Ibdal Satar, Adi Permadi, Sukma Latifatunnajib

ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) • 2021

Microbial fuel cell consisting two main components which are anode and cathode materials. In the microbial fuel cell, both anode and cathode compartments are separated with a separator. Anode generates the protons and electrons while cathode converts protons into water with the presence electrons and oxygen. During the Microbial fuel cell operation, the performance of anode is very crucial due to it provides the protons and electrons. Hence, the high efficiency microbial fuel cell is very related with the high anode performance. This work addressed to the enrichment process of electroactive bacteria (EAB) in anode of microbial fuel cell. In this work, some parameters such as current generations, , and pH changes were used to assess the enrichment process of EAB was reached. In addition, the presence of EAB on the anode surface was identified based on the morphology of anode surface. The removal of COD and the pH value were determined by using the American public health analysis method and pH tester, respectively. The morphology of anode surface was analysed by using a scanning electron microscope. Whereas, current generation was tested by using a mustimeter. The removal of COD and final pH were obtained 71.4 % and 5.7, respectively. The optimum current generation was observed 0.19 mA. The surface morphology of anode before enriched with microbes was clear surface, while after enriched with microbes was attached by microbes. The removal of COD, pH changes, current generation and morphology of anode surface could be used to assess the EAB in the anode compartment. 
 Keywords: Microbial fuel cell; anode; cathode; electroactive bacteria; pH changes.

A. Phillips, M. Ulsh, J. Porter et al.

Fuel Cells • 2017

Abstract An understanding of the impact of coating irregularities on beginning of life polymer electrolyte fuel cell (PEMFC) performance is essential to develop and establish manufacturing tolerances for its components. Coating irregularities occurring in the fuel cell electrode can either possess acceptable process variations or potentially harmful defects. A segmented fuel cell (SFC) is employed to understand how 100% catalyst reduction irregularities ranging from 0.125 to 1 cm 2 in the cathode electrode of a 50 cm 2 sized cell impact spatial and total cell performance at dry and wet humidification conditions. By analyzing the data in a differential format the local performance effects of irregularity sizes down to 0.25 cm 2 were detected in the current distribution of the cell. Slight total cell performance impacts, due to irregularity sizes of 0.5 and 1 cm 2 , were observed under dry operation and high current densities.

Piyarut Moonsri, Wilaiporn Pongpian, Prayak Juantrong

Applied Mechanics and Materials • 2016

This research studied the electricity production from organic wastes fermentation by microbial fuel cell by using a single chamber microbial fuel cell (SCMFC). Two sizes (1 L and 10 L) of simple SCMFC were fabricated by using a cylindrical plastic tank which anode compartment and cathode compartment separated by plastic plate with hole and covered with cotton fabric. The anode electrode contacted with organic matter and microorganisms where anaerobic reaction occurred to generate electron and proton. The electrons transferred through an external circuit while the protons diffused through the solution to the cathode electrode for reducing oxygen to water. From the study of the effect of different electrode types (carbon graphite rod, zinc metal, and copper metal) to the electricity generation using the SCMFC size 1 L in fermentation with synthetic sweetness solution (22%Brix) and the effective microorganism (EM) for 36 hrs, it found that the fuel cell which used copper metal as electrode produced electricity increasing over the times and has more efficient than the other electrode types. The study of electricity generation from organic waste fermentation by using the SCMFC size 10 L and using copper metal as electrode, the results showed that the fermentation of pineapple waste produced the current density, potential density, and power density higher than the fermentation of bananas and the fermentation of food garbage with EM. An optimal period of time for the production of electricity from this microbial fuel cell is the first five days of fermentation that the cells has voltage »500 mV, the current density 25.52 mA m -2 , potential density 104.69 V m -2 and power density 12.59 mW m -2 , and then decline over time five days (120 hrs). Moreover the bio-liquid fertilizer and the residues from the fermentation can be further used in agricultural because of the nutrient content (N, P, K), organic carbon and organic material contents available.

H. N. Su, S. J. Liao, L. M. Xu

Fuel Cells • 2009

Abstract A novel micro planar fuel cell power supplier, in which a six‐cell PEM unitised regenerative fuel cell (URFC) stack is used as the power generator, was designed and fabricated. Six membrane electrode assemblies were prepared and integrated on one piece of membrane by spraying catalyst slurry on both sides of the membrane. Each cell was made by sandwiching a membrane electrode assembly (MEA) between two graphite monopolar plates and six cell units were mechanically fixed in two organic glass endplates. When the stack was operated in an electrolysis mode, hydrogen was generated from the splitting of water and stored using a hydrogen storage alloy; conversely, when the stack was operated in fuel cell mode, hydrogen was supplied by the hydrogen storage alloy and oxygen was supplied from air by self‐breathing of the cathode. At room temperature and standard atmospheric pressure, the open‐circuit voltage (OCV) of the system reached 4.9 V, the system could be discharged at a constant current density of 20 mA cm –2 for about 40 min, and the work voltage was ∼2.9 V. The system showed good stability for 10 charge–discharge cycles.

, Jenny CALZADO-ARAGÓN, María del Carmen FUENTES-ALBARRÁN et al.

Engineering and Applied Sciences • 2023

Microbial fuel cells are electrochemical devices that use microorganisms as catalysts to produce electricity. Oxygen is the most used electron acceptor in the cathodic reaction of these systems, due to its abundance in the environment and high redox potential; however, the slow kinetics in oxygen reduction constitutes a limitation. Platinum (Pt) is the most widely used catalyst to accelerate the oxygen reduction reaction, but its high cost makes its use on a large scale impossible. In this study, the performance of manganese dioxide (MnO2) as a cathodic catalyst in an H-type microbial fuel cell was examined. The MnO2 layer on the carbon fiber surface was deposited by simply immersing the carbon in an aqueous KMnO4 solution. The microbial fuel cell was characterized by polarization and power curves. A maximum power peak of 6.09 mW/m2 was obtained with a current density of 22 mA/m2, showing that MnO2 can be a low-cost alternative to be used as catalytic material in the cathode of these devices.

A. Fraiwan, S. Sundermier, D. Han et al.

Fuel Cells • 2013

Abstract In this work, a microfabricated anode based on gold coated poly(ϵ‐caprolactone) fiber was developed that outperformed gold microelectrode by a factor of 2.65‐fold and even carbon paper by 1.39‐fold. This is a result of its ability to three‐dimensionally interface with bacterial biofilm, the metabolic “engines” of the microbial fuel cell (MFC). We also examined unavoidable issues as the MFC is significantly reduced in size (e.g. to the microscale); (1) bubble production or movement into the microchamber and (2) high sensitivity to flow rate variations. In fact, intentionally induced bubble generation in the anodic chamber reduced the MFC current density by 33% and the MFC required 4 days to recover its initial performance. Under different flow rates in the anode chamber, the current densities were almost constant, however, the current increased up to 38% with increasing flow rate in the cathode.

, Muhammad Farhan Hil Me, Mimi Hani Abu Bakar et al.

Jurnal Kejuruteraan • 2020

Usage of graphite electrode in a microbial fuel cell (MFC) is favored due to their electron conductivity and stability as a base material for the electrode. Also, graphite is favored as it allows the growth of biofilm, which can enhance the cell’s performance. The efficiency is reported improved through modification. Aryl diazonium modification has been reported to induce biofilm formation on the electrode faster. The modification can be done spontaneously or through electrografting of aryl diazonium salt onto the electrode surface. Control over the quantity of grafted aryl diazonium is essential. A thick layer will cause the performance of the system to drop, which may impede the electron transfer from biofilm to the electrode. Aryl diazonium is preferred as it allows a robust biofilm formation when used as a surface modification on the graphite electrode. Modification using aryl diazonium allows the electrode to be more accommodative for biofilm growth, which will increase the performance of the system. However, it does not act as a redox mediator for the system. It has been reported that power density obtained using aryl diazonium modified electrode is 250 mW.m-2, higher than unmodified graphite electrode of 125 mW.m-2. However, not all bacterial species is compatible with aryl diazonium modification. The unmodified graphite biocathode allows a higher power density compared to aryl diazonium modified biocathode. Hence, depending on the quality of aryl diazonium modification and the types of inoculum used, MFC performance can be further maximized.

Clifford S. Swanson, Yasser Ashraf Gandomi, Gabriel A. Goenaga et al.

ECS Meeting Abstracts • 2018

Over the last couple decades, microbial fuel cells (MFCs) have become a technology of interest for renewable energy production and waste treatment/reclamation. MFCs are flexible with fuel and, for this reason, have garnered interest as biosensors, unit operations in advanced wastewater treatment, and alternative power sources. MFCs oxidize organic matter at the anode where microbes perform anaerobic respiration to convert organic matter into simpler compounds (such as carbon dioxide, methane, etc.); however, the anode electrode serves as the final electron acceptor [1, 2]. The electrons produced at the anode are used at the cathode in oxygen reduction reaction (ORR), a reaction that requires the presence of a catalyst. The system design for MFCs can vary to meet different applications [3], but one of the more popular designs is a membrane less, single chamber, air cathode microbial fuel cell [4], which has the anode submerged in an oxygen-less, nutrient solution and has an air-exposed cathode. Although promising in concept, MFCs have very low power density, making them cost inefficient. A major performance limitation in MFCs has been identified in the cathode. Overall efficiency and power density a strongly influenced by cathode design and catalyst selection for the ORR [4, 5]. Previous modeling efforts have suggested oxygen crossover to the anode, oxygen diffusion to the ORR catalyst, and the catalyst used are major factors for low power density [6-8]. In this work, improved MFC performance is demonstrated using non-platinum group catalyst material. The novel catalyst was benchmarked against a platinum group catalyst. Using the novel non-platinum catalyst results in a modest increase in open circuit potential, and a significant increase in maximum current density and power density. In addition, we have investigated the influence of non-platinum catalyst loading on the overall performance. The novel catalysts used in this work demonstrated stability over months of operation. This suggests that the non-platinum group catalyst used in this work is more efficient than platinum group catalyst, improving the cell performance while simultaneously enabling lower cost. References Jr, L.B.W., C.H. Shaw, and J.F. Castner, Bioelectrochemical fuel cells. Enzyme and Microbial Technology, 1982. 4 (3): p. 6. Kim, H.J., et al., A mediator-less microbial fuel cell using a metal reducing bacterium, Shewanella putrefaciens. Enzyme and Microbial Technology, 2002. 30 (2): p. 8. He, Z., S.D. Minteer, and L.T. Angenent, Electricity Generation from Artificial Wastewater Using an Upflow Microbial Fuel Cell. Environmental Science and Technology, 2006. 39 : p. 6. Liu, H. and B.E. Logan, Electricity Generation Using an Air-Cathode Single Chamber Microbial Fuel Cell in the Presence and Absence of a Proton Exchange Membrane. Environmental Science and Technology, 2004. 38 : p. 6. Rismani-Yazdi, H., et al., Cathodic limitations in microbial fuel cells: An overview. Journal of Power Sources, 2008. 180 : p. 12. Ou, S., et al., Full cell simulation and the evaluation of the buffer system on air-cathode microbial fuel cell. Journal of Power Sources, 2017. 347 : p. 11. Ou, S., et al., Modeling and validation of single-chamber microbial fuel cell cathode biofilm growth and response to oxidant gas composition. Journal of Power Sources, 2016. 328 : p. 12. Ou, S., et al., Multi-variable mathematical models for the air-cathode microbial fuel cell system. Journal of Power Sources, 2016. 314 : p. 9. Figure 1

Mel Patrick D. Malinis, Herna Jones F Velasco, Kristopher Ray Pamintuan

International Journal of Renewable Energy Development • 2023

Plant-Microbial Fuel Cells (PMFCs) are a sustainable derivative of fuel cells that capitalizes on plant rhizodeposition to generate bioelectricity. In this study, the performance of the novel 3D-printed aquatic PMFC assembly with Eichhornia crassipes as the model plant was investigated. The design made use of 1.75 mm Protopasta Conductive Polylactic Acid (PLA) for the electrodes and 1.75 mm CCTREE Polyethylene Terephthalate Glycol (PETG) filaments for the separator. Three systems were prepared with three replicates each: PMFCs with the original design dimensions (System A), PMFCs with cathode-limited surface area variations (System B), and PMFCs with anode-limited surface area variations (System C). The maximum power density obtained by design was 82.54 µW/m2, while the average for each system is 26.99 µW/m2, 36.24 µW/m2, and 6.81 µW/m2, respectively. The effect of variations on electrode surface area ratio was also examined, and the results suggest that the design benefits from increasing the cathode surface area up to a cathode-anode surface area ratio of 2:1. This suggests that the cathode is the crucial component for this design due to it facilitating the rate-limiting step. Plant health was also found to be a contributing factor to PMFC performance, thereby suggesting that PMFCs are an interplay of several factors not limited to electrode surface area alone. The performance of the novel PMFC did not achieve those obtained from existing studies. Nevertheless, the result of this study indicates that 3D-printing technology is a possible retrofit for PMFC technology and can be utilized for scale-up and power amplification.

Kaili Zhu, Yihu Xu, Xiao Yang et al.

Membranes • 2022

The conversion of activated sludge into high value-added materials, such as sludge carbon (SC), has attracted increasing attention because of its potential for various applications. In this study, the effect of SC carbonized at temperatures of 600, 800, 1000, and 1200 °C on the anode performance of microbial fuel cells and its mechanism are discussed. A pyrolysis temperature of 1000 °C for the loaded electrode (SC1000/CC) generated a maximum areal power density of 2.165 ± 0.021 W·m−2 and a current density of 5.985 ± 0.015 A·m−2, which is 3.017- and 2.992-fold that of the CC anode. The addition of SC improves microbial activity, optimizes microbial community structure, promotes the expression of c-type cytochromes, and is conducive to the formation of electroactive biofilms. This study not only describes a technique for the preparation of high-performance and low-cost anodes, but also sheds some light on the rational utilization of waste resources such as aerobic activated sludge.

Abdelkader Hilmi, Chao-Yi Yuh, Mohammad Farooque

ASME 2010 8th International Fuel Cell Science, Engineering and Technology Conference: Volume 2 • 2009

Polarization studies and post analysis have been carried out for characterizing the electrochemical performance and processes affecting life and stability of carbonate fuel cell electrodes. Based on this understanding optimized electrodes design and new electrolyte composition were developed to improve cell performance and achieve the useful life of >5 years. The anode performance and stability were improved by developing an optimized microstructure with better electrolyte retention capabilities. Tests with an advanced electrolyte composition showed 25 mV improvement at 650°C and more than 45 mV at low temperatures compared to baseline. The NiO dissolution in advanced electrolyte is reduced by >60% compared to baseline electrolyte. Anode and cathode electrodes showed stable mechanical strength and stable electrochemical performance.

Momen Salah Kamel, Mohamed Hemida Abd-Alla, Usama M. Abdul-Raouf

Environmental Engineering Research • 2019

This study investigated the bioelectrical performance of a single-chamber microbial fuel cell (SCMFC) fueled with acetate as the electron donor and inoculated with municipal solid waste rejected fractions (MSWRFs) as a microbial inoculum. The molecular characterization of the bacterial community structures of the anodic biofilm was conducted based on 16s RNA gene sequencing. The results indicated that the highest open-circuit voltage (OCV) was 797 mV and the system had a maximum power density of 134.5 mW/m<sup>2</sup> at a stable current density of 328 mA/m<sup>2</sup>. The microbial fuel cell’s (MFC) columbic efficiency (CE) was 55% at a maximum substrate degradation rate of about 86.6% based on COD removal efficiency. The molecular analysis of the anodic bacterial isolates indicated that the phylogenetic bacterial mixture was dominated by seven strains with similarity percentage above 99% for each strain: <i>Enterococcus faecalis, Clostridium butyricum, Bacillus sp., Bacillus subterranous, Enterobacter celoaca,</i> <i>Klebsiella pneumonia,</i> and <i>Escherichia coli</i>. These results suggested that MSWRFs bacterial consortia have a moderate symbiotic structure as indicated by electrons release in parallel with substrate decomposition.

Tushar Sharma, A. Leela Mohana Reddy, T. S. Chandra et al.

Journal of Nanoscience and Nanotechnology • 2008

Microbial Fuel Cells (MFC) are robust devices capable of taping biological energy, converting sugars into potential sources of energy. Persistent efforts are directed towards increasing power output. However, they have not been researched to the extent of making them competitive with chemical fuel cells. The power generated in a dual-chamber MFC using neutral red (NR) as the electron mediator has been previously shown to be 152.4 mW/m 2 at 412.5 mA/m 2 of current density. In the present work we show that Pt thin film coated carbon paper as electrodes increase the performance of a microbial fuel cell compared to conventionally employed electrodes. The results obtained using E. coli based microbial fuel cell with methylene blue and neutral red as the electron mediator, potassium ferricyanide in the cathode compartment were systematically studied and the results obtained with Pt thin film coated over carbon paper as electrodes were compared with that of graphite electrodes. Platinum coated carbon electrodes were found to be better over the previously used for microbial fuel cells and at the same time are cheaper than the preferred pure platinum electrodes.

Fikret Kargi, Serkan Eker

Journal of Chemical Technology & Biotechnology • 2009

Abstract BACKGROUND: A circulating column microbial fuel cell (MFC) with Cu anode and AuCu air cathode was used for power generation and chemical oxygen demand (COD) removal from synthetic wastewater. The column was operated in repeated‐fed batch mode using acclimated anaerobic sludge. The contents of the column MFC were circulated while the feed wastewater was fed to the reactor in fed‐batch mode. Effects of feed COD concentration and COD loading rate on voltage difference, power density and percentage COD removal were investigated. RESULTS: The highest voltage difference (650 mV), power density (40 W m −2 ) were obtained with a feed COD of 6400 mg L −1 , yielding 45% COD removal with a COD loading rate of nearly 90 mg h −1 . Low COD loadings (<90 mg h −1 ) caused substrate limitations, and high loadings (>90 mg h −1 ) resulted in inhibition of COD removal and power generation. The highest percentage COD removal (50%) was obtained with feed COD content of 10.35 g L −1 or a COD loading rate of 145 mg h −1 . CONCLUSION: The power densities obtained with the circulating column MFC were considerably higher than those reported in the literature due to elimination of mass transfer limitations by the high circulation rates, proximity of electrodes and small anode surface area used in this study. Further improvements may be possible with optimization of the operating parameters. Copyright © 2009 Society of Chemical Industry

Susanta K. Das, K. Joel Berry

ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology • 2014

Compact and efficient fuel reforming system design is a major challenge because of strict requirements of efficient heat distribution on both the reforming and combustion side. As an alternative to traditional packed bed tubular reformers, catalytic flat plate fuel reformer offers better heat integration by combining the combustion reaction on one side and reforming reaction on the other side. In this study, with the help of a two-dimensional computational fluid dynamics (CFD) model, a catalytic flat plate fuel reformer is built and investigated its performance experimentally. The CFD model simulation results help to capture the effect of design parameters such as catalyst layer thickness, reaction rates, inlet temperature and velocity, and channel height. The CFD model study results also help to design and built the actual reformer in such a way that eliminate the limitations or uncertainties of heat and mass transfer coefficients. In our study, we experimentally evaluated the catalytic flat plate fuel reformer performance using natural gas. The effect of reformate gas on the current-voltage characteristics of a 5kW high temperature PEM fuel cell (HTPEMFC) stack is investigated extensively. The results shows that the overall system performance increases in terms of current-voltage characteristics of HTPEMFC while fed with reformate directly from the catalytic flat plate reformer.

Hossein Ghezel-Ayagh, Joseph McInerney, Ramki Venkataraman et al.

Journal of Fuel Cell Science and Technology • 2011

FuelCell Energy, Inc. (FCE) has developed products based on its Direct FuelCell® (DFC®) technology with efficiencies near 50% based on lower heating values of natural gas. DFC is an internally reformed molten carbonate fuel cell, which operates in the 550–700°C range. The combination of the internal reforming of methane and atmospheric pressure and moderately high temperature of operation has resulted in very simple power plant system configurations. Recently, FCE has developed system concepts to further increase the net electric efficiency to beyond 60% efficiency in sub-MW and MW class power plants. One of these system concepts is the arrangement of the fuel cell stacks in series for very high utilization of fuel in the stacks. Although, in principle, the concept of fuel cell stacks in series is very simple, the implementation of the concept in the actual hardware poses challenges requiring innovative solutions. These challenges include concerns with thermomechanical issues, flow and utilization patterns within the fuel cell stacks, and management of the pressure balance between the anode and the cathode. To address these issues, various analytical tools, including system-level modeling and simulation and computational fluid dynamics (CFD), were utilized. FCE has developed a comprehensive fuel cell stack operation simulation model including hydrodynamics, kinetics, electrochemical, and heat transfer mechanisms to investigate and optimize the design for performance as well as endurance. Various system configurations were developed, which included methods for fueling the second tier stacks in the series. System simulation studies using first principle mass and energy conversation laws were performed. Parametric studies were completed. Subsequent to the system modeling results, the fuel cell stack operations were analyzed using the comprehensive stack simulation model. The CFD modeling of the fuel cell stacks was performed in support of the system simulation parametric studies. The results of the CFD modeling provided insight to the thermal and flow profiles of both first and second tier stacks in series. The net outcome of the investigation was the design of the system, which met the goals of ultrahigh efficiency and yet complied with the thermomechanical requirements of the fuel cell stack components. In this paper, FCE will describe various system options for the very high efficiency systems, the issues related to the design, and the practical solutions to overcome the issues.

Elena Kipf, Roland Zengerle, Johannes Gescher et al.

ChemElectroChem • 2014

Abstract The influence of the anode material on the electrical performance of the two microbial fuel cell model organisms Geobacter sulfurreducens and Shewanella oneidensis is investigated. High‐surface‐area activated carbon and low‐surface‐area graphite felt are compared in terms of polarization curves under quasi‐steady‐state conditions. Unexpectedly, G. sulfurreducens exhibits similar current densities up to 700 μA cm −2 independent of the anode material. This is ∼50 % higher than steady‐state values reported previously. The negligible influence of electrode material on the electrical performance of G. sulfurreducens is attributed to the fact that it performs only direct electron transfer, but forms thick biofilms. In contrast, S. oneidensis , relying mainly on mediated electron transfer, apparently makes better use of high‐surface‐area activated carbon and achieves higher current densities compared to graphite felt. This underlines the importance of tailoring anode materials according to the used organisms.

Omkar S Powar, Lakshminarayana Bhatta, Raghavendra Prasad et al.

International Journal of Research -GRANTHAALAYAH • 2017

In this study electricity generation was evaluated in a two chambered microbial fuel cell. Performance of microbial fuel cells using two bacteria, Klebsiella pneumoniae and Bacillus coagulans and using three different electrodes namely graphite blocks, carbon cloth and graphite sheet was studied. The device was operated under anaerobic condition in the anode chamber and parameters were recorded for a period of 48 hours. The performance of MFC was analyzed by the measurement of open circuit voltage, polarization curves, impedance curves and cyclic voltammetry. Among different combinations of electrode tested, carbon cloth electrode produced high power density (80 mW/m2). Graphite block gave much high power compared to sheet. Finally, performance was compared with Shewanellaputrefaciens. The current study explores the applicability of carbon electrode for MFC applications.

Hongjun Ni, Kaixuan Wang, Shuaishuai Lv et al.

Energies • 2020

The variation of substrate concentration in anode chamber directly affects the power generation efficiency and decontamination performance of microbial fuel cell (MFC). In this study, three concentrations of swine wastewater with 800 mg/L, 1600 mg/L and 2500 mg/L were selected as substrates, and the performance of MFC and response characteristics of anode microbial community were investigated. The results show that the concentration of a selected substrate is positively correlated with the output voltage of MFC and chemical oxygen demand (COD) removal rate. The microbial community diversity in the anode chamber and the performance of battery can be significantly affected when concentration changes in different ways, which helps to selectively cultivate the adaptable dominant bacteria to enhance the stability and decontamination performance of MFC. The community structure of anodic biofilm is mainly composed of Proteobacteria, Bacteroidetes, Firmicutes, Chloroflexi and Spirochaetae. These findings are meaningful to improve the treatment effects of swine wastewater and can help to find out the mechanism of varying concentration that influences the production of microorganisms in MFC.

Sarowar Jahan, Md. Tarikul Islam, Suman Chowdhury

Malaysian Journal of Applied Sciences • 2020

Fuel cell based power generation systems have gained remarkable interest in this modern age, due to its high conversion efficiency and reliability. Among the different types of fuel cells, PEM fuel cells are achieving more significance due to its fast start up time and low operating temperature. This paper studies the mathematical model of proton exchange membrane of fuel cell (PEMFC) using Matlab/SIMULINK software. The paper consists of the calculation of cell voltage, stack current, ohmic loss, activation loss. This model is used to research the fuel cell behavior and the characteristic of output values at different parameters. The model consists of the cathode gas channel, gas diffuser, catalyst layer, and the membrane. In order to composite shape of the gas diffuser and for its gradient in liquid water content, the gas diffuser is modeled as a series of parallel layers with different porosity. It represents in terms of the physical and thermodynamic parameters of the fuel cell. The curve of polarization is expressed parametrically as a function of the surface over potential. This paper expresses for cathode internal as well as overall effectiveness factors, active fraction of the catalyst layer resistance, catalyst layer, limiting current density, and the slope of the polarization curve.

Miguel Ángel López Zavala, Pamela Renée Torres Delenne, Omar Israel González Peña

Energies • 2018

In this study, biodegradation performance and power generation in MFCs were improved. Domestic wastewater was biodegraded in a dual-chamber MFC system equipped with a DupontTM Nafion® 117 proton exchange membrane, graphite electrodes (8.0 cm × 2.5 cm × 0.2 cm) in both chambers and an external electric circuit with a 100 Ω resistor. Experiments were conducted using an anaerobic inoculum that was prepared onsite by acclimating mixed liquor from municipal wastewater. Aqueous hydrochloric acid (0.1 M HCl, pH 1.82) was used as the electrolyte in the cathode chamber. Free-oxygen conditions were promoted in both chambers by means of a vacuum (77.3 kPa). Low pH (< 5) and mixing conditions were maintained in the anode chamber and all the tests were carried out at 25 ± 1 °C. These conditions enhanced the hydrolysis and acidogenesis, inhibited the methanogenesis and reduced the internal losses. All of them together contributed to improve the treatment performance and power generation of the MFCs. Results of batch tests show COD reductions of up to 95%, voltages peaks of 0.954 V, maximum power densities on the order of 2.1 W·m−2 and 36.9 W·m−3, and energy generation peaks of 99.4 J·mg−1 COD removed. These values are greater than those reported in the MFCs’ literature for municipal wastewater (26 mW·m−2–146 mW·m−2), industrial wastewater (419 mW·m−2) and culture medium solutions (1.17 W·m−2), and similar to those of glucose (3.6 W·m−2). Thus, these results can contribute to further enhancing the energy generated in MFCs and moving forward to make the MFCs more ready for practical applications of bioenergy production.

Nosa AGHO, Aniekan IKPE, Godwin SADJERE et al.

International Journal of Energy Applications and Technologies • 2018

In this study, three mediatorless chamber microbial fuel cells were built and experiments were carried out using a mixture of cow dung and water. The volume of the mixture in each cell was 5309440mm3 and the ratio of the surface area of aluminum anode electrode to graphite rod cathode electrode was 2:1. The maximum open circuit voltage and current obtained was 0.73V and 10.87mA respectively. Maximum total voltage and current obtained for the period of 28 days under investigation was 14.4V and 168.1mA. The average total voltage and voltage drop during the period under investigation were 14.59V and 0.4V respectively. The average power rating per day produced from the each cell was 143.47mAH. This study has shown that cow dung is a potential substrate for energy generation using a single chamber Microbial Fuel Cell (MFC).

Gizem Hazan Akçay, İrfan Ar

International Journal of Energy Studies • 2025

Microbial fuel cells (MFCs) have attracted significant attention in recent years due to their potential in the biological treatment of waste and wastewater, as well as in energy conversion technologies. In this study, a reactor was designed using polypropylene material. The design positioned the cathode chamber inside the anode chamber to reduce diffusion resistance by minimizing the distance between the two chambers. Additionally, composite anode/cathode electrodes were developed using PTFE (polytetrafluoroethylene). As a result of the study, values for maximum voltage, maximum power density, and COD (chemical oxygen demand) removal efficiency were determined. The coulombic efficiency was also calculated and found to be 11.49%. pH and temperature values were monitored and these parameters remained within a consistent range throughout the study. The findings showed that this reactor design achieved comparable electricity generation potential and effective COD removal efficiency. Finally, voltage and COD removal values were used in Dizayn Expert 7.0.0 (Stat-Ease Inc., Minneapolis, MN, USA) for full factorial experimental modeling to validate the experimental results. Overall, the study is expected to contribute significantly to the literature on reactor designs in microbial fuel cell research.

K. Singh, Dharmendra Dharmendra

Archives of Materials Science and Engineering • 2020

Purpose: Comparative study of various agar-agar (C14H24O9) percentage and different salts concentration in the salt bridge is carried out to check the efficiency of microbial fuel cell. Design/methodology/approach: Dual chambered microbial fuel cell was used for the overall experiments. Anode and cathode chambers were made of 500 ml plastic jar. Salt bridge was fabricated with agar-agar technical and 3 M NaCl in a PVC pipe of 2 cm long. Chemical Oxygen Demand, pH and electrical conductivity of wastewater were examined. Oxygen was supplied in the cathode chamber using the aquarium pump. Voltage (open circuit voltage) was observed using digital multimeter. Graphite rods were used as anode and cathode electrodes. Findings: Salt bridge was constructed of 3 M NaCl with 5, 7.5, 10 and 12 percent variation of agar amounts in MFC. The maximum outputs were observed 301, 306, 325 and 337.25 mV with the variation of agar 5, 7.5, 10 and 12 percentages respectively as well as chemical oxygen demand (COD) removal efficiency was observed 47.92, 56.25, 52.08 and 64.58 percentages respectively. The optimum agar concentration was found to be 12 percent and a maximum voltage of 337.25 mV and COD removal of 64.58 percent was achieved. After the optimization of agar percentage two salts i.e., Sodium chloride and potassium chloride were analysed. This study also reveals that the NaCl salt bridge is more efficient than KCl salt bridge for the same agar concentration. The maximum voltage for NaCl and KCl were 319 and 312 mV respectively. Research limitations/implications: The amount of electricity production is low and field scale implementation is difficult using microbial fuel cell. The research is still on progress in this field. Originality/value: here is very little research with salt bridge and MFC. Comparative study of different mole of salt is available but agar variation is not yet studied.

T Mulyono, Misto, S M Nasifatul

Journal of Physics: Conference Series • 2021

Abstract In the past few years the fuel cell has become the centre of attention of the scientific community for the possibility of converting organic waste into electricity directly through redox reactions with the help of bacteria or enzymes. The purpose of this study was to determine the value of MFC performance due to the influence of adding vegetable waste. The soil media used is obtained from agricultural areas. The system used in the MFC is a single chamber of a vessel with a volume of 500 mL. The types of electrodes used are carbon fibres with anode thickness of 0.5 cm and cathode 1.0 cm, as well as anode diameter of 8.0 cm and cathode 8.5 cm. Vegetable wastes were given 5 mg / L each in the MFC single chamber. The results showed that the highest power was generated from a microbial fuel cell with spinach vegetable waste. The power produced is 250 mW (49 mW/cm 2 ). The incubation period for MFC can reach 30 days. Variation of the second rinse with a concentration of 499 ppm will have a pH value having a pretty good linear correlation of 0.9536 to the more electric power generated. The power produced by the MFC 6 series circuit is 1.00 mW, while the power generated by the parallel series is 0.831mW.

Luyu Wang, Hongbin Xue, Lei Gong et al.

Research Square • 2022

Abstract Microbial fuel cell (MFC) technology has the function of decarburization and denitrification and is considered advantageous in treating wastewater with a low carbon-nitrogen ratio. In the current study, MFC treats different concentrations of nitrate nitrogen. And compared with abiotic electrode treatment and microbial treatment only, MFC showed obvious treatment advantages. The best treatment effect was recorded when the nitrate-nitrogen (NO3-N) concentration was 414 mg/L. The running of the MFC system showed that it produced a stable output voltage up to 0.17 V within 160 h; And showed a power density up to 40.18 mW/m2, which was 1.58 times of M1 (138 mg/L, 25.49 mW/m2), 4.48 times of non-biological electrode; The removal rate of NO3-N was 97.48%, but the lack of anode electron supply resulted in the incomplete reduction of nitrate nitrogen and accumulation of nitrite-nitrogen (188.83 mg/L). Nitrate-nitrogen concentration in the study had no significant impact on microbial population diversity. However, the relative abundance of Proteobacteria increased from 47.3% to 65.4% when NO3-N concentration increased from 138 to 414 mg/L. Results from this study are promising for a theoretical basis for microbial cathode denitrification.

D. V. Vara Manasa

International Journal for Research in Applied Science and Engineering Technology • 2024

Abstract: Dual-chamber microbial fuel cells (MFCs) have garnered significant attention in recent years due to their promising potential for sustainable energy generation from organic waste. This review provides a comprehensive overview of the advancements, challenges, and future prospects of dual-chamber MFC technology. The paper begins with an introduction to the principles of microbial fuel cells and the rationale behind the dual-chamber configuration. It discusses the design considerations including electrode materials, membrane selection, and reactor configurations, highlighting recent innovations aimed at enhancing performance and scalability. Key advancements in dual-chamber MFCs are reviewed, focusing on improvements in power output, microbial community dynamics, and substrate utilization. Strategies such as microbial enrichment, biofilm engineering, and electrode modifications are discussed in detail, showcasing their impact on MFC performance and stability. Furthermore, the review explores the application of dual-chamber MFCs in various fields including wastewater treatment, bioenergy productions.

Abdullah Al Moinee, Nahid Sanzida

Chemical Engineering Research Bulletin • 2021

Microbial fuel cells (MFCs) are bio-electrochemical systems (BES) that can oxidize and convert biodegradable wastes directly into electricity via microbial metabolism. Since the oxidation half-cell of an MFC consists of the biodegradable electrolyte and anode, the selection of the right anode materials is essential to optimize the performance of MFCs. Anode acts as the governing support for the growth of biofilm to transfer the electrons. In general, anode materials must have a reasonable surface area for bacterial growth, good conduction, excellent biocompatibility, chemical stability, high mechanical strength, and low cost. In this work, graphite bar, aluminum foil, and carbon cloth were tested as an anode. The comparative performances of them were analyzed in a double chambered MFC containing industrial wastewater with respect to the power density and waste removal efficiency of MFCs. The carbon cloth anode provided better output than graphite bar and aluminum foil. The 10 days of batch operation for carbon cloth anode resulted in a maximum of 672.34 mWm-3 power density and 52.20% removal of chemical oxygen demand (COD).
 Chemical Engineering Research Bulletin 21(2020) 26-31

Vidia Wahyu Meidy Safitri, Tuhu Agung Rachmanto

JURNAL ENVIROTEK • 2020

ABSTRAK
 Limbah cair tahu mengandung kandungan organik tinggi dengan konsentrasi COD 1408 mg/l, TSS 191 mg/l dan pH 4,46. Salah satu penelitian dengan pemanfaatan limbah dan energi yaitu Microbial Fuel cell (MFC). Energi Kimia senyawa organik dari mikroorganisme akan dirubah menjadi energi listrik dengan reaksi katalik dari mikroorganisme dalam keadaan anaerob merupakan proses microbial fuel cells. Salah satu tantangan untuk mengembangkan sistem MFC adalah dengan memilih elektroda yang tepat. Elektroda yang digunakan harus memiliki daya konduktifitas listrik tinggi, pemukaan yang luas, non korosif, biokompatibel, stabil. Penelitian ini bertujuan untuk memgetahui jenis elektroda optimum dalam menghasilkan power density dengan variasi elektroda karbon grafit, seng dan tembaga, variasi waktu 0, 48, 96, 144, dan 192 jam. Dilakukan pre-treatment koagulasi flokulasi. Hasil penelitian menunjukkan bahwa MFC dengan elektroda karbon grafit dan karbon grafit menghaslikan power density sebesar 2292,994 mW/m2. MFC juga menurunkan konsentrasi COD hingga 88%. Waktu pengolahan dapat mempengaruhi efisiensi penyisihan COD.
 
 Kata kunci: limbah tahu, microbial fuel cell, power density
 
 ABSTRACT
 
 Tofu liquid waste contains high organic content with a COD concentration of 1408 mg / l, TSS 191 mg / l and pH 4.46. One of the researches related to waste and energy utilization is Microbial Fuel cell (MFC). Chemical energy organic compounds from microorganism will be converted into electrical energy by the catalytic reaction of microorganism in anaerobic conditions is a process of microbial fuel cells. One of the challenges to developing an MFC system is to choose the right electrodes. The electrodes used must have high electrical conductivity, a wide surface, non-corrosive, biocompatible, stable. This study aims to find out the most optimum type of electrode in producing power density with variations of carbon graphite, zinc and copper, variations of 0, 48, 96, 144, and 192 hours. The pre-treatment are Coagulation-flocculation. The results showed that MFC with carbon graphite and carbon graphite electrodes produced a power density of 2292,994 mW/m2. MFC also reduces COD concentrations up to 88%. Processing time can affect the efficiency of COD removal. 
 
 Keywords: Tofu Liquid Waste, Microbial Fuel Cells, power density

Md. Abdul Halim, Md. Owaleur Rahman, Md. Ibrahim et al.

Research Square • 2021

Abstract Background: Day by day microbial fuel cell (MFC) technology is becoming a thought-provoking topic to the researcher because for its simultaneous utilization e.g. electricity production and wastewater treatment. Since wastewater is an important source of electrolyte for MFC, the key tenacity of this study was to investigate the outcome of pH happening various (Municipal, Bhairab river and Hospital) wastewaters used as electrolyte in dual chamber MFC. Findings: The lab-scale experiment was conducted in batch mode, where zinc plate (0.0027 m 2 ) as anode and copper plate (0.0027 m 2 ) as cathode. In this study a single electrolyte (any one of earlier mentioned three electrolytes) was used in five dual-chambers MFC where the pH of the electrolyte was 6, 7, 8, 9 and 10. The MFC was worked on a temperature ranged from 27°C to 34°C. Maximum outputs were found in terms of current density (1288.9 mAm - 2 ), voltage (1132 mV) and power density (1459.02 wmw - 2 ) were obtained at pH 8 by using Bhairab river water as an electrolyte in MFC chamber. A substantial amount of COD removal (94%) was also achieved in the same MFC chamber at the same pH (i.e. pH 8). However, the optimum operating pH for MFC containing municipal wastewater and hospital wastewater was found to be 8 and 9, respectively. Conclusion: The results suggest that various wastewaters may act as feasible feedstocks for bioelectricity generation in MFC. The results also show that COD can be removed from wastewater that suggest a treatment possibility of wastewater.

Zia Ullah, Irfan Ahmad, Zeshan

Research Square • 2023

Abstract Traditional wastewater treatment processes demand high energy and are not economically feasible for domestic wastewater treatment. Microbial fuel cell (MFC) offers an alternative option for wastewater treatment with simultaneous energy recovery by utilizing the electrogenic bacteria and organic matter present in wastewater. This study investigates the performance of MFC for the treatment of domestic wastewater when operated at different hydraulic retention times (HRTs). Two dual-chamber MFCs were used each installed with a different type of anode. One of the anodes was a carbon fiber brush and the other was a graphite rod. Domestic wastewater was utilized as a substrate and the reactors were run in a semi-continuous flow at HRTs of 48, 36, 24, 12, 8, 4 and 2 h under 1000 Ω external resistance. At HRT of 8 h, maximum voltage of 319 mV and 308 were achieved for MFC with carbon fiber brush (CFBMFC) and graphite rod (GRMFC), respectively. Maximum COD removals of 80.3% and 73.9% corresponding to maximum coulombic efficiency of 5.4% and 4.2% were achieved for CFBMFC and GRMFC at an HRT of 48 h respectively. Power curves showed that maximum power density of 77 mW/m 2 and 58 mW/m 2 was achieved for CFBMFC and GRMFC, respectively.

, Agkarapin Angkatreerat

• 2009

To study the effects of relative humidity on performance of Pt/zeolite-chitosan membrane in PEM fuel cell. The studied membranes were uncrosslinked chitosan, crosslinked chitosan and doped crosslinked chitosan membranes. The doping solution was 2% by weight of sulfuric acid. Zeolite A was incorporated in the range of 0-30% by weight of chitosan. It was found that the ion exchange capacity and proton conductivity was increased with zeolite content however the tensile strength and gas permeability was decreased. The proton conductivity in planar view at 60oC of 30% crosslinked chitosan-zeolite membranes was 0.043±0.006 S/cm and increased to 0.123 ± 0.024 S/cm in doped membranes. After Pt plating by electroless technique at 60℃ for 90 min, the proton conductivity of 30% doped crosslinked chitosan-zeolite membrane was increased to 0.312±0.008 S/cm. In single cell testing at 30oC, the current density at 0.5 V of 30% crosslinked chitosan-zeolite membrane was increased from 2.9 ± 0.1 mA/cm2 at fully hydration (RH at anode-cathode sides are 100%-100%) to 5.1 ± 0.1 mA/sq.cm for zero hydration (RH at anode-cathode sides are 0%-0%) at both sides. Amongst the studied chitosan based membranes, it was found that the 30% doped crosslinked chitosan-zeolite membrane provided the best performance. The current densities at 0.5 V without external humidifier at 30, 60 and 90℃ were 9.5 ± 0.01, 9.8 ± 0.01, and 10.1 ± 0.01 mA/sq.cm, respectively.

, Clara Corbella Vidal

• 2017

Horizontal Subsurface Flow Constructed Wetlands (HSSF CWs) are natural wastewater treatment systems showing a marked redox gradient between the surface of the system and the bottom zone of the treatment bed. Therefore, they constitute a suitable environment for Microbial Fuel Cells (MFCs) implementation. MFCs are bioelectrochemical systems in which the electrons resulting from the oxidation of the organic matter are transferred, by means of exoelectrogenic bacteria, to an external circuit thus generating an electric current. The implementation of MFC into HSSF CWs (CW-MFCs) allows the removal of organic matter and the production of electricity simultaneously. Besides electricity generation, MFCs implemented in HSSF CWs could encompass other beneficial aspects of special relevance within the constructed wetlands domain such as the semi-continuous monitoring of the organic matter entering the system, the improvement of CWs¿ treatment efficiency and the assessment of the clogging state of the treatment bed. However, CW-MFC is a novel research field that lacks from specific knowledge on both HSSF CWs and MFC design and operational aspects to optimize the technology. Therefore, the objective of this thesis was to determine, quantify and maximize the benefits resulting from the synergy between HSSF CW and MFCs. To address the objectives of this study two different experimental designs were considered: pilot-scale and lab-scale CW-MFCs. Results showed that continuous flow regime and planted wetlands generate higher redox gradients through the bed gravel than unplanted wetlands operated under discontinuous flow regime. CW-MFCs performed to a better extent under the presence of a HUSB reactor as primary treatment when compared to conventional settling. More precisely, the presence of HUSB reactor stimulated the presence of exoelectrogenic bacteria in anodic biofilms. Optimal cathode to anode surface ratio was that of 4:1. In order to maximize CW-MFCs performance, the cathode shall be placed semi-submerged within the water and kept at a distance of ca. 10 cm from the anode. Overall, even under these optimal wetlands and MFC operational and design conditions the energy produced by CW-MFCs would only cover between the 3 and the 14% of the total energy requirements of a CW treatment plant. Therefore, energy surplus provided by CW-MFCs, yet interesting, is not its most advantageous feature. In terms of CW-MFCs environmental applications, MFCs showed the capacity to improve CWs treatment efficiency. Organic matter effluent concentration for connected CW-MFCs was significantly lower either in terms of total or soluble COD than unconnected CW-MFCs. Furthermore, CW-MFCs showed potential for COD assessment. Although results indicate that linear relationships can be established between both parameters, several factors can affect the precision, repeatability and operational stability of the sensor. Therefore, other alternatives such as its utilization as qualitative response tools should be considered for biosensor CW-MFCs. Finally, CW-MFCs also showed potential as a tool for indirect, continuous clogging assessment. In terms of the environmental impacts associated to the implementation of MFCs, CW system coupled with graphite-based anode MFC appeared as the most environmentally friendly solution which could reduce CW both surface requirements and system footprint (by around 20%). Also CW systems coupled with high performance MFCs would be competitive with conventional CWs in terms of costs. In conclusion, though to be at its infancy, CW-MFCs represent a novel technology able produce energy while wastewater is treated. Although it might not be a very attractive technology if the electrical gain is considered exclusively, CW-MFCs is a very promising technology when it comes down to environmental applications such as the improvement of HSSF CWs removal efficiency, or the utilization of CW-MFCs as both organic matter and clogging assessment tool. Els aiguamolls construïts horitzontals de flux subsuperficial (AC HFSS) són sistemes naturals de tractament d'aigua residual i constitueixen un entorn favorable per a la implementació de Piles de Combustible Microbianes (PCM). Les PCM son sistemes bioelectroquímics que permeten la eliminació de la matèria orgànica i la generació d'electricitat de forma simultània. A més a més de la generació d'electricitat, les PCM implementades en AC, poden generar altres beneficis que són d'especial importància en el context dels AC. El monitoreig semi-continu de la qualitat de l'aigua que entra i surt dels sistemes, la millora de la eficiència de tractament dels AC o el seguiment de l'estat de colmatació del llit de grava dels AC són alguns dels potencials beneficis resultants. Tot i això, les PCM implementades en AC, constitueixen un camp de recerca molt recent en el que encara falten coneixements específics tant sobre el disseny dels AC com sobre la operació de les PCM per optimitzar la sinèrgia entre ambdues tecnologies. Així doncs, l'objectiu de la tesi que es presenta és el de determinar, quantificar i maximitzar els beneficis que resulten de la sinergia entre els AC HFSS i les PCM. Per assolir els objectius d'aquest estudi s'han utilitzat dos dissenys experimentals diferents: PCM-AC implementades en sistemes a escala pilot i a escala de laboratori. Els resultats obtinguts demostren que el flux hidràulic continu i els aiguamolls plantats generen gradients redox superiors en el llit de grava quan es comparen amb els aiguamolls no-plantats operats en flux discontinu. A més a més, les PCM-AC generen corrents elèctrics superiors quan el tractament primari aplicat és el reactor HUSB en comparació al decantador convencional. La relació òptima de superfície càtode : ànode obtinguda és de 4:1. Finalment, per tal de maximitzar el potencial de les PCM-AC, cal situar el càtode en posició semi-submergida i a una distància de 10 cm de l'ànode. Tot i això, quan s'apliquen les condicions d'operació dels AC i l'arquitectura de les PCM òptima, l'energia produïda per les PCM-AC pot cobrir només entre el 3 i el 14% d'una planta de tractament d'aigua residual constituïda per aiguamolls construïts. Així doncs, tot i que l'energia generada per les PCM-AC constitueix un resultat positiu, no esdevé el benefici principal. En termes de les seves aplicacions ambientals, les PCM-AC han demostrat poder millorar la capacitat de tractament dels AC. La concentració de matèria orgànica a l'efluent de les PCM-AC connectades fou significativament inferior que a l'efluent dels sistemes no connectats. A més a més, les PCM-AC han mostrat potencial per a la determinació de la DQO. Tot i això, hi ha molts factors que poden afectar la precisió, la repetibilitat i la estabilitat operativa del sistema de manera que la seva viabilitat com a biosensor passa per utilitzar-les com a eina de bioindicació qualitativa. Per últim, les PCM-AC també tenen potencial per a la determinació en continu del grau de colmatació dins el llit de grava dels AC. De l'estudi dels impactes ambientals associats a la implementació de les PCM en els AC se'n conclou que els sistemes amb l'ànode de grafit constitueixen la millor alternativa en termes d'impactes ambientals per reduir tant la superfície dels aiguamolls com la seva petjada ecològica (sobre un 20% de reducció). Finalment, tot i trobar-se en un estadi d'estudi prematur, les PCM implementades en AC representen una tecnologia innovadora capaç de produir energia alhora que es tracta l'aigua residual. Encara que, si es considera de forma exclusiva el guany energètic, la sinèrgia entre ambdues tecnologies pot no semblar molt atractiva, les PCM-AC constitueixen una tecnologia molt prometedora pel que fa a les seves aplicacions ambientals tals com la millora de la eficiència de tractament dels AC o la seva utilització per a la determinació del contingut de matèria orgànica en l'aigua residual i el grau de colmatació dels sistemes.

Aicha Zerrouki, Mostefa Kameche, Ahcene Ait Amer et al.

Environmental technology • 2021

A microbial fuel cell is a biological electrochemical system that extracts electrons stored in organic matter by oxidation using catalytic properties of microorganisms at bioanode. The major problem in such device, is however limited power production due to slow kinetic of oxygen reduction at cathode. It is worthwhile to develop new materials that fulfil these requirements. The polymerization of aniline onto carbon cloth for effective electrodeposition of platinum nanoparticles has been carried out by chronoamperometry and cyclic voltammetry. Three materials were thus elaborated, namely pristine carbon cloth, carbon cloth modified with platinum and carbon cloth modified by polymerization of aniline for immobilization of Pt-nanoparticles. The FTIR spectroscopy analysis revealed characteristic band located in 1720-1650 cm-1, attributed to imine function, main component in skeleton of polymer PANI chain. The modified materials have been utilized as cathode in cell inoculated with medicinal plant wastes for improvement of oxygen reduction. Modified cathode with CC-PANI-Pt proved higher performances in all respects: increase of cell voltage from 338 to 765 mV and power density from 862 to 1510 mW/m2 and abatement of COD of microbial inoculum leachate to 88%. Another feature of cell with modified cathode CC-PANI-Pt, was the enormous electric charge density harvested upon oxidation of 1 mL of acetate 7.62 C/cm2 compared to that of cell with pristine CC cathode 0.54 C/cm2. Nevertheless, coulombic efficiency for conversion of medicinal plant wastes into bioenergy was relatively lower 9%, making in evidence that elaborated electrochemical device was rather efficient and benificial environmentally than energetically.

Abdelghani Ghanam, Sebastien Cecillon, Hasna Mohammadi et al.

Micromachines • 2023

This study introduces the utilization of self-powered microbial fuel cell (MFC)-based biosensors for the detection of biotoxicity in wastewater. Current MFC-based biosensors lack specificity in distinguishing between different pollutants. To address this limitation, a novel approach is introduced, capitalizing on the adaptive capabilities of anodic biofilms. By acclimating these biofilms to specific pollutants, an enhancement in the selectivity of MFC biosensors is achieved. Notably, electrochemically active bacteria (EAB) were cultivated on 3D porous carbon felt with and without a model toxicant (target analyte), resulting in the development of toxicant-resistant anodic biofilms. The model toxicants, Pb2+ ions and the antibiotic neomycin sulfate (NS), were deployed at a concentration of 1 mg L-1 during MFC operation. The influence of toxicity on biofilm growth and power production was investigated through polarization and power density curves. Concurrently, the electrochemical activity of both non-adapted and toxicity-adapted biofilms was investigated using cyclic voltammetry. Upon maturation and attainment of peak powers, the MFC reactors were evaluated individually as self-powered biosensors for pollutant detection in fresh wastewater, employing the external resistor (ER) mode. The selected ER, corresponding to the maximum power output, was positioned between the cathode and anode of each MFC, enabling output signal tracking through a data logging system. Subsequent exposure of mature biofilm-based MFC biosensors to various concentrations of the targeted toxicants revealed that non-adapted mature biofilms generated similar current-time profiles for both toxicity models, whereas toxicity-adapted biofilms produced distinctive current-time profiles. Accordingly, these results suggested that merely by adapting the anodic biofilm to the targeted toxicity, distinct and identifiable current-time profiles can be created. Furthermore, these toxicity-adapted and non-adapted biofilms can be employed to selectively detect the pollutant via the differential measurement of electrical signals. This differentiation offers a promising avenue for selective pollutant detection. To the best of our current knowledge, this approach, which harnesses the natural adaptability of biofilms for enhanced sensor selectivity, represents a pioneering effort in the realm of MFC-based biosensing.

Souichiro Kato

International Journal of Molecular Sciences • 2017

Geobacter species are capable of utilizing solid-state compounds, including anodic electrodes, as electron acceptors of respiration via extracellular electron transfer (EET) and have attracted considerable attention for their crucial role as biocatalysts of bioelectrochemical systems (BES’s). Recent studies disclosed that anode potentials affect power output and anodic microbial communities, including selection of dominant Geobacter species, in various BES’s. However, the details in current-generating properties and responses to anode potentials have been investigated only for a model species, namely Geobacter sulfurreducens. In this study, the effects of anode potentials on the current generation and the EET paths were investigated by cultivating six Geobacter species with different anode potentials, followed by electrochemical analyses. The electrochemical cultivation demonstrated that the G. metallireducens clade species (G. sulfurreducens and G. metallireducens) constantly generate high current densities at a wide range of anode potentials (≥−0.3 or −0.2 V vs. Ag/AgCl), while the subsurface clades species (G. daltonii, G. bemidjensis, G. chapellei, and G. pelophilus) generate a relatively large current only at limited potential regions (−0.1 to −0.3 V vs. Ag/AgCl). The linear sweep voltammetry analyses indicated that the G. metallireducens clade species utilize only one EET path irrespective of the anode potentials, while the subsurface clades species utilize multiple EET paths, which can be optimized depending on the anode potentials. These results clearly demonstrate that the response features to anode potentials are divergent among species (or clades) of Geobacter.

Anwar Ma'ruf, Tia Anggraeni

Research in Chemical Engineering (RiCE) • 2024

Microbial Fuel Cell (MFC) is a system for generating electrical energy by utilizing the interaction of bacteria with substrate. MFC generates electricity by oxidizing organic matter with the help of microbes. In this study, the substrate is tofu wastewater and cow rumen bacteria. The MFC used is a dual chamber equipped with a TiO2 clay ceramic membrane. This study aimed to determine the production of electrical energy from tofu liquid waste substrate using MFC technology with the addition of nutrients in the form of urea and bacteria from the cow's rumen. The variation of the ratio of tofu liquid waste used is 20%. 40%, 60%, 80% and 100%. While the variations in the concentration of urea used were 1 - 5 grams. The results show that the greater the variation in the ratio of tofu liquid waste, the greater the energy potential. The highest average electric power is 381 volts from the 100% tofu liquid waste ratio. In addition, the greater the urea concentration the more it produces a large energy potential. The highest average electric power is 421 volts from 5 grams of urea concentration. The TiO2 clay ceramic membrane in the MFC system was able to reduce the TSS and TDS values of tofu liquid waste. The highest percentage decrease for TSS is 37% and for TDS is 25% at the variation of the ratio of tofu liquid waste 100%.

Paweł P. Włodarczyk, Barbara Włodarczyk

Energies • 2025

A microbial fuel cell (MFC) is a bio-electrochemical system that utilizes electroactive microorganisms to generate electricity. These microorganisms, which convert the energy stored in substrates such as wastewater into electricity, grow on the anode. To ensure biocompatibility, anodes are typically made from carbon-based materials. Therefore, a carbon-based material (by-product of coconut processing) was selected for testing in this study. The anode was prepared by bonding activated coconut carbon with carbon paint on a glass electrode. The aim of this study was to analyze the feasibility of using an electrode prepared in this manner as a surface layer on the anode of an MFC. The performance of an electrode coated only with carbon paint was also evaluated. These two electrodes were compared with a carbon felt electrode, which is commonly used as an anode material in MFCs. In this research, the MFC was fed with a by-product of yeast production, namely a molasses decoction from yeast processing. Measurements were conducted in a standard two-chamber glass MFC with a glass membrane separating the chambers. During the experiment, parameters such as start-up time, cell voltage during MFC start-up, output cell voltage, and power density curves were analyzed. The carbon paint-coated electrode with the activated coconut carbon additive demonstrated operating parameters similar to those of the carbon felt electrode. The results indicate that it is possible to produce electrodes (on a base of by-product of coconut processing) for MFCs using a painting method; however, to achieve a performance comparable to carbon felt, the addition of activated coconut carbon is necessary. This study demonstrates the feasibility of forming a biocompatible layer on various surfaces. Incorporating activated coconut carbon does not complicate the anode fabrication process, as fine ACC grains can be directly applied to the wet carbon paint layer. Additionally, the use of carbon paint as a conductive layer for the active anode in MFCs offers versatility in designing electrodes of various shapes, enabling them to be coated with a suitable active and conductive layer to promote biofilm formation. Moreover, the findings of this study confirm that waste-derived materials can be effectively utilized as electrode components in MFC anodes. The results validate the chosen research approach and emphasize the potential for further investigations in this field, contributing to the development of cost-efficient electrodes derived from by-products for MFC applications.

Felipe Vejarano, Enrique Bravo-Montaño, Neyla Benítez-Campo et al.

Revista de Ciencias • 2019

A dual-chambered microbial fuel cell with aqueous cathode was operated with domestic wastewater to investigate the electrogenic ability of anaerobic bacteria from a municipal wastewater treatment plant. Curves of cell potential vs. current density, power density vs. current density and current at a fixed load of 100 Ω, were obtained daily to monitor the electrochemical evolution of the system as a function of substrate use in several batch cycles. A maximum power density of 1.11 µWcm-2 was obtained after 65 days of continuous operation and a coulombic efficiency of 7% and a chemical oxygen demand removal of 76% were found in the last batch cycle. Anaerobic culture of the bacteria from the anode biofilm resulted in the isolation of two Gram-positive and two Gram-negative bacteria with divergent sugar fermentation capabilities, while analysis of 16S rRNA gene fragments showed three clones from the phyla Firmicutes, δ-Proteobacteria and α-Proteobacteria. Scanning electron imaging analysis revealed an increase in cell diversity and proliferation of methanogenic archaea when changing from synthetic to real wastewater. These results reveal the influence of substrate concentration and presence of methanogenic microorganisms on the production of power in microbial fuel cells, suggesting that future developments could be a contribution for the use of this technology to decontaminate domestic wastewater in small communities.

Diana Y. Alvarez Esquivel, Yuting Guo, Robert K. Brown et al.

ChemElectroChem • 2020

Abstract Whey is a main by‐product of the dairy industry and is difficult to valorise for small and medium enterprises. Microbial electrochemical technologies could be the key for these enterprises to exploit this current waste product. Whey removal and conversion to electrical current was investigated at microbial anodes using potentiostatically controlled half‐cell experiments. The anodes were fed with a whey solution containing ca. 1 g L −1 COD. This can be reliably cleaned with average removal efficiencies of 65.8±10.9 %. The removal coincided with maximum current densities of 0.31±0.06 mA cm −2 and Coulomb efficiencies of 37.1±10.8 %. The anodes are based on a robust complex microbial community. This was established in bioelectrochemical reactors by end of four batch cycles showing an efficient niche differentiation from the following successive enrichments. The microbial analysis revealed a division of labour with mainly planktonic microorganisms degrading the complex whey components by fermentation to organic acids, part of which are subsequently used by the electroactive bacteria at the anode. The results show the need for deciphering microbial structure‐function relationships for future process steering as well as engineering approaches.