A. 4 to 8 hours
B. 8 to 16 hours
C. 16 to 24 hours
D. 24 to 36 hours
Related Mcqs:
- The normal value of over flow rates for plain primary sedimentation tanks, ranges between________________?
A. 25,000 to 35,000 litres/sqm/day
B. 40,000 to 50,000 litres/sqm/day
C. 50,000 to 60,000 litres/sqm/day
D. 80,000 to 100,000 litres/sqm/day - 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 - The normal values of over flow rates for secondary sedimentation tanks, ranges between__________________?
A. 25,000 to 35,000 litres/sqm/day
B. 40,000 to 50,000 litres/sqm/day
C. 50,000 to 60,000 litres/sqm/day
D. 80,000 to 10,000 litres/sqm/day - The maximum depth of sedimentation tanks, is kept__________________?
A. 3 m
B. 3.5 m
C. 4 m
D. 4.5 m - The normal values of over flow rates for sedimentation tanks using coagulant, ranges between__________________?
A. 25,000 to 35,000 litres/sqm/day
B. 40,000 to 50,000 litres/sqm/day
C. 50,000 to 60,000 litres/sqm/day
D. 80,000 to 100,000 litres/sqm/day - The recommended detention period for grit chambers is_______________?
A. 1 minute
B. 2 minutes
C. 3 minutes
D. 5 minutes - 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 - 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 - 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 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
