Douglas Call, Bruce E. Logan

Environmental Science & Technology • 2008

Hydrogen gas can be produced by electrohydrogenesis in microbial electrolysis cells (MECs) at greater yields than fermentation and at greater energy efficiencies than water electrolysis. It has been assumed that a membrane is needed in an MEC to avoid hydrogen losses due to bacterial consumption of the product gas. However, high cathodic hydrogen recoveries (78 +/- 1% to 96 +/- 1%) were achieved in an MEC despite the absence of a membrane between the electrodes (applied voltages of 0.3 < E(ap) < 0.8 V; 7.5 mS/cm solution conductivity). Through the use of a membrane-less system, a graphite fiber brush anode, and close electrode spacing, hydrogen production rates reached a maximum of 3.12 +/- 0.02 m3 H2/m3 reactor per day (292 +/- 1 A/m3) at an applied voltage of E(ap) = 0.8 V. This production rate is more than double that obtained in previous MEC studies. The energy efficiency relative to the electrical input decreased with applied voltage from 406 +/- 6% (E(ap) = 0.3 V) to 194 +/- 2% (E(ap) = 0.8 V). Overall energy efficiency relative to both E(ap) and energy of the substrate averaged 78 +/- 4%, with a maximum of 86 +/- 2% (1.02 +/- 0.05 m3 H2/m3 day, E(ap) = 0.4 V). At E(ap) = 0.2 V, the hydrogen recovery substantially decreased, and methane concentrations increased from an average of 1.9 +/- 1.3% (E(ap) = 0.3-0.8 V) to 28 +/- 0% of the gas, due to the long cycle time of the reactor. Increasing the solution conductivity to 20 mS/ cm increased hydrogen production rates for E(ap) = 0.3-0.6 V, but consistent reactor performance could not be obtained in the high conductivity solution at E(ap) > 0.6 V. These results demonstrate that high hydrogen recovery and production rates are possible in a single chamber MEC without a membrane, potentially reducing the costs of these systems and allowing for new and simpler designs.

J. Mieke Kleijn, Quentin Lhuillier, Adriaan W. Jeremiasse

Bioelectrochemistry • 2010

Aijie Wang, Wenzong Liu, Nanqi Ren et al.

International Journal of Hydrogen Energy • 2010

Adriaan W. Jeremiasse, Hubertus V.M. Hamelers, Cees J.N. Buisman

Bioelectrochemistry • 2010

This study demonstrates, for the first time, the proof-of-principle of an MEC in which both the anodic and cathodic reaction are catalyzed by microorganisms. No expensive chemical catalysts, such as platinum, are needed. Two of these MECs were simultaneously operated and reached a maximum of 1.4 A/m(2) at an applied cell voltage of 0.5 V. At a cathode potential of -0.7 V, the biocathode in the MECs had a higher current density (MEC 1: 1.9 A/m(2), MEC 2: 3.3 A/m(2)) than a control cathode (0.3 A/m(2), graphite felt without biofilm) in an electrochemical half cell. This indicates that hydrogen production is catalyzed at the biocathode, likely by electrochemically active microorganisms. The cathodic hydrogen recovery was 17% for MEC 1 and 21% for MEC 2. Hydrogen losses were ascribed to diffusion through membrane and tubing, and methane formation. After 1600 h of operation, the current density of the MECs had decreased to 0.6 A/m(2), probably caused by precipitation of calcium phosphate on the biocathode. The slow deteriorating effect of calcium phosphate, and the production of methane show the importance of studying the combination of bioanode and biocathode in one electrochemical cell, and of studying long term performance of such an MEC.

O. Modin, K. Fukushi, K. Rabaey et al.

Proceedings of the Water Environment Federation • 2009

Xueyan Zhao, Hongfei Jia, Jungbae Kim et al.

Biotechnology and Bioengineering • 2009

Abstract Carbon nanotubes (CNTs) have been used for various bioelectrochemical applications, presumably for substantial improvement in performance. However, often only moderate results observed, with many governing factors have been considered and suggested yet without much systematic evaluation and verification. In this study, CNT‐supported glucose oxidase (CNT–GOx) was examined in the presence of 1,4‐benzoquinone (BQ). The intrinsic Michaelis parameters of the reaction catalyzed by CNT–GOx were found very close to those of native GOx. However, the Nafion entrapment of CNT–GOx for an electrode resulted in a much lower activity due to the limited availability of the embedded enzyme. Interestingly, kinetic studies revealed that the biofuel cell employing such an enzyme electrode only generated a power density equivalent to <40% of the reaction capability of the enzyme on electrode. It appeared to us that factors such as electron and proton transfer resistances can be more overwhelming than the heterogeneous reaction kinetics in limiting the power generation of such biofuel cells. Biotechnol. Bioeng. 2009; 104: 1068–1074. © 2009 Wiley Periodicals, Inc.

Arvind Venkataraman, Miriam Rosenbaum, Jan B.A. Arends et al.

Electrochemistry Communications • 2010

Rachel C. Wagner, Douglas F. Call, Bruce E. Logan

Environmental Science & Technology • 2010

A. Berná, A. Esteve-Nuñez, F.D.A. Moreno-Garzón et al.

New Biotechnology • 2009

Falk Harnisch, Uwe Schröder

Chemical Society Reviews • 2009

Falk Harnisch, Uwe Schroeder

ChemInform • 2010

Abstract Review: 91 refs.

Seiya Tsujimura, Akira Wadano, Kenji Kano et al.

Enzyme and Microbial Technology • 2001

Falk Harnisch, Robert Warmbier, Ralf Schneider et al.

Bioelectrochemistry • 2009

Masaki Torimura, Hideto Yoshida, Kenji Kano et al.

Journal of Molecular Catalysis B: Enzymatic • 2000

I. Roche, K. Katuri, K. Scott

Journal of Applied Electrochemistry • 2009

Suzanne T Read, Paritam Dutta, Phillip L Bond et al.

BMC Microbiology • 2010

Abstract Background Microbial fuel cells (MFCs) rely on electrochemically active bacteria to capture the chemical energy contained in organics and convert it to electrical energy. Bacteria develop biofilms on the MFC electrodes, allowing considerable conversion capacity and opportunities for extracellular electron transfer (EET). The present knowledge on EET is centred around two Gram-negative models, i.e. Shewanella and Geobacter species, as it is believed that Gram-positives cannot perform EET by themselves as the Gram-negatives can. To understand how bacteria form biofilms within MFCs and how their development, structure and viability affects electron transfer, we performed pure and co-culture experiments. Results Biofilm viability was maintained highest nearer the anode during closed circuit operation (current flowing), in contrast to when the anode was in open circuit (soluble electron acceptor) where viability was highest on top of the biofilm, furthest from the anode. Closed circuit anode Pseudomonas aeruginosa biofilms were considerably thinner compared to the open circuit anode (30 ± 3 μm and 42 ± 3 μm respectively), which is likely due to the higher energetic gain of soluble electron acceptors used. The two Gram-positive bacteria used only provided a fraction of current produced by the Gram-negative organisms. Power output of co-cultures Gram-positive Enterococcus faecium and either Gram-negative organisms, increased by 30-70% relative to the single cultures. Over time the co-culture biofilms segregated, in particular, Pseudomonas aeruginosa creating towers piercing through a thin, uniform layer of Enterococcus faecium. P. aeruginosa and E. faecium together generated a current of 1.8 ± 0.4 mA while alone they produced 0.9 ± 0.01 and 0.2 ± 0.05 mA respectively. Conclusion We postulate that this segregation may be an essential difference in strategy for electron transfer and substrate capture between the Gram-negative and the Gram-positive bacteria used here.

Aswin K. Manohar, Orianna Bretschger, Kenneth H. Nealson et al.

Electrochimica Acta • 2008

Eileen HaoYu, Shaoan Cheng, Keith Scott et al.

Journal of Power Sources • 2007

Maria Smolander, Harry Boer, Matti Valkiainen et al.

Enzyme and Microbial Technology • 2008

Guo-Wei Chen, Soo-Jung Choi, Tae-Ho Lee et al.

Applied Microbiology and Biotechnology • 2008

Olivier Schaetzle, Frédéric Barrière, Uwe Schröder

Energy Environ. Sci. • 2008

X. Wang, Y. J. Feng, H. Lee

Water Science and Technology • 2008

The performance of electricity production from beer brewery wastewater in a single chamber membrane-free microbial fuel cell (MFC) was investigated. Experimental results showed that the MFCs could generate electricity from full-strength wastewater (2,239 mg-COD/L, 50 mM PBS added) with the maximum power density of 483 mW/m2 (12 W/m3) at 30°C and 435 mW/m2 (11 W/m3) at 20°C, respectively. Temperature was found to have bigger impact on cathode potential than anode potential. Results suggested that it is feasible to generate electricity with the treatment of beer brewery wastewater.

J NIESSEN, U SCHRODER, F SCHOLZ

Electrochemistry Communications • 2004

Justin Biffinger, Ricky Ray, Brenda Little et al.

ECS Meeting Abstracts • 2006

Abstract not Available.

Shun'ichi Ishii, Takefumi Shimoyama, Yasuaki Hotta et al.

BMC Microbiology • 2008

Abstract Background Microbial fuel cells (MFCs) are devices that exploit microorganisms to generate electric power from organic matter. Despite the development of efficient MFC reactors, the microbiology of electricity generation remains to be sufficiently understood. Results A laboratory-scale two-chamber microbial fuel cell (MFC) was inoculated with rice paddy field soil and fed cellulose as the carbon and energy source. Electricity-generating microorganisms were enriched by subculturing biofilms that attached onto anode electrodes. An electric current of 0.2 mA was generated from the first enrichment culture, and ratios of the major metabolites (e.g., electric current, methane and acetate) became stable after the forth enrichment. In order to investigate the electrogenic microbial community in the anode biofilm, it was morphologically analyzed by electron microscopy, and community members were phylogenetically identified by 16S rRNA gene clone-library analyses. Electron microscopy revealed that filamentous cells and rod-shaped cells with prosthecae-like filamentous appendages were abundantly present in the biofilm. Filamentous cells and appendages were interconnected via thin filaments. The clone library analyses frequently detected phylotypes affiliated with Clostridiales , Chloroflexi , Rhizobiales and Methanobacterium . Fluorescence in-situ hybridization revealed that the Rhizobiales population represented rod-shaped cells with filamentous appendages and constituted over 30% of the total population. Conclusion Bacteria affiliated with the Rhizobiales constituted the major population in the cellulose-fed MFC and exhibited unique morphology with filamentous appendages. They are considered to play important roles in the cellulose-degrading electrogenic community.

Daniel Aguirre de Cárcer, Phuc Thi Ha, Jae Kyung Jang et al.

Applied Microbiology and Biotechnology • 2010

Ashley E Franks, Nikhil Malvankar, Kelly P Nevin

Biofuels • 2010

T.T. More, M.M. Ghangrekar

Bioresource Technology • 2009

Effect of low-frequency ultrasound pre-treatment to inoculum on performance of microbial fuel cell (MFC) was evaluated. Mixed anaerobic sludge was pre-treated with ultrasonication duration of 2.5, 5, 7.5, and 15 min, and the performance of MFC using this inoculum was compared with the MFC inoculated without any pre-treatment to the sludge. The effect of combined pre-treatment, using ultrasonication and heating of the inoculum, on performance of the MFC was also evaluated. Maximum power density during polarization in a MFC inoculated with ultrasonication pre-treatment to the sludge for 5 min (40 kHz, 120 W) was 2.5 times higher than that obtained without any pre-treatment to the inoculum sludge. Substrate removal was higher in the MFC with ultrasonicated inoculum, than inoculum without any pre-treatment and combined pre-treated with ultrasonication and heating. These results evidently demonstrated the advantages of ultrasonication pre-treatment to the inoculum for enhancing power and organic matter removal of the MFC.

V. Fedorovich, S. D. Varfolomeev, A. Sizov et al.

Water Science and Technology • 2009

A plug flow multi-electrode bioelectrochemical reactor for wastewater treatment and simultaneous generation of electricity has been developed and its efficiency investigated. It employs a horizontally located anodic zone in which the anodic electrodes comprise porous graphite plates coated with palladium. The aerated immersed cathodic electrodes contain iron(II) phthalocyanine as a catalyst. The parameters of the device were obtained using glycerol and acetate as fuels and anaerobic sludge as an inoculum. The maximal volumetric power and current densities obtained, relative to the total volume of the anodic zone, were: glycerol: 73±1 mA/L; 43±1 mW/L; acetate: 75±1 mA/L; 40±1 mW/L. It was shown that biotransformation of glycerol into volatile fatty acids does not depend on the presence of anodic electrodes in the reaction zone, while acetate degradation takes place only if the reaction zone contains anodic electrodes as a final electron acceptor.

Vinay Sharma, P.P. Kundu

Enzyme and Microbial Technology • 2010

Bin Wang, Jong-In Han

Biotechnology Letters • 2008

K. Scott, C. Murano, G. Rimbu

Journal of Applied Electrochemistry • 2007

Hai The Pham, Nico Boon, Peter Aelterman et al.

Microbial Biotechnology • 2008

Summary In many microbial bioreactors, high shear rates result in strong attachment of microbes and dense biofilms. In this study, high shear rates were applied to enrich an anodophilic microbial consortium in a microbial fuel cell (MFC). Enrichment at a shear rate of about 120 s −1 resulted in the production of a current and power output two to three times higher than those in the case of low shear rates (around 0.3 s −1 ). Biomass and biofilm analyses showed that the anodic biofilm from the MFC enriched under high shear rate conditions, in comparison with that under low shear rate conditions, had a doubled average thickness and the biomass density increased with a factor 5. The microbial community of the former, as analysed by DGGE, was significantly different from that of the latter. The results showed that enrichment by applying high shear rates in an MFC can result in a specific electrochemically active biofilm that is thicker and denser and attaches better, and hence has a better performance.

S.‐J. You, N.‐Q. Ren, Q.‐L. Zhao et al.

Fuel Cells • 2009

Abstract To improve cathodic efficiency and sustainability of microbial fuel cell (MFC), graphite fibre brush (GFB) was examined as cathode material for power production in biocatalysed‐cathode MFC. Following 133‐h mixed culturing of electricity‐producing bacteria, the MFC could generate a reproducible voltage of 0.4 V at external resistance ( R EX ) of 100 Ω. Maximum volumetric power density of 68.4 W m –3 was obtained at a current density of 178.6 A m –3 . Upon aerobic inoculation of electrochemically active bacteria, charge transfer resistance of the cathode was decreased from 188 to 17 Ω as indicated by electrochemical impedance spectroscopy (EIS) analysis. Comparing investigations of different cathode materials demonstrated that biocatalysed GFB had better performance in terms of half‐cell polarisation, power and Coulombic efficiency (CE) over other tested materials. Additionally, pH deviation of electrolyte in anode and cathode was also observed. This study provides a demonstration of GFB used as biocathode material in MFC for more efficient and sustainable electricity recovery from organic substances.

Naroa Uría, David Sánchez, Roser Mas et al.

Procedia Engineering • 2009

Kyungmi Chung, Satoshi Okabe

Applied Microbiology and Biotechnology • 2009

Lewis Hsu, Orianna Bretschger, Kenneth Nealson et al.

ECS Meeting Abstracts • 2008

Abstract not Available.

Youngjin Choi, Eunkyoung Jung, Sunghyun Kim et al.

Bioelectrochemistry • 2003

A study has been performed to examine the effect of temperature and ethanolic stresses on the coulombic efficiency of a microbial fuel cell. The conventional-type fuel cell containing Gram-negative bacteria, Proteus vulgaris, was investigated as a model system. From current output measurements, it was found that the coulombic yields were altered by environmental stresses such as temperature shock or ethanol treatment to the bacteria. While high-temperature or ethanolic shock led to a remarkable decrement in coulombic output, the low-temperature shock induced a slight increase in microbial fuel cell efficiency. These results indicate that the membrane fluidity is affected considerably by environmental stress, which in turn affects the electron transfer process through the bacterial cell membrane to and from the electrode. This interpretation was confirmed by the cyclic voltammetric study of a mediator on an electrode surface modified with the lipids extracted from the membrane of P. vulgaris under the given stress. Markedly different electrochemical behaviors were observed depending on the environmental stress. A reciprocal relationship between coulomb output and the ratio of saturation/unsaturation of fatty acids has been observed. This is the first report, to our knowledge, that the structural adaptation of membrane fatty acids in response to the environmental shock can regulate the coulombic efficiency of a microbial fuel cell.

Hyung Joo Kim, Hyung Soo Park, Moon Sik Hyun et al.

Enzyme and Microbial Technology • 2002

R. Ganguli, B. S. Dunn

Fuel Cells • 2009

Abstract Chronoamperometric investigations with rotating disc electrodes (RDEs) were used to characterise the anodic half‐cell of yeast powered microbial fuel cells using methylene blue (MB) as a mediator. Both convection and mediator adsorption were shown to affect the anodic current. A microbe–mediator limited reaction model was developed and shown to agree well with the experimental data. A power density of ∼150 μW cm –2 was achieved in a full cell, which represented a significant increase from prior reports on yeast‐catalysed fuel cells. The increased power density was enabled by using high mediator concentrations and by controlling the mediator adsorption.