微生物燃料电池产电性能试验研究

以双室微生物燃料电池为研究对象,考察了电极间距、电极面积比和阳极室填充活性炭颗粒,阳极室填充液浓度、pH值、流通速度对微生物燃料电池输出电压和功率密度的影响,通过分析建立最优双室微生物燃料电池模型。研究结果表明,微生物燃料电池的最大输出电压为544.3 mV,最大功率密度为341.38 mW/m2,在微生物燃料电池运行1 500 min后,利用极化曲线法测定电池的内阻为375Ω。     

微生物燃料电池阳极材料研究进展

微生物燃料电池（microbial fuel cell,MFC）是一种新型的生物电化学装置,能将可生物降解有机物中的化学能直接转化成电能,而阳极材料性能是影响MFC性能的重要因素之一。通过对阳极材料进行改性和修饰可以有效地增大其比表面积、生物相容性等,以提高其微生物负载率和电子传递速率,进而提高MFC的产电性能。本文全面介绍和总结了近年来国内外关于微生物燃料电池阳极材料的研究进展,分析微生物燃料电池阳极材料在规模放大应用中存在的问题,并对微生物燃料电池阳极材料今后的发展方向进行了展望。     

阳极材料对微生物燃料电池性能影响的研究

以石墨、碳纸、碳布和碳毡为阳极材料,研究不同材料在微生物燃料电池中的产电性能,并利用循环伏安法比较不同材料的电化学活性。结果表明:在电池性能方面,以石墨为阳极微生物燃料电池电压可达0.678V,输出功率为250mW/m2;碳毡电压达0.656V,输出功率204mW/m2,碳纸0.649V,输出功率156mW/m2;碳布最差,电压不稳定,输出功率56mW/m2。循环伏安曲线和电极材料表观吸附量:碳毡作为阳极材料,具有明显的氧化峰和还原峰,对导电微生物具有显著的吸附量,其次是石墨,碳纸次之,最差的是碳布。     

微生物燃料电池中产电微生物的研究现状

随着我国社会的不断发展进步,各种环境污染问题成为科技发展首要控制的环保因素。微生物燃料电池是新开发的一种能源,其原理是利用微生物将有机物中的化学能转化成电能的过程,从而形成一种产电的装置,产电微生物作为一种催化剂来说,对微生物燃料电池有着至关重要的作用。产电微生物的种类不同也决定着他们的电子转移能力不同,导致微生物燃料电池的产电性能也不相同,电池的不同也致使了他们在实际工程中有着不同的用途。日常生活中产生的废水、沉积物等含有大量微生物的物质都可以成为产电微生物的工作来源,可以在任何环境下选取有效的产电微生物来作为微生物燃料电池的生物催化剂。文章主要对微生物燃料电池中的产电微生物进行了研究,并且对如何更好地发展微生物燃料电池进行了讨论。     

基于广州市政垃圾渗滤液的MFC性能及阳极微生物分析

为了分离纯化可适应渗滤液极端环境的产电菌,以广州市白云区李坑和兴丰两处垃圾填埋场获取的渗滤液为底物运行微生物燃料电池（microbial fuel cell, MFC）,待稳定输出多个周期后剪取阳极碳布进行单菌落培养和电镜扫描。结果显示,各组渗滤液底物MFC均能成功启动。李坑四季样的MFC峰值电压分别为0.334、0.331、0.321、0.328 V;兴丰四季样的MFC峰值电压分别为0.512、0.54、0.523、0.536 V。对各组渗滤液底物微生物燃料电池的阳极进行菌株分离纯化并单菌落培养构建阳极微生物系统发育树,发现经过MFC驯化后的阳极菌株具有较高丰度和差异性;SEM扫描发现各组实验中菌株均吸附在阳极碳布上形成稳定的膜结构,根据产电呼吸的基本电子传递机制推测渗滤液底物MFC中的微生物通过与阳极直接接触来传递电子。     

以模拟有机废水为基质的单池微生物燃料电池的产电性能

利用自制单池微生物燃料电池,以破碎厌氧颗粒污泥上清液接种,以葡萄糖模拟废水为基质,成功获得了电能。含有质子交换膜的微生物燃料电池经过206h的连续运行,最高功率密度达到了141.5mW/m2,库仑效率最大为6.9%;不含质子交换膜的微生物燃料电池具有更好的产电能力,其最高功率密度为269mW/m2,库仑效率为6.6%;扫描电镜观察发现,阳极表面的产电细菌以一种短杆菌为主,在质子交换膜表面的细菌则以椭球菌为主。     

微生物燃料电池中多孔电极内电解液的复杂流动机理研究

微生物燃料电池（简称MFC）是一种能够把微生物作为催化剂分解有机物质从而产生电能的新型环境友好型能源装置.到目前为止,对于微生物燃料电池内在连续流的条件下流体穿过多孔阳极的对流现象,人们已经做了大量研究.然而,流体穿过多孔阳极的力学机理和多孔介质与MFC的定量关系还不是很清晰.实验发现当MFC装置的距离在某个特定范围时输出功率明显增大.基于这些实验得到的数据,我们利用格子Boltzmann方法研究了阳极与阴极之间的距离和多孔阳极达西数对MFC输出功率的影响.结果表明阳极与阴极之间的距离影响MFC中流体的速度和流体在多孔阳极中的滞留时间.此外,还发现多孔阳极的达西数能够影响MFC的输出功率.     

基于非线性电导绝缘的随桥敷设高压直流电缆接头电-热场分布及优化设计

针对随桥敷设高压直流电缆接头绝缘电-热场分布问题,开展基于非线性电导增强绝缘的高压直流电缆接头电场优化设计方法研究,探究电-热-机械应力多物理场作用下聚合物绝缘材料的非线性电导率特性对直流电缆接头绝缘电场分布的影响规律,分析高压直流电缆接头增强绝缘优化设计方法。结果表明,碳化硅(Silicon carbide, SiC)掺杂大幅增强了硅橡胶绝缘的非线性电导率,提高了硅橡胶绝缘的非线性系数参数,降低了非线性电导率的阈值电场强度。当桥梁梁箱温度达到40℃时,直流电缆满载运行条件下电缆接头最大场强位于应力锥根部,达到40k V/mm;非线性电导复合绝缘可显著降低中间接头应力锥三结合点处电场强度,抑制附件增强绝缘的电场畸变。采用非线性电导硅橡胶绝缘作为高压直流电缆接头增强绝缘材料,可弥补电缆接头应力锥无法有效抑制接头绝缘直流电场畸变的不足。研究结果可为随桥敷设高压直流电缆接头绝缘电场调控与设计提供理论与试验基础。     

直流盘形悬式绝缘子离子迁移机理研究

直流绝缘子内部带电离子迁移是在杂质离子缓慢迁移、绝缘子外部空间电荷迁移形成的电荷电场和外加电场共同作用下发生的复杂离子运动。分析了离子迁移的宏观表现和微观机理及其影响,假设K^＋耗尽层厚度正比于Na^＋耗尽层．建立了直流电场下碱金属双离子迁移模型,并进行相关理论的推导,该模型促进对直流电场下绝缘子离子迁移微观过程的认识．最后提出抑制直流绝缘子离子迁移的措施：降低碱金属的氧化物浓度,采用中和效应和压抑效应。     

单室微生物燃料电池产电特性研究

采用石墨板为阴极构建了单室空气阴极微生物燃料电池(MFC),以混合菌种接种,并以乙酸钠和碳酸氢钠为碳源,研究了该MFC在间歇运行条件下的产电性能、电池内阻情况和COD去除率。结果表明,最高输出电压随着周期数增加而增加,由0.075 9 V上升到0.200 6 V,最大输出功率密度为34.80 mW/m2;在一个运行周期内,电池内阻随着时间的延长而逐渐增大,由376.6Ω上升到682.0Ω,电池内阻的增大将导致输出电压降低。COD去除率由起始的49.23%达到最大值86.99%,说明此单室空气阴极微生物燃料电池在产电的同时处理污水的效果也较好。     

Increased power output from micro porous layer (MPL) cathode microbial fuel cells (MFC)

Microbial fuel cells are bio-electrochemical transducers that utilise microorganisms to generate electricity, through the oxidation of organic matter. They consist of a negative anode and a positive cathode, separated by an ion selective membrane. The key to improve power, in open-to-air cathode MFCs, is the efficient utilisation of oxygen, by using high surface area materials and effective gas diffusion. This study investigated the effect of single micro porous layers, used as the coating on various electrode substrata, on the performance of small-scale MFCs. Furthermore, 2 of the modified small-scale (6.25 mL) MFCs were implemented as the power source for the TI Chronos digital wristwatch, thus successfully substituting the 3 V button cell, at least for the duration of the experiment.     

The effect of nitric acid,ethylenediamine, and diethanolamine modified polyaniline nanoparticles anode electrode in a microbial fuel cell

Anode materials are important in the power generation of microbial fuel cell. In this study, polyaniline was used as a conducting polymer anode in two chambers MFC. XPS and SEM were used for the characterization of functional groups of anode materials and the morphology. The power generation of microbial fuel cell was elevated by the modification of anode by nitric acid, ethylenediamine, and diethanolamine. The time that MFC reaches its maximum power generation was shortened by modification. Moreover the SEM photos prove that, it causes better attachment of microorganisms as biocatalysts on electrode surface. The best performance of among the MFCs with different anode electrodes, was the system working by polyaniline modified by ethylenediamine as that generated power of 136.2 mW/m² with a 21.3% Coulombic efficiency.     

A thermophilic microbial fuel cell design

Microbial fuel cells (MFCs) are reactors able to generate electricity by capturing electrons from the anaerobic respiratory processes of microorganisms. While the majority of MFCs have been tested at ambient or mesophilic temperatures, thermophilic systems warrant evaluation because of the potential for increased microbial activity rates on the anode. MFC studies at elevated temperatures have been scattered, using designs that are already established, specifically air-cathode single chambers and two-chamber designs. This study was prompted by our previous attempts that showed an increased amount of evaporation in thermophilic MFCs, adding unnecessary technical difficulties and causing excessive maintenance. In this paper, we describe a thermophilic MFC design that prevents evaporation. The design was tested at 57 °C with an anaerobic, thermophilic consortium that respired with glucose to generate a power density of 375 mW m⁻² after 590 h. Polarization and voltage data showed that the design works in the batch mode but the design allows for adoption to continuous operation.     

Identification of removal principles and involved bacteria in microbial fuel cells for sulfide removal and electricity generation

Simultaneous sulfide and organics removals with electricity generation can be achieved in microbial fuel cells (MFCs). In present research, principles of sulfide removal as well as the involved bacteria in the MFCs with sulfide and glucose as the complex substrate are investigated. Results indicated that electrochemical and biological oxidations are the main effects for sulfide removal. Community analysis shows a great diversity of bacteria on the anode surface, including the exoelectrogenic bacteria and sulfur-related bacteria. They are present in greater abundance than those in the MFCs fed with only sulfide and responsible for the effective electricity generation and sulfide oxidation in our proposed MFCs. The results are conducive to reveal the interactions between the pollutants and microbes in aspects of pollutants removals and energy recovery in the MFCs for sulfide removal.     

Exoelectrogens in microbial fuel cells toward bioelectricity generation: a review

Exoelectrogens are catalytic microorganisms competent to shuttle electrons exogenously to the electrode surface without utilizing artificial mediators. Diverse microorganisms acting as exoelectrogens in the fluctuating ambience of microbial fuel cells (MFCs) propose unalike metabolic pathways and incompatible, specific proteins or genes for their inevitable performance toward bioelectricity generation. A pivotal mechanism known as quorum sensing allows bacterial population to communicate and regulates the expression of biofilm‐related genes. Moreover, it has been found that setting the anode potential affects the metabolism of the exoelectrogens and hence the output of MFCs. Microscopic, spectrometry investigations and gene deletion studies have confirmed the expression of certain genes for outer‐membrane multiheme cytochromes and conductive pili, and their potential roles in the exoelectrogenic activity. Further, cyclic voltammetry has suggested the role of multifarious redox‐active compounds secreted by the exoelectrogens in direct electron transport mechanisms. Besides, it also explores the various mechanisms of exoelectrogens with genetic and molecular approaches, such as biofilm formation, microbial metabolism, bioelectrogenesis, and electron transfer mechanisms from inside the exoelectrogens to the electrodes and vice versa. Copyright © 2015 John Wiley & Sons, Ltd.     

Power generation of Shewanella oneidensis MR-1 microbial fuel cells in bamboo fermentation effluent

This study successfully demonstrates the recovery of energy from the effluent of hydrogen fermentation (EHF) by generating electrical power in batch dual-chamber microbial fuel cells (MFCs) inoculated with Shewanella oneidensis MR-1. The effluent obtained from the hydrogen fermentation process of pretreated liquid on Bambusa stenostachya Hack. bamboo which contained organic compounds such as acetate, lactate, and butyrate as carbon sources for Shewanella oneidensis MR-1 and other electro-active microorganisms. Two scenarios of the anolyte of MFC were considered. The first case comprises a supply of 10 mM of lactate in hydrogen fermentation wastewater while the second one is without lactate-supply. The power density and current density of these MFCs were determined to be 0.3–0.6 W/m² and 1.7–2.7 A/m², respectively. The highest voltage generating from MFC without lactate addition was 0.76 V while others were around 0.65 V. The percentage of COD removal on the effluent of hydrogen fermentation ranged from 75% to 83% after 8 operational days followed by the acclimation process. The differences in the impedance characteristics of these MFCs were analyzed by using EIS technique. The average thickness of biofilm formation on the anode electrode was from 7 μm to 23 μm which showed the enhanced electricity production of the MFC system. Moreover, the experimental results demonstrated that the performance of MFC without the lactate supply was better than the other one. Also, its lower substrate consumption efficiency was mentioned.     

Optimization of inner diameter of tubular bamboo charcoal anode for a microbial fuel cell

In the present study, the bamboo charcoal tube derived from the carbonization of the bamboo tube was employed as the anode. The effect of inner diameter of bamboo charcoal tube anodes was experimentally investigated on the microbial fuel cells (MFCs) performance to obtain an optimal structure. After successful star-up, bamboo charcoal tube anodes with different inner diameters (1 mm, 1.5 mm, 2 mm and 3 mm in inner diameter were named as MFC-D1, MFC-D1.5, MFC-D2 and MFC-D3) resulted in various voltage output. However, MFC-D2 and MFC-D3 still kept stable output while the MFC-D1 and MFC-D1.5 performances had a significant drop for a long-term operation (after operation for 30 days). Scanning electron microscope and electrochemical impedance spectroscopy results indicated that the reduction in the powder density for MFC-D1 and MFC-D1.5 attributed to a compact and thicker biofilm on the anode surface leading to the increased the internal resistance of MFCs. Furthermore, compared with other anodes, the highest power density (3303 W/m³) for MFC-D2 suggested that the tubular bamboo charcoal with 2 mm in diameter was more suitable for electricity generation.     

Three-dimensional graphitic mesoporous carbon-doped carbon felt bioanodes enables high electric current production in microbial fuel cells

Microbial fuel cells (MFCs) represent a new approach that can simultaneously enhance the treatment of waste streams and generate electricity. Although MFCs represent a promising technology for renewable energy production, they have not been successfully scaled-up mainly due to the relatively-low electricity generation and high cost associated with MFCs operation. Here, we investigated whether graphitic mesoporous carbon (GMC) decoration of carbon felt would improve the conductivity and biocompatibility of carbon felt anodes, leading to higher biomass attachment and electricity generation in MFCs fed with an organic substrate. To test this hypothesis, we applied 3 different GMC loading (i.e., 2, 5, and 10 mg/cm² of anode surface area) in MFCs compared to control MFCs (with pristine carbon felt electrodes). We observed that the internal resistances of modified anodes with GMC were 1.2–2.3-order of magnitude less than pristine carbon felt anode, leading to maximum power densities of 70.3, 33.3, and 9.8 mW/m² for 10, 5, and 2 mg/cm²-doped anode, respectively compared to only 3.8 mW/m² for the untreated carbon felt. High-throughput sequencing revealed that increasing the GMC loading rate was associated with enriching more robust anode-respiring bacteria (ARB) biofilm community. These results demonstrate that 3-D GMC-doped carbon felt anodes could be a potential alternative to other expensive metal-based electrodes for achieving high electric current densities in MFCs fed with organic substrates, such as wastewater. Most importantly, high electron transfer capability, strong chemical stability, low cost, and excellent mechanical strength of 3-D GMC-doped carbon felt open up new opportunities for scaling-up of MFCs using cheap and high-performance anodes.     

Cathodic limitations in microbial fuel cells: An overview

Microbial fuel cells (MFCs) are a promising technology for sustainable production of alternative energy and waste treatment. The performance of microbial fuel cells is severely affected by limitations based on irreversible reactions and processes in the anode and the cathode compartments. The purpose of this paper is to review the cathodic limitations MFCs and provide an overview on cathodic activation, ohmic and mass transport losses and substrate crossover. Recent studies that have addressed these limitations and explored approaches for improvement are also discussed. MFCs still face many challenges but with consistent advances, especially with respect to the cathode, performance can continue to improve.