Patent ID: 6177007
Filing Date: 2001-01-23
Classification: C02F,Y10S

Abstract:
A high efficiency apparatus for treating nitrogen and phosphorus contained in sewage, comprising;a treating tank including an anaerobic tank, a plurality of anoxic tanks and a plurality of aerobic tanks which communicate sequentially with one another;a final settling tank for storing sewage fed from the last aerobic tank;a sewage influent unit arranged between a primary settling tank and said anaerobic tank to supply influent to said anaerobic tank;an internal recycle unit for denitrifying nitrated materials arranged between the last of said plurality of said aerobic tanks and the last of said plurality of anoxic tanks; anda sludge denitrification tank; anda sludge returning unit arranged between said final settling tank and said sludge denitrification tank, said sludge denitrification tank supplying sludge having a nitrate nitrogen concentration of below 3 mg/l into said anaerobic tank.