氨氮是导致水体富营养化的主要污染物之一。低温会显著抑制污水处理厂的生物脱氮性能,导致出水中氨氮等浓度升高,影响受纳水体的生态环境安全。笔者系统综述了低温条件下生物脱氮面临的主要问题与强化技术,深入探讨了脱氮功能微生物的低温响应特性与潜在耐冷机理。总结认为:低温(<15 ℃)会导致微生物细胞膜流动性变差、酶活性下降及群落结构失衡,致使脱氮效能显著降低;通过工艺参数优化(如延长水力停留时间、调控溶解氧及碳源投加)、功能性填料开发、基于群体感应的菌群调控及耐冷菌剂投加可有效缓解低温抑制;耐冷微生物通过调节细胞膜组分、合成冷适应酶与冷休克蛋白及分泌胞外聚合物(EPS)等策略适应低温胁迫;其中,氨氧化古菌、完全氨氧化菌(Comammox)和异养硝化-好氧反硝化细菌相较于传统氨氧化细菌表现出显著的低温竞争优势。未来研究应重视开发低成本菌剂固定化与抗流失技术,设计基于纳米材料或仿生结构的新型功能填料,深入解析Comammox菌的耐冷机制及其种间协同代谢途径,利用多组学技术(宏基因组学、转录组学等)阐明耐冷调控网络,并探索生物强化-电化学等多技术耦合工艺,以实现低温脱氮系统的长效、高效与经济稳定运行,为低温地区污水处理提供理论支撑与技术指导。

Ammonia nitrogen is one of the primary pollutants responsible for aquatic eutrophication. Low temperatures significantly inhibit the biological nitrogen removal performance in wastewater treatment plants, leading to elevated effluent ammonia concentrations and posing risks to the ecological security of receiving water bodies. This paper provides a comprehensive review of the major challenges confronting biological nitrogen removal under low-temperature conditions and the corresponding enhancement technologies, while also delving into the cold-response characteristics and potential cold-adaptation mechanisms of functional denitrifying microorganisms. Key findings indicate that low temperatures (<15 ℃) induce reduced cell membrane fluidity, decreased enzyme activity, and microbial community structure imbalance, thereby severely compromising nitrogen removal efficiency. Strategies such as process parameter optimization (e.g., extending hydraulic retention time, regulating dissolved oxygen and carbon dosage), development of functional carriers, quorum sensing-based microbial community regulation, and inoculation of cold-adapted microbial agents can effectively mitigate low-temperature inhibition. Cold-adapted microorganisms employ strategies including modulating membrane composition, synthesizing cold-adapted enzymes and cold-shock proteins, and secreting extracellular polymeric substances (EPS) to withstand cold stress. Notably, ammonia-oxidizing archaea, complete ammonia oxidizers (Comammox), and heterotrophic nitrification-aerobic denitrification bacteria exhibit significant competitive advantages over conventional ammonia-oxidizing bacteria at low temperatures. Future research should prioritize the development of cost-effective immobilization and retention techniques for microbial agents, design of novel functional carriers based on nanomaterials or bionic structures, in-depth elucidation of the cold-adaptation mechanisms and interspecies synergistic metabolic pathways of Comammox, and systematic dissection of cold-regulatory networks using multi-omics approaches (metagenomics, transcriptomics, etc.). Furthermore, exploring integrated processes such as bioaugmentation coupled with electrochemistry is essential to achieve long-term, efficient, and economically stable operation of nitrogen removal systems in cold regions, providing robust theoretical support and technical guidance for wastewater treatment in low-temperature environments.