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.Management Sciences
Category: Chemical Environmental Engineering
Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by________________?
A. Natural aeration of water stream
B. Photosynthetic action of algae
C. Both A. & B.
D. Neither A. nor B.
Presence of bacteria in potable (drinking) water causes_________________?
A. Turbidity
B. Disease
C. Bad odour
D. Bad taste & colour
Main pollutants released from iron & steel industry is__________________?
A. CO, CO2 & SO2
B. H2S, NO & SO3
C. CO2, H2S & NO2
D. SO3, NO2 & CO2
The upper layer of atmosphere is called the ____________________?
A. Stratosphere
B. Troposphere
C. Ionosphere
D. None of these
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.
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
Which of the following dust collection equipments is the least efficient (for sub-micronic particles) ?
A. Dust catcher (gravity type)
B. Cyclone separator
C. Bag filter
D. Hollow wet scrubber
During sewage treatment, the sewage is subjected to ______________ treatment in Imhoff tank?
A. Filtration
B. Digestion
C. Sedimentation
D. Both B. and C.
Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes_______________?
A. Foaming
B. Odour nuisances
C. Undesirable plant growth
D. Turbidity
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