微生物燃料电池阴极电子受体研究进展

微生物燃料电池是一个阳极产生电子,阴极接受电子的电化学系统。阐述了微生物燃料电池各种电子受体在阴极的反应机理和研究现状,分析了目前微生物燃料电池研究存在的不足,并提出了未来的研究和发展方向。     

微生物燃料电池电极材料的最新研究进展

微生物燃料电池（microbial fuel cell,MFC）,是一种同步废水处理与产能的新技术——以微生物为催化剂降解废水中的有机物,将其中的化学能转化为电能。本文介绍了微生物燃料电池阳极和阴极材料以及电极催化剂的最新研究进展,讨论了提高微生物燃料电池性能的方法,即通过使用纳米材料修饰电极来提高微生物及催化剂的吸附面积、结合不同材料的优点制作复合材料做催化剂来克服单一材料的不足之处,以期研究和开发出高性能的微生物燃料电池;指出微生物燃料电池的应用前景是将微生物燃料电池与其它技术相耦合来提前实现它的实际应用。     

微生物燃料电池最新研究进展

介绍了微生物燃料电池(MFC)的原理、组成和特点,并针对MFC功率密度过低、构造成本高等问题,从筛选优势产电微生物、改善MFC的构造、优化电极材料以及提高电子传递效率等方面进行了介绍,同时还提到了提高产电性能的各种途径,最后对MFC的发展前景进行了展望.     

MFC处理低浓度焦化废水的试验研究

使用单室空气阴极微生物电池处理焦化废水,以电压、电流密度、功率密度、COD去除率、p H为考察指标,分别用铂、四氧化三铁、二氧化锰作阴极,对比其去除效率和产电能力。实验结果表明,铂阴极的产电能力和废水处理效果最好,开路电压最大值达到521.469 m V。当电流密度为2.4 A/m2时功率密度达到最大值0.195 W/m2,COD去除率为82.9%;二氧化锰阴极MFC效果次之,四氧化三铁阴极MFC的效果最差。     

Continuous microbial fuel cell using a photoautotrophic cathode and a fermentative anode

A complete microbial fuel cell (MFC) operating under continuous flow conditions and using Chlorella vulgaris at the cathode and Saccharomyces cerevisiae at the anode was investigated for the production of electricity. The MFC was loaded with different resistances to characterise its power capabilities and voltage dynamics. A cell recycle system was also introduced to the cathode to observe the effect of microalgae cell density on steady‐state power production and dynamic voltage profiles. At the maximum microalgae cell density of 2140 mg/L, a maximum power level of 0.6 mW/m² of electrode surface area was achieved. The voltage difference between the cathode and anode decreased as the resistance decreased within the closed circuit, with a maximum open circuit voltage (infinite resistance) of 220 mV. The highest current flow of 1.0 mA/m² of electrode surface area was achieved at an applied resistance of 250 Ω.     

High power generation with simultaneous COD removal using a circulating column microbial fuel cell

BACKGROUND: A circulating column microbial fuel cell (MFC) with Cu anode and Au? Cu air cathode was used for power generation and chemical oxygen demand (COD) removal from synthetic wastewater. The column was operated in repeated‐fed batch mode using acclimated anaerobic sludge. The contents of the column MFC were circulated while the feed wastewater was fed to the reactor in fed‐batch mode. Effects of feed COD concentration and COD loading rate on voltage difference, power density and percentage COD removal were investigated. RESULTS: The highest voltage difference (650 mV), power density (40 W m^?2) were obtained with a feed COD of 6400 mg L^?1, yielding 45% COD removal with a COD loading rate of nearly 90 mg h^?1. Low COD loadings (<90 mg h^?1) caused substrate limitations, and high loadings (>90 mg h^?1) resulted in inhibition of COD removal and power generation. The highest percentage COD removal (50%) was obtained with feed COD content of 10.35 g L^?1 or a COD loading rate of 145 mg h^?1. CONCLUSION: The power densities obtained with the circulating column MFC were considerably higher than those reported in the literature due to elimination of mass transfer limitations by the high circulation rates, proximity of electrodes and small anode surface area used in this study. Further improvements may be possible with optimization of the operating parameters. Copyright © 2009 Society of Chemical Industry     

Electricity generation from terephthalic acid using a microbial fuel cell

BACKGROUND: Pure terephthalic acid (PTA) is a petrochemical product of global importance and is widely applied as an important raw material in making polyester fiber and polyethylene terephthalate (PET) bottles. In this work, a single‐chamber microbial fuel cell (MFC) was constructed using terephthalic acid (TA) with a chemical oxygen demand (COD) concentration range from 500 mg L^?1 to 3500 mg L^?1 as the electron donor and strain PA‐18 as the biocatalyst. RESLUTS: In the single chamber MFC, several factors were examined to determine their effects on power output, including COD concentration and electrode spacing. The characteristic of the strain PA‐18 was further studied. Cyclic voltammetry showed that electrons were directly transferred onto the anode by bacteria in biofilms, rather than self‐produced mediators of bacteria in the solutions. Scanning electron microscopy (SEM) observation showed that the anodic electrode surface was covered by bacteria which were responsible for electron transfer. Direct 16s‐rDNA analysis showed that the PA‐18 bacteria shared 99% 16SrDNA sequence homology with Pseudomonas sp. CONCLUSIONS: Electricity generation from TA in MFC was observed for the first time. The maximum power density produced by TA was 160 mW m^?2, lower than that achieved using domestic wastewater. This novel technology provided an economical route for electricity energy recovery in PTA wastewater treatment. High internal resistance was the major limitation. To further improve the power output, the electron transfer rate was accelerated by overexpression of membrane the protein gene of the strain PA‐18 and by reducing the electrolyte and mass transfer resistance by optimizing reactor configuration. Copyright © 2008 Society of Chemical Industry     

阳极双电层电容对微生物燃料电池性能的影响

采用3种活性炭粉制备具有不同电容的阳极,研究了双电层电容阳极对单室空气阴极微生物燃料电池启动、运行、性能、阳极生物膜附着的影响。结果表明:当电极表面积相近的情况下,阳极双电层电容从0.0012 F增加到22.72 F时,微生物燃料电池启动时间缩短了68.0%,电池的最大功率密度增加了16.8倍,达到546.1 m W·m-2。扫描电子显微镜的结果表明高电容的阳极表面附着的微生物量比低电容电极的高1倍。因此,微生物燃料电池性能受阳极双电层电容的影响,而与阳极表面积的相关性小。     

Utilization of mixed monosaccharides for power generation in microbial fuel cells

BACKGROUND: The utilization of mixed monosaccharides commonly found in the hydrolysates of lignocellulosic biomass was evaluated for power generation in single chamber air cathode mediator‐less microbial fuel cells. RESULTS: A similar voltage generation pattern was observed for all the MFCs with different monosaccharide combinations and an external resistance of 1000 Ω. However, the different monosaccharide utilization rates ranging from 212 mg L^?1 h^?1 to 389 mg L^?1 h^?1 indicate the presence of preferential utilization of different monosaccharides. Three volatile fatty acids (VFAs), including acetic, propionic and butyric acids were detected as the main intermediates, which were generated mainly through a fermentation process. CONCLUSION: VFAs produced from initial monosaccharides contributed to a significant portion of the total electricity generated, and the fermentation process outcompeted the electricity generation process when a mixed bacterial culture was used. Copyright © 2011 Society of Chemical Industry     

微生物燃料电池中阴极长期运行的性能分析

微生物燃料电池（MFC）阴极性能在长期运行过程中逐渐下降,查明其下降原因对MFC技术的实际应用具有重要意义。采用泡沫镍阴极研究了阴极长期运行过程中阴极下降的原因。研究发现：MFC运行4个月之后功率密度相比运行1周的MFC下降达22%,测试电极极化曲线发现阴极性能的下降是导致MFC功率密度下降的主要因素。线性伏安扫描（LSV）结果显示：运行初期在-0.2 V电势下阴极电流密度为12.3 A·m^-2,而运行4个月后,阴极电流密度下降为4.2 A·m^-2,阴极性能随运行时间增加而降低主要表现在大电流区域[>-0.05 V （vs Ag/AgCl）]。对阴极表面和内部进行扫描电子电镜（SEM）分析发现：阴极表面没有明显的生物膜,氧扩散实验发现阴极氧扩散量明显降低是造成阴极性能下降的主要原因;通过能谱分析（EDS）可知阴极内部有磷酸盐析出。这些结果说明阴极内部在长期运行过程中逐渐析盐,而析盐导致泡沫镍阴极内孔隙堵塞,阻碍氧扩散到催化层,从而使阴极性能降低。     

微生物燃料电池阳极改性修饰最新研究进展

阳极是影响微生物燃料电池性能的重要因素之一,开发简易、高效的阳极改性修饰方法对微生物燃料电池的实际应用具有关键作用。对目前微生物燃料电池阳极改性修饰的最新进展展开综述,总结了分析阳极材料的方法,并对阳极修饰方法未来发展趋势进行了展望。     

活性炭空气阴极微生物燃料电池的放大和串并联组合研究

采用体积分别为28 mL(mL-MFC)和4.5 L(L-MFC)的单室空气阴极微生物燃料电池,考察了扩大化对活性炭空气阴极性能的影响.mL-MFC的最大功率密度为30 W/m3(1 200 mW/m2),L-MFC的最大功率密度为7.3 W/m3 (435 mW/m2),扩大化后活性炭空气阴极性能下降是致使L-MFC功率降低的主要原因.电化学阻抗(EIS)分析表明,L-MFC中阴极性能下降主要是由于工作水压增大,导致了阴极扩散电阻增大和氧气还原速率降低.通过串联或并联方式组合L-MFC,可明显提高电池的输出电压或电流;串并联组合后电池的功率密度有所下降,主要由电池连接时的接触电阻引起.     

M-N-C阴极催化剂的制备及其在微生物燃料电池中的应用

以聚苯胺和硝酸盐为前驱体,采用热处理法制备了M-N-C（M=Fe,Co）材料,并将其作为厌氧流化床微生物燃料电池（AFBMFC）阴极催化剂。通过X射线衍射（XRD）、红外光谱（FTIR）、扫描电子显微镜（SEM）对催化剂进行晶型结构和表面形貌的表征。采用循环伏安法（CV）对催化剂的电化学性能进行考察,并应用于AFBMFC,考察了其对电池产电性能的影响。结果表明,使用Fe-N-C催化剂的微生物燃料电池稳定运行时,开路电压达到636.0 mV,功率密度达到166.82 mW·m^-2,比使用Pt/C催化剂的微生物燃料电池的功率密度提高10%。表明Fe-N-C催化剂用做微生物燃料电池阴极催化剂具有潜在的应用前景。     

Investigation of ionic polymer cathode binders for microbial fuel cells

Microbial fuel cell (MFC) air cathodes examined here were made using poly(phenylsulfone) (Radel^®) binders sulfonated to various ion exchange capacities (IECs). We examined the effect of increasing the IEC of poly(phenylsulfone) Radel binders from 0 to 2.54 meq/g on cathode performance using linear sweep voltammetry (LSV), impedance, and single chamber air-cathode MFC tests. Unsulfonated Radel, which is a non-ionic, hydrophobic polymer, showed the highest current in LSV tests and the lowest charge transfer resistance. Increasing the binder IEC resulted in a decreased current response in LSV tests and an increased charge transfer resistance from 8 to 23 Ω. It is proposed that the presence of sulfonate groups in the cathode binder impeded the oxygen reduction activity of the cathodes by adsorption of the sulfonate to catalytic sites and by impeding proton diffusion to the catalyst surface. The unsulfonated Radel binder produced the most stable performance, and eventually the highest power density, in MFCs operated over 20 cycles (55 days). These results suggest that the use of a non-ionic binder is advantageous in an MFC cathode to facilitate charge transfer and stable performance in the neutral pH conditions found in MFCs.     

Improved electricity production from sewage sludge under alkaline conditions in an insert‐type air‐cathode microbial fuel cell

BACKGROUND: Electricity can be generated directly from sewage sludge with a microbial fuel cell (MFC), combining degradation of organic matter. This study constructed a novel insert‐type air‐cathode microbial fuel cell (ITAC‐MFC) as an alternative to a sediment‐type MFC and a two‐chambered MFC for the generation of bioelectricity and the degradation of sewage sludge organic matter. Meanwhile, a pH adjustment was carried out to enhance substrate bioavailability of sludge and to suppress methane production in the MFC. RESULTS: A maximum power density of 73 ± 5 mW m^?2 was obtained at sludge pH 10.0, much higher than those of 33 ± 3 and 4 ± 0.5 mW m^?2 obtained at pH 8.0 and 6.0, respectively. It was observed that the soluble chemical oxygen demand (SCOD) of sewage sludge at pH 10.0 was almost three times greater than that at pH 6.0. At the same time, the total chemical oxygen demand (TCOD) removal and coulombic efficiency (CE) at pH 10.0 were also much higher than at the other two conditions. CONCLUSIONS: The results demonstrated that improved electricity production and organic degradation could be achieved by maintaining the sludge pH at 10.0 in an MFC. ITAC‐MFC offers an attractive alternative for the environmentally‐friendly removal of organic matter in sewage sludge. Copyright © 2011 Society of Chemical Industry     

H2O2基燃料电池阴极催化剂的研究进展

本文综述了燃料电池中H2O2电还原催化剂的研究,其主要集中在贵金属、过渡金属的大环化合物、酶以及非贵金属氧化物,其中研究非贵金属氧化物作为H2O2电还原的催化剂将是未来发展的方向.     

Hydrogen production with carbon nanotubes based cathode catalysts in microbial electrolysis cells

BACKGROUND: Microbial electrolysis cell (MEC) has been considered as a promising new technology for the production of bio‐hydrogen from renewable biomass, but low‐cost alternatives to typical cathode material (platinum) are needed. In this study, CNTs‐based electrode alternatives to Pt were examined in a single‐chamber membrane‐free MEC. To the best of our knowledge, the use of carbon nanotube as the MEC cathode catalyst has not been reported so far. RESULTS: For all cathodes, hydrogen production rates increased in response to increase in voltage and the highest hydrogen production was achieved at 0.9 V. At an applied voltage of 0.9 V, MECs with Pt/MWNT cathodes obtained a hydrogen production rate of 1.42 m³ m^?3 day^?1 with a current density of 192 A m^?3, a coulombic efficiency of 94%, a cathodic hydrogen recovery of 65%, and electrical energy efficiency based on electricity input of 126%. CONCLUSIONS: The Pt/MWNT cathode developed demonstrated better electrocatalytic activity than the MWNT cathode and achieved performance comparable with the Pt cathode in terms of hydrogen production rate. These results demonstrate the great potential of using carbon cloth with CNTs‐based electrodes as a cathode material for MECs. Copyright © 2012 Society of Chemical Industry