Assessing the impact of waste separation on system transition and environmental performance through a city-scale life cycle assessment

Abstract

The increase in municipal solid waste (MSW) generation entails growing pressures on developing countries to achieve urban sustainability. New waste management strategies should be implemented with caution considering limited budget and uncertain outcome. Taking the city of Shenzhen, China as a case study, this research aimed to assess the positive transition of this city's MSW management system since the recent enforcement of waste separation. The life cycle assessment (LCA) results confirmed a good synergy between waste management system upgrade and environmental performance improvements. A noteworthy reduction of 51% in Global Warming Potential (GWP) was observed with determined cost of 61 US$/t CO2-eq, making waste separation a cost-effective management option for developing economies to achieve their environmental targets. Sensitivity analysis was performed to address the effect of specific waste composition and related properties on systematic environmental performance. Results emphasized the impact of a certain waste treatment pathway is not always constant therefore characterization of local waste flow is vital to facilitate integrated waste management. Municipalities from developing countries are encouraged to take mandatory separation as a first step to upgrade insufficient waste management system before heavy investment in new treatment technologies.