Iqbal Asad, Zan Feixiang, Liu Xiaoming, Chen Guanghao
Department of Civil and Environmental Engineering, Water Technology Centre, Hong Kong Branch of Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China.
School of Environmental Science and Engineering, MOHURD, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), Wuhan, 430074, China.
Water Res. 2023 Oct 1;244:120481. doi: 10.1016/j.watres.2023.120481. Epub 2023 Aug 11.
Food waste (FW) being a major solid waste component and of degradable nature is the most challenging to manage and mitigate greenhouse gas emissions (GHEs). Policymakers seek innovative approaches to achieve net zero objectives and recover resources from the FW which requires a comparative and holistic investigation of contemporary treatment methods. This study assessed the lifecycle of six alternative scenarios for reducing net GHEs and energy use potential from FW management in a metropolis, taking Hong Kong as a reference. In both impact categories, the business-as-usual (landfilling) was the worst-case scenario. The combined anaerobic digestion and composting (ADC) technique was ranked best in the global warming impact but was more energy intensive than anaerobic digestion with sludge landfilling (ADL). Incineration ranked second in net GHEs but less favourable for energy recovery from FW alone. The proposed integration of FW and biological wastewater treatment represented an enticing alternative. Integration by co-disposal and treatment with wastewater (CoDT-WW) performed above average in both categories, while anaerobic co-digestion with sewage sludge (AnCoD-SS) ranked fourth. The sensitivity analysis further identified critical parameters inherent to individual scenarios along with biogenic carbon emission and sequestration, revealing their significance on the magnitude of GHEs and scenarios' ranking. Capacity assessment of the studied treatment facilities showed a FW diversion potential of ∼60% while reducing the net GHEs by ∼70% compared to the base-case, indicating potential of net zero carbon emissions and energy footprint by increasing treatment capacity. From this study, policymakers can gain insights and guidelines for low-carbon urban infrastructure development worldwide.
食物垃圾（FW）作为主要的固体废物成分且具有可降解性，是管理和减少温室气体排放（GHEs）最具挑战性的。政策制定者寻求创新方法以实现净零目标，并从食物垃圾中回收资源，这需要对当代处理方法进行比较性和整体性研究。本研究以香港为参考，评估了大都市中六种减少食物垃圾管理净温室气体排放和能源利用潜力的替代方案的生命周期。在这两个影响类别中，照常营业（填埋）是最坏的情况。厌氧消化与堆肥相结合（ADC）技术在全球变暖影响方面排名最佳，但比污泥填埋厌氧消化（ADL）能源密集度更高。焚烧在净温室气体排放方面排名第二，但仅从食物垃圾中回收能源不太有利。提议的食物垃圾与生物废水处理一体化是一个有吸引力的替代方案。与废水共同处置和处理（CoDT-WW）在这两个类别中表现均高于平均水平，而与污水污泥厌氧共消化（AnCoD-SS）排名第四。敏感性分析进一步确定了各个方案固有的关键参数以及生物源碳排放和封存，揭示了它们对温室气体排放规模和方案排名的重要性。对所研究处理设施的能力评估表明，与基准情况相比，食物垃圾转移潜力约为60%，同时净温室气体排放减少约70%，这表明通过提高处理能力有实现净零碳排放和能源足迹的潜力。通过这项研究，政策制定者可以获得全球低碳城市基础设施发展的见解和指导方针。
