Greenhouse Gas Emission During Composting and Vermicomposting of Organic Wastes - A Review

Human-induced climate change, mainly through greenhouse gases emission (GGE), is attracting attention worldwide and has become one of the major threats to the environmental sustainability. Utmost is the need to understand the impact of waste management practices on GGE, or countries could incorporate alternative waste management strategies for various organic wastes. Strict regulatory controls limiting waste disposal in landfills and the consequent diversion of biodegradables have resulted in the adoption of sustainable waste management techniques like composting and vermicomposting. However, composting and vermicomposting systems for waste management, especially at large scale have the capacity to emit high levels of greenhouse gases (GHGs). This paper reviews the current available literature pertaining to GGE during composting and vermicomposting of various organic wastes, linking with the fate of carbon (C) and nitrogen (N) during stabilization. Further, the current study provides a comprehensive summary of the emissions and plausible mechanisms and factors responsible for the GGE during both processes. The article also highlights likely mitigation actions relating to process parameters effective in minimizing GGE during composting and vermicomposting of organic wastes.