in Environmental Strategy, Action Plan and
several Environmental reports).
Focal Point of UNDP project- Institutional Capacity Building of MEnA,
communication, reporting and planning to Environmental Inspection and Monitoring
Program (with Mr. T. Rothermyl, UNDP Director General).
Focal Point of Sensitivity mapping project. Coordination, communication and
arrangement for training courses in MEnA and USA.
Organizer and Facilitator of UNDP-GEF Project. Rehabilitation and Protection of
Wadi Gaza as a natural Reserve.
Focal Point for the Gaza Marine and coastal zone Environmental management Plan.
EU Project, LIFE Third countries.
Member of Coastal Aquifer Management Plan (CAMP). Monitoring of groundwater
in the Gaza Strip. USAID Project.
Member of Groundwater protection Plan (Dutch project).
Organizer and Facilitator of Sector Working Group on the Environment.
Member of International Water Association (IWA).
Training Courses:
August -November 1994
Water and Environmental Research, CEOHS, Birzeit
University, Ramallah, West Bank.
October - November 1995 Food Quality Control, Al Azhar University, Gaza, Gaza Strip.
November – December 1995 Water and Wastewater Management, CDG (Germany)
August– September 1996
Water and Wastewater Treatment Technologies, JICA, Japan.
18
September 1999
February 2003
October 2003
Protection of sea and sea shore from oil spills organized by
The American National Oceanic and Atmospheric
Administration (NOAA).
Short Course, Chemical Reactions at Mineral and Bacteria
Surfaces, Institute of Environmental Geochemistry,
Heidelberg, Germany.
Presenting and Publishing of Scientific Work, Springer
Verlag, Heidelberg, Germany.
TV Programs:
1. Deterioration of water quality in Palestine, an inventory studies (Arabic Language Articles
in Al Quds Newspaper) March 1996.
2. Impacts of Solid Waste leachate on the groundwater quality of selected Groundwater wells
surrounding the solid waste dumping site of Gaza Governorate. June 1996
3. Heavy metals in the groundwater of Gaza Strip, MSc Thesis - March 1999.
4. Three TV programs for the Palestinian TV about Environmental Health in Palestine
(1999-2000).
International Conferences:
1. Impacts of Climate change on ecosystems, organized by the UNDP-GEF, Amman Jordan,
February 2000.
2. Renewable sources of Energy, Organized by the Middle East Desalination Center, Oman,
Utilization of Passive Solar Energy for water desalination. May 2000.
3. Performance of Wastewater Treatment Plants in the Gaza Strip, Current situation and
future approach. Proceedings of the International Water Association (IWA) Specialist
Conference, BIOSOLIDS 2003, Wastewater Sludge as a Resource, Norwegian University of
Science and Technology (NTNU), Trondheim, Norway, June 23-25, 2003. pp. 429-437.
4. Environmental Aspects of the Gaza Strip, Case Studies: Soil Geochemistry and Fluoride
Geochemistry. Bilateral Meeting, Environmental research and Wildlife Development
Agency, Abu Dhabi, United Arab Emirates, 25-30 February 2004.
5. Fluorides in groundwater, soil and infused-black tea and the occurrence of dental fluorosis
among school children of the Gaza Strip. Third International Conference on Children’s
Health and the Environment, London, UK, 31 March-2 April 2004.
6. Deterioration of Groundwater Quality in the Gaza Strip: Alarm for Actions. Proceedings of
2nd International IWA Conference on Automation in Water Quality Monitoring, AutMoNet
2004, Vienna, Austria, April 19-20, 2004. pp. 373-378.
7. Gaza Streifen: eine brisante Umweltsituation auf heißem Terrain, Umweltbörse, institut für
Umwelt Geochemie, University of Heidelberg, 1 July 2004.
8. Seasonal variations of chemical composition of water and bottom sediments in the wetland
of Wadi Gaza, Gaza Strip. The 7th INTECOL International Wetlands Conference, Utrecht,
the Netherlands, 25 - 30 July 2004.
9. Wastewater of Gaza, Chemistry and Management Approach. Second Internatuional
Conference: Water for Life in the Middle East, Turkey, Antalya, 10-14 October 2004.
Languages:
Arabic: Mother language
English: Very Good
German: Fair
19
Things I love:
- Literature (Arabic and English).
- Virgin Nature.
- Children songs.
- Classic Music (Beethoven, Handel, Bach, Mozart,...).
- All human beings.
Referees:
1. Dr. Yuosef Abu Safieh
Minister of Environmental Affairs-Palestine.
Tel: 00972 7 282 2000
Fax: 00972 7 2 84 7198
2. Ms. Elizabeth Dowdeswell
X- Director General of the United Nation Environmental Program (UNEP).
Tel: (416) 922 3537 (Canada).
Fax: (416) 925 8125 (Canada)
Email: [email protected]
3. Prof. R. D. Schuiling (Environmental Geochemistry)
Address: University of Utrecht,
Faculty of Earth Sciences,
Budapestlaan 4, 3584 CD Utrecht,
The Netherlands.
Phone: 00 31 30 2535006 (The Netherlands).
Fax: 00 31 30 2535030
Email: [email protected]
4. Prof. Dr. German Müller (Environmental Geochemistry)
Address: University of Heidelberg,
Institute of Environmental Geochemistry,
Im Nuenheimer Feld 236,
D-69120 Heidelberg, Germany.
Phone: 00 49 6221 545227
Fax: 00 49 6221 545228
Email: [email protected]
20
Hiermit erkläre ich an Eidesstatt, dass ich die vorliegende Arbeit selbständig und ohne
unerlaubte Hilfsmittel durchgeführt habe.
Heidelberg,
20/01/2005
Basem Hasan Shomar
21
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