Zhou Hao, Wei Liangliang, Wang Dongsheng, Zhang Weijun
Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China; State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, Ministry of Ecology and Environment, China.
State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, China.
Environ Int. 2022 Aug;166:107378. doi: 10.1016/j.envint.2022.107378. Epub 2022 Jun 27.
The management and utilization of sludge in a sustainable approach require a systematic analysis of the environmental impacts generated from diverse sludge treatment and disposal processes. This study systematically assessed 12 common sludge treatment and disposal routes based on the existing operating and construction conditions of representative sludge disposal projects in China. We evaluated their environmental impacts using a life cycle assessment following the International Organization for Standardization (ISO 14040 and ISO 14044), and found that the routes of co-incineration, mono-incineration, and anaerobic digestion with or without thermal hydrolysis may be useful in terms of simultaneously controlling environmental pollution and carbon emissions in China. Therein, the route of co-incineration was recommended as the best one because its human toxicity potential (-152.31 kg dichlorobenzene (1,4-DB) eq/ton dry solid (t DS)), freshwater ecotoxicity potential (FEP, -127.40 kg 1,4-DB eq/t DS), terrestrial ecotoxicity potential (TEP, -0.81 kg 1,4-DB eq/t DS), and global warming potential (-27.26 kg CO eq/t DS) were all negative (environmental benefits). Furthermore, the toxicity impacts of the mono-incineration route were also negative, but it still needed to further enhance energy recovery to reduce carbon emissions. Despite the routes of anaerobic digestion and thermal hydrolysis in combination with anaerobic digestion had the excellent negative carbon emission attributes (-572.44 kg CO eq/t DS, -474.92 kg CO eq/t DS), they showed serious FEP and TEP owing to the heavy metals pollution caused by subsequent land use of anaerobic digested sludge. Overall, this study selected the most suitable sludge treatment and disposal routes to simultaneously satisfy the requirements of carbon emission reduction and pollution control in China and proposed optimizing suggestions for future technical improvement and development.
以可持续的方式管理和利用污泥需要对各种污泥处理和处置过程产生的环境影响进行系统分析。本研究基于中国代表性污泥处置项目的现有运营和建设条件，系统评估了12种常见的污泥处理和处置途径。我们按照国际标准化组织（ISO 14040和ISO 14044）的规定，采用生命周期评估方法评估了它们的环境影响，发现共焚烧、单焚烧以及厌氧消化（有无热解）途径在同时控制中国的环境污染和碳排放方面可能是有用的。其中，共焚烧途径被推荐为最佳途径，因为其人体毒性潜力（-152.31千克二氯苯（1,4-DB）当量/吨干固体（t DS））、淡水生态毒性潜力（FEP，-127.40千克1,4-DB当量/t DS）、陆地生态毒性潜力（TEP，-0.81千克1,4-DB当量/t DS）和全球变暖潜力（-27.26千克二氧化碳当量/t DS）均为负值（环境效益）。此外，单焚烧途径的毒性影响也为负值，但仍需要进一步提高能源回收以减少碳排放。尽管厌氧消化以及热解与厌氧消化相结合的途径具有出色的负碳排放属性（-572.44千克二氧化碳当量/t DS, -474.92千克二氧化碳当量/t DS），但由于厌氧消化污泥后续土地利用造成的重金属污染，它们表现出严重的FEP和TEP。总体而言，本研究选择了最适合的污泥处理和处置途径，以同时满足中国碳排放减少和污染控制的要求，并为未来的技术改进和发展提出了优化建议。
