Strategies for municipal community organic waste management in China under a life cycle thinking approach

This study employs life cycle assessment (LCA) to evaluate centralized and decentralized municipal organic waste (MOW) treatment strategies. Centralized treatment (Scenario 2) uses incineration and anaerobic digestion (AD), while decentralized systems (Scenarios 1, 3-7) integrate black soldier fly (BSF) breeding with composting at varying feedstock ratios. Using the CM;-2016 methodology within GaBi software, we evaluated five categories relative to each scenario: atmospheric impacts, aquatic impacts, soil impacts, human health impacts, and resource depletion. Key findings reveal that decentralized strategies significantly outperform centralized treatment across most impact categories. Particularly notable reductions include Acidification Potential (AP) (80.8-81.2 %), Global Warming Potential 100-year time horizon (GWP_100year) (96.3-97.3 %), and Human Toxicity Potential (HTP) (90.2-91.9 %). Crucially, optimal waste stream allocation maximizes specific benefits. Scenario 7 (100 % food waste (FW) -yard waste (YW) co-composting) achieved the lowest GWP_100year (1.3 t CO₂ eq.) by eliminating transport and incineration, while Scenario 4 (25 % FW to BSF larvae + 75 % composting) excelled in fossil resource conservation (Abiotic Depletion Potential-fossil (ADP-fossil), -14,526.6 MJ) and AP reduction (21.6 kg SO₂ eq.) through balanced valorization of larval protein and compost. These results demonstrate that strategically allocating MOW between centralized and decentralized pathways is pivotal for achieving tailored environmental objectives. Successful implementation requires mature decentralized technologies, supportive policy frameworks for hybrid systems, and community engagement to overcome economic and social barriers.