生物膜与活性污泥复合脱氮工艺中污泥聚集态对氧化亚氮释放的作用机制与调控原理

氧化亚氮（N2O）是一种重要温室气体，现如今受到越来越多的关注。污水生物脱氮过程是其产生的重要来源。生物膜-活性污泥复合工艺（IFAS）作为混合脱氮工艺，能够有效提高废水处理效率，减少占地面积，降低污泥产量，因此在实际工程中得到广泛应用。IFAS系统中污泥絮体和生物膜不可避免同时存在，这种混合系统势必会对N2O释放过程产生影响。但目前关于短程硝化-反硝化的污泥絮体和生物膜混合系统对N2O释放的作用机制尚不明确，也缺乏有效的调控技术。本项目拟通过理化分析、生物学解析，动力学表征和数学模拟等对IFAS系统内污泥絮体与生物膜的脱氮效能和N2O释放规律进行全面研究，综合利用污泥絮体和生物膜内种群分布特性和代谢机理的竞争及协同作用，实现IFAS工艺高效脱氮及N2O减量化排放的微调控方法。在完成污水高效脱氮的同时，实现节约曝气能耗和降低温室气体排放，对污水生物脱氮的低碳运行理论方面具有突破性意义。

Nitrous oxide (N2O) is a highly potent fugitive greenhouse gas (GHG) that arises great concern and attention. Biological nitrogen removal (BNR) process is the principal contributor to N2O emission from wastewater treatment plants (WWTPs). Integrated fixed-film activated sludge (IFAS) process combines the advantages of both suspended-growth activated sludge and attached-growth biofilm systems, which improves wastewater treatment efficiency and reduce the sludge production without expanding the area of WWTPs. Therefore, it is widely used in practical biological nitrogen removal processes. The sludge flocs and biofilm aggregates coexist in this hybrid system, and it is reasonable to hypothesize that such a mixture of these two may also affect the N2O production and emission process. However, the detailed mechanisms of the impact of the coexisting sludge flocs and biofilm on N2O turnovers in the hybrid partial nitrification and denitrification system are still not well understood. Also, effective control technology for this hybrid system is not available yet. Based on the physicochemical analysis, microbiological characterization, kinetic analysis and mathematical modeling, the mechanism and synergistic effects of the coexisting sludge flocs and biofilms on nitrogen removal efficiency and N2O emission in IFAS systems will be comprehensively studied. The micro-scale control of community structure and spatial distribution in IFAS system for optimal nitrogen removal and N2O reduction can then be achieved through optimizing the key environmental conditions and operational parameters. The outcome of this project will provide theoretical and technological supports for the development of low-carbon sustainable wastewater management technology.