ESE 2021 Technical Quiz || Environmental Engineering || Treatment of raw water

Which one of the following type of treatments will be used for neutralization of alkaline effluent?

At a water treatment plant, the coagulation sedimentation unit clarifies 40 million litres of water each day. The quantity of alum required at the plants is 18 mg/lit. If the alkalinity of raw water is 5 mg/lit as CaCO₃, find out the quantity of alum and quicklime (having 85% of CaO) required on yearly basis of the plant.

Consider the following statements

1) For chlorination of water, pH is kept between 5-7.

2) Chlorine will react with ammonia present in water and form trichloramine when pH of water is greater than 7.5

3) Presence of metal compound increases the efficiency of chlorination.

Which of the above statements are correct?

Power consumption in kW in a flocculation chamber for the following data would be:

Drag coefficient for flat blade = 1.4

Area of paddles = 25 m²

Actual paddle speed = 0.60 m/s

Relative velocity of paddles = 75%

Which of the following are common problems associated with operation of Rapid sand filter:

1. Mud ball formation

2. Air binding

3. Sand incrustation

4. Icing

5. Slaughing

Choose correct option using codes given below: