• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.813-818
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• 2004

A systematic study of microbial fuel cells comprised of thermophilic Bacillus licheniformis and Bacillus thermoglucosidasius has been carried out under various operating conditions. Substantial amount of electricity was generated when a redox mediator was used. Being affected by operation temperature, the maximum efficiency was obtained at 50$^{\circ}C$ with an open circuit voltage of ca. 0.7 V. While a small change around the optimum temperature did not make much effect on the cell performance, the rapid decrease in performance was observed above 70$^{\circ}C$. It was noticeable that fuel cell efficiency and discharge pattern strongly depended on the kind of carbon sources used in the initial culture medium. In the case of B. thermoglucosidasius, glucose alone was utilized constitutively as a substrate in the microbial fuel cell irrespective of used carbons sources. When B. licheniformis was cultivated with lactose as a carbon source, best charging characteristics were recorded. Trehalose, in particular, showed 41.2% coulombic efficiency when B. thermoglucosidasius was cultured in a starch-containing medium. Relatively good repetitive operation was possible with B. thermoglucosidasius cells up to 12 cycles using glucose as a carbon source, when they were cultured with lactose as an initial carbon source. This study demonstrates that highly efficient thermophilic microbial fuel cells can be constructed by a pertinent modulation of the operating conditions and by carefully selecting carbon sources used in the initial culture medium.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.863-869
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• 2001

A systematic study of microbial fuel cells comprised of alkalophilic Bacillus sp. B-31 has been carried out under various operating conditions. A significant amount of electricity was generated when redox mediators were used. Among the phenothiazine-type redox dyes tested, azure A was found to be the most effective both in maintaining a high cell voltage and for the long-term operation. The maximum efficiency was and for the long-term operation. The maximum efficiency was obtained at ca. $50^{\circ}C$ giving an open circuit voltage of 0.7V. A small change in temperature did not significantly affect the cell performance, but a rapid decrease in performance was observed below $20^{\circ}C$ and above $70^{\circ}C$. It was noticeable that fuel cell efficiency and discharge pattern depended strongly on the carbon source used in the initial culture medium. Regardless of the initial carbon sources, only glucose and trehalose were utilized as substrates. Galactose, however, was not substantially utilized except when galactose was used in the initial medium. Glucose, in particular, showed $87\%$ coulombic efficiency, which was the highest value ever reported, when Bacillus sp. was cultured in a maltose-containing medium. This study demonstrates that highly efficient microbial fuel cells can be constructed with alkalophilic microorganisms by fine-tuning the operating conditions and by carefully selecting carbon sources in the initial culture medium.

• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.281-285
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• 2006

Microbial fuel cells (MFC) stacked with bipolar plates have been constructed and their performance was tested. In this design, single fuel cell unit was connected in series by bipolar plates where an anode and a cathode were made in one graphite block. Two types of bipolar plate stacked MFCs were constructed. Both utilized the same glucose oxidation reaction catalyzed by Gram negative bacteria, Proteus vulgaris as a biocatalyst in an anodic compartment, but two different cathodic reactions were employed: One with ferricyanide reduction and the other with oxygen reduction reactions. In both cases, the total voltage was the mathematical sum of individual fuel cells and no degradation in performance was found. Electricity from these MFCs was stored in a supercapacitor to drive external loads such as a motor and electric bulb.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3849-3850
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• 2011

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.101-111
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• 2021

To improve the potential of single chamber microbial fuel cells (SCMFCs) as an applicable technology, the main challenge is a practical application for larger scales bioenergy production from potent exoelectrogenic microorganism with real dairy wastewater. To increase power generation, three individual MFCs were together operated in series best under the fed batch condition for 15 days. The volume of MFC 1 and MFC 2 is "300 mL" and MFC 3 is "500 mL" respectively. The individual MFCs 1, MFC 2 and MFC 3 gives an open circuit voltage of 0.60 V, 0.66 V and 0.55 V and result in total working voltage when connected in series of 1.745V, which lead an LED to glow. The maximum power densities obtained from MFC 1, MFC 2 and MFC 3 are 62 mW/㎡, 50 mW/㎡ and 45 mW/㎡ (normalized to the surface area of the anodic electrode, which was 50 ㎠ for all three MFCs), and corresponding to current densities of 141 mA/㎡, 155 mA/㎡ and 123 mA/㎡, respectively. Therefore this work suggests the cheapest way to connect microbial fuel cells in series to gain power with the lowest operating cost and chemical oxygen demand (COD) removal.

• Journal of Environmental Science International
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• v.28 no.2
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• pp.219-224
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• 2019

In this study, we evaluated the energy production from plant-microbial fuel cells using representative indoor plants, such as Scindapsus aureus and Clatha minor. The maximum power density of microbial fuel cell (MFC) using S. aureus ($3.36mW/m^2$) was about 2 times higher than that of the MFC using C. minor ($1.43mW/m^2$). It was confirmed that energy recovery is possible using plant-MFCs without fuel. However, further research is needed to improve the performance of plant-MFCs. Nevertheless, plant-MFCs have proved their potential as a novel energy source to overcome the limitations of the conventional renewable energy sources such as wind power and solar cells, and could be employed to a power source for the sensor in charge of the fourth industrial revolution.

• Environmental Engineering Research
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• v.13 no.2
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• pp.51-65
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• 2008

The increasing demand for energy in the near future has created strong motivation for environmentally clean alternative energy resources. Microbial fuel cells (MFCs) have opened up new ways of utilizing renewable energy sources. MFCs are devices that convert the chemical energy in the organic compounds to electrical energy through microbial catalysis at the anode under anaerobic conditions, and the reduction of a terminal electron acceptor, most preferentially oxygen, at the cathode. Due to the rapid advances in MFC-based technology over the last decade, the currently achievable MFC power production has increased by several orders of magnitude, and niche applications have been extended into a variety of areas. Newly emerging concepts with alternative materials for electrodes and catalysts as well as innovative designs have made MFCs promising technologies. Aerobic bacteria can also be used as cathode catalysts. This is an encouraging finding because not only biofouling on the cathode is unavoidable in the prolonged-run MFCs but also noble catalysts can be substituted with aerobic bacteria. This article discusses some of the recent advances in MFCs with an emphasis on the performance, materials, microbial community structures and applications beyond electricity generation.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2401-2404
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• 2012

• Journal of Environmental Health Sciences
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• v.38 no.2
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• pp.83-94
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• 2012

The research on microbial fuel cells (MFCs) needs various knowledge of different fields such as electrochemistry, microbiology, environmental engineering, and material engineering. Although electrochemically active bacteria are very diverse, the performance of MFCs is affected primarily by the structure of the reactor system. Thus, the development in the system architecture is critical to lower internal resistance and increase power generation for commercialization. This paper summarizes the principles of MFCs and demonstrates the infinite potential of MFCs in various applications including wastewater treatment, biosensors, biohydrogen production, remote power sources, implantable medical devices, etc.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3649-3653
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• 2013

As anode fabrication with different materials has been proven to be a successful alternative for enhancing power generation in the microbial fuel cells, a new approach to improved performance of MFCs with the use of menadione/carbon powder composite-modified carbon cloth anode has been explored in this study. Menadione has formal potential to easily accept electrons from the outer membrane cytochromes of electroactive bacteria that can directly interact with the solid surface. Surface bound menadione was able to maintain an electrical wiring with the trans-membrane electron transfer pathways to facilitate extracellular electron transfer to the electrode. In a single chamber air cathode MFC inoculated with aerobic sludge, maximum power density of $1250{\pm}35mWm^{-2}$ was achieved, which was 25% higher than that of an unmodified anode. The observed high power density and improved coulomb efficiency of 61% were ascribed to the efficient electron shuttling via the immobilized menadione.