A conventional complete-mix activated-sludge treatment process is to be used to treat 1 Mgal/d of a waste water with a BODS of 150 mg/L after primary settling. The process loading

is to be 0.20 (Ib BODs/day)/(lb MLVSS). If the hydraulic retention time (ie., reactor volume/raw waste water flow rate) is 6 hours, the mean cell-residence time is 10 days, the recirculation ratio(i.e., returned sludge flow rate/raw waste water flow rate) is 0.5; please determine: the size of the bioreactor (in Mgal) the MLVSS concentration (in mg/L) the VSS concentra tion in the returned sludge (in mg/L) the biomass in the reactor (in lb VSS) the biomass wasti ng rate (in Ib/day) the flow rate of wasting sludge stream (in MGD)