The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is____________________?

Related Mcqs:

1. The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is_____________________?

   A. 204 cu.m
   B. 208 cu.m
   C. 212 cu.m
   D. 216 cu.m

2. 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

3. 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

4. The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is __________________?

   A. 5 m
   B. 5.5 m
   C. 6.5 m
   D. 7 m

5. In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for a discharge Q, is____________________?

   A. Q/(B × D)
   B. Q/(L × D)
   C. Q/L
   D. Q/(B × L)

6. A model of torpedo is tested in a towing tank at a velocity of 25 m/sec. The prototype is expected to attain a velocity of 5 m/sec. What model scale has been used ?

   A. 1 : 5
   B. 1 : 2.5
   C. 1 :25
   D. 1:V5″
   E. 1 : 53/2

7. The detention time (t) of a settling tank, may be defined as the time required for_________________?

   A. A particle to travel along its length
   B. A particle to travel from top surface to bottom sludge zone
   C. The flow of sewage to fill the tank
   D. None of these

8. The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is________________?

   A. d² (0.011d + 0.785H)/Q
   B. d (0.022d + 0.085H)/Q
   C. d (0.785d + 0.011H)/Q
   D. d (0.285d + 0.011H)/Q

9. 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

10. The recommended detention period for grit chambers is_______________?

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