A. Oxygen
B. Nitrogen
C. Hydrogen
D. Carbon dioxide
Related Mcqs:
- The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is_______________?
A. 25 %
B. 50 %
C. 10 %
D. 5 % - 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 - 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____________________?
A. 30 minutes
B. 1 hour
C. 1 hour and 30 minutes
D. 2 hours - The effluent of a septic tank is_________________?
A. Fit for discharge into any open drain
B. Foul and contains dissolved and suspended solids
C. As good as that from a complete treatment
D. None of these - The sludge does not contain waste water from_________________?
A. Bath rooms
B. Wash basins
C. Kitchen sinks
D. Toilets - In normal conditions, the period for sludge digestion, is_______________?
A. 10 days
B. 20 days
C. 30 days
D. 60 days - In the activated sludge process__________________?
A. Aeration is continued till stability
B. Aeration is done with an admixture of previously aerated sludge
C. Sludge is activated by constant stirring
D. Water is removed by centrifugal action - The first stage of neutral process of sludge digestion, is__________________?
A. Acid fermentation
B. Acid regressio
C. Alkaline fermentation
D. None of these - The digested sludge from septic tanks, is removed after a maximum period of__________________?
A. 3 years
B. 3.5 years
C. 4 years
D. 5 years - The rate of accumulation of sludge per person per year, is_______________________?
A. 10 litres
B. 15 litres
C. 20 litres
D. 25 litres
