A complete-mix activated sludge (CMAS) process is used for secondary treatment of effluent from a primary clarifier. The design influent flowrate to the activated sludge tank is 9 x 105L/d with a BOD concentration of 320mg/L. The plant operating parameters are as follows: Dimensions of the aeration tank: 10.0m wide by 10.0m long by 4.5m deep; effluent BOD = 15.0mg/L; yield coefficient = 0.55mg VSS/mg BOD removed; endogenous decay rate of microorganisms= 0.050/d; fraction of biomass that remains as cell debris = 0.15 g VSS/g VSS; half velocity constant: %3D %3D 81g BOD/m3; maximum specific growth rate = 1.15g VSS/g VSS-d; 6COD/BOD ratio = 1.6; nbVSS in the influent = negligible; operating temperature 20C Determine: a. SRT [4] b. Oxygen demand in kg/d [3] c. MLVSS in mg/L [2]