Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai, 201306, China.
J Environ Manage. 2022 Sep 15;318:115624. doi: 10.1016/j.jenvman.2022.115624. Epub 2022 Jun 27.
Centralized biological treatments, i.e., anaerobic digestion (AD) and in-vessel composting (IVC), were supposed to be the promising processes for the disposal of food waste (FW) after source separation, while the systematic benefits were unclear for FW with high water content, salt and oil and thus influenced the selection by the local decision-makers. In this study, two large-scale working AD and IVC plants were compared for environmental impacts, nutrient recovery and economic benefits. For unit amount of FW, 89.26 kg CO-eq was released in IVC mainly due to 47.89 kWh electricity consumption, and 57.02 kg CO-eq was produced in AD. With the application of compost and energy recovery, 26.88 and 93.55 kg CO-eq savings were obtained in IVC and AD, respectively. NH emissions were the main contributor to acidification (0.35 kg SO-eq) in IVC, while AD exerted less impact on acidification (0.09 kg SO-eq) and nutrient enrichment (0.25 kg NO-eq) attributed to the counteract of energy recovery. 2029 would be the inflection point for global warming potential in AD with more clean energy applied in electricity mix in China. For nutrient recovery, more C (8.3%), N (37.9%) and P (66.7%) could be recovered in compost, while those were discharged via leachate and biogas residue in AD. The cost of IVC was 16 CNY/t (2.40 USD/t) lower than AD. Combing the three key indexes and the sale routes of products, IVC was recommended to be used in areas dominated by agriculture and forestry industries, and AD was more suitable for large cities.
集中式生物处理，即厌氧消化（AD）和罐式堆肥（IVC），被认为是源头分离后的食品废物（FW）处理的有前途的工艺，但对于高水分、盐分和油分的 FW，其系统效益尚不清楚，因此影响了当地决策者的选择。在本研究中，比较了两个大型工作的 AD 和 IVC 工厂的环境影响、养分回收和经济效益。对于单位 FW 量，IVC 中释放了 89.26kg CO-eq，主要是由于 47.89kWh 电力消耗，而 AD 中产生了 57.02kg CO-eq。通过堆肥和能源回收的应用，在 IVC 和 AD 中分别获得了 26.88kg 和 93.55kg CO-eq 的节约。NH 排放是 IVC 酸化的主要贡献者（0.35kg SO-eq），而 AD 对酸化（0.09kg SO-eq）和养分富集（0.25kg NO-eq）的影响较小，这归因于能源回收的抵消。随着中国电力组合中更多清洁能源的应用，AD 的全球变暖潜势将在 2029 年达到拐点。对于养分回收，更多的 C（8.3%）、N（37.9%）和 P（66.7%）可以在堆肥中回收，而在 AD 中则通过渗滤液和沼气残渣排放。IVC 的成本比 AD 低 16 人民币/吨（2.40 美元/吨）。综合三个关键指标和产品的销售渠道，IVC 推荐用于以农业和林业为主的地区，而 AD 更适合大城市。
