微生物燃料电池生物膜结构与电催化活性的关系

发布时间：2018-03-03 07:19

本文选题：微生物燃料电池　切入点：生物膜　出处：《扬州大学》2015年硕士论文　论文类型：学位论文

【摘要】：微生物燃料电池(Microbial Fuel Cells,MFCs)是一种微生物技术与电池技术相结合的产物,是利用微生物的催化作用分解有机底物,将化学能转化为电能的新技术。而且,很多微生物菌株具有电化学活性,这大大拓宽了MFCs的应用领域,如废水处理产电、生物传感器等。因此,MFCs研究与应用对缓解当前的资源短缺与环境危机意义重大。本文主要在双室型MFCs基础上成功构建了阳极生物膜体系,并建立了两种生物量测定方法。在空气阴极型MFCs基础上探究了碳负载MnO2作为催化剂对电池产电的影响,并比较了MnO2含量不同的阴极材料的性能。最后,研究了电子介体核黄素对粪肠球菌产电的影响。一、MFCs阳极生物膜的构建以及生物量测定方法探究本章首先考察MFCs成功启动后阳极生物膜的生长情况,电池的放电情况。调整实验条件,观察实验过程中的现象,测定细菌生长曲线。同时,作为微生物总量指标,本章探讨了微生物磷脂的测定方法和微生物蛋白质的测定方法,并用这两种方法同时对阳极生物量进行了测定。最后,初步探讨了生物量与极限电流的关系。结果发现,阳极未接种污泥的电池产电性能明显低于接种了污泥的电池产电性能,接种了污泥的电池阳极电极富集了一层生物膜,说明生物膜的形成对电池产电很重要。改变通过电池阳极电极的电流值,利用生物量测定方法对电极表面的生物膜生物量的进行测定,’结果发现该电池体系中电池能承受的极限电流为6 mA。在极限电流范围内,阳极电极表面生物量与通过的电流值成线性关系,说明适当增加通过电极的电流可以促进生物膜的生长,提高生物膜的电催化活性。二、碳负载MnO2作催化剂对空气阴极型MFCs的电化学性能影响本章以氧气为直接电子受体的空气阴极构建MFCs。以活性炭和高锰酸钾为原料,通过水热法合成碳负载MnO2作为阴极催化剂。对碳负载MnO2进行了表征。考察了MnO2含量不同的碳负载MnO2材料对空气阴极MFCs的电化学性能的影响。样品的XRD表征,氮气吸脱附曲线及孔径分布,形貌结构分析结果表明,合成的碳负载MnO2材料为介孔结构,含有8% MnO2的材料性能最好,孔径最大,为11.69 nm。电化学性能测试结果表明纯活性炭作催化剂的电池电化学性能明显比碳负载MnO2作催化剂电池电化学性能差,而且,MnO2含量为8%时,电池电化学性能也最好,放电时间最长。三、MFCs中粪肠球菌以核黄素为电子介体的细胞外电子转移革兰氏阴性菌在微生物燃料电池中的应用已经得到广泛关注。在本章节中将在微生物燃料电池中引入革兰氏阳性细菌—粪肠球菌。在加入核黄素作为电子介体的情况下研究粪肠球菌ZER6菌株形成的生物膜的产电性能。在电极表面形成的粪肠球菌生物膜细胞壁上肽聚糖表层外的葡萄糖氧化过程中发现在没有其他电子介体的存在时核黄素对电子转移起至关重要的作用。
[Abstract]:Microbial Fuel cells (MFCs) is a combination of microbial technology and battery technology. It is a new technology to decompose organic substrates and convert chemical energy into electric energy. Many microbial strains have electrochemical activity, which greatly broadens the application of MFCs, such as wastewater treatment to produce electricity, Therefore, the research and application of biosensors are of great significance in alleviating the current resource shortage and environmental crisis. In this paper, the anodic biofilm system was successfully constructed on the basis of two-chamber MFCs. On the basis of air cathode MFCs, the effect of carbon-supported MnO2 as catalyst on battery power generation was investigated, and the properties of cathode materials with different MnO2 content were compared. The effect of riboflavin on electrical production of Enterococcus faecalis was studied. The construction of anodic biofilm and the method of biomass measurement were studied in this chapter. Firstly, the growth of anodic biofilm after successful start-up of MFCs was investigated. Battery discharge. Adjustment of experimental conditions, observation of phenomena during the experiment, determination of bacterial growth curve. Meanwhile, as a total microbial index, this chapter discusses the determination of microbial phospholipids and the determination of microbial protein. At last, the relationship between the biomass and the limit current was preliminarily discussed. The results showed that the electric capacity of the anode uninoculated sludge was obviously lower than that of the inoculated sludge. A layer of biofilm is enriched at the anode electrode of the battery inoculated with sludge, which shows that the formation of the biofilm is very important for the battery to produce electricity. The biofilm biomass on the electrode surface was measured by biomass measurement method. The results showed that the limit current of the battery system was 6 Ma. There is a linear relationship between the surface biomass of the anode electrode and the current value passing through the electrode, which indicates that properly increasing the current through the electrode can promote the growth of the biofilm and increase the electrocatalytic activity of the biofilm. Effects of carbon supported MnO2 as Catalyst on Electrochemical Properties of Air Cathodic MFCs in this chapter, oxygen as direct electron acceptor is used as the direct electron acceptor to construct MFCs. Activated carbon and potassium permanganate are used as raw materials. Carbon supported MnO2 was synthesized by hydrothermal method as cathode catalyst. The carbon supported MnO2 was characterized. The influence of different MnO2 content on the electrochemical properties of air cathode MFCs was investigated. The XRD characterization of the samples was also carried out. The results of nitrogen adsorption and desorption curves, pore size distribution, morphology and structure analysis show that the synthesized carbon-supported MnO2 material is mesoporous, and the material containing 8% MnO2 has the best properties and the largest pore size. The results of electrochemical performance test showed that the electrochemical performance of pure activated carbon as catalyst was obviously worse than that of carbon-supported MnO2 catalyst, and the electrochemical performance of the battery was the best when the content of MNO _ 2 was 8. The application of extracellular electron transfer gram-negative bacteria with riboflavin as electron medium in MFCs has been widely concerned in microbial fuel cells. In this chapter, the application of Enterococcus faecalis in microbial fuel cells has been widely concerned. Gram-positive bacteria-Enterococcus faecalis were introduced into the battery. The electrical properties of biofilm formed by Enterococcus faecalis ZER6 strain were studied when riboflavin was added as the electronic medium. The biofilm of Enterococcus faecalis formed on the electrode surface was studied. Riboflavin plays an important role in electron transfer in the process of glucose oxidation outside peptidoglycan on cell wall.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM911.45

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