外加直流电场对微生物燃料电池阳极微生物的影响研究

为考察外加直流电场作用对微生物燃料电池阳极微生物的影响,采用双室型MFC反应器,在启动开始时分别加以-5,-3,-1,0,+1,+3,+5 V的直流电场,作用时间依次取2 min,30 min,1 h,24 h。结果表明,外加直流电场能够对微生物燃料电池阳极室内微生物的生长产生影响,作用时间为30 min时效果较为明显,提高作用时间后效果变化不大;±1 V的电场强度作用促进微生物的生长;较低的直流电场(±1 V)作用能够促进微生物燃料电池的阳极生物挂膜,且负电场促进效果更好,而较高的直流电场(+3 V和±5 V)作用不利于甚至损害阳极生物挂膜。     

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。     

微生物燃料电池混合菌群的产电特性与分布

将不同来源的污泥进行组合构建混合接种物的微生物燃料电池(MFC),通过比较微生物燃料电池的产电性能寻求更为优良的微生物群落,结果表明:将华南农业大学资源环境学院新肥室沼气池污泥、湖南省祁东县淹水稻田土和燕京啤酒厂废水处理二沉池污泥混合作为组合接种物的MFC性能较优,其最大输出电压0.59 V,最大功率密度10.81 W/m3。利用PCR-DGGE技术解析该电池阳极表面优势微生物的群落,分析发现阳极生物膜中占优势的菌种为Gammaproteobacteria菌纲中的Shewanella,其次为Pseudomonas aeruginosa,还存在Verrucomicrobiae和Flavobacteria菌纲的微生物。     

MnO2为阴极催化剂的微生物燃料电池处理城市垃圾渗滤液研究

主要针对城市垃圾热解预处理过程所产生的渗滤液进行研究。首先改变城市垃圾堆放温度和堆放时间,发现城市垃圾于40℃堆放6 d后所得的渗滤液中生物需氧量(Biological Oxygen Demand,BOD)、氨氮浓度约为20800、1410 mg/L,B/C比、B/N比分别为0.32和14.8,营养物质较均衡,易于生化处理,且将其进行微生物燃料电池(Microbial Fuel Cell,MFC)处理时,电池可获得0.29 V的稳定输出电压。随后,以上述渗滤液为MFC阳极基质,考察廉价易得的Mn O2作为阴极催化剂对空气阴极单室MFC电池性能以及渗滤液中有机污染物去除率的影响。结果发现,由于Mn O2催化氧还原,加速了MFC阴极接受电子的速度,使得MFC电池性能有较大提高。其中,MFC的最大功率密度由0.16 W/m3提高到0.88 W/m3,而电池稳定输出电压明显升高至0.43 V,且阳极渗滤液中BOD和NH4+-N去除率也分别达72.9%和91.6%,比对照MFC分别提高8.1%和5.0%。     

微生物燃料电池电能产生及污废水处理的研究进展

微生物燃料电池（microbial fuel cell, MFC）是采用微生物催化的电化学系统,可用于污废水处理领域。目前关于MFC的研究多集中在提高产电能力和去污效能方面。通过综述近期MFC的研究进展,建议该技术在污废水处理领域的研究重点放在产电微生物筛选培养、低成本电极材料修饰研发、调控MFC运行条件等方面,并应加强MFC与序批式反应器（sequencing batch reactor, SBR）、厌氧好氧（anoxic oxic, A/O）、膜生物反应器（membrane bio-reactor, MBR）等常见污废水处理工艺耦合联用的研究。     

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。     

电极材料对微生物燃料电池处理老龄垃圾渗滤液性能的影响

以碳毡和碳布为电极材料,老龄垃圾渗滤液为阳极底物构建生物阴极型微生物燃料电池(MFC),考察碳毡和碳布分别作为阴极和阳极材料时对MFC明在阳极材料相同时,碳毡阴极MFC料相同时,碳布阳极MFC输出电压和功率密度最大(分别为294 mV、95.31 mW/m~3)、化学需氧量和氨氮去除率最大(分别为58.78%、74.38%);阳极、阴极均为碳布的MFC内阻最小(308Ω),阳极、阴极均为碳毡的MFC内阻最大(347Ω)。     

微生物燃料电池(MFC)技术及其发展前景的研究

本文论述了能源和环境面临的问题与微生物燃料电池（MFC）的关系,介绍了MFC产能原理和效率及其国内外研究进展,分析了利用湿地微生物构建生物质能源循环式微生物电池的潜力,指出了MFC作为一种可再生的清洁新能源的广阔前景。     

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。     

Performance improvement of air-cathode single-chamber microbial fuel cell using a mesoporous carbon modified anode

A novel mesoporous carbon (MC) modified carbon paper has been constructed using layer-by-layer self-assembly method and is used as anode in an air-cathode single-chamber microbial fuel cell (MFC) for performance improvement. Using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), we have demonstrated that the MC modified electrode exhibits a more favorable and stable electrochemical behavior, such as increased active surface area and enhanced electron-transfer rate, than that of the bare carbon paper. The MFC equipped with MC modified carbon paper anode achieves considerably better performance than the one equipped with bare carbon paper anode: the maximum power density is 81% higher and the startup time is 68% shorter. CV and EIS analysis confirm that the MC layer coated on the carbon paper promotes the electrochemical activity of the anodic biofilm and decreases the charge transfer resistance from 300 to 99 Ω. In addition, the anode and cathode polarization curves reveal negligible difference in cathode potentials but significant difference in anode potentials, indicating that the MC modified anode other than the cathode was responsible for the performance improvement of MFC. In this paper, we have demonstrated the utilization of MC modified carbon paper to enhance the performance of MFC.     

Study on power generation and Congo red decolorization of 3D conductive PPy-CNT hydrogel in bioelectrochemical system

In this paper, a polypyrrole-carbon nanotube hydrogel (PPy-CNT) with 3D macroporous structure was prepared by secondary growth method. This self-supporting material with good conductivity and biocompatibility can be directly used as anode in a microbial fuel cell (MFC). The prepared material had a uniform structure with rich 3D porosity and showed good water retention performance. The effect of the mass ratio of PPy and CNT in the hydrogel were also investigated to evaluate the electrical performance of MFC. The MFC with 10:1 PPy-CNT hydrogel anode could reached the maximum power density of 3660.25 mW/m3 and the minimal electrochemical reaction impedance of anode was 5.06 Ω. The effects of Congo red concentration, external resistance and suspended activated sludge on decolorazation and electricity generation were also investigated in the MFC with the best performance hydrogel. When the Congo red concentration was 50 mg/L and the external resistance was 200 Ω, the dye decolorization rate and chemical oxygen demand (COD) removal rate could reach 94.35% and 42.31% at 48h while the output voltage of MFC was 480 mV. When activated sludge was present, the decolorization rate and COD removal rate could be increased to 99.55% and 48.08% at 48 h. The above results showed that the porous hydrogel anode had broad application prospects in synchronous wastewater treatment and electricity production of MFC.     

Electrophoretic deposition of graphene oxide on carbon brush as bioanode for microbial fuel cell operated with real wastewater

Microbial fuel cell (MFC) is a promising technology for simultaneous wastewater treatment and energy harvesting. The properties of the anode material play a critical role in the performance of the MFC. In this study, graphene oxide was prepared by a modified hummer's method. A thin layer of graphene oxide was incorporated on the carbon brush using an electrophoretic technique. The deoxygenated graphene oxide formed on the surface of the carbon brush (RGO-CB) was investigated as a bio-anode in MFC operated with real wastewater. The performance of the MFC using the RGO-CB was compared with that using plain carbon brush anode (PCB). Results showed that electrophoretic deposition of graphene oxide on the surface of carbon brush significantly enhanced the performance of the MFC, where the power density increased more than 10 times (from 33 mWm^?2 to 381 mWm^?2). Although the COD removal was nearly similar for the two MFCs, i.e., with PCB and RGO-CB; the columbic efficiency significantly increased in the case of RGO-CB anode. The improved performance in the case of the modified electrode was related to the role of the graphene in improving the electron transfer from the microorganism to the anode surface, as confirmed from the electrochemical impedance spectroscopy measurements.     

Electricity generation in microbial fuel cell systems with Thiobacillus ferrooxidans as the cathode microorganism

Microbial fuel cells (MFC) are systems that enable biochemical activities of bacteria to generate the electricity. These systems are of great interest because of their designs that enable biological activity in organic wastes to be transformed into direct electrical energy. In order to increase the commercial usage of MFCs, it is necessary to increase the power output of the system. So as to improve MFC performance, used material selection, the pH value of the used bacterial medium and the choice of the appropriate substrate are very important. In this study, oxidation bacteria Thiobacillus ferrooxidans on the cathode and mixed culture bacteria on the anode of MFC were used. Different anode and cathode pH values were examined in MFC. Best open circuit potential result (0.8 V) was obtained at anode pH 8 and cathode pH 2 conditions. In addition, three different substrates had been used in the anode. In the conditions of acetate the most stable and high valued curve was obtained. The open circuit potential had reached 0.726 V, and power density had reached 0.88 mW/cm².     

Electrodeposition of graphene by cyclic voltammetry on nickel electrodes for microbial fuel cells applications

Ni electrode was modified with graphene by the electrodeposition (ED) method to prepare an anode (anode‐ED) for microbial fuel cell (MFC). Electrochemical and morphological characterizations of anode‐ED along with the effects of anode modification on the MFC performance were investigated. The graphene modification based on cyclic voltammetric electrodeposition resulted in the decrease of charge transfer resistance (R_ct) and improved extracellular electron transfer efficiency of anode. The maximum power density obtained from the MFC equipped with anode‐ED was 25.83 and 17.86 times larger than those of MFCs equipped with bare Ni anode and anode modified with graphene by traditional hydrothermal treatment method (anode‐HT), respectively. The electrochemical impedance spectroscopy (EIS) analysis results indicated that the R_ct of anode decreased significantly after inoculation during the MFC operation. The improvement in power density was attributed to the decreasing R_ct and the biocompatibility of graphene modified on anode‐ED surface. This study presented an effective electrodeposition method to make graphene‐modified anodes, which could improve the MFC performance.     

Effect of surface modification of anode with surfactant on the performance of microbial fuel cell

Surface modification of anode using surfactant has great influence on the electrical performance of a microbial fuel cell (MFC). In this study, the effect of surface‐modified exfoliated graphite used for anode fabrication on a cube‐type MFC batch reactor was examined. The surface exfoliated graphite was modified with 5‐mM anionic surfactant, sodium dodecyl sulfate. Anaerobic sludge used as inoculum containing 70% (v/v) of artificial wastewater and 30% (v/v) of seed sludge in an anode chamber and air cathode was used in cathode side. Anode modification was explored as an approach to enhance the start‐up and improve the performance of the reactor. Scanning electron microscopy was used to evaluate the morphology and activity of electrochemically active bacteria. In the study, the start‐up time of MFC required to approach stable voltage was substantially reduced, and the maximum stable voltage was higher than the control. In addition, the activation resistance of the MFC was considerably reduced, and the maximum power density (1640 mW/m²) was 20% higher than control. However, when the surface of exfoliated graphite was modified with over 10‐mM anionic surfactant, some negative effects on start‐up time, activation resistance and maximum power density were observed. This modification also enhanced the bacterial attachment and biofilm formation on the modified anode surface. The result suggested that surface modification anode with surfactant is effective for electrical responses achieved in the MFC. Copyright © 2015 John Wiley & Sons, Ltd.     

In-situ modified titanium suboxides with polyaniline/graphene as anode to enhance biovoltage production of microbial fuel cell

Microbial fuel cell (MFC) has been the focus of much investigation in the search for harvesting electricity from various organic matters. The electrode material plays a key role in boosting MFC performance. Most studies, however, in the field of MFC electrode material has only focused on carbonaceous materials. The finding indicates that titanium suboxides (Ti₄O₇, TS) can provide a new alternative for achieving better performance. Polyaniline (PANI) together with graphene is chosen to in-situ modify TS (TSGP). The MFC reactor with TSGP anode achieves the highest voltage with 980 mV, and produces a peak power density of 2073 mW/m², which is 2.9 and 12.7 times those with the carbon cloth control. The rather intriguing result could be due to the fact that TSGP has the high conductivity and large electrochemical active surface area, greatly improving the charge transfer efficiency and the bacterial biofilm loading. This study has gone some way towards exploring the conducting ceramics materials in MFC.     

Relationship of methane and electricity production in two-chamber microbial fuel cell using sewage sludge as substrate

The relationship of methane and electricity production from sewage sludge in a two-chamber microbial fuel cell (MFC) was studied. The results showed that methane production in the anode chamber could enhance the electricity production from sewage sludge, and the output voltage of the MFC with methane production (0.505–0.600 V) was higher than that of the MFC without it (0.506–0.576 V) in the stable electricity-producing stage. The polarization curves analysis of the two MFCs suggested that methane production could improve the performance characteristics of the MFC. Simultaneous methane and electricity production from sludge in the two-chamber MFC could maintain the mixed sludge in a suitable pH range in the anode chamber for electricity production. Meanwhile, simultaneous methane and electricity production could enhance the hydrolysis of sludge, which increased the reduction of sludge concentration (about 8.31% VSS) and offered more substrates to alleviate the competition between methane and electricity production. Additionally, the addition of 2-Bromoethanesulfonate (BES) could substantially affect the dominant archaea but had little effect on the dominant bacteria in the anode chamber.     

Graphite nanopowder functionalized 3-D acrylamide polymeric anode for enhanced performance of microbial fuel cell

3-D highly conductive polyvinyl formaldehyde sponges functionalized with acrylamide are fabricated using polyvinyl alcohol with varying concentrations of graphite nanopowder. The properties of the fabricated anodes are analyzed and its application in microbial fuel cells is evaluated. A comparative study with Graphite felt is also performed to evaluate its commercial viability. The presence of Hydroxyl and Amine functional groups enhanced the hydrophilic and biocompatible nature of the synthesized anodes. The phylogenetic analysis substantiated the biocompatible nature and mercury porosimetry showed macroporous nature of the fabricated anode. The highest power density of ~8 W/m² is recorded for C10 establishing solid biofilm formation. A ~94% COD removal revealed the versatility of the anode for MFC based wastewater treatment. The MFC performance was twice than that of control and was also highest among the most reported modified 3-D anodes. The durability study displayed the commercial opportunity of the anode for real-time MFC operation.