Application of recirculation prehydrolysis technology in food waste pretreatment and its environmental impact analysis: a case study in Shanghai

Abstract

Food waste is characterized by a high generation rate, high moisture content, and rapid biodegradability, making it a biomass waste with significant resource potential. This study applies life cycle assessment (LCA) using the SimaPro 12.0 software and the ReCiPe 2016 Midpoint method to evaluate the environmental performance of three food waste treatment scenarios in Shanghai (phase I, phase I with 30% recirculation prehydrolysis, and new phase II). The results show the following: (1) the overall system achieved a negative carbon footprint, mainly from the carbon sink effects of biogas power generation, solid waste incineration, and grease recovery; (2) the deodorization unit had the highest carbon emissions, followed by pretreatment and slurry treatment units; (3) standardized results indicated slurry treatment and deodorization, and pretreatment had the greatest environmental impacts; (4) among the scenarios, phase II performed the best in reducing greenhouse gases, controlling ecotoxicity, and improving resource efficiency; and (5) sensitivity analysis identified electricity as the most critical factor, followed by chemicals, while water had a minor influence. This study provides insights into optimizing food waste treatment, enhancing resource recovery, and supporting sustainable waste management.