The question refers to a well-mixed aeration pond or aeration lagoon that can be modeled according to the diagram below. The pond is simply a body of water that holds the wastewater for some detention time before the waste degrades or leaves in the effluent stream. There is no recycle line. You should derive a mass balance on X to solve these problems, make sure to include all terms in the mass balance. You may assume no X flows in with the influent. A rectangular, well-mixed aeration lagoon that has the same conceptual model above is 60 m long, 5 m wide, and 2 m deep. It receives 400 m3/d of wastewater with a BOD5 of 336 mg BOD5/L for treatment. The biodegradation rate constants for the wastewater are yield coefficient = 0.8 mg VSS/mg BODs, endogenous decay constant = 0.08 d—1 , maximum specific microbial growth rate = 1.10 d—1 , and the half velocity constant = 76.0 mg BOD5/L. Note: BOD refers to substrate concentration and it also refers to how much O2 is required to consume the substrate. (a) What is the efficiency of BOD5 removal of the lagoon? (b) The pond’s efficiency of BOD5 removal depends on oxygen being always available for the microbes to use in degrading the wastewater organic carbon. How much oxygen gas (in kg/d) must be supplied daily to the pond?
The question refers to a well-mixed aeration pond or aeration lagoon that can be modeled according to the diagram below. The pond is simply a body of water that holds the wastewater for some detention time before the waste degrades or leaves in the effluent stream. There is no recycle line. You should derive a mass balance on X to solve these problems, make sure to include all terms in the mass balance. You may assume no X flows in with the influent.
A rectangular, well-mixed aeration lagoon that has the same conceptual model above is 60 m long, 5 m wide, and 2 m deep. It receives 400 m3/d of wastewater with a BOD5 of 336 mg BOD5/L for treatment. The biodegradation rate constants for the wastewater are yield coefficient = 0.8 mg VSS/mg BODs, endogenous decay constant = 0.08 d—1 , maximum specific microbial growth rate = 1.10 d—1 , and the half velocity constant = 76.0 mg BOD5/L. Note: BOD refers to substrate concentration and it also refers to how much O2 is required to consume the substrate.
(a) What is the efficiency of BOD5 removal of the lagoon?
(b) The pond’s efficiency of BOD5 removal depends on oxygen being always available for the microbes to use in degrading the wastewater organic carbon. How much oxygen gas (in kg/d) must be supplied daily to the pond?
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 3 images
