Ammonia nitrogen and nitrate nitrogen are the most important nitrogen-containing pollutants in water. Due to the increasing serious eutrophication of water bodies, sewage treatment plants have increasingly strict requirements for nitrogen removal. Biological nitrogen removal has become one of the primary considerations in municipal sewage treatment processes. At the same time, from its own perspective, the sewage plant urgently needs to reduce operating costs by reducing fan energy consumption and other means. Therefore, on the premise of meeting the emission standards regulated by regulations, the energy consumption of the blower and the consumption of chemicals can be more accurately controlled to achieve the purpose of controlling operating costs. The DUC2-NH online ammonia nitrogen controller developed and produced by Daruifuno has two SPST relays and two 4-20mA current outputs, which can more accurately control equipment such as blowers and control the ammonia nitrogen co…