Activated sludge treatment method and activated sludge treatment apparatus for wastewater

摘要

PPROBLEM TO BE SOLVED: To provide an activated sludge treatment technology of wastewater preventing breeding of mold fungi making sludge separation difficult and efficiently removing nitrogen and phosphorus from wastewater with a simple apparatus. PSOLUTION: Wastewater W in a single treatment tank 10 is subjected to sludge treatment of denitrating nitrate nitrogen and nitrifying ammonia nitrogen using activated sludge S, a part of which is separated from the treatment tank and charged into a separation tank 30, to collect and separate activated sludge from the treated wastewater. New wastewater Wa is supplied to a part of the separated activated sludge and set into an anaerobic condition in a pretreatment tank 40, returned to the treatment tank, and added to residual treated wastewater. These treatment and operation are repeated to activate denitrated fungi in the pretreatment tank. By completing denitrification of residual nitrate nitrogen in activated sludge, nitrification and taking-in of phosphate phosphorus into activated sludge are carried out in the sludge treatment in the treatment tank. PCOPYRIGHT: (C)2008,JPO&INPIT