Question

A municipal corporation is required to treat 1000 m³/day of water. It is found that an overflow rate of 20 m/day will produce a satisfactory removal of the discrete suspended particles at a depth of 3m. The diameter (in meters, rounded to the nearest integer) of a circular settling tank designed for the removal of these particles would be_______

Answer 1

\(Q = 1000\frac{{{m^3}}}{{day}}\)

Overflow Rate = 20 m/day

H = 3m

Surface Area of circular Tank

\(= \frac{{1000}}{{20}} = 50{m^2}\)

Assuming diameter to be ‘d’

Hence, \(\frac{\pi }{4} \times {d^2} = 50\)

\(d = \sqrt {\frac{{50 \times 4}}{\pi }} = 7.98 = \;8\;m\)