311. The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is________________? September 7, 2025 by Admin A. d² (0.011d + 0.785H)/Q B. d (0.022d + 0.085H)/Q C. d (0.785d + 0.011H)/Q D. d (0.285d + 0.011H)/Q ✅ The correct answer is option A.
