A. sulphuric acid
B. copper sulphate
C. lime
D. sodium permanganate
Related Mcqs:
- The detention period and overflow rate respectively for plain sedimentation as compared to sedimentation with coagulation are generally_______________?
A. less and more
B. less and less
C. more and less
D. more and more - In a BOD test, 1.0 ml of raw sewage was diluted to 100 ml and the dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm at the end of 5 day incubation at 20°C. The BOD of raw sewage will be___________?
A. 100 ppm
B. 200 ppm
C. 300 ppm
D. 400 ppm - When there is no recirculation of sewage, then recirculation factor is_______________?
A. 0
B. 1
C. infinity
D. none of the above - The specific gravity of sewage is_______________?
A. much greater than 1
B. slightly less than 1
C. equal to 1
D. slightly greater than 1 - The length of rectangular sedimentation tank should not be more than_______________?
A. B
B. 2B
C. 4B
D. 8Bwhere B is the width of the tank
- Percentage of bacterial load that can be removed from water by the process of plain sedimentation is about_______________?
A. 10 to 25
B. 50
C. 75
D. 100 - The settling velocity of a particle in a sedimentation tank increases if______________?
A. particle size is decreased
B. the surface area of tank is increased
C. the depth of tank is decreased
D. none of the above - For a given discharge, the efficiency of sedimentation tank can be increased by______________?
A. increasing the depth of tank
B. decreasing the depth of tank
C. increasing the surface area of tank
D. decreasing the surface area of tank - The settling velocity of a particle in a sedimentation tank depends on__________________?
A. depth of tank
B. surface area of tank
C. both depth and surface area of tank
D. none of the above - The velocity of flow of water in a sedimentation tank is about__________________?
A. 5 to 10 cm/sec.
B. 15 to 30 cm/sec.
C. 15 to 30 cm/minute
D. 15 to 30 cm/hour
