$2.$ A preanoxic basin for the CMAS nitrification$-$secondary clarifier system is used to produce an effluent NH$4-$N and NO$3-$N concentration of $0\mathrm{.}50$ and $6\mathrm{.}0$ g$/$m$3,$ respectively. Please determine the SDNR at $15$ oC$.$ Use kinetic coefficients given in Table $8-14.$

Assume:

Flowrate $=22,000$ m$3/$d$,$

Aerobic $=10\mathrm{.}0$ h$,$ Anoxic $=2\mathrm{.}0$ h$,$ Aerobic $=20\mathrm{.}0$ d

Return activated sludge ration, R $=0\mathrm{.}65$

$=80\%$

Process schematic flow diagrams are shown below.

Wastewater characteristics.