A perfectly mixed aeration pond with no recycle (return line) serves as the biological reactor for a small community. The pond receives 30 cubic meters/day of influent with a BOD5 of 350 mg/L that must be reduced to 20 mg/L before discharge. It has been found that the kinetic constants for the system are Ks=100mg/L, BOD5 kd=0.10 d^(-1),?m=1.6 d^(-1), and Y is 0.60 mg VS/mg BOD5.
(a) What must the hydraulic detention time be in the aeration pond?
(b) What mass of microbes will be produced in the pond each day?