The waste materials that can be broken down or decomposed into simple substances in nature, by the action of microorganisms, such as bacteria, in due course of time are called biodegradable waste materials. The biodegradable waste decomposes naturally and becomes harmless to humans, other organisms and environment after some time. For example, dead plants and animals (including bones), animal excreta (cattle dung, urine), leather goods, tea leaves, wool, paper, plant parts, hay and wood, cotton clothes, cardboard, seeds, grains and compost (manure made from decayed plants and vegetable stuff) are all biodegradable materials.
Non-Biodegradable Waste Materials:
The waste materials that cannot be decomposed to simple, non-poisonous substances in the nature are called non-biodegradable waste materials. For example, plastic, polythene bags, synthetic fibres, glass objects, metal articles like aluminium cans, silver foils, certain detergents, fertilizers, pesticides like DDT and radioactive wastes. For instance, DDT is a non-biodegradable waste. It cannot be degraded or decomposed into simple compounds by the action of microorganisms in nature.
Thus, it gets accumulated in the environment and harms humans, other animals, and even vegetables and plants. Thus, DDT has been banned for use in most of the countries.
Recycling of Biodegradable Waste:
Some of the biodegradable wastes can be recycled to restore our natural resources and ecological balance. We may again use the products of recycled materials for our day-to-day activities.
Prevention and Control of Soil Pollution:
Effluents from industries and factories should not be allowed to enter the soil indiscriminately. ii. Drainage system should be so developed that the polluted water does not get mixed up with the soil. iii. Proper toilet facilities should be provided to all and awareness should be created about the harmful effects of defecation in open places. iv.
Fertilizers, pesticides and insecticides should be used judiciously so that excess chemicals are not washed into the soil. v. Safe methods of disposal of domestic, agricultural and industrial solid wastes should be adopted.