A. Raising low lying areas by dumping
B. Concreting
C. Both A. and B.
D. Neither A. nor B
Related Mcqs:
- If the grit in grit chambers is 4.5 million litres per day, its cleaning is done____________________?
A. Manually
B. Mechanically
C. Hydraulically
D. Electrically - The grit chambers of sewage treatment plants, are generally cleaned after__________________?
A. 2 days
B. 7 days
C. 12 days
D. 14 days - The recommended detention period for grit chambers is_______________?
A. 1 minute
B. 2 minutes
C. 3 minutes
D. 5 minutes - In a grit chamber of a sewage treatment plant ____________________?
A. Flow velocity 0.15 m to 0.3 m/sec is kept
B. Depth of 0.9 m to 1.20 m is kept
C. One minute of detention period is kept
D. All the above - 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 detention time (t) of a settling tank, may be defined as the time required for_________________?
A. A particle to travel along its length
B. A particle to travel from top surface to bottom sludge zone
C. The flow of sewage to fill the tank
D. None of these - ¾th or ¼th extra space is left in sewer pipes at maximum discharge for_________________?
A. Low estimates of the average and maximum flows
B. Large scale infiltration of storm water
C. Unexpected increase in population
D. All the above - Design period of 40 to 50 years is adopted for_________________?
A. Branch sewers
B. Main sewers
C. Trunk sewers
D. All the above - Sewer pipes need be checked for_________________?
A. Minimum flow
B. Maximum flow
C. Both A. and B.
D. None of these - The standard B.O.D. of water is taken for_________________?
A. 1 day
B. 2 days
C. 3 days
D. 5 days
