A secondary settling tank is to be designed for a municipal wastewater treatment facility. The influent TSS is 1,000 mg/L and the average design flow is 1.5 MGD (peaking factor =2) and Qe/Q = 1. State regulations require that the overflow rate be no more than 600 gpd/ft2 for average daily flow and 2000 gpd/ ft2 for peak hourly flow and effluent TSS = 10 mg/L. The detention time required at average flow is 2 hours. Determine the following:
The diameter of the settling tank if it were circular (1 ft increments)?
List one advantage and one disadvantage to circular tanks.
The weir loading rate at peak flow if weirs are set 2 feet in from the tank diameter.