2. A biological reactor is used to treat wastewater from a small community (Q=100,000 gpd). The influent BOD5 concentration to the reactor is 200mg/L and the required effluent BOD5 concentration is 30mg/L. The reaction rate constant in the reactor =0.25/ day. Estimate the hydraulic retention time (HRT) if the reactor is a CFSTR and the HRT if the reactor is a PFR. 2. A biological reactor is used to treat wastewater from a small community (Q=100,000 gpd). The influent BOD5 concentration to the reactor is 200mg/L and the required effluent BOD5 concentration is 30mg/L. The reaction rate constant in the reactor =0.25/ day. Estimate the hydraulic retention time (HRT) if the reactor is a CFSTR and the HRT if the reactor is a PFR