Ammonium Measurement

Nitrogen is present in various compounds and forms and is considered a "master of transformation." In municipal wastewater, it primarily exists as urea, which is partially converted to ammonium nitrogen in the sewer network through a process known as ammonification.

In the aeration tank of a wastewater treatment plant, the existing ammonium nitrogen is first oxidized to nitrite and then to nitrate. This process, known as nitrification, requires oxygen, which is supplied through aeration in the aeration tank. Since ammonium is toxic to aquatic organisms like fish even at low concentrations, strict regulations govern the permissible ammonium levels in wastewater.

Ammonium and nitrate are the two most important nitrogen parameters in wastewater treatment. Ensuring compliance with and monitoring their limits is a central task of a wastewater treatment plant. This monitoring occurs not only at the plant's effluent but also upstream, where the regulation and control of biological cleaning processes take place. Measurement technologies help make these processes transparent and enable quick responses to changes in concentration levels. This applies to both nitrification and deammonification, where ammonium is partially converted into nitrite.

To reuse wastewater or safely discharge it into the environment, it must be treated in wastewater treatment plants through a multi-stage process. These treatment processes include mechanical, biological, and chemical stages, supplemented by the processing of the resulting sludge. Continuous monitoring is required at every stage to enable intervention when necessary. This monitoring is ensured by capturing relevant parameters, with the placement of measuring instruments being critical. Throughout these processes, regular monitoring of ammonium levels is indispensable.