1) Return activated sludge rate

2) Will this process remove organic nitrogen?

3) If organic nitrogen is to be removed, how would you modify the process?

4) If primary clarifier is added, how would all of the above variables change, increase or decrease?

-. (20 Points): A conventional activated-sludge wastewater treatment plant without primary clarification operates under the following conditions: Design flow = 2.14 MGD: Influent BOD, = 185 mg/L; Influent SS = 212 mg/L. Aeration basin: 4 units: 40 ft. width, 40 ft. length and 15.5 ft. depth MLVSS = 2,600 mg/L and it is 80% of MLSS Wasting is done from the secondary clarifier. Waste flow rate = 39,000 gal/day Concentration of microorganisms in returned activated sludge = 8,600 mg VSS/L Effluent BODs = 15 mg/L and Effluent TSS = 15 mg/L