A stream survey revealed that the reaeration constant is 0.05 d-1 and the de oxygenation rate constant is 0.030 d-1. If the initial deficit is 5.00 mg/L and the ultimate

BOD after mixing is 12.0 mg/L, how long will it take to reach the critical point in the DO sag? a. 16.43 d b. 25.46 d c. 17.05 d d. 9.27 d