Resource impacts of municipal solid waste treatment systems in Chinese cities based on hybrid life cycle assessment

Municipal Solid Waste (MSW) management in Chinese cities is a significant challenge. However, the comprehensive resource impacts of MSW treatment systems in Chinese cities are unclear. This study presents a mixed-unit hybrid life cycle assessment for MSW treatment systems. The comprehensive resource impacts of six MSW treatment systems in China are evaluated using this method: (1) landfilling, (2) landfilling with landfill gas utilization, (3) incineration with leachate spray, (4) composting+landfilling, (5) composting+incineration, and (6) incineration with leachate centralized treatment. The results show that composting+incineration has the lowest resource impacts except for raw coal extraction. Reusing by-products of MSW treatment systems can reduce resource extraction of the entire economy. By reusing the by-products, landfilling induces the largest extraction of fossil fuels and biomass, whereas landfilling with landfill gas utilization induces the largest extraction of mineral ores. Improving the diesel efficiency of the collection and transportation process, increasing by-product recovery efficiency, and decreasing moisture content of MSW have significant impacts on reducing resource impacts of MSW treatment systems. We also observed trade-offs in resource impacts of different MSW treatment systems. Compared to landfilling, landfilling with landfill gas utilization can reduce the induced fossil fuel extraction but increase the induced metal ore extraction. We observed similar situation when comparing incineration with leachate spray with composting+landfilling.Findings of this study provide scientific foundations to improve the resource efficiency of MSW treatment systems in Chinese cities. They also provide insights into the MSW management in other countries.