三江平原包气带耦合多电子受体ANAMMOX脱氮过程与机制

三江平原稻田湿地氮肥的大量施用对地下水形成严重威胁。作为地下水污染的最后屏障，包气带氨氮污染控制对保障区域地下水质量具有重要意义。生物脱氮是氨氮污染控制的主要途径，但包气带含氧层厚度小且缺乏碳源，传统脱氮作用有限。厌氧氨氧化(ANAMMOX)的发现，为包气带广泛厌氧寡营养区域的氨氮污染控制提供了新途径。但三江平原包气带多电子受体共存、环境复杂，ANAMMOX的电子受体耦合途径及过程有待考察，热区及关键控制因素不明。本项目拟探寻三江平原包气带ANAMMOX的电子受体耦合体系；揭示多电子受体耦合ANAMMOX的关键过程及影响机制，并解析其微生物机理；在此基础上开发强化包气带ANAMMOX脱氮的技术，识别其强化脱氮阈值并阐明热区生化反应层的演化规律。研究成果可为包气带氨氮污染控制提供理论依据和技术支持。

The surplus application of nitrogen fertilizer in paddy wetlands of Sanjiang Plain is a serious threat to groundwater. As the last barrier of groundwater pollution, ammonia nitrogen pollution control in vadose zone is of great significance to safeguard regional groundwater quality. Nitrification-denitrification was considered as the major process of biological nitrogen removal. But due to the low concentrations of oxygen and organic carbon in the vadose zone, nitrogen removal capacity of nitrification-denitrification is limited. With the discovery of anaerobic ammonium oxidation (ANAMMOX) coupled with the single electron acceptor, ANAMMOX is found to be a new way for ammonia nitrogen pollution removal in anaerobic oligotrophic habitat of the vadose zone. However, vadose zone of Sanjiang Plain is a habitat with multi-electron acceptors. The process and mechanism of ANAMMOX coupled with multi-electron acceptors are unclear, and the enhanced strategies need to be developed. The project is to identify electron acceptors coupled with ANAMMOX and the hotspot structures in the vadose zone of Sanjiang Plain. The key process and influence mechanism of ANAMMOX coupled with multi-electron acceptors are revealed, and the microbiology mechanism is investigated. The control strategies of enhanced ANAMMOX in the vadose zone are developed, with the nitrogen removal threshold and the evolution characteristics of hotspot layers further clarified. These findings would provide the theoretical basis and technical support for the nitrogen pollution control in the vadose zone of paddy wetlands in Sanjiang Plain.