| 摘要 |
<p>PURPOSE: To keep the generation of excessive sludge zero for a long period of time by holding even activated sludge wherein a bulking phenomenon is recognized to high sludge concn. CONSTITUTION: The high concn. return sludge 26 flocculated and conc. by a flocculation device almost perfectly separating even bulking sludge into a clarified liquid and high concn. sludge and a solidliquid separation chamber 12 having a concn. device is supplied and transferred to an aeration tank from an anaerobic tank 2-1. In a storage tank, the sum of an anaerobic stagnation time capable of suppressing the propagation of filamentary bacteria and the stagnation time in an aeration tank wherein an inflow substrate is little is set to a starvation time Ht and the stagnation time of an aeration tank wherein the inflow substrate is much is set to a sufficiency time CL. An activated sludge method wherein a flocculation device is incorporated and the sludge load of BOD20 in the aeration tank is set to <=0.1kg/kg.day and a condition of Ht/Ct>=1.5 is satisfied can suppress the generation of excessive sludge zero for a long period of time.</p> |
