question_answer

Water pollution can be stopped best by

A) Treating effluents to remove injurious chemicals

B) Rearing more fishes

C) Cultivating useful water plants

D) Spraying with DDT

Correct Answer: A

Solution :

For control of water pollution, sewage oxidation ponds or filter beds or septic tanks or decomposition ponds have been developed. These oxidation ponds have luxuriant growth of algae and bacteria. Algae release and anerobic bacteria break down sewage using this .