Sewage consists primarily of which of the following?

1.Water, containing less than one part of solid per thousand parts of water

2.Solids that can be either dissolved or suspended

3.A normal mixture of solid and gas

4.Gaseous waste

A1, 2 and 3

B2 and 3

C1 and 2 ✓ Correct

D3 and 4

Correct answer: (C) 1 and 2

Explanation

Sewage is chiefly water holding under one part solid per thousand parts water, with those solids either dissolved or suspended.

Statement 1 is right: sewage is over 99.9 percent water by content.

Statement 2 is right: its small solid fraction exists in dissolved and suspended forms.

Statement 3 is wrong: sewage is not a normal mixture of solid and gas.

Statement 4 is wrong: sewage is not primarily gaseous waste.

Treatment removes and breaks down these solids before the water is released.

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