The internal resistance of a microbial fuel cell and its dependence on cell design and operating conditions

The internal resistance R_int of a mediator-less microbial fuel cell (MFC) has been determined as a function of cell voltage using electrochemical impedance spectroscopy (EIS) for a MFC with and without Shewanella oneidensis MR-1. The same tests were performed for a MFC containing small stainless steel (SS) balls in the anode compartment with a graphite feeder electrode as in a packed bed cell. It has been found that R_int decreased with decreasing cell voltage as the increasing current flow decreases the polarization resistance of the anode and the cathode. The ohmic components of R_int played a very minor role. In the presence of MR-1 R_int was lower by a factor of about 100 than R_int of the MFC with buffer and lactate as anolyte. R_int was also significantly lower for the anode containing SS balls with buffer and lactate as anolyte. For the MFC containing SS balls in the anode compartment no significant further decrease of R_int could be obtained when MR-1 was added to the anolyte since in this case the polarization resistance of the anode was lower than that of the cathode. Similar trends were observed in the cell voltage (V)-current (I) curves that were obtained using potentiodynamic sweeps and the power (P)-V curves that were calculated from the V-I curves.     

The polarization behavior of the anode in a microbial fuel cell

Microbial fuel cell (MFC) systems are unique electrochemical devices that employ the catalytic action of bacteria to drive the oxidation of organic compounds. These systems have been suggested as renewable energy sources for small remote devices; however, questions remain about how MFCs can be efficiently optimized for this purpose. Several electrochemical techniques have been employed in this study to elucidate the limiting factors in power production by MFCs. Impedance spectra were collected for the anode and cathode at their open-circuit potential (OCP) before and after all other electrochemical tests. Cell voltage-current curves were obtained using a potential sweep technique and used to determine the maximum power available from the system. Potentiodynamic polarization in two different potential regions was used to determine the exchange current for the reaction occurring at the anode at its OCP and to explore the polarization behavior of the anode and the cathode in a wide potential range. Cyclic voltammetry was used to evaluate the redox activity of the anode. These techniques used in combination showed that the microorganism Shewanella oneidensis MR-1 is solely responsible for the observed decrease of the OCP of the anode, the increased rate of oxidation of lactate, the larger cell voltage and the increased maximum power output of the MFC.     

不同来源菌群接种微生物燃料电池处理淀粉废水的研究

以人工模拟淀粉废水为底物运行微生物燃料电池(MFC),分别采用淀粉废水、生活污水和二者的混合液为接种液,考察不同来源菌群接种下,MFC产电能力与废水处理效果。研究结果表明,采用混合液接种时,MFC启动时间相对于淀粉废水和生活污水接种分别缩短了29.6%和26.9%,最大产电功率密度分别提高了156%和6.1%;COD、NH4+-N去除率略有提高。对利用混合液接种的MFC进一步优化,结果表明,当MFC基质pH为9,NaCl质量浓度为1.0 g/L,基质COD为3 100 mg/L,温度为30℃时,MFC的产电能力与废水处理效果最佳,产电功率密度达4.63W/m3,COD去除率为86.3%,NH4+-N去除率为82.6%。     

利用无膜微生物燃料电池废水处理并回收电能

An upflow mode membrane-less microbial fuel cell （ML-MFC） was designed for wastewater treatment. Granular graphite electrodes, which are flexible in size, were adopted in the ML-MFC. Microbes present in anaerobic activated sludge were used as the biocatalyst and artificial wastewater was tested as substrate. During the electrochemically active microbe enrichment stage, a stable power output of 536 mW.m-3 with reference to the anode volume was generated by the ML-MFC running in batch mode. The voltage output decreased from 203 mV to about 190 mV after the ML-MFC was changed from batch mode to normally continuous mode, indicating that planktonic electrochemically active bacterial strains in the ML-MFC may be carried away along with the effluent. Cyclic voltammograms showed that the attached microbes possessed higher bioelectrochemical activity than the planktonic microbes. Forced aeration to the cathode benefited the electricity generation obviously. Higher feeding rate and longer electrode distance both increased the electricity generation. The coulombic yield was not more than 20% throughout the study, which is lower than that of MFCs with membrane. It is proposed that dissolved oxygen diffused from the cathode to the anode may consume part of the substrate.     

Treatment of cassava mill wastewater and production of electricity through microbial fuel cell technology

Cassava mill wastewater has a high organic content and is an important economic product of traditional and rural low technology agro-industry in many parts of the world. This study explores the utilization of agro-industrial wastewater collected from cassava mills as a resource for electricity generation by microbial fuel cells (MFCs). Mixed culture sludge was used to inoculate the bottom chamber of the MFCs whilst cassava mill wastewater was used in the MFCs. Experimental results showed that the MFCs could generate electricity from full-strength cyanide laden wastewater (16000 mg-COD/L, 86 mg/L cyanide) with a maximum power density of 1771 mW/m². The results from this study demonstrate the feasibility of using MFC technology to generate electricity whilst simultaneously treating cyanide laden cassava mill wastewater effectively. Using MFCs for cassava mill wastewater treatment provides an attractive way to reduce the cost of wastewater treatment in addition to generating electricity.     

微生物燃料电池耦合型废水处理反应器研究进展

随着生物电化学技术研究的发展,多种应用于废水处理的新型微生物燃料电池(MFC)耦合反应器不断出现,在污染物降解和能量回收中展现了多种优势。重点综述了近年来报道的典型的MFC耦合型废水处理反应器,并对其耦合机理、运行效果及存在的问题进行了比较分析,以期为生物电化学耦合型废水处理反应器的进一步优化和发展提供参考。     

微生物燃料电池与人工湿地耦合系统研究进展

将微生物燃料电池(microbial fuel cell, MFC)与人工湿地(constructed wetland, CW)相结合是近几年来出现的一种新型产能及废水净化工艺。在综述CW-MFC耦合系统产电机理及其发展的基础上进一步分析讨论了当前研究中影响系统性能的组成要素(植物、微生物、电极及分隔材料)和运行参数(碳源、氧化还原电位及水力停留时间)两个方面,最后总结了当前尚未解决的关键问题,对今后耦合系统的潜在应用进行了展望。     

微生物燃料电池在废水处理中的研究进展

随着全球工业化进程加快,水污染和能源短缺问题日益严重。微生物燃料电池（MFC）作为一种新型微生物电化学工艺,可以在降解有机物的同时产电,具有清洁、节能、经济等优势,引起人们的广泛关注,成为水处理领域的研究前沿。本文首先介绍了MFC原理和电子传递机制,分析影响其处理性能的关键因素（阳极材料、阴极材料、接种微生物、反应器构型和系统运行参数）;然后回顾了近年来MFC在废水（生活废水、农业废水和工业废水）处理领域的应用,并拓展性地阐述了MFC与其他技术（电芬顿、光催化、人工湿地系统和微生物电解池）的耦合应用;最后指出MFC存在的问题,并提出未来可行的发展方向,包括深度挖掘机理、优化接种微生物种群、改进装置材料与构型、改善进水模式与运行参数和研究新的耦合系统等。     

不同温度下微生物燃料电池的运行特性

实验采用双室型微生物燃料电池（MFC）,以生活废水中厌氧菌作为生物催化剂,葡萄糖为燃料,通过5个不同温度条件下的间歇运行,应用循环伏安、交流阻抗、极化测试等电化学方法考察温度对电池产电性能的影响。结果表明,一定温度范围内,提高温度有助于增强微生物的电化学活性,降低传荷阻抗,提高电池输出功率密度和交换电流密度。32 ℃时,电池产电效能最佳,电池功率密度和交换电流密度分别达到156.2 mW/m2和8.02×10?5 mA/m2,温度太低或太高均不利于细菌的电化学活性。体系温度为18 ℃、25 ℃、32 ℃、39 ℃、46 ℃时,传荷阻抗Rct在阳极内阻中占的比例分别为97.99%、84.02%、47.36%、91.30%、99.61%,说明传荷阻抗在阳极内阻中占绝对份额,MFC是传荷过程控制下的电化学反应体系。     

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。     

电极对微生物燃料电池同时处理有机废水和含铜重金属废水产电性能的影响

实验以有机废水为阳极底物,以活性污泥中的混合菌为阳极接种微生物,以含铜废水为阴极液,构建双室MFC,探讨电极对MFC同时处理有机废水和含铜重金属废水产电性能的影响.结果表明:MFC对阳极有机废水COD的去除率最高为79.1%,对阴极液中Cu²⁺的去除率最高为95.6%.活性炭/石墨棒电极MFC产电性能最优,开路电压最高为800mV,是石墨棒电极MFC的1.25倍,是活性炭/碳纸电极MFC的1.3倍,是碳纸电极MFC的1.5倍.当电极距离为2cm时,MFC开路电压580mV,内阻为181Ω,产电性能最优.电极表面积为75cm²时,MFC的开路电压470mV,是电极表面积为50cm²的MFC的1.1倍,是电极表面积为30cm²的MFC的2.1倍.当A_An/A_cat=0.4时MFC产能最佳,MFC的开路电压最高为600mV,最大功率密度48.2mW/m².     

啤酒废水处理技术研究进展

总结和介绍了国内近年来在啤酒废水处理方面取得的一些进展。主要有好氧处理的SBR技术、曝气生物滤池法，厌氧处理的UASB技术、好氧-厌氧综合处理以及新兴的生物处理方法，并且概要介绍了各种方法的处理工艺及其优缺点。     

微生物燃料电池处理偶氮含盐废水的产电性能和降解过程

偶氮含盐废水生化处理流程复杂、电耗高,且降解机理尚不明确。本研究基于酸性重铬酸钾法水热处理获取改性阳极,进而构建微生物燃料电池（microbial fuel cell,MFC）对偶氮含盐废水进行处理。考察了不同二价阴离子对MFC产电性能和降解有机物效果的影响,并探究了MFC对直接红13的降解机理。结果表明,偶氮含盐废水中含有硫酸钠时的产电性能高于含有碳酸钠的情况,MFC最大功率密度为265.38mW/m²、最大电流密度为1.10A/m²;MFC处理偶氮含盐废水时,对直接红13的去除率低于无额外添加盐时的效果（71.13%）,对葡萄糖共基质的降解影响程度为：添加硫酸钠>添加碳酸钠>无额外添加盐。微生物群落和降解产物分析表明,MFC阳极生物膜通过变形菌门、拟杆菌门等微生物的协同作用实现了对直接红13的生物电化学降解,产电下降解产物以还原产物芳香胺为主。     

Development of microbial fuel cell with anoxic/oxic design for treatment of saline seafood wastewater and biological electricity generation

BACKGROUND: Sustainable technologies need to be developed to treat saline seafood wastewater (SSW) efficiently. This study focused on the feasibility of a continuously operated microbial fuel cell (MFC) with modified anoxic/oxic (A/O) architecture (A/O–MFC) for power generation and treatment of SSW simultaneously. RESULTS: Hydraulic retention time (HRT) was shown to have an impact on polarization and power output of the A/O–MFC and the maximum power density of 16.2 W m^?3 was obtained at a current density of 41.7 A m^?3 and HRT of 4.2 h. High salinity together with advective flow mode enabled a low and constant internal resistance of approximately 100 Ω throughout the experiments. Besides, pH of waste stream in both compartments was found always near neutral level. Increasing HRT could improve eliminability of soluble chemical oxygen demand (sCOD) and biological nitrification. CONCLUSIONS: This study provides a proof‐in‐concept demonstration to utilize an MFC for effective and sustainable treatment of SSW along with recovery of electrical energy. Copyright © 2010 Society of Chemical Industry     

微生物燃料电池处理含柠檬酸钠废水的研究

柠檬酸钠由于其优良的性质被广泛应用于食品、医药、化工等诸多领域,越来越广泛的应用导致工业和市政污水中柠檬酸钠的含量升高,加剧了水体的富营养化。将柠檬酸钠作为微生物燃料电池（microbial fuel cell, MFC）阳极底物,研究得到了柠檬酸钠单独作为混合菌种MFC底物时的产电性能。结果显示,与乙酸钠和葡萄糖相比,以柠檬酸钠为底物的MFC（Na₃C₆H₅O₇-MFC）获得的最大功率密度为742.96 mW·m^-2,是乙酸钠（NaAc-MFC）和葡萄糖（Glu-MFC）的1.77倍和1.12倍。NaAc-MFC和Glu-MFC的启动时间分别约为Na₃C₆H₅O₇-MFC（57 h）的1.8倍和2.9倍。同时,Na₃C₆H₅O₇-MFC对COD的去除率为87.65%,与NaAc-MFC和Glu-MFC相差不大。Na₃C₆H₅O₇-MFC的库仑效率高达61.31%,明显优于NaAc-MFC和Glu-MFC。实验结果表明MFC可以有效地降解柠檬酸钠,能够处理含柠檬酸钠废水,并为柠檬酸钠单独作为底物应用于MFC提供了依据。     

Performance degradation study of a direct methanol fuel cell by electrochemical impedance spectroscopy

A stability test of a direct methanol fuel cell (DMFC) was carried out by keeping at a constant current density of 150 mA cm⁻² for 435 h. After the stability test, maximum power density decreased from 68 mW cm⁻² of the fresh membrane-electrode-assembly (MEA) to 34 mW cm⁻² (50%). Quantitative analysis on the performance decay was carried out by electrochemical impedance spectroscopy (EIS). EIS measurement of the anode electrode showed that the increase in the anode reaction resistance was 0.003 Ω cm². From the EIS measurement results of the single cell, it was found that the increase in the total reaction resistance and IR resistance were 0.02 and 0.05 Ω cm², respectively. Summarizing the EIS measurement results, contribution of each component on the performance degradation was determined as follows: IR resistance (71%) > cathode reaction resistance (24%) > anode reaction resistance (5%). Transmission electron microscopy (TEM) results showed that the average particle size of the Pt catalysts increased by 30% after the stability test, while that of the PtRu catalysts increased by 10%.     

微生物燃料电池处理高盐废水的研究进展

高盐废水通常采用生化、蒸发和膜处理3种方法处理,但无论采用何种方法,高盐废水处理均存在难度大和成本高等问题。微生物燃料电池（MFC）是一种基于产电微生物催化氧化有机物获得电能的装置,应用MFC处理废水可实现在处理废水的同时回收废水中能量,从而降低废水处理成本。近年来,应用MFC处理高盐废水来降低处理成本的研究逐渐开展并成为一个研究热点。本文综述了MFC处理高盐废水研究的最新进展,分析了盐度对MFC产电、污染物脱除、微生物生长和群落的影响,基于耐盐微生物、生物膜、反应器结构及扩展应用等方面提出未来MFC处理高盐废水的研究方向。     

光合混菌生物阳极MFC对高浓度淀粉废水的处理

以光合混菌PB-Z为阳极菌,在室温、自然光照和静置的环境下以高浓度淀粉废水为基质,探讨微生物燃料电池(MFC)的处理效果,并通过更换氮源、优化氮源浓度和添加Ca2+的方式进行改善。结果表明,PB-Z在初试实验中,COD去除率为61.84%,TN去除率为62.89%。更换氮源、优化氮源浓度和添加Ca2+都可以提升其COD的去除率,确定了最佳氮源为氯化铵,最佳氨氮浓度为6 mmol/L和最佳Ca2+质量浓度为30 mg/L,优化后的COD去除率为94.64%,氨氮去除率为70.13%,为MFC处理淀粉废水的工业化提供了实验基础。