MINSKNING AV KVÄVE OCH FOSFOR MED BIOLOGISK METOD / Biological Removal of Nitrogen and Phosphorus
The process is here called ”Simultaneous Denitrification” though intensive treatment with activated sludge is concerned and biological removal of both nitrogen and phosphorus is obtained. However, nowadays nitrogen removal is more interesting, as phosphorus removal is possible by several methods. The process has no specific aeration or anoxic zones. Nitrification is intensive, primarily because of extensive reactivation of recirculated sludge, and occurs within the same volumes and simultaneously with decomposition of organic material. Denitrification is considered to occur primarily in biological sedimentation tanks. Decomposition of organic material is always proceeding as long as oxygen is available in any form (free oxygen, nitrate, sulphate, phosphate). The following contact filtration guarantees a stable and high effect in any case, and the process usually leads to sludge and phosphorus escape from the biological system. The dose rate to the biological system is <7 g Fe/m3 (Guggenheim process). “Complete abstract not presented.”