摘要
【目的】氧化亚氮(N_(2)O)是强温室气体,其排放占污水处理系统碳足迹的80%以上,精准解析其生成机制是优化污水处理工艺与降低碳排放的关键。【方法】基于微电极技术,系统综述N_(2)O在污泥聚集体内的原位监测方法,并结合扩散-反应耦合模型,量化溶解氧梯度对N_(2)O生成的调控作用。研究涵盖传统硝化-反硝化工艺与新型短程脱氮工艺(如厌氧氨氧化)的应用场景。【结果】在传统硝化-反硝化体系中,污泥聚集体内N_(2)O释放呈现显著空间异质性。好氧区N_(2)O排放因子达2.1%,其中53.6%由曝气吹脱贡献;反硝化过程中,低碳氮比(C/N<3)和低pH值(<6.5)分别通过电子供体竞争与N_(2)O还原酶(NOS)抑制使N_(2)O产率提升至基准值的2.7倍和65.0%。在厌氧氨氧化颗粒中,N_(2)O生成热点(600~1300μm)与厌氧氨氧化菌活性关联性较低,氨氧化菌反硝化路径贡献率达68%±5%。基于扩散-反应模型优化氧传质[如膜曝气生物膜反应器(MABR)]可将N_(2)O排放因子降至0.0058%。【结论】微电极技术揭示了N_(2)O生成的微尺度机制,但需进一步开发多参数微电极阵列,耦合微生物组学与计算流体动力学(CFD)模拟技术,实现“传质-反应-菌群”跨尺度解析,以推动污水处理工艺的低碳化与精准调控升级。
[Objective]Nitrous oxide(N_(2)O),a potent greenhouse gas,contributes over 80%of the carbon footprint in wastewater treatment systems.Accurately analyzing its generation mechanism is critical for optimizing treatment processes and reducing carbon emissions.[Methods]Using microelectrode technology,this paper systematically reviewes the in situ monitoring of N_(2)O within sludge aggregates and quantifies the regulation of N_(2)O generation by dissolved oxygen gradients through a coupled diffusion-reaction model.The study encompasses traditional nitrification-denitrification processes and novel short-cut nitrogen removal systems(e.g.,anaerobic ammonium oxidation).[Results]In traditional nitrification-denitrification systems,N_(2)O release exhibite significant spatial heterogeneity within sludge aggregates.The N_(2)O emission factor in aerobic zone reaches 2.1%,of which 53.6%is contributed by aeration stripping.During denitrification,low carbon/nitrogen ratios(C/N<3)and low pH value(<6.5)increases N_(2)O yields to 2.7 times and 65.0%of baseline values,respectively,due to electron donor competition and nitrous oxide reductase(NOS)inhibition.In anaerobic ammonium oxidation granules,N_(2)O production hotspots(600~1300μm)showes limited correlation with anaerobic ammonium oxidation bacterial activity,while ammonia-oxidizing bacteria denitrification contributes 68%±5%of total N_(2)O.Optimizing oxygen mass transfer via the diffusion-reaction model[e.g.,membrane aeration biofilm reactor(MABR)]reduces the N_(2)O emission factor to 0.0058%.[Conclusion]Microelectrode technology elucidates microscale N_(2)O generation mechanisms.Future efforts should focus on developing multi-parameter microelectrode arrays integrated with microbiomics and computational fluid dynamics(CFD)simulations to enable cross-scale analysis of"mass transfer-reaction-microbial community"interactions,advancing decarbonized and precision-controlled wastewater treatment.
作者
孔海霞
KONG Haixia(Xi′an Branch,North China Municipal Engineering Design&Research Institute Co.,Ltd.,Xi′an 710018,China)
出处
《净水技术》
2025年第7期23-31,138,共10页
Water Purification Technology
基金
陕西省重点产业链项目(2022ZDLSF06-05)。
作者简介
孔海霞(1982-),女,高级工程师,主要从事污水、污泥处理与资源化研究等工作,E-mail:50250667@qq.com。
