Question# $6$: $$

$9$ points$)$

# cl$]$

Design a circular secondary clarifier to accommodate flow from a CM activated sludge aeration tank which treat wastewater flow of $1500\frac{m^3}{d},$ the influent BOD is $220m\frac{g}{L}$ while the effluent BOD must meet standards of $10m\frac{g}{L}.$ The pilot plant analysis shows that $Y=0\mathrm{.}5$ and $k_d=\frac{0\mathrm{.}06}{d}$ for operational purposes the underflow sludge concentration is $10000m\frac{g}{L},$ select $\frac{F}{M}=0\mathrm{.}3$ and $MLSS=4000m\frac{g}{L}.$ Then calculate the amount of $O_2$ and the air flow which required to aerate the activated sludge for the aeration tank.