3) (20 points) A BOD test is run using 50 mL of treated wastewater mixed with 250 mL ofpure water. The initial DO of the mix is 9.0 mg/L. After 5 days, the DO is 4.5 mg/L.After a long period of time, the DO is 2.5 mg/L, and it is no longer decreasing with time.Assume there is no nitrogenous BOD and that all BOD is carbonaceous. a. What is the 5-day BOD of the wastewater?b. What is the ultimate BOD?c. What would be the remaining BOD after five days have elapsed?d. Estimate the reaction rate constant, k (day).

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