Abstract: Novel food waste treatment technologies have been successively developed and implemented, yet corresponding carbon emission studies remain insufficient. To quantify the carbon emission of food waste treatment, China’s first local standard DB4403/T 468—2024 Guidelines for Carbon Emission Accounting for Food Waste Treatment Projects was adopted to conduct a comprehensive carbon emission analysis. Five representative treatment approaches of typical projects were evaluated, including direct incineration with other waste, co-incineration after tri-phase separation, anaerobic digestion, black soldier fly rearing, fermentation to acid, encompassed scope 1 to 3 emissions and carbon offset components. The results showed that the net carbon emissions of the five projects (converted into CO2 equivalent, calculated as food waste), from low to high were anaerobic digestion (-90.82 kg/t), followed by fermentation to acid (-81.04 kg/t), co-incineration after tri-phase separation (-80.96 kg/t), black soldier fly rearing (-41.78 kg/t), and direct incineration with other waste (-3.01 kg/t). Carbon emission of scope 1 (0-52.43 kg/t) primarily attributed to direct discharge of food waste, wastewater and waste residue treatment. Carbon emission of scope 2 (19.32-67.17 kg/t) primarily attributed to the electricity consumption of food waste and wastewater treatment. Carbon emission of scope 3 (2.23-7.21 kg/t) primarily attributed to chemical inputs. Carbon offsets (-185.75 to -81.08 kg/t) derived from power generation (-123.75 to -81.08 kg/t), biodiesel production (-62.00 kg/t), bio-based carbon sources (-40.59 kg/t), organic fertilizer (-34.56 kg/t), feedstock materials (-19.80 kg/t). Technical recommendations for low-carbon development include enhancing gas control systems, optimizing energy mix, and improving resource recovery efficiency.

Key words: 　food waste, treatment project, carbon emission, accounting method