微生物燃料电池空气阴极和扩大化的研究进展

分别从空气阴极材料和阴极构造的角度对空气阴极微生物燃料电池的研究进展进行了综述,并讨论了扩大化MFC的研究进展。     

空气阴极微生物燃料电池研究进展

微生物燃料电池（MFC）是一种利用微生物做催化剂,处理废水的同时能产电的新型污水处理技术,因其＂变废为宝＂的能力而得到快速的发展。其中,以空气做阴极的单室MFC,因其省却了不断添加阴极液的过程、提高功率输出的同时降低成本而受到越来越多的关注。单室MFC装置可以分为管状、立方体状和短臂型结构,空气阴极的结构组成包括膜、催化层、集电材料、基层和扩散层。膜和催化层通常用热压法进行结合。目前报道的研究结果表明,有扩散层时获得的功率密度更高。已研究的扩散层的粘结剂有PTEF、PDMS、EF以及Nafion。选择合适的构型、催化剂以及扩散层的层数和粘结剂对改善电池产电性能极为重要。如何将多个装置串联以扩大废水处理量、提高功率密度的同时提高电子回收率是需要进一步解决的问题。     

厌氧流化床微生物燃料电池空气阴极研究

流化床微生物燃料电池(AFBMFC)的阴极导电性和催化剂性能是影响微生物燃料电池产电性能的重要因素。本文首先在阴极负载少量银研究其对AFBMFC产电性能的影响。其次,制备四种铂钴合金催化剂,考察了催化剂对AFBMFC产电性能的影响。研究表明,阴极碳基层负载少量的银可以显著改善AFBMFC的产电性能,银负载量为0.7 mg·cm^-2时AFBMFC最大输出电压和输出功率密度分别为纯碳基层阴极的154%和330%。600℃比950℃制备的PtCo合金催化剂有较好的催化性能,在保证催化剂总量不变的情况下,铂用量为原来的50%,AFBMFC产电性能仍有较大幅度的提高。     

微生物燃料电池MnO2/S-AC泡沫镍空气阴极的制备及其性能

利用超级电容器活性炭(S-AC)直接还原KMnO₄制备出复合比例分别为1:3、1:1和3:1的MnO₂/S-AC复合催化剂, 进而负载于泡沫镍上制得MnO₂/S-AC泡沫镍空气阴极。通过X射线衍射(XRD)、扫描电镜(SEM)、能量散射X 射线谱(EDX)和比表面积(BET)及孔分布测试对所制复合催化剂表征可知, 随复合比例的增加, 在S-AC表面的MnO₂由纳米薄片聚集成粒径为300～500 nm的颗粒, MnO₂/S-AC的内部及外部表面积都有所减少。基于线性扫描伏安曲线、功率密度曲线和极化曲线分析微生物燃料电池(MFC)的阴极性能和产电性能。复合比例为1:3时, MFC最大功率密度达到321.2 mW·m^-2, 比阴极负载S-AC时提高了约20%, 这与其较高的比表面积和MnO₂良好的催化活性相关。MnO₂/S-AC复合催化剂控制在一定的质量比时, 可以有效提高阴极性能及MFC的产电效果, 有助于空气阴极MFC的的放大和工程应用。     

空气阴极微生物燃料电池处理生活污水产电特性研究

采用空气阴极微生物燃料电池,处理主要成分为葡萄糖、乙酸钠、蛋白胨和可溶性淀粉的模拟生活污水,探讨MFC处理模拟生活污水的特性。文章探讨了模拟污水不同浓度对产电的影响,结果表明不同的基质浓度对产电效率影响不是非常显著,MFC最大输出功率为23.67 mW·m-2,COD最大去除率为88%。以不完全复合碳源和单一碳源为基质,探讨了接种混合菌的MFC对基质的选择性。试验结果表明乙酸钠、葡萄糖对接种混合菌的MFC产电不利,MFC处理复杂有机碳源(蛋白胨、淀粉)的产电效率优于处理简单分子有机碳源(葡萄糖、乙酸钠)。试验讨论了硼砂缓冲液对产电的影响,50 mmol·L-1的硼砂缓冲液输出功率密度最大,最大功率为19.77 mW·m-2,COD最大处理率为72%。与投加PBS缓冲液相比,硼砂缓冲液调节阳极电解液效果不佳,硼砂缓冲液出水pH为7.73,且在产电密度方面有微小的下降,但在同等基质浓度的生活污水时电池的库仑效率提高约2倍。     

同步废水处理和产能的上流式空气阴极生物燃料电池

以活性炭颗粒为阳极,气体电极为阴极,葡萄糖模拟废水为基质构建了上流式直接空气阴极单室生物燃料电池(UACMFC),在连续运行条件下考察了电池的产电性能和水力停留时间(HRT)对电池性能的影响.结果表明,UACMFC具有较好的产电能力和稳定性,在外阻为9 000 Ω条件下,最大输出电压为0.915 V.HRT对生物燃料电池的产电性能和COD的去除效果均有影响,水力停留时间为8 h时,电池的最大输出功率密度为44.3 W·m-3(废水),COD去除率为45%.     

微生物燃料电池阴极系统的研究进展

微生物燃料电池,简称MFCs,其阴极系统通常由电极材料、催化剂、电子受体和阴极室等组成。MFCs阴极是电子受体进行还原反应的场所,是影响MFCs性能的重要因素,决定了反应器的经济性和持久性。文章根据MFCs阴极系统的构造,综述了阴极的材料、催化剂、电子受体以及构型在国内外的最新研究进展,指出了当前MFCs阴极设计存在的问题和今后MFCs研究努力的方向。     

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。     

微生物燃料电池阴极催化剂研究进展

针对微生物燃料电池中铂碳阴极催化剂的局限性,阐述了新材料催化剂的研究进展,列举了多种催化剂均表现出了良好的ORR性能,且成本低廉,解决了Pt/C阴极价格昂贵的问题,使微生物燃料电池的推广应用成为可能。     

活性炭修饰微生物燃料电池阳极的研究

利用活性炭修饰碳布作为微生物燃料电池阳极,并与多壁碳纳米管修饰的阳极和未修饰的碳布进行了的比较。结果表明,装配活性炭修饰碳布阳极运行的微生物燃料电池获得的最大功率密度为510 mW/m2,相较于多壁碳纳米管修饰的阳极和未修饰的碳布阳极分别提升了7%和54.5%。电极的电化学性质利用循环伏安法(CV)和交流阻抗谱(EIS)测试表明,活性炭修饰碳布具有良好的电化学特性。     

Dual functions of activated carbon air-cathode: Nitrobenzene removal and electricity production in microbial fuel cells

The removal of nitrobenzene (NB) in microbial electrochemical systems generally requires electrical power to operate systems in the mode of microbial electrolysis cells (MECs). The present study demonstrates that single-chamber microbial fuel cells (S-MFCs) assembled with a bioanode and an activated carbon (AC) air cathode could simultaneously remove NB and generate electricity. S-MFCs with 1 mM NB exhibit long term NB tolerance and stable electricity production, with NB removal up to 98% in an operation cycle and a maximum power of 16.2 ± 1.3 W m⁻³. High NB loadings significantly inhibited the activity of anodic biofilms, but the inhibition was reversible. Investigating the removal of NB and its reduction product aniline (AN) in different operations supported the fact that the adsorption at the AC air cathode is the main pathway for the removal of NB and AN from solution, except for the partial conversion of NB to AN by anaerobic reduction in solution. In S-MFCs, the activated carbon in the cathode plays both functions: catalyzing the oxygen reduction reaction and adsorbing NB and AN, so that the S-MFC assembled with the AC air cathode, unlike most NB removing MECs, functions as a system with both NB removal and electricity production.     

Silver–carbon electrocatalyst for air cathodes in alkaline fuel cells

A method for producing electrocatalysts containing silver supported on different carbons was developed. The catalysts were investigated in air (oxygen) diffusion electrodes in alkaline electrolyte (7 M KOH). Depending on the carbon support used, up to a threefold improvement in electrode performance was achieved compared with the activity of the uncatalysed carbon in this media. At ambient temperature and atmospheric pressure, a current density of 150 mA/cm^–2 was obtained at electrode potential 1.2 V vs zinc (0.75 vs HE). A correlation between electro catalytic activity and wetted surface area of the electrocatalysts was found.     

利用生物活性炭提高微生物燃料电池产电性能

通过比较三组微生物燃料电池（MFC）的产电性能,考察使用生物活性炭（BAC）对提高MFC产电性能所起的作用。它们分别是：在阳极室内未投加活性炭的、投加了柱状活性炭的和投加了小颗粒活性炭的3种MFC。投加时机是在电池启动阶段,此时微生物在活性炭上驯化出生物膜,即形成生物活性炭,目的是辅助阳极富集更多微生物。结果表明,投加了小颗粒活性炭的MFC在产电性能和污水处理上具有优势。该电池最大容积功率密度达到1540 mW/m³ ,COD去除率达到了88%。     

Effect of graphite felt and activated carbon fiber felt on performance of freshwater sediment microbial fuel cell

BACKGROUND: Sediment microbial fuel cells (SMFCs) could be used as power sources and one type of new technology for the removal of organic matters in sediments. Various types of materials have been used as electrodes. Nevertheless, there is still room to improve electrode materials and enhance their effect on the performance of SMFCs. In this work, performances of SMFCs with activated carbon fiber felt (ACFF) and with nitric acid‐treated ACFF were compared with graphite felt (GF) materials. RESULTS: The maximum power density of the SMFC with ACFF electrode was the highest (33.5 ± 1.5 mW m^?2). Nitric acid‐treated GF electrode slightly increased the maximum power density of SMFC, while the nitric acid treated‐ACFF resulted in significant decline in the maximum power density of SMFC. The maximum power density further increased to 74.5 ± 7.5 mW m^?2 in SMFC using GF cathode and ACFF anode. CONCLUSIONS: ACFF as anode can enhance the transport of electrons from the oxidation of organic matter in the sediment, while the output power was found to reduce in SMFC with ACFF cathode. Further efforts are needed to study the formation conditions of the biocathode and new electrode modification technology. Copyright © 2012 Society of Chemical Industry     

Use of novel permeable membrane and air cathodes in acetate microbial fuel cells

In the existing microbial fuel cells (MFCs), the use of platinized electrodes and Nafion^® as proton exchange membrane (PEM) leads to high costs leading to a burden for wastewater treatment. In the present study, two different novel electrode materials are reported which can replace conventional platinized electrodes and can be used as very efficient oxygen reducing cathodes. Further, a novel membrane which can be used as an ion permeable membrane (Zirfon^®) can replace Nafion^® as the membrane of choice in MFCs. The above mentioned gas porous electrodes were first tested in an electrochemical half cell configuration for their ability to reduce oxygen and later in a full MFC set up. It was observed that these non-platinized air electrodes perform very well in the presence of acetate under MFC conditions (pH 7, room temperature) for oxygen reduction. Current densities of −0.43 mA cm⁻² for a non-platinized graphite electrode and −0.6 mA cm⁻² for a non-platinized activated charcoal electrode at −200 mV vs. Ag/AgCl of applied potential were obtained. The proposed ion permeable membrane, Zirfon^® was tested for its oxygen mass transfer coefficient, K₀ which was compared with Nafion^®. The K₀ for Zirfon^® was calculated as 1.9 × 10⁻³ cm s⁻¹.     

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。     

Microbial fuel cells operated with iron-chelated air cathodes

The use of non-noble metal-based cathodes can enhance the sustainability of microbial fuel cells (MFCs). We demonstrated that an iron-chelated complex could effectively be used as an aerated catholyte or as an iron-chelated open air cathode to generate current with the use of MFCs. An aerated iron ethylenediaminetetraacetic acid (Fe-EDTA) catholyte generated a maximum current of 34.4 mA and a maximum power density of 22.9 W m⁻³ total anode compartment (TAC). Compared to a MFC with a hexacyanoferrate catholyte, the maximum current was similar but the maximum power was 50% lower. However, no replenishment of the Fe-EDTA catholyte was needed. The creation of an activated carbon cloth open air cathode with Fe-EDTA–polytetrafluoroethylene (PTFE) applied to it increased the maximum power density to 40.3 W m⁻³ TAC and generated a stable current of 12.9 mA (at 300 mV). It was observed that the ohmic loss of an open air cathode MFC was dependent on the type of membrane used. Moreover, increasing the anode electrode thickness of an open air cathode MFC from 1.5 to 7.5 cm, resulted in a lowering of the power and current density.     

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。