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)。     

微生物燃料电池运行影响因素的研究

研究自行设计的微生物燃料电池在常温常压下,以厌氧污泥为接种源,以葡萄糖为底物原料,以不同溶液作为电子受体的条件下测试其稳定运行的影响因素与工艺条件。实验结果表明:该微生物燃料电池可稳定运行约30d,并在注入新的底物后,电压又快速回升至稳定电压。以铁氰化钾溶液作为电子受体,输出电压可达0.75V,输出功率为2100mW/m~2;以高锰酸钾溶液作为电子受体,输出电压为1.023V,输出功率为2638mW/m~2。     

石墨束微生物燃料电池产电性能研究

试验研究了以乙酸钠为燃料,以石墨束为阳极的双室微生物燃料电池的产电情况.试验结果表明,经过6d的启动期,电池输出电压达到稳定状态,以乙酸钠为燃料时最大输出电压可达到698mV,并可持续10d左右,电池内阻为44.6Ω,最大体积功率密度可达6 321.1 mW/m3,最大面积功率密度为745.5 mW/m2,COD的去除率可达85%以上.燃料电池在外阻为510Ω条件下运行1个周期,其库仑效率约为20%.     

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。     

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。     

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。     

集胞藻PCC-6803催化的光合微生物燃料电池性能研究

以集胞藻PCC-6803(Synechocystis PCC-6803)为阳极催化剂搭建直接利用太阳能的双室H-型光合微生物燃料电池(PMFC),通过极化曲线法、交流阻抗法、循环伏安法等电化学方法,开展电极面积比、质子交换膜、内阻等因素对光合微生物燃料电池产电的影响研究。试验结果显示:在PMFC运转过程中,其输出功率稳定,且达到的最大功率密度为72.3 mW/m2;阴阳极面积大小对PMFC产电性能没有显著影响,说明双室光合微生物燃料电池中,质子交换膜传递质子的速率较慢,限制了PMFC发电效能的提高。PMFC启动后,随着生物膜的增长,其欧姆内阻、极化内阻、总内阻都呈现下降的趋势,且欧姆内阻下降的速率小于极化内阻,从而使欧姆内阻占总内阻的比率变大,进一步说明质子交换膜传递质子的速率是限制PMFC发电的关键因素。     

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。     

直接碳燃料电池(DCFC)实验研究

直接碳燃料电池是一种高效、清洁的燃料电池技术,其原理是碳和氧气勿需气化和重整而直接通过电化学反应产生电能,效率可达80%,燃料利用率约达100%。自行组装了DCFC单体电池,工作温度为500～700℃;该电池采用熔融氢氧化物作电解质,并掺入一定量的催化剂;石墨作阳极,不锈钢作阴极,加湿氧气作氧化剂。对不同的电解质、不同的氧气流量下DCFC的输出性能进行了试验研究。结果表明,KOH比NaOH的导电性好,电池运行更稳定,更有利于电池的输出;氧气流量为70mL/min时,该电池的输出性能最佳,最大电流密度、功率密度分别为105mA/cm2和0.041W/cm2,开路电压达到0.74V。电流密度为45mA/cm2时,输出电压0.65V,可连续稳定运行20h。提出了热解-直接碳燃料电池联合系统,并以C10H22为例,分析了联合系统发电效率高达76.5%,表明该系统在未来集中式电厂中有很好的应用前景。     

微生物燃料电池耦合处理重金属-有机废水性能研究

以双室微生物燃料电池(MFC)为研究对象,构建阳极为糖蜜废水、阴极为不同金属离子废水的微生物燃料电池,对其产电性能和去污能力进行测定。结果表明:微生物燃料电池可同时处理有机废水和金属离子废水,其中,Ag~+为阴极液时,其MFC稳定性最好,最高输出电压为198 m V、最大功率密度为23.1 m W/m~2、内阻为500Ω,Cu~(2+)为阴极液时分别为149 m V、13.9 m W/m~2、600Ω,Zn~(2+)为阴极液时分别为16 m V、1.9×10~(-6)m W/m~2、900Ω。阳极化学需氧量(COD)去除率以Ag~+为阴极液时最高,可达72%,Cu~(2+)和Zn~(2+)分别为54%和19.2%。阴极金属离子去除率Ag~+为72%、Cu~(2+)42%、Zn~(2+)19.8%。     

碳粉催化剂镍基体空气阴极微生物燃料电池特性研究

试验以泡沫镍材料作为空气阴极MFC的电极材料,并利用碳粉作为催化剂,在1.24 A/m2的电流密度下获得了214 mW/m2的最大功率密度输出。电位分析结果表明,阴极开路电位为+12 mV,阳极开路电位为-466 mV。采用改变外阻的调节方式,获得了18.6%~57.8%的库伦效率。试验结果表明,碳粉可以作为催化剂材料在泡沫镍基体空气阴极MFC系统中使用。     

Experimental studies of the effect of cathode diffusion layer properties on a passive direct methanol fuel cell power output

A great challenge in a passive direct methanol fuel cell (pDMFC) is how to reduce both methanol and water crossover, from the anode to the cathode side, without significant losses on its power output. Different approaches including improving the membrane and modifying the cell structure and materials have been proposed in the last years.In this work, an experimental study was carried out to evaluate the effect of the cathode diffusion layer (CDL) properties on the power output of a pDMFC. Towards a cost reduction, lower catalyst loadings were used on both anode and cathode electrodes. Since the main goal was the optimization of a pDMFC using the materials commercially available, different carbon-fibber materials were employed as CDL. The experimental results were analysed based on the polarization curves and electrochemical impedance spectroscopy measurements with innovative electric equivalent circuit allowing the identification of the different losses, including the activation resistance of the parasitic cathode methanol oxidation.A maximum power density of 3.0 mW/cm² was obtained using carbon cloth with a lower thickness as CDL and a methanol concentration of 5 M.     

Pyrolyzing pyrite and microalgae for enhanced anode performance in microbial fuel cells

Developing low-cost and high-performance anodes is of great significance for wider applications of microbial fuel cells (MFCs). In this study, microalgae and pyrite were co-pyrolyzed (P/MC) and then coated on carbon felt (CF) with PTFE as a binder. P/MC modification resulted in increased electroactive surface area, superhydrophilicity and higher biocompatibility. Besides, the P/MC-CF anode reduced the charge transfer resistance from 35.1 Ω to 11.4 Ω. The highest output voltage and the maximum power density of the MFC equipped with the P/MC-CF anode were 657 mV and 1266.7 mW/m², respectively, which were much larger than that of the MFC with the CF anode (530 mV, 556.7 mW/m²). The P/MC-CF anode also displayed higher columbic efficiency (39.41%) than the CF anode (32.37%). This work suggests that pyrolyzing microalgae with pyrite is a promising method to enhance the performance of MFCs.     

Composite‐modified anode by MnO2/polypyrrole in marine benthic microbial fuel cells and its electrochemical performance

Low power limits the application of microbial fuel cells (MFCs). Our research mainly focuses on the modification of the electrode and looking for new anode material for high‐power marine benthic microbial fuel cells(BMFCs). A MnO₂/PPy composite‐modified anode was fabricated by in situ chemical polymerization. Surface topography and properties were characterized by scanning electron microscopy and infrared spectroscopy, respectively, indicating that the MnO₂/PPy composite is of a ‘mosaic‐like’ microstructure. The electrochemical performance and wettability of different kinds of anode were investigated respectively. Cyclic voltammetry and linear sweep voltammetry tests show that MnO₂/PPy composite‐modified electrode has a typical capacitance feature; its capacitance is 3.1 times higher than that of unmodified electrode. Contact angle of the composite‐modified anode reduces to 46 ± 0.5°, and its kinetic activity increased for more than 1.1 times. The maximum output power density of MnO₂/PPy composite‐modified cell reached 562.7 ± 10 mW m^?2, which is 2.1‐fold of the unmodified one. Finally, the composite‐modified anode provides an alternative potential choice for high‐performance cell, and the possible influence mechanism of composite materials on the BMFCs was also analyzed. Copyright © 2016 John Wiley & Sons, Ltd.     

Improvement of sediment microbial fuel cell performances by design and application of power management systems

One of the ways to generate clean and non-destructive energy is to use the energy stored in the biomass resources by the microbial fuel cells (MFCs). Sediment Microbial Fuel Cells (SMFCs) are a special type of MFCs that use organic materials in aquifers sediment to generate electricity. In this research, the effects of an increase in the electrode surface are investigated. The results showed that the increase in cathode electrode surface had better efficiency than the multi-cathode mode (maximum power generated for a 3-cathode electrode (27 cm³) and 1-cathode electrode (27 cm³) was 526 mW/cm² and 800 mW/cm², respectively. Another parameter affecting the performance of these systems is temperature. In the next step, the power generation rate was measured in different step currents and at different sample times. In the final stage, a power management system (PMS) was designed to optimally utilize the output energy of the improved SMFC, leading to an increase in the output voltage to 3.3 V.     

Enhanced performance of sediment microbial fuel cell by immobilization of Shewanella oneidensis MR-1 on an anode surface

The anodic microbial community especially relative abundance of exoelectrogens is crucial for performance enhancement of sediment microbial fuel cell (SMFC). In this study, Shewanella oneidensis MR-1 was immobilized on an active carbon fiber anode and the SMFC's performance was evaluated. The maximum power density of SMFC with immobilized strain MR-1 (SMFC-ImSW) displayed 61.0 mW/m², and SMFC with conventional bioaugmentation (SMFC-SW) and no treatment (SMFC-CK) of strain MR-1 obtained 11.1 and 2.4 mW/m², respectively. The chemical oxygen demand removal efficiency of SMFC-ImSW was 14.2% and 24.2% higher than SMFC-SW and SMFC-CK groups, respectively. Furthermore, the organics removal efficiencies of sediment were also increased in SMFC-Imsw. GFP-tagging and RT-PCR results showed that strain MR-1 was colonized on the anode biofilm of SMFC-ImSW. Cyclic voltammetry and Electrochemical impedance spectroscopy results showed that higher redox potential and charge transfer efficiency presented with immobilized strain MR-1. MiSeq sequencing results showed that Sphaerochaetaceae and Marinilabiaceae were also enriched on the anode biofilm, which are related to power generation. These results demonstrated that immobilized bioaugmentation is an ideal approach to improve SMFC performance.     

β-FeOOH modified carbon monolith anode derived from wax gourd for microbial fuel cells

The preparation of high-performance anode materials is of significance for enhanced power generation in microbial fuel cells (MFCs). Herein, porous carbon monolith was prepared by simple freeze drying of wax gourd and subsequent pyrolysis (WGC). β-FeOOH was coated on WGC to further improve the performance of the anode (β-FeOOH/WGC). The maximum power density of the MFCs with WGC and β-FeOOH/WGC anode was 913.9 and 1355.1 mW/m² respectively, which was much higher than that of the control (558.2 mW/m²). WGC possessed three-dimensional pore structure, nitrogen and oxygen-containing functional groups, which endowed it with satisfactory bacterial loading. Improved MFC performance after β-FeOOH modification could be ascribed to two aspects: β-FeOOH enhanced the electrochemical activity and decrease the transfer resistance; β-FeOOH was conducive to exoelectrogens formation. This study demonstrated that the synthesis of β-FeOOH modified carbon monolith anode offered an efficient route to enhance the power generation of MFCs.     

Electrooxidation study of pure ethanol/methanol and their mixture for the application in direct alcohol alkaline fuel cells (DAAFCs)

Aliphatic alcohol mainly, ethanol, methanol and their mixture were subjected to electrooxidation study using cyclic voltammetry (CV) technique in a three electrodes half cell assembly (PGSTAT204, Autolab Netherlands). A single cell set up of direct alcohol alkaline fuel cell (DAAFC) was fabricated using laboratory synthesized alkaline membrane to validate the CV results. The DAAFC conditions were kept similar as that of CV experiments. The anode and cathode electrocatalysts were Pt-Ru (30%:15% by wt.)/Carbon black (C) (Alfa Aesar, USA) and Pt (40% by wt.)/High Surface Area Carbon (C_HSA) (Alfa Aesar, USA) respectively. The CV and single cell experiments were performed at a temperature of 30 °C. The anode electrocatalyst was in the range of 0.5 mg/cm² to 1.5 mg/cm² for half cell CV analysis. The cell voltage and current density data were recorded for different concentrations of fuel (ethanol or methanol) and their mixture mixed with different concentration of KOH as electrolyte. The optimum electrocatalyst loading in half cell study was found to be 1 mg/cm² of Pt-Ru/C irrespective of fuel used. The single cell was tested using optimum anode loading of 1 mg/cm² of Pt-Ru/C which was found in CV experiment. Cathode loading was kept similar, in the order of 1 mg/cm² Pt/C_HSA. In single cell experiment, the maximum open circuit voltage (OCV) of 0.75 V and power density of 3.57 mW/cm² at a current density of 17.76 mA/cm² were obtained for the fuel of 2 M ethanol mixed with 1 M KOH. Whereas, maximum OCV of 0.62 V and power density of 7.10 mW/cm² at a current density of 23.53 mA/cm² were obtained for the fuel of 3 M methanol mixed with 6 M KOH. The mixture of methanol and ethanol (1:3) mixed with 0.5 M KOH produced the maximum OCV of 0.66 V and power density of 1.98 mW/cm² at a current density of 11.54 mA/cm².