Water Treatment Questions & Answers - Page 6

26.

Acid used mostly for removal of milk stone is

A.

phosphoric acid

B.

nitric acid

C.

gluconic acid

D.

tartaric acid

Correct answer is B

No explanation has been provided for this answer.

27.

Permanent hardness of water is caused by the presence of

A.

bicarbonates of calcium and magnesium

B.

carbonates of sodium and potassium

C.

chlorides and sulfates of calcium and magnesium

D.

phosphates of sodium and potassium

Correct answer is C

No explanation has been provided for this answer.

28.

Application of quaternary ammonium compounds as sanitizing agents tends to

A.

favor gram positive bacteria

B.

decrease gram positive bacteria

C.

increase the percentage of gram(-)ve rods on utensils

D.

none of the above

Correct answer is C

No explanation has been provided for this answer.

29.

Secondary treatment uses __________ to consume wastes.

A.

micro-organisms

B.

chemicals

C.

filtration

D.

none of these

Correct answer is A

No explanation has been provided for this answer.

30.

Temporary hardness of water is caused by the presence of

A.

chlorides of calcium and magnesium

B.

sulfates of calcium and magnesium

C.

bicarbonates of calcium and magnesium

D.

carbonates of sodium and potassium

Correct answer is C

No explanation has been provided for this answer.