NITRIFICATION REACTION ACCELERATING METHOD UTILIZING SEDIMENTATION TANK SLUDGE OF SEWAGE TREATING EQUIPMENT BY IMMERSED FILTER BED METHOD

摘要

PURPOSE:To increase the efficiency of nitrogen removal in an immersed filter bed method as one of a sewage treating methods. CONSTITUTION:In order to utilize the nitrification activity of a sedimentation tank sludge of a sewage treating equipment by the immersed filter bed method as one of biological membrane methods, the nitrification activity in a contact aeration tank is accelerated by returning the sedimentation tank sludge to the contact aeration tank and keeping a sedimentation ratio of an activated sludge in the contact aeration tank at about 20% of the sedimentation ratio at which the nitrification activity is manifested most markedly. A treated water containing nitrogen nitrificated in the contact aeration tank is transferred to a next sedimentation tank to perform solid-liquid separation into its sludge and supernatant liquor, thus the treating function to remove the nitrogen being nitrient salts is increased by returning the supernatant liquor containing the nitrificated nitrogen to an anaerobic filter bed tank which denitration reaction progresses.