A. 25 %
B. 50 %
C. 10 %
D. 5 %
Related Mcqs:
- 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 - In normal conditions, the period for sludge digestion, is_______________?
A. 10 days
B. 20 days
C. 30 days
D. 60 days - Acid regression stage of sludge digestion at a temperature 21°C extends over a period of______________?
A. 15 days
B. 30 days
C. 60 days
D. 90 days - The first stage of neutral process of sludge digestion, is__________________?
A. Acid fermentation
B. Acid regressio
C. Alkaline fermentation
D. None of these - In a sludge tank, the gas mainly produced, is_________________?
A. Oxygen
B. Nitrogen
C. Hydrogen
D. Carbon dioxide - 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 - To maintain aerobic biological activity, the moisture content of the compost mass should be about_________________?
A. 45 %
B. 50 %
C. 55 %
D. 60 % - The sludge does not contain waste water from_________________?
A. Bath rooms
B. Wash basins
C. Kitchen sinks
D. Toilets - The rate of accumulation of sludge in septic tanks is recommended as____________________?
A. 30 litres/person/year
B. 25 litres/person/year
C. 30 litres/person/month
D. 25 litres/person/month - Sludge banks are formed if sewage is disposed of in____________________ ?
A. Rivers
B. Seas
C. Lakes
D. None of these
