电子流内部调控对导电曝气膜阴极微生物燃料电池脱氮的作用机理研究

Aiming at recycling energy from organic matter degradation, reducing the ratio of C/N in denitrification process and improving nitrogen removal efficiency, this project proposes an electroconductive aerated membrane – microbial fuel cell (EAM-MFC) process with cathode of electroconductive aerated membrane for denitrification and electricity generation. Focusing on the biochemical and electrochemical reaction behaviors of nitrogen-containing compounds at the bio-cathode and their spatio-temporal migration and transformation, this research adopts comprehensive analysis methods involving chemistry, electrochemistry, chromatograph and microsensor, etc. to trace and analyze the fate of electron current at the cathode, clarifies the internal control of electron current caused by the distribution of dissolved oxygen on cathodic biofilm and the ratio of electron donors and its action mechanism on the migration and transformation pathway and process control of nitrogen-containing compounds at the cathode of MFC, analyzes the concentration and distribution of oxygen and nitrogen compounds in cathodic biofilm and the main microbial population structure and distribution with the help of molecular biology method and microelectrode monitoring technology so as to illustrate the microcosmic relationship between functional microbial properties and technological parameters from both the qualitative and quantitative aspects, and establishes the control theory of EAM-MFC process for denitrification and electricity generation based on the internal control process of electron current through the coordinated regulation and optimization of key operating parameters in EAM-MFC process, providing theoretical support for its practical application in sewage denitrification.

本课题以回收有机物降解能量，降低脱氮过程C/N比，提高脱氮效率为目的，提出了以导电曝气膜为阴极的微生物燃料电池（EAM－MFC）脱氮产电工艺。围绕含氮化合物在生物阴极上的生化反应行为、电化学反应行为及其随时空的迁移转化，利用化学、电化学、色谱、微传感器等综合分析手段，对阴极上电子流的归趋进行追踪和分析，阐明由阴极生物膜溶解氧分布及电子供体配比引起的电子流内部调控原理，及其对含氮化合物在MFC阴极的迁移转化途径与过程控制的作用机制；借助分子生物学方法和微电极监测技术，分析阴极生物膜内氧、氮化合物浓度、分布及主要微生物菌群构成及分布关系，从定性和定量两方面阐明功能微生物菌群结构与工艺参数之间的微观关系；通过协同调控和优化EAM-MFC关键运行参数，构建基于电子流内部调控过程的EAM-MFC脱氮产电控制理论，为该工艺实际应用于污水脱氮提供理论支撑。

本课题从有效利用微生物燃料电池产生的微弱电能出发，提出基于导电膜曝气阴极的微生物燃料电池（EAM-MFC）脱氮工艺。围绕溶解氧–外供电子配比–电子流调控三者的关系，通过比较不同工艺条件下（溶解氧、外电子供体比例、碳氮比等）阴极含氮化合物在电子流调控下的迁移转化过程。探明阴极溶解氧浓度变化及电子供体配比关系导致的电子流内部调控对MFC 阴极脱氮过程的作用机制。借助分子生物学方法，辨析溶解氧、电子供体配比、电压、电流密度等引起的EAM-MFC 阴极生物膜微生物菌群结构特征随时间和环境因子变化的动态演替规律，揭示MFC阴极生物膜脱氮过程的微生物学机理。通过设计调整电极结构、特性和修饰改性阴极材料，强化系统用于低碳氮比废水脱氮时的产电利用效率。研究表明EAM-MFC耦合系统能够有效利用MFC产生的微弱电流，实现阴极原位脱氮利用，是一种行之有效的污水脱氮工艺。通过本课题的开展，共发表文章11 篇；申请专利5项，授权3项；培养研究生6名。