If the grit in grit chambers is 4.5 million litres per day, its cleaning is done____________________?

Related Mcqs:

1. The grit and silt of the grit chambers, may not be used for_________________?

   A. Raising low lying areas by dumping
   B. Concreting
   C. Both A. and B.
   D. Neither A. nor B

2. The grit chambers of sewage treatment plants, are generally cleaned after__________________?

   A. 2 days
   B. 7 days
   C. 12 days
   D. 14 days

3. The recommended detention period for grit chambers is_______________?

   A. 1 minute
   B. 2 minutes
   C. 3 minutes
   D. 5 minutes

4. The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is_____________________?

   A. 0.05552 cumec
   B. 0.05554 cumec
   C. 0.05556 cumec
   D. 0.0556 cumec

5. In a grit chamber of a sewage treatment plant ____________________?

   A. Flow velocity 0.15 m to 0.3 m/sec is kept
   B. Depth of 0.9 m to 1.20 m is kept
   C. One minute of detention period is kept
   D. All the above

6. For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is__________________?

   A. 16 m
   B. 20 m
   C. 24 m
   D. 30 m

7. To prevent settling down of sewage both at the bottom and on the sides of a large sewer, self-cleaning velocity recommended for Indian conditions, is_________________?

   A. 0.50 m/sec
   B. 0.60 m/sec
   C. 0.70 m/sec
   D. 0.75 m/sec

8. The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is____________________?

   A. 100 cm
   B. 110 cm
   C. 120 cm
   D. 150 cm

9. In a sludge digestion tank if the moisture content of sludge V1 litres is reduced from p1 % to p2 % the volume V2 is____________________?

   A. [(100 + P1)/(100 – P2)] V1
   B. [(100 – P1)/(100 + P2)] V1
   C. [(100 – P1)/(100 – P2)] V1
   D. [(100 + P2)/(100 – P1)] V1

10. The rate of accumulation of sludge per person per year, is_______________________?

    A. 10 litres
    B. 15 litres
    C. 20 litres
    D. 25 litres