A. Velocity at dry weather flow
B. Velocity of water at flushing
C. Velocity at which no accumulation remains in the drains
D. Velocity of water in a pressure filter
0
If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is_________________?
0
A well oxidized sewage contains nitrogen mainly as___________________?
A. 100 mg/l
B. 200 mg/l
C. 300 mg/l
D. 400 mg/l
0
In a sludge tank, the gas mainly produced, is_________________?
A. Nitrates
B. Nitrites
C. Free ammonia
D. None of these
0
are available in size Stoneware sewers________________?
A. Oxygen
B. Nitrogen
C. Hydrogen
D. Carbon dioxide
0
In normal conditions, the period for sludge digestion, is_______________?
A. 10 cm
B. 15 cm
C. 20 cm
D. All the above
0
In trickling filter, B.O.D. is reduced to___________________?
A. 10 days
B. 20 days
C. 30 days
D. 60 days
0
The grit chambers of sewage treatment plants, are generally cleaned after__________________?
A. 30 to 40%
B. 40 to 60%
C. 60 to 80%
D. 80 to 90%
0
Maximum permissible velocity 1.5 m/sec, is adopted in drains_______________________?
A. 2 days
B. 7 days
C. 12 days
D. 14 days
0
If the discharge of a sewer running half is 628 1.p.s., i = 0.001, and n = 0.010, the diameter of the sewer, is__________________?
A. With beds of rocks and gravels
B. Lined with stones
C. Both A. and B.
D. Neither A. nor B.
Download App