Composting and Heavy Metals

Composting is the best alternative for the management of sewage sludge (SS) generated from water treatment plants. The treatment of biodegradable wastes through composting process causes many physical and biochemical changes in the composting biomass, this happened due to development of microbial populations. In the composting process, microbes and their secreted enzymes play a key role in the biological and biochemical conversions of the composting biomass. The thermophilic phase of the composting process, which is the first step of the composting process, may affect the exchangeable and carbonate fractions of the heavy metals. Natural zeolite has been used widely for reducing the bioavailability of heavy metals during the composting of SS, water hyacinth etc. Vermicomposting is a low-cost technology system that primarily uses earthworms for the degradation of organic wastes. Organic waste composting is one of the most economically feasible techniques to convert organic material into a stable, humic-like substance that can be used as a soil amendment.