污水生物处理普遍存在好氧区总氮损失现象，关于该现象的生物化学机制是目前国内外生物脱氮领域的一大难题。强化这一现象并构建自养/异养菌群协同脱氮体系是提高脱氮效率的有效途径。目前难以维持稳定高效的好氧区总氮去除的关键在于对该现象的氮素归趋和自养/异养脱氮菌群的协同机制不清楚。.本研究以揭示污水处理好氧区总氮损失的生物化学机制和自养/异养菌群代谢活性与环境条件的动态响应机制为目标。其特色和创新在于①采用15N同位素示踪技术解析好氧区总氮损失的动态变化及氮素转化途径；②采用13C-DNA-SIP分析特定条件下自养/异养菌群的协同作用及对总氮损失的贡献。以定量PCR、高通量测序和生态基因组学手段作为13C-DNA分析的下游技术进行微生物鉴别。通过微生物原位功能表达的过程优化与调控，建立将新型自养脱氮与传统异养反硝化脱氮相结合的单级好氧/限氧工艺用于低C/N比污水的处理，取得稳定高效的总氮去除。

Biological nutrients removal is most commonly applied in wastewater treatment due to its economic and efficient characteristic. The phenomenon of total nitrogen loss generally occurred in the aerobic zone of wastewater treatment processes. Enhancing this phenomenon and developing cooperative action of autotrophic/heterotrophic denitrifying bacteria is an effective strategy to improve nitrogen removal efficiencies. Presently, the biochemical mechanism of this phenomenon has not been clearly explained, which is one difficult problem to solve in the field of biological nitrogen removal from wastewater. The key to achieve stable nitrogen removal in the aerobic zone is gain a clear insight into the fate of nitrogen and cooperation mechanism of autotrophic/heterotrophic denitrifying bacteria. ..In this study, the biochemical mechanism of total nitrogen loss in aerobic zone of real wastewater treatment processes and the dynamic response of metabolic activities of autotrophic/heterotrophic bacteria corresponding to environmental factors are revealed. The dynamics of nitrogen loss in the aerobic zone and the reaction routes of nitrogen are investigated using 15N stable isotope tracing techniques. Meanwhile, the cooperative action of autotrophic/heterotrophic bacteria and their contributions to nitrogen loss in the aerobic zone are analyzed using 13C-DNA-SIP. Real-time quantification PCR, high-throughput sequencing and ecological genomics are used to be the downstream technology of 13C-DNA for identification of autotrophic/heterotrophic bacteria. Through regulation and optimization of in-situ function of microorganisms, single-stage aerobic or oxygen-limited system combining establishment of innovative processes (novel autotrophic nitrogen removal) with the improvement of traditional process (heterotrophic denitrification) is developed to treat real wastewater with low ratios of carbon to nitrogen, aimed to achieve stable and efficient nitrogen removal.