Water Treatment Questions & Answers - Page 7

31.

Zeolite used in zeolite softening process for the treatment of hard water gets exhausted after certain time of usage but can be regenerated by flushing it with

A.

10% calcium chloride solution

B.

10% magnesium sulfate solution

C.

10% magnesium chloride solution

D.

10% sodium chloride solution

Correct answer is D

No explanation has been provided for this answer.

32.

Permanent hard water may be softened by passing it through

A.

sodium silicate

B.

sodium bicarbonate

C.

sodium hexametaphosphate

D.

sodium phosphate

Correct answer is C

No explanation has been provided for this answer.

33.

Hardness of water does not

A.

have any bad effect in boiler

B.

make cooking of foods difficult

C.

make it unfit for drinking

D.

cause difficulty in the washing of clothes with soaps

Correct answer is C

No explanation has been provided for this answer.

34.

The chemical oxygen demand (COD) measures the

A.

amount of oxygen required for growth of microorganisms in water

B.

amount of oxygen that would be removed from the water in order to oxidize pollution

C.

amount of oxygen required to oxidize the calcium present in waste water

D.

none of the above

Correct answer is B

No explanation has been provided for this answer.

35.

Conventional tertiary treatment is

A.

chemical coagulation and flocculation

B.

filtration

C.

sedimentation

D.

none of these

Correct answer is A

No explanation has been provided for this answer.