污水再生与增值利用的碳排放研究进展

资源紧缺与气候变化已成为制约人类繁荣发展的巨大挑战。如何对污水资源进行再生利用是循环经济发展的重要议题之一,也是污水治理低碳转型的潜在路径。以再生水、能源、微生物蛋白和鸟粪石等污水资源化产品为研究对象,分析总结了不同污水资源化技术与工艺的生命周期碳排放研究现状。分析指出,污水再生与增值利用具有可观的减碳效益,但应结合利用场景在系统水平开展量化评估。此外,数据来源、系统边界和功能单位等是碳排放评估的关键影响因素。未来,揭示污水再生与增值利用全生命周期过程的碳减排效益,提出污水资源化利用的零(负)碳技术路径,发展污水治理协同资源化的低碳模式,也应是亟待解决的科技难题。

RESEARCH ADVANCES ON CARBON EMISSION OF WASTEWATER RESOURCE RECOVERY AND VALORIZATION

Resource scarcity and climate change have become grand challenges affecting human prosperity.How to reuse valuable resources from wastewater is important to achieve circular economy,and low-carbon transformation of wastewater treatment.This review is intended to provide an overview of the current state-of-the-art in research on both direct and indirect carbon emissions of different wastewater resource recovery technologies and processes,with the aim of producing clean water,energy,microbial protein,struvite,and other high value-added products.We found that wastewater resource recovery and valorization could create substantial benefits in reducing unwanted carbon emissions,but the advantages would vary with different end-use practices,which reflects the necessity of the inclusion of contextual scenarios in system analysis.Moreover,we highlighted the importance of data source,system boundary,and functional unit,since they would greatly influence the results of a carbon emission assessment.Last but not the least,we also claimed that many future efforts are still needed to analyze the life cycle carbon reduction effects attributed to wastewater resource recovery and valorization,create novel approaches enabling zero-emission or even negative emissions of greenhouse gases through wastewater resource valorization,and eventually evolve wastewater treatment and resource recovery schemes in a truly carbon-free manner.