Question

The town of Camp Verde has been directed to upgrade its primary WWTP to a secondary plant that can meet an effluent standard of 25.0mg/L BOD5 and 30 mg/L suspended

solids. They have selected a completely mixed activated sludge system for the upgrade. The existing primary treatment plant has a flow rate of 2,506 m/d. The effluent from the primary tank has a BOD 5 of 240 mg/L. Using the following assumptions, estimate the required volume of the aeration tank 1. BOD 5of the effluent suspended solids is 70% of the allowablesuspended solids concentration. 2. Growth constant values are estimated to be: Kg = 100 mg/L BOD5;%3Dkd = 0.025 dl; Hm = 10 d'; Y= 0.8 mg VSS/mg BOD5 removed.%3D 3. The design MLVSS is 3,000 mg/L.

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