Dutch technology removes nitrogen from sewage water
An innovative solution from the Dutch company Byosis ensures efficient nitrogen removal from sewage water.
Published on March 25, 2025
Team IO+ selects and features the most important news stories on innovation and technology, carefully curated by our editors.
A record amount of sewage was purified in 2023, according to the latest figures from Statistics Netherlands (CBS). This was due to a record amount of rainfall in 2023. A negative consequence was that the large amount of sewage meant that fertilizers such as nitrogen and phosphorus were less effectively removed from the sewage and the residual discharges were greater.
Nitrogen remains behind
The poorer purification performance for phosphorus and nitrogen was caused by the extremely high supply of sewage water. The high supply lowers the concentration of substances in the sewage water and the water flows faster through the sewage treatment plant, making it more difficult to remove these substances from the sewage water. The amount of nitrogen that remained in the water (also called residual discharge) was 15.2 million kilograms, 17 percent more than in 2022.
Sewage treatment can be more effective
Sewage treatment plants clean wastewater so that it can be reused. This is usually done biologically. Bacteria extract ammonia and nitrite from the water and convert it into nitrogen gas and water. However, this process is slow and sensitive to disruptions.
An innovative chemical process
But innovative companies are coming to the rescue. Byosis, for example, has developed a solution for removing nitrogen from various waste and residual flows using special installations. The nitrogen is recovered as a raw material. Instead of biological processes, the company uses physical and chemical processes, which makes the technology fast, flexible, and less sensitive to disruptions. This approach prevents both legionella contamination and the emission of nitrous oxide.
The innovative installation consists of several columns in which gas is sent along the wastewater to absorb ammonia. The ammonia is then washed and converted into pH-neutral ammonium sulfate, a substitute for fertilizer. Thanks to this approach, Byosis succeeded in removing 85% of the nitrogen from the wastewater, which is an impressive result. Byosis is involved in the preliminary design of a stripper installation for various water boards.
From sewage to swimming: How clean are Dutch canals?
Vacations, that time when we relax, explore new places, cultures and... technologies? This summer I, Alma, am diving into the latest innovations for smart holidaymakers.