A municipal WWTP discharges 22.5 MGD of secondary effluent containing 45 mg/L of ultimate BOD at 26.7 C with 1.3 mg/L of dissovled oxygen. The stream flow is 237 ft^3/s at an average velocity of 2.1 ft/s and an average depth of 7ft. The temperature of the stream before the wastewater enters is 16 C. The stream is 80% saturation with oxygen and has an ultimate BOD of 2.3 mg/L. The reaction (kr) and deoxygenation (kd) rate coefficients are 0.35 d^-1 and 0.2 d^-1 respectively at 20 C. The arrhenius temperature correction coefficients are Theta=1.024 for kr and Theta=1.056 for kd.
Determine 1.) wastewater flow rate in ft^3/s,
2.) temperature of the combined wastewater and stream,
3.) DO concentration of the mixture,
4.) DO deficit of the mixture,
5.) Ultimate BOD concentration of mixture,
6.) distance downstream (Xc) to the point of minimum DO concentration,
7.) the minimum DO concentration in the stream