Question

Give scientific reason.

Sewage should not be discharged into the river without treatment.

Answer 1

1. Sewage is rich in organic matter.
2. Releasing such sewage into natural water bodies like rivers would increase its organic content.
3. The organic matter would get oxidized using the dissolved oxygen in the water.
4. This reduces the levels of dissolved oxygen and adversely affects the aquatic life in the water body.
   Hence, sewage should not be discarded into the river without treatment and should be released in rivers only after oxidation by microbial techniques.