Hume steel pipes are__________________?
(A) Steel pipes
(B) Steel shell coated from inside with cement mortar
(C) Steel shell coated from outside with cement mortar
(D) Both
The detention period for plain sedimentation water tanks, is usually____________________?
(A) 4 to 8 hours
(B) 8 to 16 hours
(C) 16 to 24 hours
(D) 24 to 36 hours
If the peak discharge of a storm water drain (S.W. Drain) is expected to exceed 150 cumecs, the free board to be provided, is_________________?
(A) 100 cm
(B) 90 cm
(C) 80 cm
(D) 50 cm
Skimming tanks are__________________?
(A) Used to remove the grease and oil
(B) Those from which sludge is skimmed out
(C) Tanks provided with self- cleansing screens
(D) Improved version of grit chambers
The formula which accepts the value of rugosity coefficient n = 0.012 to be used in Manning’s formula, is given by______________________?
(A) Bazin
(B) Crimp and Bruges
(C) William-Hazen
(D) Kutter
The grit chambers of sewage treatment plants, are generally cleaned after__________________?
(A) 2 days
(B) 7 days
(C) 12 days
(D) 14 days
In trickling filter, B.O.D. is reduced to___________________?
(A) 30 to 40%
(B) 40 to 60%
(C) 60 to 80%
(D) 80 to 90%
In normal conditions, the period for sludge digestion, is_______________?
(A) 10 days
(B) 20 days
(C) 30 days
(D) 60 days
are available in size Stoneware sewers________________?
(A) 10 cm
(B) 15 cm
(C) 20 cm
(D) All the above
In a sludge tank, the gas mainly produced, is_________________?
(A) Oxygen
(B) Nitrogen
(C) Hydrogen
(D) Carbon dioxide