Composting is the transformation of organic waste into compost. A pile of organic waste is attractive to micro-organisms that are normally present in the environment. If the water content is sufficiently high, the micro-organisms start to consume the nutritional substance. This means they break down the organic molecules, produce carbon dioxide, water and heat. At the end of the process, the initial waste is transformed into a substance called compost.
In commercial composting plants, this process is controlled and optimized in order to achieve a high conversion speed, control of the effluent, control of the quality of the final compost, etc.