A 1.0 x 106 gallon reactor is used in a sewageireatment ptant.Tbe influent concentration is 100 mg/L-1 . the effluent concentration is 25 mg/L-1 , and the flow rate through the reactor is 500 gal/min-1 .
(a) What is the first-order rate constant for decay of BOD in the reactor? Assume that the reactor can be modeled as a CMFR. Report your answer in units of h-1 .
(b) Assume that the reactor should be modeled as a PFR with first-order decay, not as a CMFR. In that case, what must the first-order decay rate constant be within the PFR reactor?
(c) It has been determined that the outlet concentration is too high, and that as a result, the residence time in the reactor must be doubled. Assuming that all other variables remain constant, what must be the volume of the new CMFR?