Life cycle assessment of municipal solid waste management strategies for midsized metropolitan areas in developing countries

The goal of this paper is to conduct an environmental analysis of a municipal solid waste management system in a midsized region of Southeast Brazil with two million inhabitants. While the current municipal solid waste management system has already eradicated dumps, it landfills practically all its waste, with < 2% open composting and recycling. Therefore, alternatives such as closed composting (CC), anaerobic digestion (AD) with electricity or biomethane production, and incineration are proposed via scenarios in which legal requirements are observed and diversion targets are set. Life cycle assessment (LCA) was performed using EASETECH, a specific software for municipal solid waste (MSW) management systems. The results show that the high diversions scenario (70% recyclables/biowaste) with upgraded biomethane from AD and recycling had 76% greater environmental savings than the similar scenario with the new Brazilian diversion targets (25.8% recyclables, 18.1% biowaste). CC performed much worse than AD, with 80% less savings, although it was marginally better than open composting, with a 95% difference in savings. Despite the benefits of incineration, these scenarios were penalized for their toxicity. Recycling is always recommended if feasible.