反硝化厌氧甲烷氧化和厌氧氨氧化协同竞争机制的解析和调控

Nitrogen removal with methane consumption by coupled DAMO (Denitrifying anaerobic methane oxidation) and Anammox (Anaerobic ammonium oxidation) processes could save energy consumption and carbon source, which conforms to the requirement of energy conservation and emission reduction in the wastewater treatment. However, the interaction between DAMO and Anammox processes is not well understood at present, resulting in the lack of effective microbial control strategy. This project will perform a comprehensive study on the interaction between DAMO and Anammox processes. Two typical reactors (one suspended reactor and one membrane reactor) will be started in the lab, and the dominant community in reactors will be monitored to figure out how to effectively start and stably run reactors. The stable isotope study and key enzymes inhibition experiments will be designed to systematically understand the synergistic and competitive relationship between DAMO and Anammox processes. Then, environmental factors affecting the nitrogen and carbon pathway will be tested in short-term and long-term experiments. Finally, based on the cooperation of DAMO and Anammox microorganisms, the control strategy of reactors will be proposed, to provide theoretical and technological supports for the development of novel nitrogen removal strategy in wastewater treatment.

反硝化厌氧甲烷氧化（DAMO）和厌氧氨氧化（Anammox）耦合技术可利用强温室气体甲烷完成生物脱氮过程，节约曝气能耗和碳源，符合现代污水处理对节能减排和资源综合利用的要求。但目前对DAMO和Anammox在同一生态系统中的相互作用机制及影响条件尚不明确，缺乏有效的生物调控手段。项目拟采用两种不同的反应器（悬浮态和膜生物反应器）富集微生物，研究其中优势微生物种群特性，探索如何高效启动和稳定运行DAMO和Anammox耦合反应器。基于同位素示踪和关键酶抑制实验，将定量研究DAMO和Anammox耦合系统在碳氮代谢过程中的协同与竞争机制。解析不同环境因素对耦合作用的短期和长期影响，优化系统调控策略，实现DAMO细菌、DAMO古菌、Anammox细菌等微生物种群的协同代谢，为研发基于DAMO和Anammox耦合作用的高效生物脱氮技术提供理论依据和技术指导。

反硝化厌氧甲烷氧化（DAMO）与厌氧氨氧化（Anammox）耦合脱氮系统是近年来的研究热点。耦合系统可利用污水处理过程中厌氧消化段产生的甲烷进行反硝化，且无需外加碳源，具有潜在应用前景。本项目通过富集、批次实验、同位素示踪实验，采用常规化学分析、分子生物学分析等手段对DAMO和Anammox耦合富集系统进行了深入研究。首先，分别搭建了悬浮式与中空纤维膜生物反应器，实现了不同工艺参数下的DAMO和Anammox耦合培养系统的快速启动。其中，以硝酸盐作为唯一氮源时，73天即可成功启动DAMO功能微生物反应器。后在反应器底物中添加了氨氮1.5个月后，反应器可以实现以甲烷为唯一碳源的硝酸盐和氨氮同时移除。经高通量测序，反应器中检测出一定丰度的Anammox细菌，但未检测出已知的DAMO微生物，说明DAMO-Anammox耦合过程可能有其他代谢过程参与。进一步实验表明，DAMO和Anammox耦合系统脱氮过程中可能生成乙酸，采用了同位素标记示踪的方法对CH4和CO2进行监测，证明了厌氧环境中CH4被氧化生成了乙酸盐。CH4到乙酸盐的这一间接转化途径为DAMO和其他微生物之间建立了新的协同关系。其次，在实验室搭建了硝化反应器、DAMO和Anammox耦合反应器形成的二级脱氮工艺，氨氮去除率稳定在97%以上，证实了以甲烷为唯一碳源，从氨氮到氮气的氮移除。