Composting is an anaerobic microbially driven process that converts organic wastes into stable sanitary humus like material. This material can then be safely returned to the natural environment. This method is actually a low moisture, solid substrate fermentation process.
In large- scale operations using largely domestic solid wastes, the final product is mostly used for soil improvement. In the more specialised operations using raw substrates (like straw, animal manure etc.), the compost (final product) becomes the substrate for the production of mushroom.
The primary aim of a composting operation is to obtain final compost with a desired product quality in a limited time period, and within limited compost. The basic biological reaction of the composting process is the oxidation of the mixed organic substrates to produce carbon dioxide, water and other organic by-products. However, it is important to ensure that a composting plant functions under environmentally safe conditions.
Composting has long been recognised not only as a means of safely treating solid organic wastes, but also as a technique of recycling organic matter. This technique will increasingly play a significant role in future waste management schemes, since it enables the reuse of organic material derived from domestic, agriculture and food industry wastes.