Question

A water treatment plant is designed to treat $1m^3/s$ of raw water. It has $14$ sand filters. Surface area of each filter is $50m^2$. What is the loading rate (in $m^3/day/m^2$) with two filters out of service for routine back-washing?

• A. 144

Answer 1

The correct option is A 144
$\text{Loading rate}=\frac{\text{Q(discharge in)}{m}^3/\text{day}}{\text{Area of working filter}}$

Given, $Q=1m^3/sec$
$=86400\times 1m^3/day$

Surface area of each filter = $50m^2$
No. of working filter = 12

$\therefore$ Surface loading rate = $\frac{86400\times 1}{12\times 50}$

Loading rate = $144m^3/day/m^2$