The half-saturation constant (kinetic constant) of the Monod equation which governs the reactions in an activated sludge tank is 250 mg of COD per Liter. The maximum specific growth rate of the organisms driving this reaction is 5.0 days -1 and the growth rate is 0.54 day-1. The activated sludge tank has a volume of 40 m3 and the flow rate into it is 400 m3/day. The Mixed Liquor Volatile Suspended Solids (i.e., MLVSS which is X) in the activated sludge tank has a concentration of 3.0 kg/m . Assume the death rate (kd) is zero. (a) What is the: 3
(a) hydraulic retention time (in days), and
(b) concentration of COD in the effluent (in mg/L)?