5. A perfectly mixed aeration pond with no recycling (return line) serves as the small community’s biological reactor. The pond receives 30 m3/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 = 100 mg/L BOD5, Kd = 0. 1 day−1, μm = 1. 6 day−1, and Y is 0. 6 mg VSS/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?