Environmental impacts and sustainability assessment of municipal solid waste treatment: incineration combined with anaerobic digestion/black soldier fly larvae.

The comprehensive evaluation of the environmental, economic, and energy implications of municipal solid waste (MSW) treatment is essential to evaluate the sustainable management strategies, particularly in the context of the waste sorting policy, which has been implemented 5 years in China. A representative full-scale MSW treatment plant in Shanghai, featuring three distinct process configurations-namely, (1) incineration (INC), (2) anaerobic digestion (AD)-INC, and (3) black soldier fly larvae (BSFL)-INC, has been selected and assessed systematically using life cycle assessment (LCA). The global warming potential (GWP) was primarily attributed to direct process emissions from incineration, while AD-INC and BSFL-INC systems yielded net environmental benefits across multiple non-GWP impact categories and demonstrated superior economic performance. The enhanced sustainability is largely attributable to improved resource recovery efficiency, particularly via electricity generation and the production of protein feed and organic fertilizer in the case of BSFL-INC. The sensitivity analysis further revealed that a higher proportion of food waste significantly amplified GWP-related environmental benefits within integrated processes. Under projected decarbonization trajectories of the regional electricity grid, both AD-INC and BSFL-INC systems might maintain the environmental and economic advantages through 2060, highlighting their long-term viability in the context of energy transition. These findings suggest that the integration of biological treatment (AD or BSFL) with incineration offers a promising strategy for reducing environmental burdens and maximizing resource recovery in densely populated megacities.