Microbial Fuel Cells Research Articles

Performance Evaliuation of Microbial Fuel Cell in Treating Industrial Effuelent and Energy Production

Performance Evaliuation of Microbial Fuel Cell in Treating Industrial Effuelent and Energy Production

Design and Optimization of Critical-Raw-Material-Free Electrodes towards the Performance Enhancement of Microbial Fuel Cells

Microbial fuel cells (MFCs) are sustainable energy recovery systems because they use organic waste as biofuel. Using critical raw materials (CRMs), like platinum-group metals, at the cathode side threatens MFC technology’s sustainability and raises costs. By developing an efficient electrode design for MFC performance enhancement, CRM-based cathodic catalysts should be replaced with CRM-free materials. This work proposes developing and optimizing iron-based air cathodes for enhancing oxygen reduction in MFCs. By subjecting iron phthalocyanine and carbon black pearls to controlled thermal treatments, we obtained Fe-based electrocatalysts combining high surface area (628 m2 g−1) and catalytic activity for O2 reduction at near-neutral pH. The electrocatalysts were integrated on carbon cloth and carbon paper to obtain gas diffusion electrodes whose architecture was optimized to maximize MFC performance. Excellent cell performance was achieved with the carbon-paper-based cathode modified with the Fe-based electrocatalysts (maximum power density-PDmax = 1028 mWm−2) compared to a traditional electrode design based on carbon cloth (619 mWm−2), indicating the optimized cathodes as promising electrodes for energy recovery in an MFC application.

Biological mechanisms affecting the release of greenhouse gases from microbial fuel cell-constructed wetland by simultaneously altering structure and electron shuttles

The utilization of microbial fuel cells (MFCs) for regulating greenhouse gas (GHG) emissions in constructed wetlands (CW) has attracted significant attention. The impact of structural modifications, the introduction of iron-carbon materials on pollutant removal and GHG release from MFC-CW has not been systematically studied. In this study, four types of MFC-CWs were constructed, including MFC-CW with separated aerobic and anaerobic zones (SC), MFC-CW with unseparated aerobic and anaerobic zones (IC), SC added with iron-carbon (SFC), and IC added with iron-carbon (IFC). The aim was to investigate the effects of structural changes and electron shuttle additions on the GHG release. The results revealed that IFC simultaneously enhanced pollutant removal and GHG emissions reduction, compared to IC. However, no significant enhancements were observed in SC and SFC. The cumulative emissions of nitrous oxide (N2O) and methane (CH4) in SC were reduced by 51.83% and 89.33% respectively, compared to IC. The modifications made to the structure of MFC-CWs influenced the relationship between functional bacteria (Chlorobium, Azospira, and Denitratisoma) and electrochemically active bacteria (EAB), resulting in increased values of nirS/nosZ and pmoA/mcrA. Comparing the SFC and IFC, despite an improvement in denitrogenation efficiency, the effect of structural alteration on N2O reduction was slight. The electrons in the iron-mediated process were not effectively used for N2O reduction. This study confirmed the crucial involvement of electron shuttles and the structure of MFC-CWs in controlling contaminant removal and GHG emissions.

The Important Role of Denitrifying Exoelectrogens in Single-Chamber Microbial Fuel Cells after Nitrate Exposure

The Important Role of Denitrifying Exoelectrogens in Single-Chamber Microbial Fuel Cells after Nitrate Exposure

EXPLORING FACTORS AFFECTING NITROGEN ISOLATION BY CATION EXCHANGE MEMBRANE AND THEIR IMPLICATIONS FOR MICROBIAL FUEL CELL PERFORMANCE IN WASTEWATER TREATMENT

This study explores the utilization of a cation exchange membrane (CEM) in a microbial fuel cell (MFC) system to isolate nitrogen from wastewater influents. While employing a CEM in an MFC system has drawbacks, such as increased internal resistance and reduced power output, it also provides a means for optimal energy recovery from organics while allowing isolated nitrogen to be treated in subsequent steps. This study evaluated the diffusion of ammonium through CEM in a dual-chamber MFC under different operating conditions. Results indicated that the MFC reactor with CEM as a separator isolated 88-93% of the nitrogen input, demonstrating the feasibility of this approach for nitrogen separation in wastewater treatment applications. Factors affecting nitrogen isolation, including COD input at the anode, dissolved oxygen (DO) at the cathode, and external resistance (ER), are identified. Higher COD input at the anode and the DO at the cathode were found to enhance nitrogen separation, while increased ER had an adverse effect on nitrogen isolation capacity. Additionally, changes in the surface characteristics of the CEM during operation could impact nitrogen isolation, emphasizing the need for careful monitoring and maintenance of the CEM to ensure consistent performance over time. In conclusion, this study highlighted the potential of using a CEM in MFC systems for nitrogen isolation, provided insights into the factors affecting the efficacy of nitrogen separation, and underscored the need for monitoring and maintenance of the CEM. These results could significantly impact the development of more efficient and sustainable wastewater treatment using the MFC system.

Bio-carbon microtubules in microbial fuel cells for superior performance of 3D free-standing anode derived from Rhus Typhina

Microbial fuel cells (MFCs) have emerged as a promising technology for sustainable energy production. However, the power density of MFCs is limited by the anode performance. In this study, Rhus typhina was used as a raw material for the synthesis of 3D freestanding electrodes by freeze-drying and one-step carbonization. Based on the unique micron-scale tubular structure, Rhus typhina carbon (RtC) increases the active bacterial colonization surface area several times and improves the extracellular electron transfer (EET) by augmenting the interaction between the bacteria and the anode. In addition, 16S rRNA gene sequence analysis indicates that the obtained RtC-900 anode promotes enrichment of the major exoelectrogens (Geobacter), and the relative abundance reaches 70.3%. The maximum power density of the dual-chamber MFC with the 3D free-standing anode is 6.01 W m−2, and the stable power output over 300 days is superior to that of conventional MFC in performance.

Microbial fuel cells with polychlorinated biphenyls contaminated soil as electrolyte: energy performance and decontamination potential in presence of compost

The electrical performance of Terrestrial Microbial Fuel Cells (TMFCs) with soil as the electrolyte was tested with two concentrations (150 or 250 ng/g soil) of PCBs (Polychlorinated biphenlys) and compost (3 % w/w) in an experiment lasting 60–80 days. Energy output levels were recorded daily by varying the external resistance for detecting the best operating conditions. PCB concentrations and microbiological analyses (total microbial abundance and activity) were performed at the start and end of the experiment. The highest power generation (207 ± 80 mW/m2 at 112.5 Ω) was recorded in the presence of compost with the lowest PCB concentration, when compared to TMFCs without compost (1.5 ± 0.2 mW/m2 at 300.8 Ω). The results demonstrated that the power generation was correlated with a lower internal resistance and a higher microbial activity. Moreover, chemical results indicated a possible threshold of PCB concentration for the concurrently electricity production and PCB degradation. In fact, PCB removal was obtained only in the cells with high PCB concentration, achieving a reduction of 21 % and 16 % with and without compost, respectively. The microbiological results showed that an additional organic carbon source (methanol or compost) promoted microbial activity and abundance. A positive correlation was found between microbial activity and TMFC electrical output only in the case of PCB low concentration, in the presence of compost. No previous studies addressed the performance of TMFCs with different levels of PCBs in terms of soil decontamination and electricity production. Although a longer experiment is needed, considering PCB persistence in soils, this experiment provided useful information and a new insight on the TMFC effectiveness for soil decontamination and electricity production. The results presented here support considerations about soil resilience through microbial communities and orient further research on contaminant degradation by TMFCs.

Effect of Magnesium Oxide Nanoparticles (MgO) on Wastewater Treatment and Electric Current Generation Using Microbial Fuel Cell Technology

Effect of Magnesium Oxide Nanoparticles (MgO) on Wastewater Treatment and Electric Current Generation Using Microbial Fuel Cell Technology

Silver nanowire-doped conductive polymer hydrogel anode for increasing electron transfer and COD removal rate simultaneously in microbial fuel cell

Microbial fuel cell (MFC) can generate electrons through microbial metabolism of organic matter in sewage. In this paper, carbon felt as base material, the conductive polymers polyaniline and polypyrrole combined with silver nanowires were doped in hydrogel, a super hydrophilicity, low electron transfer resistance, good biocompatibility hydrogel MFC anode (PANI-PPy-Ag NWs/CF) were prepared. It showed a hand-torn bread structure, this three-dimensional (3D) porous structure increased microbial attachment amount. The anode could reach a maximum voltage output of 0.66 V in only 5.5 h, and produce a maximum power density of 2196.61 mW/m3. Due to the doping of silver nanowire, a new electronic mode was explored, coulomb efficiency of 31.01 % and an ultra-high COD removal rate (96.69 %) was obtained. This study introduces a conductive composite hydrogel MFC anode, which provides a new idea for the material diversity, electrical production and sewage removal performance of MFC anode.

Reduction of Toxic Metal Ions and Production of Bioelectricity through Microbial Fuel Cells Using Bacillus marisflavi as a Biocatalyst.

Industrialization has brought many environmental problems since its expansion, including heavy metal contamination in water used for agricultural irrigation. This research uses microbial fuel cell technology to generate bioelectricity and remove arsenic, copper, and iron, using contaminated agricultural water as a substrate and Bacillus marisflavi as a biocatalyst. The results obtained for electrical potential and current were 0.798 V and 3.519 mA, respectively, on the sixth day of operation and the pH value was 6.54 with an EC equal to 198.72 mS/cm, with a removal of 99.08, 56.08, and 91.39% of the concentrations of As, Cu, and Fe, respectively, obtained in 72 h. Likewise, total nitrogen concentrations, organic carbon, loss on ignition, dissolved organic carbon, and chemical oxygen demand were reduced by 69.047, 86.922, 85.378, 88.458, and 90.771%, respectively. At the same time, the PDMAX shown was 376.20 ± 15.478 mW/cm2, with a calculated internal resistance of 42.550 ± 12.353 Ω. This technique presents an essential advance in overcoming existing technical barriers because the engineered microbial fuel cells are accessible and scalable. It will generate important value by naturally reducing toxic metals and electrical energy, producing electric currents in a sustainable and affordable way.

Perspectives on microbial fuel cells cathode improvement for bioenergy generation

Studies have shown the unlimited benefits attributed to using microbial fuel cell (MFC) in our scientific societies for the conversion of organic waste materials into bio-energy with the aid of micro-organisms catalyzed anode and enzymatic-microbial influenced cathode via electrochemical reactions. However, numerous shortcomings calling for serious investigations have equally been identified despite the inestimable benefits of this clean energy technology. A major one is the need for MFC cathode improvement to enhance bioenergy generation. The current situations and challenges of using MFC together with loop holes that are needed to be filled by researchers were critically explained. Additionally, this paper examines the importance of microbial fuel cells (MFCs) as a source of renewable energy generation. The major focus was on techniques of improving the output of MFCs via its cathode. The addition of catalyst on cathode surface, upscale integration of MFCs and antifouling of gas diffusion electrodes used in MFCs were discussed. Relevant areas that can be considered for future research on improvement of MFCs cathode for long term operation were stated.

The performance of microbial fuel cell with sodium alginate and super activated carbon composite gel modified anode

Microbial fuel cells (MFCs) have the functions of wastewater treatment and power generation. The incorporation of modified anodes enhances the sustainable power generation performance of MFCs. In this study, to evaluate the feasibility of sodium alginate (SA) as a biocompatible binder, hydrogel mixed with super activated carbon (SAC) and SA was modified the carbon cloth anode of MFC. The results showed that the maximum output voltage in the SAC/SA hydrogel modified anode MFC was 0.028 V, which was increased by 115%, compared with the blank carbon cloth anode. The internal resistance of MFC was 9429 Ω, which was 18% lower than that of control (11560 Ω). The maximum power density was 6.14 mW/m2, which was increased by 365% compared to the control. After modification of SAC/SA hydrogel, the chemical oxygen demand (COD) removal efficiency reached to 56.36% and was 12.72% higher than the control. Coulombic efficiency with modified anode MFC reached 17.65%, which was increased by 104%, compared with the control. Our findings demonstrate the feasibility of utilizing SA as a biocompatible binder for anode modification, thereby imparting sustainable and enhanced power generation performance to MFCs. This study presented a new selectivity for harnessing algal bioresources and improving anode binders in future MFC applications.

Batch and semi-continuous treatment of cassava wastewater using microbial fuel cells and metataxonomic analysis

The treatment of agroindustrial wastewater using microbial fuel cells (MFCs) is a technological strategy to harness its chemical energy while simultaneously purifying the water. This manuscript investigates the organic load effect as chemical oxygen demand (COD) on the production of electricity during the treatment of cassava wastewater by means of a dual-chamber microbial fuel cell in batch mode. Additionally, specific conditions were selected to evaluate the semi-continuous operational mode. The dynamics of microbial communities on the graphite anode were also investigated. The maximum power density delivered by the batch MFC (656.4 μW m-2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-2}$$\\end{document}) was achieved at the highest evaluated organic load (6.8 g COD L-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document}). Similarly, the largest COD removal efficiency (61.9%) was reached at the lowest organic load (1.17 g COD L-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document}). Cyanide degradation percentages (50–70%) were achieved across treatments. The semi-continuous operation of the MFC for 2 months revealed that the voltage across the cell is dependent on the supply or suspension of the organic load feed. The electrode polarization resistance was observed to decreases over time, possibly due to the enrichment of the anode with electrogenic microbial communities. A metataxonomic analysis revealed a significant increase in bacteria from the phylum Firmicutes, primarily of the genus Enterococcus.

Bioanode boosts efficacy of chlorobenzenes-powered microbial fuel cell: Performance, kinetics, and mechanism

Microbial fuel cell (MFC) is a promising device for water decontamination and energy generation. However, the correlation between power generation and pollutant degradation has not been clarified. Herein, a ruthenium–activated carbon (Ru–AC) bioanode was constructed for chlorobenzenes (CBs) treatment. The pollutant tolerance was improved by Ru–AC anode, and the minimum removal efficiencies of CB and ortho-dichlorobenzene (o-DCB) reached 75.1 % and 69.3 %, respectively, which were considerably higher than those of other MFCs (16.3 %–39.7 %). Correspondingly, the maximum output voltage reached 360.7 mV for the Ru–AC anode, whereas the values obtained from others reached 45.2–149.6 mV. Interaction models were introduced to quantify the relationship between power generation and pollutant degradation. The conversion of highly toxic chlorophenols to organic acids could be accelerated by boosting the mass and electron transfer, thereby simultaneously enhancing CBs removal and power generation. This work provided important insights into pollutant-powered MFC development.

16S rRNA Analysis of Electrogenic Bacterial Communities from Soil Microbial Fuel Cells

Electrogenic bacteria present in bioelectrical devices such as soil microbial fuel cells (SMFCs) are powered by the oxidation of organic and inorganic compounds due to microbial activity. Fourteen soils randomly selected from Bergen Community College or areas nearby, located in the state of New Jersey, USA, were used to screen for the presence of electrogenic bacteria. SMFCs were incubated at 35–37 °C. Of the 14 samples, 11 generated electricity and enriched electrogenic bacteria. The average optimal electricity production by the top 3 SMFCs was 152 microwatts. The highest electrical production was produced by SMFC-B1C and SMFC-B1B, with 162 and 152 microwatts, respectively. Microbial DNA was extracted from the biofilm grown on the anodes, followed by PCR analysis of the 16S rRNA V3–V4 region. Next-generation sequencing was performed to determine the structure and diversity of the electrogenic microbial community. The top 3 MFCs with the highest electricity production showed a bacterial community predominantly composed of bacteria belonging to the Bacillota and Pseudomonadota phyla with a significant presence of Euryarcheota members of methanogenic archaea. SMFC-B1C showed a more diverse electrogenic community, followed by SMFC-B1B and SMFC-B1. When analyzing the top 10 bacteria in the SMFCs, 67 percent belonged to the class Clostridia, indicating that anaerobic conditions were required to enrich electrogenic bacterial numbers and optimize electrical production. The ongoing optimization of SMFCs will provide better production of electricity and continuous enhancement of microbial activity to sustain longer operational times and higher levels of electrogenesis. The characterization of electrogenic microbial communities will provide valuable information to understand the contribution of different populations to the production of electricity in bioelectrical devices.

Assessment of biomass material as valuable electrode for high energy performance in microbial fuel cell with biodegradation of organic pollutant

Microbial fuel cells (MFC) have becomea more popular bio-electrochemical approach due to their environmental friendliness and sustainability. The anode is a vital component of the MFC, and its unstable material remains one of the primary causes of poor electron transportation throughout the reactor operations. This study seeks to improve MFC electron transport and naphthalene biodegradation by employing modified palm kernel shell (PKS)-based anode electrodes. These anode fabrications were successfully developed through the combination of PKS-based rGO hybridized into metal oxide modifiers (ZnO and TiO2). The anode electrodes were subsequently assigned PKS-rGO, PKS-rGO/TiO2, and PKS-rGO/ZnO. The power density displayed for PKS-rGO was 35.1 mW/m2, whereas the power density for the PKS-rGO/TiO2 composite anode was found to be 38.2 mW/m2. On the other hand, PKS-rGO/ZnO had a maximum power density of 45.4 mW/m2. The maximum current density (CD) in the anode PKS-rGO/ZnO was 114.0 mA/m2, indicating a comparable pattern of power output. Bacillus sp. and Niallia sp. were identified as exo-electrogens in the microbial study. In the MFC operation, the highest biodegradation efficiency was 85.50 % in the PKS-rGO settings, 92.80 % in PKS-rGO/TiO2, and94.30 % in PKS-rGO/ZnO. SEM and microbiological studies revealed that our anodes were highly biocompatible with microbes. Furthermore, this result proposes future research directions for the mortality ofanodic microbial communitiesin MFC.

Optimization and Modeling of a Dual-Chamber Microbial Fuel Cell (DCMFC) for Industrial Wastewater Treatment: A Box–Behnken Design Approach

Microbial fuel cells (MFCs) have garnered significant attention due to their capacity to generate electricity using renewable and carbon-neutral energy sources such as wastewater. Extensive experimental work and modeling techniques have been employed to dissect these processes and understand their respective impacts on electricity generation. The driving force is to enhance MFC performance for practical applications commercially. Among the various statistical modeling approaches, one particularly robust tool is the Design of Experiments (DoE). It serves to establish the relationships between different variables that influence MFC performance and allows for the optimization of the MFC configuration and operation for scaled-up performances in terms of bioelectricity generation. This study focused on optimizing microbial fuel cells (MFCs) for bioelectricity production using industrial wastewater treatment, employing the Box–Behnken design (BBD) methodology. Through an analysis of response surface models and ANOVA tests, it was found that a combined approach of reduced quadratic, reduced two-factor interaction, and linear models yielded sound results, particularly in voltage yield, COD removal, and current density. Second-order regression models predicted optimal conditions for various parameters, with surface area, temperature, and catholyte dosage identified as critical input variables for optimization. Under these conditions, conducted by the four-factor and three-level Box–Behnken design methodology in a double-chamber MFC unit considering eight output variables—CCV yield, % COD removal, current density, power density, % TSS removal, % CE, and % PO43−—the optimum values were 700 mV, 54.4%, 54.4 mA/m2, 73.7 mW/m2, 99%, 21.2%, and 100%, respectively. At optimum operating conditions, the results revealed a desirability of 76.6% out of a total of 92 iterations. The paper highlights the effectiveness of statistical ANOVA fit-statistics modeling and optimization in enhancing DCMFC performance, recommending its use as a sustainable bioenergy source. Furthermore, validation results supported the above optimization output response findings and confirmed the viability of biorefinery wastewater as an anolyte for scaling up DCMFC bioelectricity generation.

Voltage recovery from frozen microbial fuel cells in the laboratory and outdoor field reactors

Extreme temperature variations are a problem that must be faced in the practical application of microbial fuel cells (MFCs), but MFCs are not extensively described for low and even freezing temperatures. This study assessed the effect of low-temperature shock on the power generation performance and microbial community structure of MFCs. Two scales of MFCs, the small (mL-MFC) and the large (L-MFC), were constructed in the laboratory and their performance was evaluated before and after freezing at −18 °C. The experimental results demonstrate that both MFCs were capable of rapidly restoring their voltage to the previous level after thawing. For the mL-MFC (rGO/Ag), the power density recovered from 194.30 ± 10.84 mW/m2 to 195.57 ± 4.02 mW/m2 after thawing. For L-MFC (carbon felt electrodes), the power density increased significantly from the initial 1.79 mW/m2 to 173.90 mW/m2 after thawing, but the performance degradation problem after reactor amplification still needs to be solved. The sediment microbial fuel cell (SMFC) was successfully constructed and operated in a natural outdoor environment to maintain high voltage output after the period of frost. Microbial analysis indicated after the frost period, psychrotolerant microorganisms enriched on the anode, such as Flavobacterium and Psychrobacter, while the relative abundance of anaerobic methanogenic bacterium decreased. Overall, freeze-thaw operations had a non-negative impact on the performance of MFCs and provided some references for their practical applications.

A Critical Review on the Advancement of the Development of Low-Cost Membranes to Be Utilized in Microbial Fuel Cells

Microbial fuel cells provide a promising solution for both generating electricity and treating wastewater at the same time. This review evaluated the effectiveness of using readily available earthen membranes, such as clayware and ceramics, in MFC systems. By conducting a comprehensive search of the Scopus database from 2015 to 2024, the study analyzed the performance of various earthen membranes, particularly in terms of wastewater treatment and energy production. Ceramic membranes were found to be the most effective, exhibiting superior power density, COD removal, and current density, with values of 229.12 ± 18.5 mW/m2, 98.41%, and 1535.0 ± 29 mW/m2, respectively. The review emphasizes the use of affordable resources like red soil, bentonite clay, CHI/MMT nanocomposites, and Kalporgan soil, which have proven to be effective in MFC applications. Incorporating earthen materials into the membrane construction of MFCs makes them more cost-effective and accessible.

Sewage sludge-derived biocarbons as catalysts of bioanodes in a dual-chamber microbial fuel cell using nejayote as substrate

In this work, nejayote (wastewater from tortilla industry) was evaluated as substrate of a dual-chamber microbial fuel cell (MFC). For this purpose, novel bioanodes were built using Bacillus subtilis (B. subtilis) as the electrochemically active microorganism (EAM), and sewage sludge-derived biocarbon (SSB) and methanol-functionalized SSB (FSSB) as catalysts. The relationship between the physicochemical properties of SSB and FSSB, biocompatibility, electrochemical performance and the percentage of COD removed was analyzed. Up to 70% of chemical oxygen demand (COD) from nejayote was successfully removed using the SSB + B. subtilis bioanode, with the advantage of energy generation by the MFC (Pcell= 1.44 mW m-2 and jcell= 41 mA m-2). An adverse effect was observed when functionalizing SSB to produce FSSB. Despite a fair biocompatibility, the FSSB + B. subtilis bioanode promoted fermentation reactions that increased the COD and charge transfer resistance. The improved performance of SSB + B. subtilis was ascribed to a reasonable biocompatibility, low charge transfer resistance and less limitation to the diffusion of proton species between the biofilm and the substrate. Therefore, the treatment of nejayote in a MFC with the SSB + B. subtilis bioanode was identified as a promising alternative for decreasing COD and generating small amounts of energy, instead of using energy for its remedy.