Question $1$: Estimate the solids generated in the primary and secondary clarifiers at a secondary

$($activated sludge$)$ treatment plant. Assume that the primary settling tank removes $65\%$ of the

TSS and $33\%$ of the BOD$5.$ Also determine the volume of each sludge, assuming $6\%$ and $1\mathrm{.}2\%$

of solids in the primary and secondary effluents, respectively.

Average plant flow $=3785m\frac{3}{d}$

Primary influent TSS $=240m\frac{g}{L}$

Primary influent BOD$=200m\frac{g}{L}$

Secondary effluent BOD$=30m\frac{g}{L}$

Secondary effluent TSS $=24m\frac{g}{L}$

Bacterial yield $=0\mathrm{.}23kg$ sludge solids per kg BOD removed