Life cycle assessment of MSW management in medium-scale cities: A Brazilian case study

Municipal solid waste management in medium-scale cities is a difficult task in developing countries, because high moisture content of waste, the technical complexity of improved technologies, and outdated regulations that permit landfilling of MSW. Therefore, the objective of this study is to provide the assessment of environmental impacts from six scenarios, considering waste-to-energy alternative systems. The scope comprises MSW generated in CIMASAS, a consortium of 11 municipalities in southeast Brazil. An environmental assessment was accounted for via LCA using SimaPro® software, considering the CML IA method baseline. To complement the analysis, the IMPACT 2002+ methodology was applied. Additionally, four indicators were used to evaluate the energy and environmental performance of the different systems: Specific power generation, Specific fossil Energy consumption, Fossil energy ratio, and Carbon footprint. Results indicate that there is a need to reduce waste disposal in landfills, which was the worst scenario for all impact categories. The results indicated improved environmental performance in integrated systems that benefit from electricity generation, recovery of materials from waste sorting/recycling, and production of biofertilizers. The analysis also demonstrated that the best environmental performance corresponds to an integrated system of gasification and anaerobic digestion along with waste sorting/recycling, the only alternative to provide a reduction in carbon footprint.