Q $=0\mathrm{.}035$ m$3$

$/$s$.$ The BOD$5$ from the primary treatment effluent $=225$ mg$/$L$,$ S $=5$ mg$/$L$,$

MLVSS $=2,400$ mg$/$L$,$ Y $=0\mathrm{.}45$ mg VSS$/$mg BOD$5,$ kd

$=0\mathrm{.}06/$day$,$ Ks

$=70$ mg$/$L BOD$5$

$,$

$\backslash$mu m

$=3/$day$.$

Determine the following:

i$.$ Mean Cell Residence Time

ii$.$ Hydraulic Retention Time

iii. Aeration tank volume

iv$.$ F$/$M ratio