Life cycle assessment of municipal solid waste source-separated collection and integrated waste management systems in Hangzhou, China

Municipal solid waste (MSW) source-separated collection was started in Hangzhou since 2010. Life cycle assessment (LCA) is conducted to evaluate its effect on the environment. Four MSW management (MSWM) systems are compared, and the functional unit is defined as the annual MSW generation in the city. Scenario 1 is the mixed collection system, where 50.77 % of the MSW is landfilled and 49.23 % incinerated. Scenario 2 represents the current system under source-separated collection. In addition, two future MSWM plans in the city are also modeled. A new incineration plant is planned to be built as the short-term plan (scenario 3); while food waste biological treatment techniques will be introduced according to the city’s long-term plan (scenario 4). Results show that a total 30, 18, 28 and 29 % of global warming, acidification, nutrient enrichment and photochemical ozone formation has been saved after source separation, respectively. Meanwhile, both the short- and long-term MSWM plans provide positive effect to environmental improvements. Sensitivity analysis further reveals that food waste biological technique is essential with the continuous rise of source separation efficiency; and MSW destined for landfill should be controlled efficiently.