潮汐流人工湿地-微生物燃料电池耦合系统去除硝态氮的脱氮菌响应机制研究

Nitrate nitrogen pollution in wastewaters with low C/N ratios (such as, tail water from municipal sewage treatment plant, and agricultural runoff) tends to migrate and thus is of serious concern. The tidal flow constructed wetlands–microbial fuel cell (CW–MFC) coupling system is a novel sewage treatment technology that combines wastewater treatment and biomass power generation. This system is expected to play an important role in nitrate nitrogen removal for the treatment of wastewater with low C/N ratio. However, the responses mechanism of denitrifier on nitrate nitrogen removal in such wastewater through the CW–MFC coupling system remains unknown. Thus, this project proposes to construct coupling devices using tidal-flow CW and MFC. The effects of nitrate nitrogen concentration at the influent on nitrate nitrogen removal and electricity generation performance during the treatment of sewage under simulated low C/N ratio conditions is also analyzed. This research focuses on the spatial distributions of denitrogen bacterial communities and activities involved in main nitrogen reaction processes (including nitrification, denitrification, anammox, and dissimilatory nitrate reduction to ammonium) at each medium in the CW–MFC coupling system under different nitrogen concentrations at influent. This approach can thoroughly identify the relative contributions of various biological denitrification processes to nitrate nitrogen transformation and denitrifier characteristics on the feedback mechanism of each biological denitrification activity. Finally, the denitrogen functional genes responding to nitrate nitrogen removal are analyzed to determine the driving factors behind synergistic nitrate nitrogen removal through the CW–MFC coupling system and optimal regulation strategies that maximize nitrate nitrogen removal. Moreover, ensuring electricity generation capacity is proposed. The project is believed to provide theoretical basis and technical support for the application of CW–MFC coupling system in nitrate nitrogen pollution reduction in sewage with low C/N ratio.

低碳氮比（C/N）污水中易迁移硝态氮的污染问题尤为突出，潮汐流人工湿地（CW）+微生物燃料电池（MFC）耦合系统是一种兼顾污水处理和生物发电双重功能的前瞻性技术，有望在低C/N污水硝态氮处理方面发挥重要作用，但利用潮汐流CW-MFC移除硝态氮的脱氮菌响应机制研究匮乏。针对以上问题，本项目拟从建立潮汐流CW-MFC耦合装置入手，探明进水硝态氮浓度对模拟低C/N污水硝态氮去除效果和产电性能的影响；重点研究不同进水氮浓度下各介质中脱氮菌空间特征以及硝化、反硝化、厌氧氨氧化和硝态氮异化还原成铵的反应活性，明晰各生物脱氮过程对硝态氮转化的相对贡献，深入揭示脱氮菌特征对各生物脱氮活性的反馈机制，剖析联合体下脱氮功能基因对硝态氮去除的响应，明确协同去除硝态氮的驱动因子，提出优化调控策略以达到最佳硝态氮移除效果并保证一定产电能力。本项目预期研究成果可为此技术在低C/N污水氮污染削减方面的应用提供理论依据。

低碳氮比（C/N）污水中易迁移硝态氮的污染问题尤为突出，潮汐流人工湿地（CW）-微生物燃料电池（MFC）耦合系统是一种兼顾污水处理和生物发电双重功能的前瞻性技术，有望在低C/N污水硝态氮处理方面发挥重要作用，但利用潮汐流CW-MFC移除硝态氮的脱氮菌响应机制研究匮乏。针对以上问题，本项目建立潮汐流CW-MFC耦合装置，探明进水浓度、运行方式对模拟低C/N污水硝态氮去除效果和产电性能的影响；重点研究各介质中脱氮菌空间特征以及硝化、反硝化和硝态氮异化还原成铵的反应活性，剖析联合体下脱氮功能基因对硝态氮去除的响应，建立潮汐流CW-MFC耦合系统中优势脱氮菌属相对丰度与污水中氮去除之间的关系，确定协同脱氮的驱动因子，优化运行方式以达到最佳硝态氮移除效果并保证一定产电能力。本项目预期研究成果可为此技术在低C/N污水氮污染削减方面的应用提供理论依据。