【摘要】 对北方某大型城市污水处理厂表面曝气型氧化沟工艺进行了为期1年的氧化亚氮（N₂O）排放通量监测。结果显示，曝气区的N₂O气相排放因子比非曝气区高2～3个数量级，而两个区域的液相排放因子则处于同一量级；无论是曝气区还是非曝气区，N₂O主要是以液相形式存在；从总排放因子来看，两区域均呈现出冬春季低、夏秋季高的趋势。双同位素溯源结果显示，曝气区与非曝气区的N₂O均来源于不同过程的混合：在以反硝化过程为主的非曝气区中可以测得有41.71%的N₂O来源于硝化过程，而曝气区中反硝化过程的贡献率达到了41.69%。N₂O排放因子的波动与进水NH₄⁺-N浓度和C/N呈现显著相关。非曝气区与曝气区的活性污泥结构并无显著不同，活性污泥存在着一个相对稳定的微生物菌群，优势菌属Acinetobacter、Intestinibacter、Trichococcus均具有较高的代谢多样性和生存灵活性。这些结果为未来城市污水生物处理过程中N₂O的产排控制策略构建指明了主要关键因子与潜在控制方向。更多还原

【Abstract】 Nitrous oxide（N₂O） emission fluxes were monitored for one year in a surface aeration oxidation ditch at a full-scale municipal wastewater treatment plant in northern China. Results showed that the gaseous N₂O emission factor in the aeration section was 2-3 orders of magnitude higher than those in the non-aeration section, while the liquid phase emission factor remained comparable between the two sections. In both sections, N₂O predominantly existed in the liquid phase. The total emission factors in both sections exhibited a seasonal pattern with lower values in winter-spring and higher values in summer-autumn. Dual isotope source tracking revealed that N₂O in both sections originated from mixed nitrogen removal processes: in the non-aeration section, 41.71% of N₂O originated from nitrification, while in the aeration section, denitrification contributed 41.69%. N₂O emission factors showed significant correlation with influent NH₄⁺-N concentration and C/N ratio. The activated sludge structure showed no significant difference between non-aeration and aeration sections, maintaining a relatively stable microbial community. The dominant genera, including Acinetobacter, Intestinibacter, and Trichococcus, demonstrated high metabolic diversity and survival flexibility. These findings identify key factors and potential control strategies for N₂O production and emission regulation in future municipal wastewater biological treatment processes.更多还原