Question

When huge amount of sewage is dumped into a river, its B.O.D. will

(a) increase

(b) decrease

(c) sharply decrease

(d) remain unchanged

Answer 1

Correct option: (a) increase

Explanation:

By dumping of huge amount of sewage, the oxygen levels are depleted, which are reflected in terms of BOD values of water. The number of microbes also increases tremendously and these also consume most of the oxygen. Thus BOD of the river water