1. Introduction
Solid waste generation is a natural phenomenon and amount of waste produced is directly proportional to the population growth. Less population means less demand for food and shelter, as well as lesser pressure on other natural resources for their various needs. The last five decades have resulted in an uncontrolled exploitation of different kinds of natural resources due to rapid urbanization, industrialization and changes in the way of life. The uncontrolled misuse of the abundant resources has finally resulted in generation of a huge quantity of complex solid waste. The sustainable waste management practices are necessary to keep the environment clean and green. In present circumstances it is advisable that waste products of one industry should be investigated be with an intention to use it as raw material for other industry to get the desired product.
Urban/municipal solid waste (MSW) is usually regarded as the waste that is generated from human settlements, small industries, commercial and municipal activities (Table 1). There are few more sources from which MSW originates i.e. waste water treatment plants (sewage sludge), household (glass, paper, metals, etc.), public areas (waste from parks, streets, etc.) (Table 1). Often the residential waste is referred as MSW, and in high income countries about 25–35% of the overall waste comes from residential sources (World Bank, 1999).