Sensitivity analysis and improvements of the recycling rate in municipal solid waste life cycle assessment: Focus on a Latin American developing context

摘要

The life cycle assessment (LCA) of municipal solid waste (MSW) systems in developing countries is a matter of research. Obtain reliable results is challenging since field data and local databases are not always available. The research presented in this paper explores this issue in La Paz (Bolivia), where six environmental impact categories were assessed. The LCA, related to the formal MSW management system of the city, involves a sensitivity analysis of ten parameters and the scenario assessment in relation to the increase of the recycling rate. Results report that the environmental impacts are mostly sensitive in relation to landfill gas collection efficiency, use of plastic bags, the transportation distances of collected waste, and the replacement rate of virgin materials. Global warming potential is the impact category most variable (341.38-551.95 kg CO_2 -eq t_(MSW)~(-1), although it is not considerably reduced by recycling, which contributed mostly to the human toxicity and freshwater aquatic ecotoxicity. Doubling the amount of MSW recycled, from 235 t to about 473 t per year, human toxicity potential reduces of about 18% while freshwater aquatic ecotoxicity of about 12%. This research contributes for evaluating the most sensitive parameters in an MSW-LCA and to support policymakers towards waste recycling and sustainable development in Latin America developing cities.