低C/N废水处理中厌氧氨氧化和反硝化耦合的分子生态学机理研究

For low C/N ratio wastewater treatment, conventional nitrification-denitrification process needs supplies of oxygen and organic carbon, which increases the operational costs. Integration of anaerobic ammonium oxidation (ANAMMOX) and denitrification can achieve synchronous removal of nitrogen and carbon in anaerobic reactors and is considered as an economical and efficient process for low C/N ratio wastewater treatment. However, few concerns currently focus on the integration of ANAMMOX and denitrification, and the related molecular ecological mechanisms remain unknown. To attain the application of the coupled reaction in wastewater treatment engineering, studies have to be conducted to reveal the microbiological mechanisms of the coupling reaction, as well as the microbial diversity and functions in the coupling reaction systems. This project aims to investigate the effects of various environmental factors and operational parameters on ANAMMOX and denitrification performance in upflow blanket filters and the responses of microbial community structure and denitrofication genes abundance to the changing factors/parameters, based on concentration and isolation of ANAMMOX and denitrification bacteria, characterization of nitrogen removal efficiency, and qualitative and quantitative analysis of functional genes. Pyrosequencing and Illumian high-throughput sequencing, metagenomics analysis and real time polymerase chain reaction will also be used to reveal the relationship between ANAMMOX and denitrification bacterial communities, and between denitrofication genes distribution and microbial community structure during the start and running of the reactors, so as to explore the potential molecular ecological mechanisms underlying the coupled reaction of ANAMMOX and dinitrification. This project wishes to provides new theoretical and practical supports for the efficient and economical treatment of low C/N wastewater.

传统硝化-反硝化工艺处理低C/N废水需要消耗氧气和碳源，处理成本高。厌氧反应器中厌氧氨氧化（ANAMMOX）和反硝化耦合可实现碳氮同步去除，是一种经济、高效低C/N废水处理工艺，但目前国内外ANAMMOX和反硝化耦合工艺研究处于起步阶段，其分子生态学机理尚不清楚。本项目拟从ANAMMOX和反硝化菌富集和筛选、脱氮性能表征、脱氮功能基因定性/定量检测等角度研究环境条件和工艺参数优化对厌氧复合床反应器中ANAMMOX和反硝化反应的影响，分析菌群结构和功能基因丰度对环境条件和工艺参数变化的响应机制；同时应用Illumina与Pyrosequencing高通量测序、宏基因组学分析、实时定量PCR等方法研究反应器启动和运行过程中ANAMMOX和反硝化菌群之间的关系，以及功能基因分布与菌群结构之间关系，探索ANAMMOX和反硝化耦合的潜在分子生态学机理，为低C/N废水生物处理提供新的技术与理论支撑。

传统硝化-反硝化工艺处理低C/N废水需要消耗氧气和碳源，处理成本高。厌氧反应器中厌氧氨氧化（ANAMMOX）和反硝化耦合可实现碳氮同步去除。本课题从ANAMMOX和反硝化菌富集和筛选、脱氮性能表征、脱氮功能基因定性或定量检测等角度研究环境条件和工艺参数优化对厌氧复合床反应器中ANAMMOX和反硝化反应的影响，分析菌群结构和功能基因丰度对环境条件和工艺参数变化的响应机制。通过接种不同种类的污泥，均可以有效富集厌氧氨氧化菌并实现高效率的厌氧氨氧化过程，同时废水中低浓度的有机物可以促进厌氧氨氧化与反硝化过程的耦合，强化总氮的去除效率。该耦合工艺中，不仅存在较高丰度的厌氧氨氧化菌，同时富集了高丰度的反硝化菌，该耦合工艺能够同时去除废水中的硝态氮和氨氮。在该耦合工艺中，陶厄氏菌为主导的反硝化菌，能够产生亚硝态氮，进而为厌氧氨氧化菌提供基质，促进废水中氨氮的去除。针对耦合工艺的参数优化发现，该耦合工艺不仅能够适应高浓度基质废水，且高水力负荷的条件下，低浓度基质废水耦合效果更好。在碳氮比为0.6时，耦合工艺能够获得最佳的总氮去除效率，且进水中的有机物对厌氧氨氧化菌没有抑制作用。添加同时，进水中不同类型的碳源（葡萄糖和乙酸钠）均可以促进耦合工艺脱氮，实现厌氧氨氧化菌和反硝化菌的共存，但葡萄糖为碳源的厌氧氨氧化（ANAMMOX）和反硝化耦合的运行稳定性和抗冲击能力要高于乙酸钠为碳源的反应器。而且，废水基质的变化并未对反应器处理效能产生明显的影响，耦合工艺始终保持较高的去除效能。但进水基质的变化会影响反应器的菌群结构，同时影响关键的脱氮菌的分布。其中，硝态氮有助于反硝化菌陶厄氏菌的富集生长，而厌氧氨氧化菌中Candidatus_Brocadia丰度会受到抑制作用而Candidatus_Jettenia丰度逐渐提高