Question

what are biodegradable and non biodegradable substances?

Answer 1

Substances that are capable of being broken down rapidly by the action of microorganisms are called biodegradable substances.
Ex:food, human and animal wastes.
Substances that can not be able to break down rapidly by the action of microorganisms or that can not be broken down into non-poisonous and harmful substances are called non biodegradable substances.
Ex: plastics, polythene bags, etc

Answer 2

biodegradable substances : those waste materials which can be broken down to non-poisnous sunstances in nature in due course of time by the action of micro-organisms like certain bacteria, are called biodegradable substances.
for eg: animal bones, leather, compost, jute, cotton ,etc.

non-biodegradable substances : the waste materials which cannot be broken down to to non-poisnous or harmless substances in nature are called non-biodegradable substances.
for eg: D.D.T (dichloro diphenly trichloroethane), plastics, polythene, synthetic fibres, etc.