Q$2$

$\{[4=1500)21$Min

concentiation $=(10-1m\frac{g}{L}),$PAC$=cost\frac{20}{M}\frac{R}{k}g]$

Q$1)$ A treated wastewater with a flow rate of $1500\frac{L}{m}in$ is to be treated with powdered activated carbon$($PAC$)$

to reduce the concentration of TOC from $10m\frac{g}{l}$ to $1m\frac{g}{L}.$ To limit the cost of treatment to OMR $30000$

per year, assuming the following data, determine $($i$)$ Carbon adsorption capacity

$($ii$)$ GAC bed life,

and $($ii$)$ Carbon usage rate.

$[310=30$ Marks $]$

PAC density $=450\frac{g}{L}$

PAC cost$=2OM\frac{R}{K}g$

Q$2)$ Determine $($i$)$ amount of lime required per month in Kgs and $(2)$ Mass of sludge produced per month in

$Kgs$ in reducing the phosphorus concretion from $10$ to $1m\frac{g}{1}.$ Based on laboratory testing, $1\mathrm{.}667$ mole of

lime will be required per mole of phosphorus. The flow rate is $1000\frac{m^3}{d}.$ M$.$W of Ca$=40,$ MW of

Phosphate $=30\mathrm{.}97,$ and MW of calcium phosphate $=502.$