Design a complete$-$mix activated sludge process for only Cremoval to treat an domestic wastewater with one of the following characteristics at peak month conditions;

$\backslash$table$[[$Item$,$Unit,Value$],[$Flow$,\frac{m^3}{d},15000],[$BOD$,m\frac{g}{l},200],[$sBOD$,,100],[$COD$,m\frac{g}{l},400],[sCOD,,180],[$TSS$,m\frac{g}{l},200],[$nbVSS$,m\frac{g}{l},100],[$TKN$,m\frac{g}{l},35],[$Total phosphorus,$m\frac{g}{l},8],[\backslash$table$[[$Min$.$ Wastewater$],[$Temperature$]],C,15]]$

$Y=0\mathrm{.}45gVS\frac{S}{g}$COD

$k_d=0\mathrm{.}10gVS\frac{S}{g}VSS.d$

${}_m=2\mathrm{.}5gVS\frac{S}{g}VSS.d$

$K_s=20$mgCO$\frac{D}{L}$

$f_d=0\mathrm{.}10gVS\frac{S}{g}VSS$

bCOD$=1\mathrm{.}6(BOD)$

Aeration tank MLSS $=4000m\frac{g}{L}$

Clarifier effluent TSS $=15m\frac{g}{L}$

SVI$=120m\frac{l}{g}$

a$)$ Find minimum volume required for the aeration tank,

b$)$ Choose total WAS pump capacity $)$ if excess sludge is wasted from RAS line

c$)$ Choose total RAS pump capacity $(\frac{m^3}{h}r)$

d$)$ Find out the $O_2$ requirement $(k\frac{g}{d})$

Effluent will satisfy the EU discharge requirements for discharge from urban wastewater treatment plants to sensitive areas, which are subjected to eutrophication.

Please note that total effluent COD will include nbsCOD and bsCOD. Effluent substrate concentration$($S$)$ formula derived from mass balance around whole system include only biodegradable COD remaining after treatment.