System for treating total phosphorus from effluent water of sewage treatmentplant during the dry season and treating storm water runoff selectively during rainy day

摘要

PURPOSE: A total phosphorus treatment of effluence from a sewage disposal in a dry season and a system for selectively treating rainwater outflow in a raining season are provided to miniaturize a facility for the system and to efficiently implement a coagulating process. CONSTITUTION: A coagulation treating unit, a primary precipitating bath, and a sludge-weighted coagulating additive separating unit are prepared. The coagulation treating unit includes a high speed stirring unit(1), a low speed stirring unit(2), and a precipitating bath(3). The high speed stirring unit stirs target water and a coagulating agent at a high speed. The slow speed stirring unit stirs the mixed target water at a low speed to form macro floc. The target water is precipitated, and overlying water is introduced into a biological sewage treating unit. The precipitated material at the primary precipitating bath is separated into sludge and a weighted coagulating additive.