APPARATUS AND METHOD FOR WASTE WATER TREATMENT

摘要

An apparatus for waste water treatment wherein sludge is circulated between an anaelobic tank and an aeration tank, and thereby waste water is biologically treated, characterized in that in the step of sending a sludge from the aeration tank to the anaelobic tank, the sludge is withdrawn from a position lower than that of an aeration device arranged at the lowest position among such devices provided in the aeration tank. The apparatus allows, for example, the removal of both nitrogen and phosphorus by the use of only two treatment tanks of an anaelobic tank and an aeration tank without the use of a coagulating agent.