A wastewater treatment plant discharges 0.18 m3 /s of treated wastewater into a creek. The creek has a flow rate of 0.20 m3 /s. The BOD5 of the wastewater discharge is 38 mg/L. Upstream of the wastewater discharge from the creek, the BOD5 is 2 mg/L. The BOD rate constants k are 0.25 d-1 and 0.08 d-1 for the wastewater discharge and the creek water, respectively. The temperature of both the creek and the municipal wastewater discharge is 20ËšC. Calculate the initial ultimate BOD right after the mixing of the wastewater discharge and creek.
