Life cycle assessment of the integrating system of anaerobic digestion and aerobic composting for treating rural organic solid waste

With the rapid development of modern society and the continuous increase in resource consumption in rural areas of China, the management of rural organic solid wastes has encountered substantial environmental and economic challenges. Although the integration of anaerobic digestion and aerobic composting offers promising potential for sustainable rural organic solid waste management, comprehensive environmental evaluations of this integrated system remain limited, representing a critical research gap. This study employed life cycle assessment to compare the integrated system with standalone anaerobic digestion and aerobic composting scenarios, assessing eighteen mid-point impact categories and three end-point indicators (human health, ecosystems, and resources). The results demonstrated that the integrated scenario achieved superior environmental performance, yielding a net reduction with significant benefits in human health (-0.027 DALY) and resource conservation (-14.44 USD2013). Notably, it outperformed standalone systems in fifteen of the eighteen impact categories, with pronounced advantages in global warming potential, ecotoxicity, and fossil resource scarcity. However, the integrated system exhibited relative limitations in water consumption, terrestrial acidification, and ozone depletion. Sensitivity analysis revealed that a 10 % reduction in electricity consumption shifted the ecosystem impact of the integrated system from a burden (6.57 ×10 −5 species·yr) to a net benefit (-2.3 ×10 −5 species·yr). This study addresses the identified research gap by providing a systematic environmental assessment, underscoring the importance of adopting integrated rural organic solid waste management strategies tailored to regional conditions in China. • Rural organic solid wastes (ROSW) management has faced significant challenges. • Three scenarios for ROSW managements were evaluated based on life cycle assessment. • Integration of anaerobic digestion and aerobic composting (AD-AC) was promising. • AD-AC scenario maximized resource recovery and achieved reduction in GHG emissions. • Sensitivity analysis highlighted importance of reducing electricity consumption.