异养硝态氮还原过程中厌氧氨氧化菌和反硝化菌的生长动力学特征与竞争机制

Biological nitrogen removal via anammox can save oxygen consumption and organic carbon source. Therefore, if it can be applied to sewage treatment, it is expected to make sewage treatment from energy consumption to energy-neutral or energy-positive. At present, these studies mainly focus on nitritation/anammox. However, no breakthrough has been made on the stability of nitritation, especially under low temperature conditions. . Our recently study found that the stable denitratation/anammox was achieved in the anoxic zone of a simulated sewage treatment system. It is more interesting to discover that the dominant bacteria was anammox bacteria rather than denitrifier for heterotrophic nitrate reduction. This provides a basis for achieving stable denitratation/anammox. However, anammox has rarely been reported in the anoxic zone of wastewater treatment plants. Therefore, it is necessary to make a further study on under what conditions anammox bacteria can become dominant bacteria for dissimilatory nitrate reduction. . Based on this study, the methods of metagenomics, the isotopic tracer technique and the immobilization of microorganisms will be used to study the growth kenetics of denitrifier and anammox bacteria under various conditions. The growth competition mechanism of these two bacteria will be revealed. The key limiting factors for making anammox bacteria the dominant bacteria in dissimilatory nitrate reduction will be determined. And the conditions will be optimized for making anammox bacteria a dominant bacterium in the anoxic zone. Finally, the stable realization of denitratation/anammox will be promote in sewage treatment.

厌氧氨氧化脱氮可节省耗氧量和有机碳源，若能应用于城市污水处理，有望使其由能量消耗转为能量自给或外供。目前该研究主要集中在短程硝化-厌氧氨氧化，但短程硝化的稳定性尤其是低温条件下仍未取得突破。. 申请人近期在模拟城市污水处理系统缺氧区，实现了稳定短程反硝化-厌氧氨氧化，更有意思地发现了异养硝态氮还原的优势菌是厌氧氨氧化菌而非反硝化菌, 这就为稳定实现短程反硝化-厌氧氨氧化提供了基础。但实际污水厂缺氧区很少发现厌氧氨氧化，因此什么条件下厌氧氨氧化菌能成为异养硝态氮还原的优势菌值得深入研究。. 本项目将在此基础上，采用宏基因组、同位素示踪、微生物固定化等方法研究各种条件下异养硝态氮还原过程中厌氧氨氧化菌和反硝化菌的生长动力学特征；揭示两种菌的生长竞争机制，确定厌氧氨氧化菌成异养硝态氮还原优势菌的关键限制因子，优化条件使其成为缺氧区优势菌，促进稳定实现城市污水短程反硝化-厌氧氨氧化脱氮。

污水厌氧氨氧化脱氮有望使城市污水厂实现能量自给或外供。短程反硝化是为城市污水厌氧氨氧化脱氮稳定提供亚硝态氮的方法之一。本研究通过对异养硝态氮还原过程对pH等环境条件的响应，发现高pH促进亚硝态氮积累，可促进反硝化菌与厌氧氨氧化菌协作脱氮，进而构建了滤池生物膜系统和颗粒污泥系统实现了城市污水短程反硝化厌氧氨氧化脱氮；明确了内碳源做电子供体，可实现短程反硝化厌氧氨氧化深度脱氮，为推动厌氧氨氧化脱氮技术在城市污水处理厂的应用提供了支撑。