Question

You have designed a treatment system for contaminant Z. The treatment system consists of a pipe that feeds into a CSTR. The pipe has a volume of 15 m3 and the CSTR has a volume of 60 m3 . The inflow is 10 m3 /d and the influent Z concentration is 2,500 mg/L. If the effluent from the CSTR has a Z concentration of 500 mg/L, what is the degradation

Answer 1

Answer:

0.667 per day.

Explanation:

Our values here are

$Q=10m^3/dV_p=15m^3\\V_{cstr}=60m^3\\c_p=2500mg/L\\c_{cstr}=500mg/L$

Degradation constant=k and is unknown.

We calculate the concentration through the formula,

$cc_{cstr} =\frac{c_{in}}{1+K(V/Q)} \\cc_{cstr}=\frac{c_p}{1+K*\frac{V_{csrt}}{Q}}$

Replacing values we have

$1+k(\frac{60}{10})=\frac{2500}{500}\\1+k=5\\K(6)=5-1\\K(6)=4\\K=2/3\\K=0.667/day$

That is the degradation constant of Z-contaminant