光催化燃料电池强化废水生物脱氮新方法研究

We still face serious challenge toward the safety of aquatic environment all over China nowadays. Many districts, especially these located in the regions near the big rivers, restricted higher discharge limit of COD again and again, also ammonia and total nitrogen, which is extreme challenge to traditional wastewater treatments, biological or chemical, due to their extremely high expenditure of energy or cost according to the new discharge limit. In this research, a new photocatalysis fuel cell wastewater treatment was introduced, in which COD is efficiently degradated by photocatalysis holes and organic amine / total nitrogen is reduced via pathway of first photochemical oxidation to nitrite/nitrate and then bilogical reduction, which is enhanced by the eletron from photocathode, to nitrogen. During this process, waste chemical energy hiden in wastewater is fully reproduced into micro electricity energy which is reused to systhesis useful compound or help to reduce nitrite/natrite, avoiding any kind waste of energy. This new treatment process especially fits low COD wastewater treatment for biological denitrification could be simultaneously enhanced by electron provided, in which carbon source is not essecially demanded with autotrophic bacteria. Detailed research is mainly focused on: 1) Synthesis of multi-dimension photocatalysis cathode with high specific surface area to contact and light catalytic combust big refractory organic molecule in order to significantly improve COD degradation capability. The photocathode is also doped with microstructure and substance in order to further develop features of light harvest, pollutant enrichment capacity, low electrode resistance, and et al. All these features is to improve efficiency of photocatalysis, degradation of COD with low concentration and low resistance to electron transportation. 2) Electrical performance study of the photocatalysis fuel cell, including output voltage, current density, FF, and et al. this research is conducted with the target of improving electrical performance with low internal resistance and high capacity to provide more photo electron. 3) Research of enhance biological denitrification process under photo electron from photocatalysis anode, including the culturing, acclimation, and denitrification rate test of biofilm on cathode, also insight of the mechanism of photo electro enhanced denitrification process.

目前，我国水环境的形势依然严峻，沿江等COD排放标准一再提高，氨氮、总氮等指标也日趋严格。而一味地强化处理效果以满足严格的排放标准将消耗大量的能量，亟需开发基于清洁能源的高效低耗废水深度处理新方法。本研究将光催化燃料电池技术引入废水深度处理领域，将废水中有机物的化学能转变为电能，不仅在阴极高效深度处理低浓度COD及残存的氨氮，并在阴极同步强化微生物反硝化脱氮，同时还能产生一定的电能。具体研究主要从以下几个方面展开：1）研究高效多维光催化阳极与负载催化剂阳极的合成方法，研制具有高降解效能大电流的新型大比表面光催化阳极。2）研究燃料电池输出电压、电流与FF因子等产电特性，优化燃料电池内阻，并对电池串并联性能进行优化。3）研究光生电子阴极强化微生物反硝化脱氮新方法，以燃料电池供给光生电子，驯化并强化电生物膜阴极反硝化脱氮，并研究强化电生物膜脱氮机理。

在国家自然科学基金（批准号：21477076）的资助下，针对本项目提出的基于光催化燃料电池系统的低浓度城市污水同步COD去除与脱氮处理研究的科学问题，通过贾金平教授、应迪文讲师、李侃助理教授、三位博士生和五位硕士生的研究，申请书中所列研究计划的要点已基本完成。本项目分析了目前低浓度城市污水处理的瓶颈问题，在光催化燃料电池高效光阳极、光催化燃料电池全电池特性、阴极产物设计方面进行了研究。在高效光阳极方面，制备了微米深孔结构的深丘型二氧化钛纳米管电极、1D结构的二氧化钛纳米线电极，并对其在光降解模拟染料有机物的降解构效关系与产电性能进行了研究；在光催化燃料电池全电池的性能优化方面，分别从反应器原理、光电流组成以及界面反应的角度，阐述了光催化燃料电池的电位匹配理论，提出了光催化燃料电池改进的方法；在光生电子的利用即阴极产物的选择性合成方面，本项目研究了阴极利用光生电子产H2O2反应适用的催化剂以及利用光生电子强化脱氮阴极反应微生物膜，阐述了阴极反应产物设计下的光催化燃料电池设计的可行性。.受本项目资助，已发表与本项目相关SCI源论文（含录用）8篇，国内核心期刊2篇，会议论文2篇，其中在本领域A类刊物上发表论文6篇（包括Water Research 1篇，Applied Catalysis B: Environmental 1篇，Bioresource Technology 1篇，Journal of Power Sources 2篇，Chemical Engineering Journal 1篇）。同时还有3篇文章在审阅或整理中。已申请专利3项。共培养了3名博士研究生，5名硕士研究生。项目研究过程中参加了国内外各种学术会议，邀请国内外知名专家进行指导，组织课题组成员到国内外知名高校和研究所参观学习。