Biological Ammonia Removal - AdEdge Water Technologies

Biological Ammonia Removal - AdEdge Water Technologies
Biological Ammonia Removal
For Groundwater Applications
Background
NoMonia is a two-stage aerobic treatment system for the removal
of ammonia from drinking water. NoMonia is a treatment
approach that enhances the natural nitrification process during
which, in the presence of oxygen, NH3 is converted to nitrite and
then to nitrate.
NH4+ → NO₂- → NO3Although ammonia is not a regulated contaminant in drinking
water, high levels of ammonia may be of concern.
Ammonia in water may create high chlorine demand for
disinfection (if addressed by breakpoint chlorination). In the
presence of TOC, excess chlorine is a concern due to the creation
of DBP. High ammonia levels may interfere with the removal
of other regulated contaminants such as arsenic, iron, and
manganese (if only a pre-oxidation stage is included). Ammonia
in the raw water may also result in nitrification in the distribution
systems and can cause corrosion, poor taste, and odor issues.
Legacy treatment approaches for the removal of ammonia such
as ion exchange or reverse osmosis generate high TDS waste
water, a challenge that is eliminated in the NoMonia biological
treatment process.
Technological and Environmental Challenges
Resolved by NoMonia
The amount of ammonia that can be oxidized during the natural
process of nitrification is limited by th e oxygen availability and
its saturation level in the water. NoMonia, a treatment process
that was developed and patented by the U.S. EPA, successfully
addresses the oxygen requirement for water with high
ammonia levels. AdEdge was granted a license from the EPA to
commercialize NoMonia.
Figure 1: Map of the ammonia contamination in the contiguous United
States.
• The NoMonia process is optimized to continuously achieve
super saturated water with enough O2 for the treatment
process. Oxygen levels are maintained by aeration of the
contactor (EPA Patent # US 8,029,674, October 4, 2011).
• NoMonia can address multiple contaminant removal in a single
treatment process. These contaminants often co-exist ammonia
(iron, manganese, and arsenic).
• As opposed to other treatment options such as reverse osmosis,
ion exchange, advanced oxidation, or breakpoint chlorination,
NoMonia does not generate large volumes of concentrated
waste water (like brine) or consume large quantities of
chemicals.
• NoMonia is a biological process executed by naturally-occurring
bacteria that originate from the raw water. An aerated low
pressure atmospheric biological contactor is followed by a filter
media for final polishing.
• Compared to other treatment alternatives, NoMonia is simple
to operate, has low operational costs, and low backwash
frequency.
How it works
The system operates under saturating O2 concentrations to
enable bacterial oxidation of the ammonia to nitrate, followed by
the filtration of oxidized metals (if present).
1. Aeration Contactor: Up-flow, gravel-filled atmospheric vessel
where oxygen is introduced and most of the microbial activity
takes place. This is the core component of the system (patented).
2. Filter: Pressurized mixed media sand filled vessel (biofilter)
where polishing bacterial activity and filtration of oxidized metals
takes place. The aeration contactors can be integrated with the
existing filter systems.
Figure 2: Process flow diagram of the NoMonia process.
AdEdge Water Technologies, LLC • 2055 Boggs Road • Duluth, Georgia 30096 • www.adedgetech.com • 678-835-0052
FREQUENTLY ASKED QUESTIONS
Q: What are the acceptable levels of ammonia in drinking water?
A: Based on the World Health Organization’s report in 2003, the acceptable ammonia level in drinking water is 0.2 mg/L.
Q: What are the highest levels of ammonia that NoMonia can handle?
A: Nitrification generates NO2 and NO3 and their respective EPA regulatory limits are 0.1 mg/L and 10 mg/L. Therefore, the target
maximum ammonia concentration for NoMonia is up to 10 mg/L NH4+.
Q: What is the source of the biological activity?
A: The source of the biological activity is naturally-occurring bacteria in the raw water.
Q: What are concerns about ammonia in drinking water?
A: If nitrification occurs in the distribution network, it may lead to corrosion, biofilm generation, poor taste and odor, and elevated
nitrate levels. Additionally, it requires high levels of chlorine in order to reach safe concentrations of residual chlorination.
Q: Are there any existing commercial installations of NoMonia?
A: There are two full scale systems:
1. Palo, Iowa (NH4+ = 3.3 mg/L, Fe = 0.63 mg/L, Mn = 0.01 mg/L; 300 gpm; 2013 startup)
2. Fonda, Iowa (NH4+ = 3.5 mg/L, Fe = 4.7 mg/L, Mn = 0.15 mg/L; 200 gpm; 2015 startup)
Both sites are pilot to full-scale EPA demonstration projects and custom designed. There are two additional pilot sites that are
scheduled to start up in July 2016.
Q: What is the substrate in the biological filter?
A: The media used in the two stages of treatment are conventional, commercially available filter medias, e.g., AdEdge’s AD26,
ADGS+, gravel, anthracite, etc.
Q: What is the difference between the two stages?
A: Aeration and microbiological activity takes place in the contactors, and the filters are still biologically active for polishing and
for the filtration of particulates such as oxidized metals.
Q: Can NoMonia integrate with existing filtration systems?
A: Yes, NoMonia can be added to an existing filtration system as a retrofit.
Q: Are there any nutrients added to the treatment process?
A: Orthophosphate and polyphosphate. PO4 is essential for the initiation, acclimation, and maintenance of healthy biofilm. A
carbon source is not required because nitrifying bacteria are autotrophs (convert CO2 and water to carbohydrates).
Q: Is NoMonia based on gravity or pressure vessels?
A: Aerated contactors = atmospheric. Filters = typical design using pressure vessels.
Q: How is O2 supplied to the process?
A: Traditional aeration is not sufficient. Saturation levels of DO are below the requirements of the treatment system.
The diffuser design is critical to generate continuous oxygen supply and prevent clogging (patented process).
Q: What is the backwash schedule? What is the quality of the backwash waste water?
A: Maintenance of the contactor is minimal, but monthly backwashes could be beneficial. Filters are typically backwashed once a
week based on water quality. The water source for backwash water could be treated water or chlorinated finished water
for the biofilter. The final water source and backwash schedule will be determined during a pilot period.
Q: Is there any monitoring equipment?
A: DO levels, nitrite (limit 1 mg/L), and nitrate levels. Nitrite in the contactor indicates nitrification. Nitrate appears later when
nitrite levels drop. Alkalinity (decreases in the process as a result of the interaction of H+ with CaCO3) can serve as a process
efficiency monitoring tool. In all cases, nitrite and nitrate levels are maintained below regulatory concerns.
Q: What is the acclimation period of the system?
A: 25 - 45 days typically. The goal is to achieve complete conversion of nitrite to nitrate.
Q: What are the estimated operational costs?
A: The estimated operational costs are $0.20 - $0.50/1000 gallons. These costs are verified during piloting.
AdEdge Water Technologies, LLC • 2055 Boggs Road • Duluth, Georgia 30096 • www.adedgetech.com • 678-835-0052
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