完全生物调控、面向极端条件运行的微生物燃料电池构建及对环状硝基污染物降解效能

Microbial fuel cell (MFC) is a promising wastewater treatment technology for its ability of simultaneously removing organic waste and electricity generation. In order to keep the MFC reactors in the optimal operating status, researchers are always adjusting the operation parameters of MFCs with physical or chemical methods during the experiments. It is a route of "adjusted wastewaters to MFCs" and is not suitable to be used in future practical engineering, for its high cost. This study tries to solve the problem with the method of totally microbial control by both the anodic and cathodic microbes, aiming at MFC operations in more complicated or even extreme conditions, and degradation of cyclic nitro pollutants in the reactor at the same time. Firstly, the MFCs are operated stably at selected extreme conditions (pH 4, TDS 30 g/L,corresponding to the feature of nitrophenol wastewater) for a long time to culture the according function microbes on the anodes, and the composition and time-course variations of the cultured anodic microbes are analyzed with molecular biological methods. The stable operation of MFC under anodic microbial control is realized. Then, the biocathode capable of nitrophenol degradation is constructed by microbial inoculation.The mechanism of degrading process from nitrophenol to aminophenol on the biocathode is investigated, including formation of intermediate products and effects of electron donor on nitrophenol degradation. Finally,the outlet after nitrophenol reduction is drawn into anode chamber where other substrates are oxidized. Pollutant degradation at extreme conditions in MFCs with coordinated regulation of anodic and cathodic microbes is achieved. This study aims at degrading the pollutants economically and effectively, and turning the route of MFC research into "adjusted MFCs to wastewaters". The results will contribute theoretically and technically to the future application in wastewater treatment of MFCs.

微生物燃料电池（MFC）应用于废水处理研究时，通常需采取物化手段调节电池运行条件以保证其性能。这是"废水适应电池"的路线，其高成本难以适应未来实际工程推广。本项目拟采用MFC阳极、阴极完全微生物调控的方法，使MFC可在更接近实际、乃至极端环境中稳定运行并实现环状硝基污染物降解。针对硝基酚废水特性，选在取极端条件：pH 4、TDS 30g/L下运行电池，驯化阳极功能菌群，并考察其种群结构及动态演化，实现阳极生物调控下电池的稳定运行；向电池阴极接种构建生物调控型阴极，实现硝基酚向氨基酚还原转化并探究还原过程中间产物形成与否、电子供体消耗与还原效率的关联，揭示硝基酚在生物型阴极降解机制；阴极还原后出水在阳极进行易降解基质氧化，实现阳极、阴极生物协同调控下污染物强化降解。本研究旨在完全生物调控的MFC中实现污染物降解，结果将推动MFC技术走上"电池适应废水"的道路，为废水处理工程应用提供技术支撑。

环状硝基污染物是一类典型的有毒、难降解物质，其经济、高效降解是化工废水处理领域的技术难题之一。微生物燃料电池是一种生物电化学技术，结合了生物处理、电化学氧化、电化学还原等传统废水处理过程，在难降解化工废水处理领域具有较大的应用潜力。有毒难降解物质有望在微生物燃料电池系统中实现经济、有效降解，为生物电化学技术在废水处理应用奠定理论和技术基础。. 本项目以典型有毒难降解环状硝基污染物--对硝基酚类为微生物燃料电池阴极基质，采用生物阴极型、化学阴极型反应器，开展了硝基酚在生物电化学系统阴极的生物强化电化学还原效能及过程对比研究。采用分批运行反应器，考察了不同硝基酚浓度、不同阳极电子供体浓度下，硝基酚在阴极的强化还原效能、还原产物氨基酚的产率、微生物燃料电池系统的效率；同时，对不同外电阻、不同pH值下的硝基酚降解及系统运行情况进行了实验研究。实验结果表明，生物阴极型微生物燃料电池反应器相比化学阴极型反应器具有如下优势：阴极硝基酚降解效率更高、还原产物氨基酚生成率更高、阳极电子供体消耗较少、系统产电性能优于化学阴极。在生物阴极型微生物燃料电池中，可实现无需能量输入，完全在微生物代谢驱动下经济、有效地实现硝基酚的降解。. 本项目共发表论文2篇，其中SCI收录论文1篇，EI收录论文1篇，另有1篇文章已投稿；申请国家发明专利1件。. 本研究在完全生物调控的生物电化学系统中实现了环状硝基污染物的强化还原。相比传统生物电化学系统，可在无外加电能的条件下实现完全微生物自驱动下的污染物经济、有效降解。开辟了有毒难降解物质在生物电化学系统中的降解新途径，为实现生物电化学系统在含难降解有机物废水中的应用提供了科学依据和技术基础。.