PLEASE explain in detail!! Thank u so much :)

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PLEASE explain in detail!! Thank u so much

Please Explain In Detail Thank U So Much 1 (249.85 KiB) Viewed 62 times

17. The "Solids Retention Time" is a very important property of the secondary treatment step in municipal wastewater treatment plants. The secondary treatment process outlined below has an inflow of wastewater (QIN) of 0.300 m3/s, and this inflow has a soluble BODs concentration (So) of 220 mg/L. The activated sludge bacterial biomass (X) in the secondary treatment reactor is 2,100 mg/L. If it is necessary to maintain a Feed to Mass ratio (F/M) of 0.52 (mg BODs/mg VSS*day) in this system, what volume should be used for the secondary treatment reactor? (3 pts) P.C. V, X, S S.C. So Os Lee Xe, Sh Act. Sludge Basin RAS Q1, Sr, Xr WAS Qw, Sw, Xw It is also necessary to have a Solids Retention Time (SRT) of 9.0 days. If the bacterial concentration in the "wasted" sludge flow (Xw) is 10,000 mg/L, what is the flow of water/sludge (Qw) through the waste activated sludge line being sent to the anaerobic digestion from the secondary clarifier? (3 pts) If 90% of the activated sludge settled out in the secondary clarifier is returned to the Activated Sludge Basin, what is the mass flow (Q*X,) of bacterial biomass in the Return Activated Sludge (RAS) line? (4 pts) Conceptually explain why it is necessary maintain a high Solids Retention Time (SRT) and a low Feed to Mass (F/M) ratio in secondary treatment. (5 pts)