School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
Sci Total Environ. 2022 Feb 10;807(Pt 1):150751. doi: 10.1016/j.scitotenv.2021.150751. Epub 2021 Oct 5.
China produces vast amounts of food waste every year. However, the environmental impact of the current treatment of food waste and its potential for improvement are not very clear. Therefore, this study applied life cycle assessment to compare the current major treatment options for food waste and to systematically quantify the environmental impact of current and future food waste treatment in China based on the amount and treatment mode of food waste. In 2020, 125 million tons (Mt) of food waste was generated in China. Its treatment consumed 30.1 Mt oil-Eq of fossil fuels and 16.7 Mt of freshwater, and released 37.5 Mt of CO-Eq. A promising finding was that if the proportion of food waste treated by anaerobic digestion exceeded 40% and landfilling was terminated by 2050, most impact categories would be reduced by more than 50%. Although anaerobic digestion is a potentially more environmentally friendly treatment option due to more output of energy and resources, it is worth noting that it consumed more freshwater than incineration and landfilling. Electricity consumption contributed more than 50% of the environmental burden of anaerobic digestion. Therefore, for the upstream of anaerobic digestion, China should further implement policies of waste classification and promote zero-waste cities, so that less impurities and more food waste would enter anaerobic digestion instead of landfills. Whereas downstream, the resource utilization of biogas and digestate enhance should be enhanced so as to strengthen the environmental sustainability of anaerobic digestion.
中国每年产生大量的食物垃圾。然而，目前食物垃圾处理的环境影响及其改善潜力并不十分清楚。因此，本研究应用生命周期评价比较了目前食物垃圾的主要处理方法，并根据食物垃圾的数量和处理方式，系统地量化了中国当前和未来食物垃圾处理的环境影响。2020 年，中国产生了 1.25 亿吨食物垃圾。其处理消耗了 3010 万吨石油当量的化石燃料和 1670 万吨淡水，并释放了 3750 万吨二氧化碳当量。一个有希望的发现是，如果通过厌氧消化处理的食物垃圾比例超过 40%，并在 2050 年前终止填埋，那么大多数影响类别将减少 50%以上。尽管由于更多的能源和资源产出，厌氧消化是一种潜在的更环保的处理选择，但值得注意的是，它比焚烧和填埋消耗了更多的淡水。电力消耗对厌氧消化的环境负担贡献超过 50%。因此，对于厌氧消化的上游，中国应进一步实施垃圾分类政策，并推广无废城市，使较少的杂质和更多的食物垃圾进入厌氧消化，而不是进入垃圾填埋场。而在下游，应加强沼气和消化物的资源利用，以加强厌氧消化的环境可持续性。
