Zeng Ke, Yuan Ming, An Zhihao et al.

Materials Research Express • 2021

Abstract This study aimed to modify chitosan microspheres to have large specific surface area as cathode catalysts in microbial fuel cell. Nitrogen-rich chitosan microspheres were first prepared and were used as precursors to prepare the activated carbon materials. The activation effects of KOH and activation temperature on the graphitization degree, specific surface area and electrochemical performance were investigated. The materials were characterised through various microscopic analyses and the electrochemical properties of the materials as cathode catalyst were also investigated. Before and after the activation, the materials remained in microspheric morphology, shown by SEM measurement, while the specific surface area of the activated material increased significantly and reached 1562 m 2 g −1 measured by BET. The graphitization degree of the material showed synchronized increase with calcination temperature, which was detected by Raman spectroscopy. The materials activated were rich in nitrogen, revealed by XPS for elemental analysis. When activated at the temperature of 850 °C, the material demonstrated lower internal resistance (0.6 Ω cm −2 ), higher alternating current density (24.27 × 10 –4 A·cm −2 ) and the highest power density (1531 ± 51 mW·m −2 ) which was 1.4 times that of the original carbon felt. It was illustrated by the electrochemical tests that the material prepared from the precursor chitosan microspheres as cathode catalyst has the high activity of oxygen reduction reaction in MFCs.

Thuschapol Kulchartvijit, Chamaporn Chianrabutra, Sirapan Sukontasing et al.

Trends in Sciences • 2022

Microorganisms actively catabolize substrate, and bioelectricity is generated. Microbial fuel cells (MFCs) could be utilized as a power generator in small devices. The discovery of species of microorganisms is called Rhodopseudomonas palustris KU-EGAT 13. The experiments have been conducted with the production of electricity from this type of microorganism in a single chamber microbial fuel cell. The study used 4 surface roughness of anode electrode single chamber micro fuel to study the performance of microbial fuel cell effect from the anode. Three stainless steel plates were polished to uniform roughness to the magnitude between 0.05 and 1 µm. After 24 h of experimentation, the rough electrode’s open-circuit voltage (OCV) and power densities were much higher than that produced by the smooth one. Moreover, the smooth surface is higher than the charge-transfer resistance of the rough electrode. The rough surface’s better electrochemical performance is due to denser biofilm grown on the surface, which was observed by scanning electron microscopy (SEM) and figuring out the microbial number in an image using an ImageJ program.
 HIGHLIGHTS
 
 The new discovery of species of microorganisms is called Rhodopseudomonas palustris KU-EGAT 13 which can produce electricity in a single chamber microbial fuel cell
 The performance of MFCs has gotten an effect from the different anode surface roughness.The biomass growth is larger than a rougher anode surface, which contributes to anode’s efficiency
 After observed by SEM, found that when it is in the highest anode surface roughness directed towards the number of microbes stick on the surface
 
 GRAPHICAL ABSTRACT

Bálint Lóránt, Krisztina László, Gábor Márk Tardy

Periodica Polytechnica Chemical Engineering • 2021

Microbial fuel cells (MFCs) are capable of converting the chemical energy of biodegradable organic matter directly into electricity, thus they can be applied in various fields: waste elimination, biosensor industry and production of renewable energy. In this study, the efficiency of noble metal free carbon aerogel based cathode catalysts was investigated and compared to plain glassy carbon cloth without catalyst (CC ) and platinum containing carbon powder catalyst ( PtC ) in H-type MFCs. Surface extension by carbon aerogel (CA ) enhanced the maximum power density by 34 % compared to CC, to 14.1 W m−3. With nitrogen doped carbon aerogel (NCA) the performance was further increased to 15.7 W m−3. Co-doping the resorcinol-melamine-formaldehyde based aerogel with graphene oxide (GNCA) resulted in an additional power increase of 70 %, indicating that the electrocatalytic activity of NCAs can be considerably improved by co-doping with graphene oxide. Although the performance of GNCA remained below that of PtC (50.2 W m−3) in our investigations, it can be concluded that GNCA based coatings may provide a noble metal free, and therefore competitive and sustainable alternatives for cathode catalysis in MFC based technologies.

Paweł P. Włodarczyk, Barbara Włodarczyk

Energies • 2024

A microbial fuel cell (MFC) is a bioelectrochemical system that generates electrical energy using electroactive micro-organisms. These micro-organisms convert chemical energy found in substances like wastewater into electrical energy while simultaneously treating the wastewater. Thus, MFCs serve a dual purpose, generating energy and enhancing wastewater treatment processes. Due to the high construction costs of MFCs, there is an ongoing search for alternative solutions to improve their efficiency and reduce production costs. This study aimed to improvement of MFC operation and minimize MFC costs by using anode material derived from by-products. Therefore, the proton exchange membrane (PEM) was abandoned, and a stainless steel cathode and a carbon anode were used. To improve the cell’s efficiency, a carbon fiber anode supplemented with activated coconut carbon (ACCcfA) was utilized. Micro-organisms were provided with molasses decoction (a by-product of yeast production) to supply the necessary nutrients for optimal functioning. For comparison, an anode made solely of carbon fibers (CFA) and an anode composed of activated carbon grains without carbon fibers (ACCgA) were also tested. The results indicated that the ACCcfA system achieved the highest cell voltage, power density, and COD reduction efficiency (compared to the CFA and ACCgA electrodes). Additionally, the study demonstrated that incorporating activated coconut carbon significantly enhances the performance of the MFC when powered by a by-product of yeast production.

Rachel Ann Yoho

The FASEB Journal • 2010

Nine microbial fuel cells were constructed using different cathode materials and carbon cloth anodes for voltage production from a pig manure substrate. The cathode materials included: copper, brass, carbon cloth, titanium, sheet lead, galvanized low carbon steel, low carbon steel, aluminum foil‐faced fiberglass, and stainless steel. The open circuit voltage (OCV) of each of these cells was collected over time. The internal resistance (Rint) was measured using a decade resistance box at periodic intervals. From this information, the current (I) could be calculated. Data collection on six of the cells was discontinued due to low voltage production. The remaining three cells (copper, brass, and carbon cloth) continuously generated an OCV for over eighteen weeks. As compared to the discontinued cells, the copper and brass cathode cells produced consistently higher voltages (approximately 0.65 V and 0.55 V) and had currents in the range of 15 to 25 mA and 8 to 10 mA, respectively, for the majority of their life spans. The carbon cloth cathode cell produced high voltages (approximately 0.68 V), but displayed a current of less than 10 mA. These three cells displayed an average bacterial load reduction of approximately 93.6%. This information can be applied towards the development of more efficient microbial fuel cells with higher OCV and current outputs, and cells with increasing efficacy at reducing the bacterial load.

Lyne Woodward, Boris Tartakovsky, Michel Perrier et al.

Biotechnology Progress • 2009

Abstract This study demonstrates real‐time maximization of power production in a stack of two continuous flow microbial fuel cells (MFCs). To maximize power output, external resistances of two air–cathode membraneless MFCs were controlled by a multiunit optimization algorithm. Multiunit optimization is a recently proposed method that uses multiple similar units to optimize process performance. The experiment demonstrated fast convergence toward optimal external resistance and algorithm stability during external perturbations (e.g., temperature variations). Rate of the algorithm convergence was much faster than in traditional maximum power point tracking algorithms (MPPT), which are based on temporal perturbations. A power output of 81–84 mW/L A (A = anode volume) was achieved in each MFC. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009

Yiming Li, Shunde Yin

Clean Technologies • 2024

Significant research endeavors have focused on microbial fuel cell (MFC) systems within wastewater treatment protocols owing to their unique capacity to convert chemical energy from waste into electricity while maintaining minimal nutrient concentrations in the effluent. While prior studies predominantly relied on empirical investigations, there remains a need to explore modeling and simulation approaches. Assessing MFC systems’ performance and power generation based on real wastewater data is pivotal for their practical implementation. To address this, a MATLAB model is developed to elucidate how MFC parameters and constraints influence system performance and enhance wastewater treatment efficiency. Leveraging actual wastewater data from a municipal plant in Guelph, Canada, six sets of MFC models are employed to examine the relationship between power generation and six distinct parameters (inflow velocity, membrane thickness, internal resistance, anode surface area, feed concentration, and hydraulic retention time). Based on these analyses, the final model projects a total power generation of 50,515.16 kW for the entire wastewater treatment plant in a day, capable of supporting approximately 2530 one-person households. Furthermore, the model demonstrates a notably higher chemical oxygen demand (COD) removal rate (75%) compared to the Guelph WWTP. This comprehensive model serves as a valuable tool for future simulations in similar wastewater treatment plants, providing insights for optimizing performance and aiding in practical applications.

G Samudro, P Andarani, Syafrudin et al.

IOP Conference Series: Earth and Environmental Science • 2019

Abstract Energy demand rises significantly correlated to human activities in recent years. In contrary, energy supply from unrenewable resource decreases gradually from year to year. OMW as one of the renewable resources has not been expanded well in Indonesia. Therefore, SMFC will answer the alternative technology to generate electricity from OMW. The objectives of this study are conducted to compare of waste volumes on power generation and COD removal in SMFC and determine the optimum waste volume for SMFC application affected by river sediment microorganism source and mixed waste type. SMFC reactor as MFC single chamber was designed by 2.5-liter volume of plastic houseware utilized with single graphene anode and cathode to increase the power generation. The waste volume as the independent variable was adjusted 1/3; 1/2; 2/3 of the 2.5- liter volume of SMFC reactor, whereas river sediment microorganism source and mixed waste were dependent variables. The power density and COD removal percentage in 1/3VR, 1/2VR, and 2/3VR were compared on days 21 which was the typical day of the optimum performance of SMFC. The result shows that power density and COD removal of waste volume 2/3VR was higher than 1/3VR and 1/2VR. Power density of waste volume 2/3VR increased 1.5 - 3 times of power density of waste volume 1/3VR and 1/2VR, respectively. COD removal of waste volume 1/3, 1/2, and 2/3 remained stable. The optimum waste volume, the higher power density and COD removal, in addition to the result that 2/3 of the waste volume was the optimum result.

Fitriana Fitriana, M A'an Auliq, Faisal Akbar et al.

Jurnal Media Elektro • 2023

Currently, the utilization of cocoa pod has not been maximized, resulting in waste and foul odors that disturb the environment. However, cocoa pod contain a relatively high amount of cellulose compounds that serve as an energy source or nutrition for bacteria to carry out metabolic activities, thus holding the potential to be used as a substrate in microbial fuel cells (MFC). Based on this, the aim of this research is to investigate the bioelectricity generated by a MFC using cocoa pod husk as a substrate, including voltage, current, and power density, in order to determine the potential of cocoa pod husk waste as an electrical energy source. In this study, a double chamber MFC consists of an anode chamber with copper electrodes and a cathode chamber with zinc electrodes, separated by a salt bridge. The bacteria used were Saccharomyces cerevisiae, and the substrate was made from cocoa pod husk waste. Bioelectricity testing involved measuring the voltage, current, and power density produced by the MFC over several minutes. The measurement results for maximum voltage, maximum current generated, and maximum electrical power (at 6 days) from the reactor were as follows: 36.0 mV, 0.19 mA, and 456 mW/m2, respectively.

Ahmed Mustafa Sadeq, Zainab Ziad Ismail

Advancements in Life Sciences • 2024

Background: Detection of bacterial species using 16S rRNA is a popular approach in microbiology. This method focuses on 16S rRNA gene which includes both conserved regions shared among bacterial species and variable regions unique to each species. This study aimed for the first time to apply this technique for identifying and classifying the bacterial species which contribute to the formation of anodic biofilm in a tubular photosynthetic microbial desalination cell (PMDC).Methods: A tubular photosynthesis microbial desalination cell was designed and set up for simultaneous wastewater biotreatment and desalination of seawater associated with clean power generation.16S rRNA sequencing was used for characterization of the dominant microbial strains in the anodic biofilm. The materials involve DNA extracting from bacteria and PCR amplifying for 16S rRNA gene. The kinetic of the bacterial growth in relation to the substrate utilization was studied.Results: The results revealed the identification of 19 new dominant microbial strains; 13 in the initial shallow biofilm and 6 in the developed biofilm. Results of evaluating the PMDC performance demonstrated that maximum removal efficiency of organic content from sewage was 93±3% associated with power generation of 24.3±2.5 mW/m3 and 70±4% desalination efficiency of saline water. Results of the kinetic study of biomass growth demonstrated that among the 5 examined models, Monod and Blackman models significantly fitted the experimental data with determination coefficients (R2) of 0.951 and 0.907, respectively.Conclusion: This study adds to our knowledge of the anode biofilm's involvement in PMDC performance by identifying dominant microbial strains using 16S rRNA sequencing. The findings emphasize microbial contributions to simultaneous treatment of wastewater, desalination of sea water, and electricity generation. This experimental and theoretical investigation paves the way for future breakthroughs in microbial desalination technology, addressing crucial water scarcity issues.Keywords: Photosynthesis microbial desalination cell; Microbial characterization; Biofilm; Bacterial strains; Energy production

B. S. Shilpa, H. S. Dayananda, P. Girish et al.

Journal of Engineering Research and Reports • 2021

The current climate change threat by green house gas emissions from the combustion of fossil fuels has necessitated a search for alternative non-polluting, reliable, renewable and sustainable sources of energy such as solar energy and it’s derivatives. The present work focuses on power generation by Plant-Microbial Fuel Cell using Phragmitesaustralis (Reed plant). The plants were grown in fuel-cell, graphite as anode and carbon felt as cathode, separated by proton-exchange-membrane. During anaerobic microbial metabolism of carbohydrates in the roots, protons and electrons are released, the electrons are donated to the anode by the microbes. These electrons can be channeled through a circuit bearing a load to the cathode. In this work, carbon granules as substratum (control), red soil and carbon granules mixture (30:70) as substratum in varied condition was considered. For control substratum, the max.voltage measured was 0.327 V and power density of 2.06x10-3 mW m-2 was obtained. When red soil mixed with carbon granules in the ratio 30:70, the voltage measured was 0.6 V and the power density was found to be 3.78x10-3 mW m-2. When graded red soil (0.0018 m) mixed with carbon granules in the ratio 30:70, the voltage measured was 0.623 V and the power density was found to be 3.98x10-3 mW m-2. The result proves that the plant microbial fuel cell can be used for generating electricity and is a promising renewable energy technology.

Luke R. Johnson, Xiaohua Wang, Calita Quesada et al.

Electrochem • 2025

Laboratory data from in-cell tests at and near open circuit potentials (OCV) and ex-situ H2O2 vapor exposure tests are used to develop a fluoride emission rate (FER) model for a state-of-the-art 12-µm thin, low equivalent weight, long-chain perfluorosulfonic acid (PFSA) ionomer membrane that is mechanically reinforced with expanded PTFE and chemically stabilized with 2 mol% cerium as an anti-oxidant. The anode FER at OCV linearly correlates with O2 crossover from the cathode and the high yield of H2O2 at anode potentials, as observed in rotating ring disk electrode (RRDE) studies. The cathode FER may be linked to the energetic formation of reactive hydroxyl radicals (·OH) from the decomposition of H2O2 produced as an intermediate in the two-electron ORR pathway at high cathode potentials. Both anode and cathode FERs are significantly enhanced at low relative humidity and high temperatures. The modeled FER is strongly influenced by the gradients in water activity and cerium concentration that develops in operating fuel cells. Membrane stability maps are constructed to illustrate the relationship between the cell voltage, temperature, and relative humidity for FER thresholds that define H2 crossover failure by chemical degradation over a specified lifetime.

Zainab Ziad Ismail, Ali Jwied Jaeel

Journal of Engineering • 2023

In order to reduce the environmental pollution associated with the conventional energy sources and to achieve the increased global energy demand, alterative and renewable sustainable energy sources need to be developed. Microbial fuel cells (MFCs) represent a bio-electrochemical innovative technology for pollution control and a simultaneous sustainable energy production from biodegradable, reduced compounds. This study mainly considers the performance of continuous up flow dual-chambers MFC fueled with actual domestic wastewater and bio-catalyzed with anaerobic aged sludge obtained from an aged septic tank. The performance of MFCs was mainly evaluated in terms of COD reductions and electrical power output. Results revealed that the COD removal efficiency up to 89% was obtained for wastewaters having an average initial COD concentration of 350 mg/L. Stabilized power outputs were clearly observed achieving a maximum value of 170 mW/ m2.

Y. Lee, S. W. Oa

Water Science and Technology • 2014

A cylindrical two chambered microbial fuel cell (MFC) integrated with an anaerobic membrane filter was designed and constructed to evaluate bioelectricity generation and removal efficiency of organic substrate (glucose or domestic wastewater) depending on organic loading rates (OLRs). The MFC was continuously operated with OLRs 3.75, 5.0, 6.25, and 9.38 kg chemical oxygen demand (COD)/(m3·d) using glucose as a substrate, and the cathode chamber was maintained at 5–7 mg/L of dissolved oxygen. The optimal OLR was found to be 6.25 kgCOD/(m3·d) (hydraulic retention time (HRT) 1.9 h), and the corresponding voltage and power density averaged during the operation were 0.15 V and 13.6 mW/m3. With OLR 6.25 kgCOD/(m3·d) using domestic wastewater as a substrate, the voltage and power reached to 0.13 V and 91 mW/m3 in the air cathode system. Even though a relatively short HRT of 1.9 h was applied, stable effluent could be obtained by the membrane filtration system and the following air purging. In addition, the short HRT would provide economic benefit in terms of reduction of construction and operating costs compared with a conventional aerobic treatment process.

Zainab Ziad Ismail, Ali Jassim Mohammed

Journal of Engineering • 2017

In recent years and decades, there is a great need for developing new alternative energy sources or renewable sustainable energy. On the other hand, new technology approaches are growing . towards benefits from the valuable nutrients in wastewater which are unrecoverable by traditional wastewater treatment processes. In the current study, a novel integrated system of microbial fuel cell and anoxic bioreactor (MFC-ANB) was designed and constructed to investigate its potential for slaughterhouses wastewater treatment, nitrogen recovery, and power generation. The system consisted of a double-chamber tubular type MFC with biocathode inoculated with freshly collected activated sludge. The MFC-ANB system was continuously fed with real-field slaughterhouse wastewater, with initial concentrations of COD and ammonium were 990 mg/L and 200 mg-N/L, respectively. The MFC-ANB system was operated for a total period of 43 days. Maximum removal efficiencies of COD, ammonium, nitrate, nitrogen recovery, Columbic efficiency, and power generation were 99%, 99.3%, 100%, 100%, 13.37% and 162.22 mW/m2 , respectively.

Padmanaban Ponmani, P. Parthiban, Mahesh Ramanujam et al.

Research Journal of Chemistry and Environment • 2023

The development of a high-efficiency anode is essential for the use of microbial fuel cells. The metallic conductivity, corrosion resilience, low cost of conducting polyaniline (PANI) and recycled graphene (RGn) pique our interest. In this study, PANI-RGn nanoparticles are polymerized in situ on cotton fabric wrapped with aluminium mesh as the anode for a microbial fuel cell. The MFC was designed as a dual-chambered system and the chambers are separated by a proton exchange membrane (PEM) salt bridge using canteen wastewater. The process parameters including cathodic chamber aeration, nutrient dosage, nitrogen fluxing, stirring and anode geometry, were optimized. The potential difference (mV) and these systems' current (mA) performance have been analyzed. On the use of PANI-RGn carbon cloth as electrodes, the output voltage was found to be of the order of 180mV. The system developed herewith is highly cost-effective because of the use of graphene that has been generated from waste plastic through catalytic pyrolysis. Hence, the present study revealed that a potential green energy alternative is PANI-RGn in situ polymerized cotton fabric and circular aluminium-mesh electrode in anoxic MFC.

Mohammad Shirkosh, Yousef Hojjat, Mohammad Mahdi Mardanpour

Scientific Reports • 2022

Abstract The presented paper fundamentally investigates the influence of different electron transfer mechanisms, various metal-based electrodes, and a static magnetic field on the overall performance of microfluidic microbial fuel cells (MFCs) for the first time to improve the generated bioelectricity. To do so, as the anode of microfluidic MFCs, zinc, aluminum, tin, copper, and nickel were thoroughly investigated. Two types of bacteria, Escherichia coli and Shewanella oneidensis MR-1 , were used as biocatalysts to compare the different electron transfer mechanisms. Interaction between the anode and microorganisms was assessed. Finally, the potential of applying a static magnetic field to maximize the generated power was evaluated. For zinc anode, the maximum open circuit potential, current density, and power density of 1.39 V, 138,181 mA m -2 and 35,294 mW m -2 were obtained, respectively. The produced current density is at least 445% better than the values obtained in previously published studies so far. The microfluidic MFCs were successfully used to power ultraviolet light-emitting diodes (UV-LEDs) for medical and clinical applications to elucidate their application as micro-sized power generators for implantable medical devices.

Mariagiovanna Minutillo, Simona Di Micco, Paolo Di Giorgio et al.

Energies • 2021

Microbial fuel cells (MFCs) have recently attracted more attention in the context of sustainable energy production. They can be considered as a future solution for the treatment of organic wastes and the production of bioelectricity. However, the low output voltage and the low produced electricity limit their applications as energy supply systems. The scaling up of MFCs both by developing bigger reactors with multiple electrodes and by connecting several cells in stacked configurations is a valid solution for improving these performances. In this paper, the scaling up of a single air-cathode microbial fuel cell with an internal volume of 28 mL, has been studied to estimate how its performance can be improved (1523 mW/m3, at 0.139 mA). Four stacked configurations and a multi-electrode unit have been designed, developed, and tested. The stacked MFCs consist of 4 reactors (28 mL × 4) that are connected in series, parallel, series/parallel, and parallel/series modes. The multi-electrode unit consists of a bigger reactor (253 mL) with 4 anodes and 4 cathodes. The performance analysis has point ed out that the multi-electrode configuration shows the lowest performances in terms of volumetric power density equal to 471 mW/m3 at 0.345 mA and volumetric energy density of 624.2 Wh/m3. The stacked parallel/series configuration assures both the highest volumetric power density, equal to 2451 mW/m3 (274.6 µW) at 0.524 mA and the highest volumetric energy density, equal to 2742.0 Wh/m3. These results allow affirming that to increase the electric power output of MFCs, the stacked configuration is the optimal strategy from designing point of view.

Ganjar Samudro, Syafrudin, Winardi Dwi Nugraha et al.

E3S Web of Conferences • 2017

This research is conducted to analyze and determine the optimum of COD concentration containing leaves litter, canteen and composite waste to power density and COD removal efficiency as the indicator of SMFC performance. COD as the one of organic matter parameters perform as substrate, nutrient and dominating the whole process of SMFC. Leaves litter and canteen based food waste were obtained from TPST UNDIP in Semarang and treated in SMFC reactor. Its reactor was designed 2 liter volume and equipped by homemade graphene electrodes that were utilized at the surface of organic waste as cathode and in a half of reactor height as anode. COD concentration was initially characterized and became variations of initial COD concentration. Waste volume was maintained 2/3 of volume of reactor. Bacteria sources as the important process factor in SMFC were obtained from river sediment which contain bacteroides and exoelectrogenic bacteria. Temperature and pH were not maintained while power density and COD concentration were periodically observed and measured during 44 days. The results showed that power density up to 4 mW/m 2 and COD removal efficiency performance up to 70% were reached by leaves litter, canteen and composite waste at days 11 up to days 44 days. Leaves litter contain 16,567 mg COD/l providing higher COD removal efficiency reached approximately 87.67%, more stable power density reached approximately 4.71 mW/m 2 , and faster optimum time in the third day than canteen based food waste and composite waste. High COD removal efficiency has not yet resulted in high power density.

Pritha Chatterjee, M. M. Ghangrekar

Water Science and Technology • 2013

Two different binder materials of varying water affinity, viz. poly vinyl alcohol (PVA) and poly-tetrafluoroethylene (PTFE), and biocide vanillin were tested for cathode fouling in a single chamber air-cathode microbial fuel cell (MFC) constructed with a low-cost baked clayware cylinder and operated under fed-batch mode. PVA and PTFE loadings of 0.5 mg/cm2 were used for MFC-1 and MFC-2, respectively as a binder; and a 1:1 mixture of PVA + PTFE was used as binder in MFC-3 with same binder loading. Vanillin was mixed with PVA and also applied at a loading of 0.5 mg/cm2 for MFC-4. Results showed organic matter removal efficiencies around 90% for all MFCs both before and after fouling. Coulombic efficiency was, however, found to decrease 50% after fouling in the MFC-3 coated with both PVA and PTFE. After 5 weeks of operation, due to fouling 56, 40 and 69% reduction in power densities were observed in MFC-1, MFC-2 and MFC-3, respectively. In the MFC-4 having PVA and vanillin, the least fouling was observed. A consistent volumetric power of 233 mW/m3 was observed for MFC-4, thus potentially offering a suitable solution to alleviate the problem of fouling in the making of single-chamber air-cathode MFCs.

Umair Fazal, AN Tabish, Samina Akbar et al.

Research Square • 2021

Abstract Microbial fuel cells (MFCs) are devices that exploit the electrochemically active microorganisms for the oxidative conversion of organic compounds into electricity. MFC technology is therefore expected to be a viable solution for domestic and industrial wastewater treatment as an alternative to the currently applied activated-sludge process. Despite its potential, the technology is facing application challenges because of high cost, low stability, and limited understanding of cell design and operation. In this experimental study, a double-chambered MFC with graphite electrodes and a proton-conducting membrane is used in a batch mode to study the potential of resource recovery from dairy effluent and identify the process limitations. Results showed a promising cell performance as the chemical oxygen demand of the wastewater reduced from 4520 mg/l to 850 mg/l in 10 days including the time required for biofilm development. The highest open-circuit voltage of 396 mV was recorded on the third day along with the highest power density of 36.39 mW/m 2 corresponding to a current density of 0.30 A/m 2 . Further, the electrochemical impedance spectroscopy revealed that the activation polarization of aerated cathode is the main contributor to cell internal resistance followed by the ohmic resistance.

Nastaran Khodaparastasgarabad, Jayesh Sonowane, Lingling Gong et al.

ChemRxiv • 2023

In addition to offering a promising approach for niche applications in environmental sensing and portable power sources, microfluidic microbial fuel cells (MFCs) can also accelerate the development of mainstream energy applications through studies into fundamental mechanisms and optimization, without complications from nutrient cycling, membrane fouling, or uncontrollable concentration gradients. However, the main hurdle in leveraging microfluidic MFCs for discovery and optimization is their underperformance compared to macrosystems on certain key metrics, notably area-normalized power. To bridge this gap, we showcase a strategy that focuses on (i) technology improvements, (ii) establishment of new performance benchmarks, and (iii) presentation of a universally applicable normalization method for direct comparisons across all MFC scales and that complements areal power densities. Using a pure-culture Geobacter sulfurreducens electroactive biofilm (EAB) applied to a new system that adheres to the strategy above, we observed optimal anode colonization, resulting in the highest recorded power density for a microfluidic MFC of 3.88 W m-2 (24.37 kW m-3) and a normalized energy recovery (0.21 kWh m-3) that nearly matches the average value observed in macrosystems. With these results, the performance gap between micro- and macroscale MFCs is closed, and a road map to move forward is presented.

M. Kondratenko, A. Kulikovsky

Fuel Cells • 2018

Abstract A recent quasi–2D numerical model for low–temperature PEMFC impedance is modified and applied for the first time for fitting the experimental spectra of HT–PEMFC measured at low stoichiometries of the oxygen flow in the range of current densities from 20 to 160 mA cm −2 . The double layer capacitance, the proton conductivity and the oxygen diffusivity of the cathode catalyst layer exhibit linear growth with current density, while the ORR Tafel slope and the GDL oxygen diffusivity are independent from the cell current. The physics behind these dependencies is discussed.

Daqian Jiang, Baikun Li

Water Science and Technology • 2009

In this study, two novel electrode materials were tested to enhance bacterial adhesion and increase power production in microbial fuel cells (MFCs). Polypyrrole (PPy), a nontoxic conductive polymer, was coated on the plain carbon cloth electrodes to bridge with the biopolymers on bacterial cell membranes and to improve the power production. The PPy-coated electrodes increased the initial power from 20 mW/m2 to 160mW/m2 in the first 4-day period. But there was no clear difference between two PPy coating thicknesses (5-cycle coating and 50-cycle coating) in terms of the bacterial adhesion and power production. Granular activated carbon (GAC), a commonly used bacterial support material with high surface area, exhibited a good bacterial adhesion and high power output. GAC-SCMFCs (single chamber MFCs) generated 5W/m3 and maintained the peak power for 6 days. Compared with plain carbon cloth electrodes, GAC-SCMFCs had lower internal resistances and higher power generations. However, GAC-SCMFCs had lower columbic efficiency and energy conversion efficiency than the conventional two chamber MFCs.

Krisna Adhitya Wardhana, Agus Jatnika Effendi

JURNAL SELULOSA • 2019

Membraneless-Microbial Fuel Cell (ML-MFC) satu kompartemen dengan katoda kontak udara saat ini sedang dikembangkan dan menjadi alternatif solusi untuk sumber energi terbarukan yang mampu menghasilkan listrik dari proses degradasi substrat. MFC membutuhkan substrat yang kaya senyawa organik seperti air limbah dari proses pencucian pulp. Pada air limbah ini terdapat lindi hitam dalam kondisi terencerkan yang mengandung lignin dan kaya senyawa organik sehingga memiliki potensi untuk digunakan sebagai substrat dalam reaktor MFC. Selain itu, penggunaan substrat berupa air limbah industri memiliki efek yang baik terhadap lingkungan karena berkontribusi dalam pengurangan kontaminan. Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi awal Chemical Oxygen Demand (COD) air limbah pencucian pulp sebagai substrat terhadap arus dan voltase listrik yang terjadi dalam MFC. Dalam penelitian ini, reaktor MFC mengolah air limbah pencucian secara batch dengan 4 variasi konsentrasi COD yaitu 613 mg/L, 833 mg/L, 940 mg/L, dan 1620 mg/L dengan pH 8,91 - 10,03. Hasil penelitian menunjukkan MFC mampu mereduksi COD air limbah pencucian pulp sebesar 34 - 48%. Terkait potensi listrik, akumulasi arus listrik yang terjadi pada MFC sebesar 12,67- 39,17 mA/m2 pada kisaran voltase tertinggi dari 4 reaktor sebesar 214 - 287 mV. The Concentration Variation of Wastewater From Pulp Washing Process in Membraneless Air Cathode Microbial Fuel CellA one compartment Membraneless-Microbial Fuel Cell (ML-MFC) with an air cathode was recently developed and became alternative solution for renewable energy sources to generate electricity from substrate degradation. MFC needs proper substrate that was rich in organic content such as wastewater from pulp washing process. The wastewater contains black liquor that was already diluted and contains lignin and high organic content, so that it would be potential as MFC substrate. Furthermore, the utilization of industrial wastewater as substrate can contribute positive effect to the environment namely contaminant reduction. This research was conducted to understand the effect of initial Chemical Oxygen Demand (COD) concentration of wastewater from pulp washing process to electricity current and voltage occured from MFC. The wastewater from pulp washing process with 4 initial COD concentrations (61, 833, 940, and 1620 mg/L) and pH ranged from 8,91 to 10,03 were batch treated in a batch system using the MFC. The results showed that 34-48% COD removal can be performed by MFC. Related with electricity potency from MFC, electricity accumulation current happened on 12,67 mA/m2 - 39,17 mA/m2 at highest voltage from 4 reactors of 214-287 mV.

Kalpana Sharma, Soumya Pandit, Bhim Sen Thapa et al.

Catalysts • 2022

Congo red is an azo dye widely used as a colouring agent in textile industries. It is a serious threat due to its carcinogenic effects. Its degradation has been challenging due to its complex yet stable structure. The present study was aimed to investigate the effective degradation of Congo red by bioremediating bacteria isolated from different environments. To investigate predominant microorganisms that degrade Congo red and its functions in microbial fuel cells (MFCs), strains isolated from cow dung (Enterococcus faecalis SUCR1) and soil (Pseudomonas aeruginosa PA1_NCHU) were used as a co-culture inocula. The remarkable results establish that E. faecalis as an excellent microbial source for the biological degradation of dye-contaminated wastewater treatment alongside bioactive treating wastewater with varied concentrations of congo red dye. The highest efficiency percentage of dye degradation was 98% after 3 days of incubation at pH 7 and 37 °C, whereas findings have shown that the decolorization at pH 5 and 6 was lower at 66% and 83.3%, respectively, under the same incubation conditions. Furthermore, the co-culture of E. faecalis SUCR1 and P. aeruginosa at a 1:1 ratio demonstrated improved power generation in MFCs. The maximum power density of 7.4 W/m3 was recorded at a 150 mg L−1 concentration of Congo red, indicating that the symbiotic relation between these bacterium resulted in improved MFCs performance simultaneous to dye degradation.

Deepak Pant, Gilbert Van Bogaert, Christof Porto-Carrero et al.

Water Science and Technology • 2011

Microbial fuel cells (MFCs) are novel bioelectrochemical devices for spontaneous conversion of biomass into electricity through the metabolic activity of the bacteria. Microbial production of electricity may become an important source of bioenergy in future because MFCs offer the possibility of extracting electric current from a wide range of soluble or dissolved complex organic wastes and renewable biomass. However, the materials used in these devices are still not economic and researchers use different materials as cathode and anode in MFCs. This results in variable performance which is difficult to compare. We tested several commercially available materials for their suitability as anode in an acetate fed MFC. Besides, a novel non-platinized activated carbon (AC) based, gas porous air cathode was also tested. Both the anode and cathode were tested in a half cell configuration. Carbon cloth, graphite cloth and dynamically stable anode (DSA) served as ideal anode material with carbon cloth and graphite mesh reaching the open circuit voltage (OCV) of acetate oxidation (−500 mV vs. Ag/AgCl). The effect of increasing concentration of acetate on anode OCV was also investigated and results showed that on increasing the acetate concentration from 10 mM to 40 mM has no adverse impact on the anodic activity towards electrochemical oxidation of acetate. The AC cathode showed stable current (−1.2 mA/cm2) over a period of 100 days.

Ghasem Najafpour, Parisa Nouri, Mostafa Rahimnejad

Linnaeus Eco-Tech • 2017

Microbial Fuel Cell (MFC) is an efficient system for generating low power where wastewater is substrate for the biocatalyst. In this work, Annular Single Chamber Microbial Fuel Cell (ASCMFC) with spiral anode was fabricated and tested. Carbon cloth and stainless steel 400 meshes were selected as cathode and anode electrodes, respectively. In order to enhance the conductivity of anode, the graphite coating was applied. A 40% platinum as catalyst was used on carbon based cathode in MFC. The carbon cloth was coated with 5% Nafion solution. In fact Nafion acts as Proton Exchange Membrane (PEM) in the fabricated MFC. For the first time, wastewater of Chocolate industry with COD 1400 mg/L was used as substrate in anode compartment. Also a mixture of anaerobic sludge from wastewater treatment plant (Qaem-Shahr, Iran) was introduced into MFC. Maximum voltage obtained in the ASCMFC system was 792 mV in an open-circuit mode. Also, Fabricated MFC operating at 30 ◦C, the maximum achieved power density using an external resistance of 500Ω was about 4.8 W/m3. The upshots from single chamber MFC were compared to dual chamber MFC. The findings demonstrate that, due to the generated high power density and voltage by the cell, the ASCMFC has a great potential for COD removal and wastewater treatment.

Anthony C. Okafor, Hector-Martins C. Mogbo

Journal of Fuel Cell Science and Technology • 2011

In this paper, the effects of gas flow rates and catalyst loading on polymer electrolyte membrane fuel cell (PEMFC) performance was investigated using a 50 cm2active area fuel cell fixture with serpentine flow field channels machined into poco graphite blocks. Membrane electrode assemblies (MEAs) with catalyst and gas flow rates at two levels each (0.5 mg/cm2, 1 mg/cm2; 0.3 l/min, 0.5 l/min, respectively) were tested at 60 °C without humidification. The cell performance was analyzed by taking ac impedance, Tafel plot, open circuit voltage, and area specific resistance measurements. It was observed that MEAs with lower gas flow rate had lesser cell resistance compared to MEAs with a higher gas flow rate. Tafel plot shows the highest exchange current density value of 10−2.05 mA cm2 for MEA with 0.5 mg/cm2 catalyst loading tested at reactant gas flow rate of 0.3 l/min signifying it had the least activation loss and fastest reaction rate. Open circuit voltage-time curve shows a higher output voltage and lesser voltage decay rate for MEAs tested at higher gas flow rates.

J. Ma, X. Gao, J. Li et al.

Fuel Cells • 2019

Abstract The anodic activity of anodic catalyst for borohydride oxidation reaction (BOR) and inhibiting the borohydride hydrolysis reaction (BHR) are crucial to development for direct borohydride fuel cells (DBFC). In this paper, binder free CoSn x ‐B/Ni‐foam ( x = 0, 0.33, 0.5, 1) anode catalysts for BOR were prepared by chemical reduction method. It is found that the tin (Sn) is favor for improving the catalytic activity of cobalt (Co) for BOR, meanwhile, the catalytic activity is in relation to Co/Sn atom ratios. A maximum power density of 158 mW cm −2 of DBFC anodic catalytic is achieved at 293 K using CoSn 0.33 ‐B/Ni‐foam which is 1.58 times that of Co‐B/Ni‐foam (100 mW cm −2 ). The constant discharge test of DBFCs showed that the specific capacity or fuel conversion efficiency decrease with the catalytic activity increasing. However, for the same electrocatalyst, the fuel conversion efficiency increased with the discharge current grown, indicating that there is a BHR which was independent of electrocatalyst in the discharge process. The results showed that CoSn x ‐B/Ni‐foam had superior activity for BOR, suggesting their potential application as anodes in DBFC.

R. K. Ahluwalia, X. Wang

Journal of The Electrochemical Society • 2024

Hybrid fuel cell-battery configurations are investigated that overcome thermal management issues in fuel cell powertrains for heavy-duty Class 8 trucks. The battery is sized so that it has sufficient capacity to provide supplemental power and energy on a hill climb transient at end-of-life. A dynamic load sharing strategy is developed to distribute the power demand between the fuel cell system (FCS) and the energy storage system in a manner that optimizes their lifetimes. The FCS end-of-life is identified as the terminal point beyond which the stack cannot generate the rated power with target power density at 0.7 V and 40 °C ambient temperature. Reaching the target lifetime with a-Pt/C cathode catalyst in one hybrid configuration requires voltage clipping to 813 mV, idle power limited to 50 kW, catalyst overloading to 0.45 mg cm −2 total Pt in anode and cathode, and 44% active membrane area oversizing. The stack and FCS drive cycle efficiencies decrease by 4.2% and 5.4%, respectively, during the electrode lifetime. The FCS performance, durability and cost are compared with the targets of 68% peak efficiency, 0.30 mg cm −2 total Pt loading, 2.5 kW/g PGM Pt group metal (PGM) loading, 750 mW cm −2 power density, 25,000-h lifetime and $80/kW cost.

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Global NEST Journal • 2019

<p>Two identical four air-cathode single chamber membrane-less microbial fuel cells were stacked and tested under in series and in parallel electrical configurations. Fermentable household waste extract (FORBI; 0.8 g COD/L) was used as substrate, in all cases. Linear Sweep Voltammetry (LSV) was carried out for the construction of polarization curves which revealed that the highest power ouput (3.88 mW) was obtained under parallel connection as in series connection was found lower due to voltage drop phenomena. Electrochemical Impedance Spectroscopy measurements (EIS) gave an insight in the electrochemical processes occurring within the stack under both electrical connections. The contribution of the individual resistances to the overall internal resistance was defined, designating the significant role of the solution resistance (Rs) and the charge transfer resistance (RCT) under closed circuit conditions.</p>

L. Franck‐Lacaze, C. Bonnet, S. Besse et al.

Fuel Cells • 2009

Abstract The effects of ozone at concentrations near 1000 vppm in air on the performance of a single polymer electrolyte membrane fuel cell (PEMFC) were investigated. Ozone was injected to the cathode alternately with far longer operation periods at 0.54 A cm –2 with ozone‐free air. Impedance spectra were recorded before, during and after exposure to ozone. After the first ozone injection, the loss in voltage was reversible, so were the changes in the resistances of the cell. Subsequent injection periods damaged irreversibly the PEMFC assembly. TEM observations with energy dispersive X‐ray spectroscopy analysis of the various parts of the PEMFC assembly together with the variations of the resistances allowed the ageing mechanism to be highlighted. Ozone was shown to allow partial dissolution of the Pt of the cathode catalyst. The charge transfer resistance was noticeably increased accordingly. Platinum re‐precipitated in the membrane bulk, and was also observed in the cathode‐side GDL. In addition, the likely degradation of the polymer near the triple‐point in the cathode could hinder gas solubility and water removal, as indicated by larger diffusion resistances.

Melda Latif, Paskalina Aprila Tiy, Mumuh Muharam et al.

JURNAL NASIONAL TEKNIK ELEKTRO • 2023

Plant Microbial Fuel Cell (P-MFC) is one of Microbial Fuel Cell type. It can produce electricity and source for plant living. By using the humus soil in the anode chamber, the electron can flow to the cathode chamber. The principle of Plant Microbial Fuel Cell is same with the battery. It flows the direct current. This research makes dual chamber of P-MFC prototype. The salt bridge is used as connection between anode chamber to cathode chamber. The humus soil comes from burning organic waste. Its color is black and contains a lot of microbes. The plant selected in this research was Water Spinach. The number of water spinach were 20 and 25 stems. P-MFC which has more Water Spinach will produce more voltage and current than the others. For 25 Water Spinach, P-MFC produced 762.4 mV no-load average voltage and 125.8 mV, 085 mA for load condition. The result was bigger caused by for more plants will be more microbes resulted in the humus soil.

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Global NEST Journal • 2023

<p>Dual-chamber microbial fuel cell (MFC) was constructed to treat heavy metal wastewater (Pb2+ solution). The results showed the maximum voltage, the maximum electric power density and pb2+ removal were 9.6 mV, 371.0 mV/m2 and 52.3% respectively. The effects of different cathode chamber environments on the production potential (V, volts) and Pb2+ removal rate of strained CD-1 were investigated. The results show that when the cathode chamber is soil, the maximum voltage is 8.88mV, and when the cathode chamber is solution, the maximum voltage is 12.11mV. The removal efficiency of heavy metals polluted from near to far from the electrode plate in the soil is 68.9%, 62.1%, 57.5%, and the removal efficiency of heavy metals in the solution is 67.46%. It can be concluded that when the soil is the cathode chamber. The removal rate of local heavy metals was the highest. When the solution was used as a cathode chamber, the average removal rate of heavy metals was the highest. The bacteria, named strain CD-1, as the electricity production bacteria (EPB) used in the dual chamber microbial fuel cell (MFC), was isolated from activate sludge and identified on its morphology, physichemical properties and phylogenetic positions. The results indicated that strain CD-1 was Gram-negative, rod. Oxidase and catalase reactions were positive. Strain CD-1 could use gluconate, lactose, D-fructose, L-Arabinose, D-arabinose, acetate, propionate, butyrate, lactate, sucrose and glucose, not use melibiose, galactose, N-acetylglucosamine, ethanol and glycerol.16S rRNA gene sequences analysis showed that strain CD-1 was most related to Ochrobactrum sp. (AJ245941）with the homology similarities of 98%. Based on the above results, strain CD-1 was belonged to the genus of Ochrobactrum and seemed to represent a novel species.</p>

A. Chukwujekwu Okafor, Hector-Martins Mogbo

ASME 2010 8th International Fuel Cell Science, Engineering and Technology Conference: Volume 1 • 2009

In this paper, the effects of gas flow rates, and catalyst loading on polymer electrolyte membrane fuel cell (PEMFC) performance was investigated using a 50cm2 active area fuel cell fixture with serpentine flow field channels machined into poco graphite blocks. Membrane Electrode Assemblies (MEAs) with catalyst and gas flow rates at two levels each (0.5mg/cm2, 1mg/cm2; 0.3L/min, 0.5L/min respectively) were tested at 60°C without humidification. The cell performance was analyzed by taking AC Impedance, TAFEL plot, open circuit voltage, and area specific resistance measurements. It was observed that MEAs with lower gas flow rate had lesser cell resistance compared to MEAs with a higher gas flow rate. TAFEL plot shows the highest exchange current density value of −2.05 mAcm2 for MEA with 0.5mg/cm2 catalyst loading operated at reactant gas flow rate of 0.3L/min signifying it had the least activation loss and fastest reaction rate. Open circuit voltage curve shows a higher output voltage and lesser voltage decay rate for MEAs tested at higher gas flow rates.

Bi‐Lin Lai, Zhi‐Hui Xiao, Peng‐Yang Jiang et al.

ChemElectroChem • 2022

Abstract Microbial fuel cells (MFC) are expected to alleviate the energy crisis and environmental pollution. However, both the slow oxygen reduction reaction (ORR) kinetics and the formation of biofilm on the cathode prevent the efficient operation of MFC. Herein, zeolitic imidazole framework (ZIF)‐derived Ag−Fe−N/C catalysts with good electrocatalytic activity are developed by a synthetic strategy of chemisorption, calcination, and photo‐deposition. The optimal Ag−Fe−N/C‐2 has a half‐wave potential (E 1/2 ) of 0.87 V vs. RHE in 0.1 M KOH. The MFC assembled as a cathode exhibits excellent power generation with a maximum power density of 523±7 mW m −2 and long‐term stability, which is better than commercial Pt/C. In addition, the Ag−Fe−N/C‐2 catalyst has the antibacterial ability, which affects the microbial community structure on the cathode biofilm. The results indicate that Ag−Fe−N/C as a bifunctional cathode catalyst with excellent electrocatalytic and antibacterial activity is beneficial to the efficient and long‐term stable operation of MFC.

N. Rajalakshmi, T.T. Jayanth, K.S. Dhathathreyan

Fuel Cells • 2003

Abstract Proton exchange membrane fuel cell (PEMFC) performance degrades when impurities are present in the anode fuel gas, referred to as catalyst poisoning. This paper investigates the effect of carbon dioxide and ammonia as impurities in the anode gas of the PEMFC, and found that the presence of CO 2 decreases the performance of the fuel cell by up to 10%. The performance loss depends on the CO 2 concentration and the exposure time. The voltage loss is recoverable on passing pure hydrogen gas, indicating that a permanent poisoning of the catalyst layer has not taken place. Exposure of the fuel cell to ammonia beyond 20 ppm, even for a short duration, causes permanent PEMFC failure, probably due to the deterioration of the membrane.

Barbara Włodarczyk, Paweł P. Włodarczyk

Energies • 2023

Wastewater has high potential as an energy source. Therefore, it is important to recover even the smallest part of this energy, e.g., in microbial fuel cells (MFCs). The obtained electricity production depends on the process rate of the electrodes. In MFC, the microorganisms are the catalyst, and the cathode is usually made of carbon material (e.g., with the addition of Pt). To increase the MFC efficiency (and reduce costs by reducing use of the noble metals), it is necessary to search the new cathode materials. In this work, the electricity production from yeast wastewater in membrane-less microbial fuel cells with Cu-Ag cathode was analyzed. In the first place, the measurements of the stationary potential of the electrodes (with Cu-Ag catalyst obtained by the electrochemical deposition technique) were performed. Because the cathode is constantly oxidized during the operation of ML-MFC, it was necessary to pre-oxidize the cathodes. Without pre-oxidation, there is a risk of changing the catalytic properties of the electrodes (along with the level of oxidation of the cathodes’ surface) throughout their operation in the ML-MFC. These measurements allowed to assess the oxidation activity of the Cu-Ag cathodes. Additionally, the influence of anodic charge on the catalytic activity of the Cu-Ag cathodes was measured. Next, the analysis of the electric energy production during the operation of the membrane-less microbial fuel cell (ML-MFC) fed by process yeast wastewater was performed. The highest parameters (the power of 6.38 mW and the cell voltage of 1.09 V) were obtained for a Cu-Ag catalyst with 5% of Ag, which was oxidized over 6 h, and after 3 anodic charges. This research proved that it is feasible to obtain the bio-electricity in the ML-MFC with Cu-Ag cathode (fed by yeast wastewater).

Somil Thakur, Bhaskar Das

Environmental Progress & Sustainable Energy • 2020

Abstract Microbial Fuel Cells (MFCs) are capable of producing bioelectricity using bacteria as catalysts that break down the organic matter present in wastewater (WW). The present work demonstrates the synergistic effect of Luffa aegyptiaca (LA) combined with graphite plate as anode material on voltage generation as well as pollution removal as chemical oxygen demand (COD). Three different feed combinations of WW and Reverse Osmosis (RO) concentrate that is ‐ Experiment‐1 (75:25), Experiment‐2 (50:50), and Experiment‐3 (25:75) have been considered and their performances are compared with the system without LA in the anode. The result shows that low organic loading rate (OLR) and more RO concentration in feed inlet led to more voltage and normalized energy recovery (NER) that is – 530 mV and 19.51 Whkg −1 COD −1 , respectively.