An activated sludge treatment process uses a rectangular tank that can be modeled as two completely mixed reactors in series. The volume of the tank is 300 cubic meters (for modeling purposes 150 cubic meters each) and the flow rate into the system is 900 m3/day. The influent BOD concentration is 180 mg/L and the first order reaction rate coefficient is 0.5 hr-1. What is the effluent concentration of BOD? If the Biomass Yield, Y is equal to 0.6 mg SS/mg of BOD metabolized, what is the rate of SS (biomass) production in the aeration tanks (mg/L-day)? If the post-secondary clarifier effluent SS concentration is 10 mg/L, the sludge recycling rate is 33%, and the waste sludge flow rate is 5 m3/day, what is the SS concentration in the waste sludge (hint: assume the system is at steady state and complete a mass balance)? What is the sludge age?

An activated sludge treatment process uses a rectangular tank that can be modeled as two completely mixed reactors in series. The volume of the tank is 300 cubic meters (for modeling purposes 150 cubic meters each) and the flow rate into the system is 900 m3/day. The influent BOD concentration is 180 mg/L and the first order reaction rate coefficient is 0.5 hr-1. What is the effluent concentration of BOD? If the Biomass Yield, Y is equal to 0.6 mg SS/mg of BOD metabolized, what is the rate of SS (biomass) production in the aeration tanks (mg/L-day)? If the post-secondary clarifier effluent SS concentration is 10 mg/L, the sludge recycling rate is 33%, and the waste sludge flow rate is 5 m3/day, what is the SS concentration in the waste sludge (hint: assume the system is at steady state and complete a mass balance)? What is the sludge age?

Sustainable Energy

2nd Edition

ISBN:9781337551663

Author:DUNLAP, Richard A.

Publisher:DUNLAP, Richard A.

Chapter14: Ocean Thermal Energy Conversion And Ocean Salinity Gradient Energy

Section: Chapter Questions

Problem 20P

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