A. large area is required for construction
B. maintenance and operation cost are high
C. BOD removal is very low
D. none of the above
Related Mcqs:
- The main disadvantage of cement concrete sewers is________________?
A. less strength
B. difficulty in construction
C. difficulty in transportation due to heavy weight
D. less life - In facultative stabilization pond, the sewage is treated by________________?
A. aerobic bacteria only
B. algae only
C. dual action of aerobic bacteria and anaerobic bacteria
D. sedimentation - The major disadvantage of lime soda process of water softening is that_________________?
A. it is unsuitable for turbid and acidic water
B. huge amount of precipitate is formed which creates a disposal problem
C. the effluent cannot be reduced to zero hardness
D. it is unsuitable for softening the water of excessive hardness - The detention period for oxidation ponds is usually kept as______________?
A. 4-8 hours
B. 24 hours
C. 10 to 15 days
D. 3 months - If the total hardness of water is greater than its total alkalinity, the carbonate hardness will be equal to________________?
A. total alkalinity
B. total hardness
C. total hardness – total alkalinity
D. non carbonate hardness - Chlorine demand of water is equal to________________?
A. applied chlorine
B. residual chlorine
C. sum of applied and residual chlorine
D. difference of applied and residual chlorine - The minimum and maximum diameters of sewers shall preferably be_________________?
A. 15 cm and 100 cm
B. 15 cm and 300 cm
C. 30 cm and 450 cm
D. 60 cm and 300cm - Generally the detention period for grit chambers is kept as_______________?
A. 1 minute
B. 5 minutes
C. 2-4 hours
D. 12 hours - As compared to higher pH values, the contact period required for efficient chlorination at lower pH values is___________________?
A. smaller
B. larger
C. same
D. none of the above - As compared to geometrical increase method of forecasting population, arithmetical increase method gives________________?
A. lesser value
B. higher value
C. same value
D. accurate value
