Efficient nitrogen removal from wastewater

Nitrogen compounds such as nitrate and ammonium need to be removed from industrial wastewater and leachate for several reasons. It can contribute to eutrophication, which depletes oxygen in water bodies and harms aquatic life. High concentrations of ammonium in wastewater also directly poison fish. Both lead to dead fish in the short term, and loss of biodiversity in the long term. Ammonium itself also can be toxic to organisms at high concentrations. Too much nitrate in our drinking water can harm or even kill pregnant women and babies, as it increases the methemoglobin in blood.

All this combined is why environmental regulations become stricter and stricter. Not complying can lead to big (monetary) penalties. Additionally, untreated ammonium in wastewater can interfere with certain industrial processes and lead to operational challenges. Nitrogen removal and ammonium removal from wastewater is thus very important.

ANAMMOX (anaerobic ammonium oxidation) is considered one of the best methods for nitrogen removal and ammonium removal in wastewater. That’s because ANAMMOX bypasses the need for the separate steps of nitrification and denitrification, combining aspects of both into a single, more efficient process that directly converts ammonium and nitrite to nitrogen gas without first forming nitrate with an organic carbon source (adsorption). This makes it particularly valuable in settings where reducing energy consumption and operational costs are priorities. Current ANAMMOX installations use up to 60% less energy.

The biological processes in ANAMMOX also produce significantly less sludge and have a smaller carbon footprint compared to conventional nitrification/denitrification in wastewater treatment. Lastly, ANAMMOX can be integrated into existing wastewater treatment plants. It is now applied in the food, manure, (petro)chemical, metallurgical and semiconductor industry and used for public leachate treatment.

Effluent from anaerobic reactors still contains low levels of BOD and possibly ammonia and phosphate. The CIRCOX® bioreactor is a very efficient aerobic system for the treatment of anaerobic effluents. It uses biofilm on a carrier material in an airlift reactor for simultaneous BOD removal and nitrogen removal from wastewater. This compact system for nitrification in wastewater treatment is a fully closed aerobic system with outstanding purification performance. The purified effluent can be directly discharged to surface water. It is also used for nitrogen removal


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