Environmental impact of organic fraction of municipal solid waste treatment by composting in Sri Lanka

In Sri Lanka, the management of the organic fraction of municipal solid waste (OFMSW) is a challenge. Composting is an environmentally and economically friendly treatment method for reducing the quantity of waste going to landfills. Although composting has many advantages, it has unavoidable environmental impacts, such as atmospheric emissions and resource consumption that should be considered. This work assessed the environmental impacts of a full-scale composting plant in Sri Lanka using life cycle assessment (LCA). The impact assessment results indicated that the composting system created burdens for global warming (218 kg CO2 eq/tonne OFMSW), stratospheric ozone depletion (3.13 x 10(-3) kg CFC-11 eq/tonne OFMSW), fine particulate matter formation (0.75 kg PM2.5 eq/tonne OFMSW), terrestrial acidification (6.17 kg SO2 eq/tonne OFMSW), and fossil resource scarcity (0.613 kg oil eq/tonne OFMSW). Impacts on freshwater eutrophication, ozone formation (human health and terrestrial ecosystems), human carcinogenic toxicity, ecotoxicity (freshwater, terrestrial, and marine), marine eutrophication, human non-carcinogenic toxicity, land use, water consumption, and mineral resources scarcity were avoided due to compost production. Ammonia, methane, and nitrous oxide emissions were the main impacting elements in the composting system. Finally, the findings of this study could help in decision-making and policy formation for waste management in Sri Lanka.