1. (20 pts) In a laboratory experiment you are trying to create a system that can...

  

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1. (20 pts) In a laboratory experiment you are trying to create a system that can replicate the advantages associated with a plug flow process for an activated sludge process to treat highly concentrated waste. As a result, you are using a series of 5 aerated mixed reactors. Each reactor is 10 m and the total flow into the system is 5 m/hr. The first order reaction coefficient is 0.8 hr. The inlet concentration of BOD is 1083 mg/L. a. If there is no recycled sludge, what is the expected BOD concentration in the effluent. What is the ratio of this system (effluent concentration) compared to an ideal plug flow reactor of the same volume (ignore the volume of piping in your system). b. c. The answer in part a above cannot be achieved without sludge recycle. So we install a sludge recycling system with a recycle flow rate of 1 m/hr, a sludge effluent flow of 1 L/hr and a 99.99% biomass removal efficiency in the secondary settling tank (Note: Final BOD in effluent will change and it is recycled, therefore a mass balance is required). Please plot the Biomass Production rate (mg/L/hr) and BOD concentration versus the tank number (ie 1-5). The Yield, Y=0.42 mg/L Biomass / mg/L BOD. d. What is the Biomass concentration in the sludge effluent? 1. (20 pts) In a laboratory experiment you are trying to create a system that can replicate the advantages associated with a plug flow process for an activated sludge process to treat highly concentrated waste. As a result, you are using a series of 5 aerated mixed reactors. Each reactor is 10 m and the total flow into the system is 5 m/hr. The first order reaction coefficient is 0.8 hr. The inlet concentration of BOD is 1083 mg/L. a. If there is no recycled sludge, what is the expected BOD concentration in the effluent. What is the ratio of this system (effluent concentration) compared to an ideal plug flow reactor of the same volume (ignore the volume of piping in your system). b. c. The answer in part a above cannot be achieved without sludge recycle. So we install a sludge recycling system with a recycle flow rate of 1 m/hr, a sludge effluent flow of 1 L/hr and a 99.99% biomass removal efficiency in the secondary settling tank (Note: Final BOD in effluent will change and it is recycled, therefore a mass balance is required). Please plot the Biomass Production rate (mg/L/hr) and BOD concentration versus the tank number (ie 1-5). The Yield, Y=0.42 mg/L Biomass / mg/L BOD. d. What is the Biomass concentration in the sludge effluent?

Answer rating: 100% (QA)

Plug Flow Reactor System for Wastewater Treatment Given Number of reactors n 5 Volume per reactor V 10 m Total flow rate Q 5 mhr First order reaction ... View the full answer