1. A secondary treatment process with sludge recycle from the bottom of the secondary clarifier is operated based on the following conditions. The system is at steady-state. = - Influent flowrate = 10,000 m3/d Influent nb VSS = 40 mg/L Influent BOD = 150 mg/L Effluent BOD = 2 mg/L Hydraulic retention time = 4 h h SRT = 6 d Y=0.5 g VSS/ g COD fa = 0.15 g VSS/g VSS ka = 0.08 g VSS/g VSS/d bCDO = 1.6 (BOD) = = Calculate the following: (a) The aeration tank oxygen requirement (in kg/d) (10 points) (b) The aeration tank oxygen uptake rate (i.e., R/V) (in mg/L/h) (5 points) (c) The aeration tank biomass concentration (in mg/L) (5 points)