Design a complete$-$mix activated sludge $($CMAS$)$ system to treat $22,700\frac{m^3}{d}$ of primary effluent

$($including recycle flows$)$ to accomplish BOD removal and nitrification with an effluent $N{H}_4-N$

concentration of $0\mathrm{.}50\frac{g}{m^3}$ and $BO{D}_e$ and $TS{S}_{e}15\frac{g}{m^3}.$ The aeration basin mixed$-$liquor

temperature is $12C.$

Design conditions and assumptions:

Biodegradable COD $($bCOD$)$ or BOD concentration in the primary effluent $(S_o)=224\frac{g}{m^3}$

nbVSS concentration in the primary effluent $(x_{o,i})=20gVS\frac{S}{m^3}$

$N{H}_4-N$ concentration in the primary effluent $(S_{o,NH4})=25\frac{g}{m^3}$

$N{H}_4-N$ concentration in the bioreactor $=N{H}_4-N$ concentration in the effluent $(S_{NH4})=0\mathrm{.}5\frac{g}{m^3}$

Design MLSS concentration $=3000\frac{g}{m^3}$

MLVSS $=80\%$ of MLSS

Design SRT theoretical SRT