生活废水微生物燃料电池产电特性研究

发布时间：2018-03-14 04:35

本文选题：微生物燃料电池　切入点：产电　出处：《太原理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：当今世界,能源的大量消耗所引起的全球性能源危机以及伴随着能源消耗所带来的环境问题,都激励着人们去寻找、探求可再生的环境友好型能源利用新技术。把大量生活废水中有价值的能源利用回收,已成环境化学领域研究一个重要课题。微生物燃料电池(MFC)是一种能将化学能转化为电能新型电化学反应装置。MFC涉及生物学、电化学和环境学等多个学科领域,属于交叉学科。MFC以产电微生物做催化剂,将物质中所蕴含的化学能转化为电能,它具有绿色环保、操作安全、容易控制、原料来源广泛等诸多优点。MFC在处理生活污水上的应用,能够实现处理废水和产生电能的统一结合,有望改变现有高成本处理生活废水的现状。其应用前景极为广阔,但也面临极大挑战。现如今,MFC的研究尚处在实验室发展阶段,有很多技术问题需要解决,也有很多理论研究需要进一步完善。本论文使用双室MFC反应装置,以生活污水处理厂AAO工艺中缺氧池厌氧污泥做细菌接种源,通过对MFC在线驯化,运用交流阻抗、循环伏安等电化学测定方法,考察微生物燃料电池的产电性能。 (1)通过向电池阳极液中添加葡萄糖,使阳极液中葡萄糖浓度分别为1.00g/L、0.33g/L、0.25g/L、0.17g/L、0.10g/L,每个浓度条件为一个周期,电池共运行五个周期,考察葡萄糖浓度对MFC产电特性的影响。在一定范围内,提高葡萄糖浓度有助于微生物的生长繁殖,加速成熟生物膜的形成,有利于提高电池电化学活性和电池产电能力。但浓度过高,会出现“饱和效应”,无助于产电效率的提高。适合微生物生长繁殖的葡萄糖浓度对提高细菌电化学活性和电池产电性能作用明显。细菌的产电活性高,有利于电子的传导,减小阳极过电位。在同一过电位时,葡萄糖浓度为0.33g/L时的电池电流密度最大。且葡萄糖浓度为0.33g/L时,电池具有最大的功率密度26.70mW/m2。葡萄糖浓度为1.00g/L、0.33g/L、0.25g/L、0.17g/L、0.10g/L时对应的传荷阻抗在阳极内阻中所占比例分别为96.9%、95.6%、97.7%、99.3%、99.7%,说明电化学反应的控制步骤为传荷过程。 (2)考察体系温度变化对MFC产电的影响。通过不同温度下五个周期的运行,研究温度对MFC产电特性的影响。各周期温度分别为18℃、25℃.32℃、39、C、46℃,研究发现,在一定温度范围内,温度升高有利于细菌生长、繁殖,对驯化形成成熟产电生物膜和加快新陈代谢都有帮助,能有效提高菌群的电化学活性和产电能力。同时温度对电解液的传导率、离子的迁移速率及质子在溶液中的传质等过程都有影响。温度升高,电池中的离子迁移速率提高,电解液的传导性增强,传质阻力和电解液阻力都下降,电荷在阴极的转移速率也加快。温度过低,细菌体内酶的活性较低,新陈代谢缓慢；温度过高,会使酶等蛋白质失活,甚至会造成细菌的死亡,对电池体系的电能输出不利。在这些因素的共同影响下,发现体系温度在32℃时,生物膜的电化学活性最好,产电菌群的产电活性高,有利于电子的传导。在同一电流密度下,体系温度为32℃时的电池的阳极过电位最低。且此温度下,电池有最大功率密度为156.2mW/m2。温度分别保持在18℃、25℃、32℃、39℃和46℃时,所对应的交换电流密度分别是1.67×10-6mA/m2、1.68×10-5mA/m2、8.02×10-5mA/m2.01×10-5mA/m2、2.20×10-6mA/m2。32℃时的电池的交换电流密度最大。
[Abstract]:In today's world, a large number of energy consumption caused by the global energy crisis and with environmental problems caused by the consumption of energy, encourage people to look for new technology, environmentally friendly renewable energy utilization. The search value has a large number of domestic wastewater in the use of energy recovery, has become an important research topic in environmental chemistry the field of microbial fuel cell (MFC) is a kind of can be converted into electrical energy.MFC model of electrochemical reaction device relates to biological chemical, electrochemical and environmental science and other disciplines, interdisciplinary.MFC in electricigens as catalyst, the chemical substances contained in the energy into electrical energy, it is green environmental protection, safe operation, easy control, wide source of raw materials and many other advantages of.MFC applied in treatment of urban sewage, wastewater treatment and electricity to achieve unity energy production, is expected to change The current situation of high cost treatment of domestic wastewater is very broad. But it is also facing great challenges. Now, the research of MFC is still in the stage of laboratory development, there are many technical problems to solve, and many theoretical studies need further improvement.
In this paper, a dual chamber MFC reactor was used to make bacterial inoculation source of anaerobic sludge and anaerobic sludge in AAO process of domestic sewage treatment plant. The electrochemical performance of microbial fuel cell was investigated by MFC on-line domestication, electrochemical impedance spectroscopy and cyclic voltammetry.
(1) by adding glucose to the anode solution, the anode fluid glucose concentration were 1.00g/L, 0.33g/L, 0.25g/L, 0.17g/L, 0.10g/L, each concentration for a cycle, running a total of five cell cycles, glucose concentration on MFC production of electricity effect. In a certain range, improve the glucose concentration contribute to the growth of microbes, accelerates the formation of biofilm, improve battery electrochemical activity and electricity production capacity. But the concentration is too high, there will be a "saturation effect", is not conducive to the electricity production efficiency. The concentration of glucose for microbial growth and reproduction of bacteria significantly improve the electrochemical activity and MFC effect of electrocatalytic activity of bacteria is high, is conducive to electronic conduction, decreases the anodic overvoltage. At the same overpotential, the glucose concentration of the battery when the current density is 0.33g/L the most. And the glucose concentration Is 0.33g/L when the power density of 26.70mW/m2. glucose concentration is the biggest battery for 1.00g/L, 0.33g/L, 0.25g/L, 0.17g/L, 0.10g/L when the corresponding charge transfer impedance for the anode resistance in respectively 96.9%, 95.6%, 97.7%, 99.3%, 99.7%, concluded that the control step of the electrochemical reaction is charge transfer process.
(2) the effects of temperature change on the output power of MFC system. Through the different temperatures of five cycles of operation, to study the effect of temperature on power generation of MFC. The cycle temperature was 18 degrees, 25 degrees C.32, 39, C, 46 DEG C, the study found that in a certain temperature range, temperature rise to the bacterial growth and reproduction, the domestication of mature biofilm production has accelerated and help The new supersedes the old. can effectively improve the electrochemical activity, bacteria and electricity production. At the same time, temperature on the conductivity of electrolyte, have an effect on migration rate and proton ions in the solution of the mass transfer process. Temperature ion mobility in the cell increase, enhanced electrolyte conductivity, mass transfer resistance and electrolyte resistance decreased, the charge transfer rate also accelerated in the cathode. The temperature is too low, the bacterial enzyme activity in vivo is low, the temperature is too high, will slow The new supersedes the old.; enzyme etc. The inactivation of protein, and even cause the death of bacteria, the battery system power output disadvantage. Under the combined effect of these factors, find the system temperature at 32 DEG C, the best electrochemical activity of the biofilm, exoelectrogens electricity production activity is high, is conducive to electron transfer at the same current density. Under the system, the anode temperature is 32 DEG C when the battery over potential minimum. And this temperature, the battery has a maximum power density of 156.2mW/m2. temperature were maintained at 18 degrees, 25 degrees, 32 degrees, 39 degrees and 46 degrees, respectively, corresponding to the exchange current density is the biggest exchange current density of 1.67 * 10-6mA /m2,1.68 * 10-5mA/m2,8.02 * 10-5mA/m2.01 * 10-5mA/m2,2.20 * 10-6mA/m2.32 C battery.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM911.4

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