A. 1 to 2
B. 4 to 5
C. 9 to 10
D. 15 to 20
Related Mcqs:
- Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in____________________?
A. Coagulation and flocculation of colloids
B. Oxidation of carbonaceous matter to CO2
C. Nitrification or oxidation of ammonia derived from breakdown of nitrogenous organic matter
to the nitrite and eventually to the nitrate
D. All A., B. and C. - During sewage treatment, the sewage is subjected to ______________ treatment in Imhoff tank?
A. Filtration
B. Digestion
C. Sedimentation
D. Both B. and C. - In a sedimentation tank, the detention period for water ranges from _____________ hours?
A. 2 to 4
B. 8 to 12
C. 16 to 20
D. 24 to 32 - Fine grit present in sewage is removed in the _____________ during sewage treatment?
A. Grit chamber
B. Detritus tank
C. Trickling filter
D. Skimming tank - Aerobic biological oxidation ponds used for the purification of polluted water__________________?
A. Destroys/removes pathogen from the sewage
B. Is not very effective for non-biodegradable substances (e.g. ABS) containing effluents
C. Destroys/removes pathogen much more effectively if the sewage is chlorinated
D. All A., B. & C. - ____________ substances present in sewage are removed in grit chamber during sewage treatment?
A. Organic
B. Fatty
C. Inorganic
D. Dissolved - Biological oxidation ponds remove organic matters present in the polluted water by _______________?
A. Using the activities of bacteria and other micro organisms
B. Aerobic oxidation
C. Both A. & B.
D. Neither A. nor B. - The type of bacteria which is active in trickling filter during biological treatment of sewage is the _____________ bacteria?
A. Anaerobic
B. Saprophytic
C. Aerobic
D. Parasitic - The function of skimming tank in sewage treatment is to remove _____________ substances?
A. Dissolved solid
B. Suspended solid
C. Oil & fatty
D. Gritty & inorganic - Which of the following processes is involved in the biochemical treatment of sewage effluents ?
A. Oxidation
B. Reduction
C. Dehydration
D. Fermentation
