微生物燃料电池产电性能及处理偶氮染料废水研究

发布时间：2018-03-10 05:28

本文选题：微生物燃料电池　切入点：阳极修饰　出处：《河南师范大学》2014年博士论文　论文类型：学位论文

【摘要】：近年来兴起和快速发展的微生物燃料电池(Microbial fuel cell, MFC)技术能直接利用废水中多种有机物作为燃料，在降解污染物的同时直接收获电能，是一种革命性的废水处理工艺，受到国内外学者的广泛关注。目前限制MFC实际应用的一个关键问题就是输出功率较低。在影响其功率输出的诸多因素中，阳极因为影响微生物的吸附和生长代谢，以及电子从微生物到电极之间的传递而被认为是一个关键因素。目前广泛采用的商业化的碳基材料存在比表面积有限，，电化学活性较小等不利因素。利用能增加电极比表面积和促进电子传递的某种电活性材料对碳材料表面进行修饰是一种行之有效的解决方法。本文从产电和废水处理两方面着手，探索借助阳极修饰的方法提高MFC产电性能的可行性；并以典型偶氮染料甲基橙为目标污染物，考察甲基橙在MFC中的脱色效果及同步产电性能。论文主要研究内容和成果如下： (1)用柠檬酸盐还原氯金酸的方法制备粒径约为20nm的金纳米粒子。首次利用层层组装技术将金纳米粒子修饰到碳纸电极表面，并利用紫外-可见光谱监测了薄膜的规律生长。循环伏安和电化学交流阻抗实验表明：纳米金修饰碳纸电极较空白碳纸电极表现出更好的电化学行为，包括更大的电活性表面积，更快的电子转移速率及更小的界面电子传递阻力。相比空白碳纸阳极组装的MFC，利用纳米金修饰碳纸阳极组装的MFC达到最大输出功率346mW m-2，提高了50%，启动时间为175h，缩短了36%。实验结果表明：层层组装技术是将纳米金修饰到碳纸电极上的一种简单有效的方法，而且利用该修饰电极能够有效提高微生物燃料电池的产电性能。 (2)利用化学还原氧化石墨烯(Graphene Oxide, GO)的方法制备并表征了石墨烯(Graphene, GR)。采用层层组装技术将石墨烯修饰到碳纸电极表面，并探讨该方法能否有效提高MFC的电能输出和对甲基橙的高效去除。循环伏安和电化学交流阻抗实验表明：石墨烯修饰碳纸电极较空白碳纸电极表现出更好的电化学行为。扫描电子显微镜结果显示：修饰电极表面的粗糙度增加，有利于更多的细菌附着在阳极表面。相比空白碳纸阳极组装的MFC，利用石墨烯修饰电极作为阳极的MFC达到最大输出功率368mWm-2，提高了51%，启动时间为180h，缩短了31%。阳极和阴极极化曲线表明：两种反应器的阴极电压之间没有明显区别，而阳极电压存在明显区别，这说明提高微生物燃料电池能量输出的关键是石墨烯修饰阳极，而不是阴极。同时，相比于空白阳极MFC，石墨烯修饰阳极MFC在实现更高能量输出的同时，还实现了更高效的甲基橙去除，脱色率提高11%，COD去除率提高16%。该研究为提高微生物燃料电池的产电性能和甲基橙同步脱色提供了一种简单有效的方法。 (3)采用所构建的双室方形微生物燃料电池处理甲基橙模拟废水。在进水甲基橙浓度为50-800mg L1、共基质（葡萄糖）浓度为0-2.0mg L1的条件下，系统考察了MFC对甲基橙的脱色效果和同步产电的影响。在MFC以甲基橙-葡萄糖为混合燃料连续工作6个月后，通过生物多样性分析揭示了阳极生物膜微生物组成的基本信息。结果发现：在一定浓度范围内，阳极室中加入的甲基橙对微生物燃料电池产电有积极的促进作用。当使用1g L-1葡萄糖为单一燃料时，MFC的最大输出电压为565mV，当在阳极液中添加甲基橙浓度分别为50、100、200、300和500mg L1时，MFC的最大输出电压分别提高至658、640、629、617和605mV。从脱色方面看，甲基橙在MFC中可以实现加速脱色，相比于开路情况(相当于普通厌氧反应器)，反应8h后甲基橙在MFC中的脱色率提高了57%；在葡萄糖浓度一定的条件下，随着甲基橙负荷的增加，脱色效率随之下降。另外，研究发现共基质的存在对甲基橙的高效脱色和同步产电是必须的。在所研究共基质浓度范围内，共基质浓度越大，脱色效率和COD去除效率越高，同时输出电压也越大。而在无共基质存在的条件下，8h内MFC对300mg L-1甲基橙的脱色率仅为7.5%，最大输出电压仅为140mV。454-高通量测序揭示了阳极生物膜的微生物种群基本信息，经NCBI网站比对的测序结果表明：经过长时间的驯化，阳极生物膜已经优化出了对甲基橙具有降解能力的Bacteroidia、Desulfovibrio和Trichococcus及其适合产电的Geobacter两大菌群。
[Abstract]:The rise in recent years and the rapid development of the microbial fuel cell (Microbial fuel, cell, MFC) technology can use a variety of organic compounds in wastewater as fuel in the degradation of pollutants and harvest power, is a revolutionary wastewater treatment process, attracted wide attention of scholars. A key problem in the limit of MFC the actual application is the low output power. The factors influencing the power output, because the anode effects of adsorption and growth of microbes and microbes to transfer electrons from between the electrodes and is considered to be a key factor. The commercialization of carbon based materials are widely used in the electrochemical surface area limited. Less active and other unfavorable factors. By increasing the electrode surface area and promoting the electron transfer of electroactive materials on carbon surface modification is an effective The solution.
This article from the electricity generation and wastewater treatment in two aspects, explore the method by means of anode modification feasibility to improve the performance of MFC; and the typical azo dye methyl orange as target pollutant, the decolorization effect in MFC of methyl orange and synchronous electricity production. The main research contents and results are as follows:
(1) reduction of chloroauric acid to prepare a particle size of about 20nm gold nanoparticles with citric acid salt. For the first time using the LbL assembly technique will be modified with gold nanoparticles to carbon paper electrode surface, and UV Vis Spectrum Monitoring film growth pattern. The results indicated that cyclic voltammetry and electrochemical impedance experiments: Gold nanoparticles modified compared with the blank carbon paper electrode carbon paper electrode shows better electrochemical behavior, including more electroactive surface area, interfacial electron electron transfer rate and smaller transfer resistance faster. Compared to blank carbon paper anode assembly MFC, using nano gold modified carbon paper anode assembly of MFC reached the maximum output power of 346mW m-2, increased by 50%, to start time is 175h, shorten the 36%. experimental results show that the self-assembly technology is the gold nanoparticles modified to a simple and effective method of carbon paper electrode, and the use of the modified electrode It can effectively improve the electrical performance of the microbial fuel cell.
(2) by chemical reduction of graphene oxide (Graphene Oxide GO) method of preparation and characterization of graphene (Graphene, GR). By using the layer by layer self-assembly technique of graphene modified carbon paper electrode surface, and discusses the method can effectively improve the power output and the efficient removal of methyl orange MFC show. Cyclic voltammetry and electrochemical impedance experiments: graphene modified carbon paper electrode compared with the blank carbon paper electrode showed better electrochemical behavior. Scanning electron microscopy results showed that the modified electrode surface roughness increases, is conducive to more bacteria attached on the surface of the anode. Compared to blank carbon paper anode assembly of the MFC, using a graphene modified electrode as anode the MFC reached the maximum output power of 368mWm-2, increased by 51% and the start time of 180h, shorten the 31%. anodic and cathodic polarization curves show that no voltage between the cathode two reactor The obvious difference, and the anode voltage has the obvious difference, which shows that the key to improve the energy output of the microbial fuel cell is a graphene modified anode and cathode instead. At the same time, compared to the blank MFC anode, graphene modified anode in MFC to achieve higher energy output at the same time, also achieved a more efficient removal of methyl orange, the decolorization rate increased 11%, the removal rate of COD increased 16%. the study provides a simple and effective method for improving microbial fuel cell electricity generation and synchronization of methyl orange decolorization.
(3) the construction of the dual chamber microbial fuel cell square treatment of methyl orange wastewater. When the influent concentration of methyl orange 50-800mg L1, CO substrate (glucose) concentration was 0-2.0mg L1, investigated the decolorization of methyl orange MFC and effect of synchronous electricity production. In the MFC methyl orange - glucose mixed fuel after working for 6 months, the biodiversity analysis reveals the basic information of the composition of the anodic microbial biofilm. The results showed that in a certain range of concentration, into the anode chamber of methyl orange has a positive effect on performance of microbial fuel cell. When using 1g L-1 glucose as fuel, the maximum output voltage MFC for 565mV, when the anolyte added concentration of methyl orange were 50100200300 and 500mg L1, the maximum output voltage of MFC were increased to 658640629617 and 605mV. from the decolorization Look, can accelerate the decolorization of methyl orange in MFC, compared to the open circuit condition (equivalent to ordinary anaerobic reactor), after 8h reaction in MFC methyl orange decolorization rate increased by 57%; in the condition of glucose concentration is constant, with the increase of methyl orange load, decolorization efficiency declined. In addition, the study found that there were the matrix of efficient decolorization of methyl orange and synchronous electricity production is a must. In the study of CO substrate concentration, CO substrate concentration increased, the decolorization rate and COD removal efficiency is high, while the output voltage is greater than that in the condition of CO substrate, 300mg L-1 on decolorization rate of methyl orange 8h MFC is only 7.5%, the maximum output voltage is only 140mV.454- high-throughput sequencing revealed the microbial population basic information of the anode biofilm, sequencing by NCBI site comparison results showed that after long time domestication, the anode biofilm has The degradation ability of Bacteroidia, Desulfovibrio and Trichococcus and the two major Geobacter bacteria suitable for electricity production were optimized.

【学位授予单位】：河南师范大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：X788;TM911.45

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