湖底污泥微生物燃料电池的研究

发布时间：2018-05-31 08:30

本文选题：微生物燃料电池 + 湖底污泥　；参考：《重庆大学》2014年硕士论文

【摘要】：微生物燃料电池是一种将生物能直接转化为电能的环境友好、可循环使用的新技术，尤其在废水处理、新型能源等领域极具发展前景。微生物燃料电池的电化学性能主要与负极材料种类、生物相容性以及微生物与电极间电子传递阻力密切相关。本文旨在通过各类电化学测试技术，针对以湖底污泥为菌源，自然状态下运行的微生物燃料电池及其负极修饰展开研究。本文首先对采自民主湖的菌源进行5个周期的小电流间歇通电驯化，得到电化学活性菌源。然后分别使用不锈钢网、泡沫镍和碳刷3种材料作为负极，以标准三电极和双室质子交换膜电池系统分析评价其电化学性能。结果表明，开路电压和循环伏安曲线峰电流在一定时间内随着培养时间延长，分别呈现负移和增大的趋势，表明电化学活性逐步改善。时间进一步延长，随着营养物质的消耗和负极室内细菌代谢产物积累，性能有降低趋势。同期交流阻抗分析显示，培养后电极电化学阻抗、扩散阻抗均有不同程度下降。最后电池系统测试表明，不锈钢网、泡沫镍和碳刷最大开路电压分别为300mV，380mV和460mV，最大输出功率分别为0.071μW，7.284μW和41.823μW。在上述研究基础上，采用邻苯二酚紫对电极材料进行修饰。循环伏安、交流阻抗等电化学测试均表明邻苯二酚紫能作为电子传输中介体，在电极表面吸附成膜，提高电子传输效率，所以对提升电极电化学性能有一定作用。电池组装测试表明，邻苯二酚紫对不锈钢网和泡沫镍系统的修饰效果较为明显，最大输出功率分别提升14%和60%；修饰后碳刷系统虽然开路电压提升38%，但输出功率下降78%，结合循环伏安测试结果和碳刷电极使用后形貌分析，认为邻苯二酚紫在碳纤维间吸附，对孔隙率、表面积等电极结构产生较大影，造成产电能力下降。综上所述，本文以湖底污泥为菌源，分别采用不锈钢网、泡沫镍和碳刷成功搭建了自然条件下运行的双室微生物燃料电池，采用邻苯二酚紫对负极材料进行修饰初见成效。此外，电池负极室电解液化学需氧量测试表明，装置运行期间化学需氧量降解率最高可达85%以上，，表现出对污水净化的潜在能力。
[Abstract]:Microbial fuel cell is a kind of environment-friendly and recyclable new technology which can directly convert bioenergy into electric energy, especially in the field of wastewater treatment and new energy. The electrochemical performance of microbial fuel cells is mainly related to the types of negative electrode materials, biocompatibility and electron transfer resistance between microbes and electrodes. The purpose of this paper is to study the modification of microbial fuel cell and its negative electrode under natural condition by various electrochemical testing techniques. In this paper, we first acclimated the bacteria collected from the lake of Democracy with five cycles of intermittent low current electrification, and obtained the electrochemically active bacteria source. Then three kinds of materials, stainless steel mesh, foamed nickel and carbon brush, were used as negative electrodes, and their electrochemical performance was evaluated by standard three-electrode and two-chamber proton exchange membrane battery system. The results showed that the open circuit voltage and the peak current of cyclic voltammetry curve showed a negative shift and an increasing trend with the increase of culture time in a certain time, indicating that the electrochemical activity was gradually improved. With the consumption of nutrients and the accumulation of bacterial metabolites in the negative electrode room, the performance decreased with the further prolongation of the time. Simultaneous AC impedance analysis showed that the electrochemical impedance and diffusion impedance of the electrode decreased in varying degrees after culture. The final battery system test shows that the maximum open circuit voltage of stainless steel net, foamed nickel and carbon brush is 300mV 380mV and 460mV, respectively, and the maximum output power is 0.071 渭 W 7.284 渭 W and 41.823 渭 W respectively. Based on the above study, the electrode material was modified with catechol violet. The electrochemical measurements such as cyclic voltammetry and AC impedance indicate that catechol violet can act as an electron transport intermediary, adsorb on the electrode surface to form a film and improve the efficiency of electron transport, so it plays a certain role in improving the electrochemical performance of the electrode. The battery assembly test showed that the modification effect of catechol violet on stainless steel mesh and nickel foam system was obvious. The maximum output power was increased by 14% and 60%, respectively. Although the open circuit voltage of the modified carbon brush system was increased by 38%, the output power decreased by 78%. Combined with the results of cyclic voltammetry and the morphology analysis of the carbon brush electrode, it was concluded that the catechol violet adsorbed on the carbon fiber. The electrode structure of porosity, surface area and so on has a large shadow, resulting in the decrease of electricity production capacity. To sum up, in this paper, the sludge from lake bottom was used as the source of bacteria, stainless steel mesh, nickel foam and carbon brush were used to set up the dual chamber microbial fuel cell under natural conditions, and the negative electrode material was modified with catechol violet. In addition, the chemical oxygen demand (COD) of electrolyte in the negative electrode chamber of the battery was measured. It was shown that the highest degradation rate of COD was more than 85% during the operation of the unit, which showed the potential ability of purifying the wastewater.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM911.4

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