Ammonia Wastewater Treatment

Solutions for removal of ammonia/ammonium for discharge compliance or reducing load on biological processes

We help clients to manage the ammonia in their industrial wastewaters, treating only as much as is necessary. We help to remove ammonia load, achieve discharge compliance, or ease the burden on downstream biological processes. Work with us to understand your options to boost capacity and reliability.

Ammonia Challenges

Ammonia (NH3) is critical to many industrial and agricultural processes. As a serious and common water pollutant, it is heavily scrutinized and regulated. High ammonia concentrations can prevent the discharge or reuse of many wastewaters.


Biological treatment is widely used to remove ammonia, producing harmless nitrogen gas. However, biological treatment systems can be overburdened by increasing industrial wastewater volumes, or ammonia or organics loads.


Saltworks helps clients to meet ammonia challenges by providing new treatment systems or expanding existing ones. We ease the burden on downstream processes such as biological ammonia treatment or your discharge point.

Photo of a wastewater aeration system
Digital image of ammonium molecules

Using and Optimizing an Ammonia Stripper

Depending on your project, you could benefit from an ammonia stripper. Stripping ammonia produces a concentrated ammonium sulfate solution (~35%). This involves a high-pH stripping tower that removes ammonia, which is then absorbed in a low-pH scrubbing tower. The solution may be:

  • Used directly in agriculture, if shipping distances are small,
  • Concentrated in an advanced reverse osmosis (RO) system, producing clean freshwater for reuse or discharge,
  • Crystallized as low-volume solids in an evaporative crystallizer, easily stored and shipped,
  • Sent to a smaller dedicated biological destruction process, 
  • Converted to nitrogen gas via chemical or electrochemical methods such as breakpoint chlorination.

Choosing the Right Ammonia Treatment

Saltworks optimizes ammonia treatment, boosting capacity. We start with a comprehensive mass and energy balance review, mapping the economics of alternatives. Once complete, we present options for optimizing the use of an ammonia stripper or for other options.


Stripping does not fit every project. Sometimes other options or combinations make sense, including:

  • Concentration of ammonia wastewater via a low-pH reverse osmosis process. XtremeRO concentrates ammonia-laden wastewaters to over 130,000 mg/L total dissolved solids (TDS).
  • Concentration and crystallization of ammonia bicarbonate (if your ammonia exists as ammonia bicarbonate without high organics), saving significant stripper costs and avoiding chemical consumption.
  • Electrochemical destruction ammonia, which due to high power loads may only be optimal at small scale or with low-cost (off-peak) power.
A photo of a Saltworks engineer inspecting water in a selective contaminant removal process
Photo of reverse osmosis vessels in a Saltworks XtremeRO plant

Reverse Osmosis for Ammonia 

RO treatment of ammonia requires specialized knowledge and plant configuration. Saltworks installs RO systems engineered to reject ammonia, operating at over 98% recovery. The result is clean freshwater that can be discharged, while wastewater is concentrated up to 50 times.


RO has moderate capital costs and very low operating costs assuming brine management costs are low. However, RO works best with non-scaling waters with TDS < 80,000 mg/L and when low-cost options for downstream ammonia brine management are available.


We can help you to consider your options—and if warranted, deliver an ammonia RO concentrator plant. We can also help with that final 2% concentrated ammonium waste.

Breakpoint Chlorination

Ammonia wastewater is also treatable with chlorine (gas or hypochlorite), with simple equipment. Breakpoint chlorination is when there is sufficient chlorine to react with all present ammonia. Products include non-toxic chloramines, harmless nitrogen gas, and hydrochloric acid (wastewater becomes acidic).


Breakpoint chlorination is an excellent polish, removing virtually all ammonia and beneficially sanitizing the water. However, it requires appropriate safety training and equipment, and chlorine consumption is directly proportional to ammonia mass, so for some wastewaters, it can require large, expensive quantities of chlorine.


Because of relatively high operating costs, but low capital costs, it is best suited for low ammonia levels (e.g. < 50 mg/L NH3) or low flow rates (i.e. < 10 m3/day), especially when the need is periodic (e.g. 10% of the year).


Contact us with your ammonia wastewater chemistry, flow rates, and treatment goals to learn more.

breakpoint chlorination for ammonia graphic

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