Environmental Engineering

Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in

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Question: 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 nitrogeneous organic matter to the nitrite and eventually to the nitrate.

[D].

all (a), (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.

Biological oxidation ponds remove organic matters present in the polluted water by

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Question: 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).

Answer: Option C

Explanation:

No answer description available for this question.

Oil and grease present in an emulsified state in waste water discharged from industries can be removed by

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Question: Oil and grease present in an emulsified state in waste water discharged from industries can be removed by
[A].

biological oxidation.

[B].

skimming off.

[C].

settling out using chemical reagents.

[D].

chlorination.

Answer: Option C

Explanation:

No answer description available for this question.

Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in

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Question: Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in
[A].

food industry.

[B].

municipal sewage treatment.

[C].

petroleum refinery.

[D].

iron & steel plant.

Answer: Option A

Explanation:

No answer description available for this question.

Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of

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Question: Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of
[A].

ozone and iodine.

[B].

chlorine or its compounds.

[C].

ultraviolet light for irradiation of water.

[D].

all (a), (b) & (c).

Answer: Option D

Explanation:

No answer description available for this question.

Corrosion in boilers can be prevented by

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Question: Corrosion in boilers can be prevented by
[A].

deaeration of feed water.

[B].

enhancing pH of feed water by adding alkali.

[C].

feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen and prevents corrosion.

[D].

all (a), (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.