Multiple choice

A plain sedimentation tank with a length of 20 m, width of 10 m and a depth of 3 m is used in a water treatment plant to treat 4 million litres of water per day (4 MLD). The average temperature of water is 20°C. The dynamic viscosity of water is 1.002 x 10–3 N.s/m2 at 20°C. Density of water is 998.2 kg/M3. Average specific gravity of particles is 2.65.

What is the surface overflow rate in the sedimentation tank?

  1. 20 m3/ m2/ day

  2. 40 m3/ m2/ day

  3. 67 m3/ m2/ day

  4. 133 m3/ m2/ day
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 $\text{Surface overflow rate} = \frac{Q}{Area of the tank}\\ = \frac{4 \times 10^6 \times 10^{-3}}{20 \times 10}m^3/day = 20 m^3 / m^2 / day$

Keep practicing — related questions