Air binding phenomena in rapid sand filters occur due to_________________?

Question: White smoke coming out of the chimney of a furnace indicates the use of
[A].

low excess air.

[B].

very high excess air.

[C].

gaseous fuel in the furnace.

[D].

liquid fuel in the furnace.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Fluorosis (a bone disease) is caused by the presence of high concentration of __________ in atmospheric air.
[A].

hydrocarbons

[B].

hydrogen flouride

[C].

hydrogen sulphides

[D].

nitrogen dioxide

Answer: Option B

Explanation:

No answer description available for this question.

Question: __________ is removed from water by lime-soda process.
[A].

Foul smell and taste

[B].

Iron and manganese

[C].

Temporary hardness

[D].

Permanent hardness

Answer: Option C

Explanation:

No answer description available for this question.