In water treatment, rapid gravity filters are adopted to remove_______________?

Question: Lagoons used for purification of polluted water
[A].

are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds.

[B].

use micro-organisms/bacteria in presence of dissolved oxygen.

[C].

gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended solid < 1 mg/litre and BOD = 3.8 mg/litre.

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

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.