The types and sources of solid wastes :
The various types of solid wastes are briefly described below:
1. Municipal wastes :
These include garbage (i.e. biodegradable food waste); Rubbish (i.e. non-biodegradable solid waste from homes, offices, markets, hotels, etc.);
Construction and demolition wastes: Sludges from septic tanks; wires’, conduits pipes; ashes; abandoned vehicles etc.
2. Special wastes :
These include hazardous wastes like toxic substances (pesticides, heavy metal sludges); radioactive wastes; Biological waste; explosives, inflammable substances, corrosive materials, etc.
3. Domestic wastes :
These include wastes generated from domestic cooking and serving of food. Examples Garbage, waste paper, plastic, cloth etc
4. Agricultural wastes :
These wastes result from farms, feed lots and live-stock yards. Examples Corn residues, baggasse from sugarcane manures, paddy husk, etc
5. Industrial wastes :
(a) Process wastes:
Here waste depends on the products being manufactured.
Examples Plastic wastes, rubber wastes, metal scraps, food-processing wastes, etc.
(b) Non-process wastes:
Here waste is common to all industries. Examples Office and cafeteria wastes, packing wastes, etc
Causes of generation of solid wastes :
The main causes for the rapid growth in the quantity of solid wastes are described below:
Solid waste generated per person multiplied by total population results in increased generation of solid waste every day.
Urbanization requires various construction activities like construction of buildings, markets, shopping malls, roads, railways, airports, bridges, dams, water supply and sewage disposal systems. Each construction activity also generates solid wastes.
Consumers with high purchasing capacity discard ‘obsolete goods’. This leads to solid waste generation.
(iv) Advances in Technology:
These lead to large scale production of goods for consumption based society preferring disposable items and almost every item ‘packaged’. All these result in generation of huge quantities of solid wastes.