Performance Of Microbial Fuel Cells Research Articles

Boosting the Power Performance of Microbial Fuel Cells by Using Dual Nanomaterial-Modified Carbon Felt Electrodes

Boosting the Power Performance of Microbial Fuel Cells by Using Dual Nanomaterial-Modified Carbon Felt Electrodes

Analysis of the potential of the electroactive biofilm growth in a microbial fuel cell type H

Microbial fuel cells (MFC) constitute an attractive alternative as an environmental remediation technology since they can generate electrical current using organic waste as a substrate. Since the performance of MFCs depends on the characteristics of the biofilm on the anode surface, it is important to assess the genetic information of the microorganisms that grow on the electrode. For this purpose, a sewage sludge sample was obtained from a wastewater treatment plant and used to inoculate a type H MFC. Electrochemical characterization, on one hand, indicates that while the biofilm has a typical electrochemical performance reflected by the generated voltage (near 0.4 V) and by the electroactivity observed in cyclic voltammetry experiments, and on the other hand, the metagenomic analysis shows that the most abundant genera are Pseudomonacea, Nitrosomonas, Hyphomonas, and Opitutus. The study also indicates that the biofilm’s electroactive microorganisms can metabolize amino acids, lipids, and carbohydrates and possess genetic tools for ionic transport and energy production. Regarding the electron acceptor/donator capabilities, several oxidases, reductases, and complexes were identified, mainly terminal cytochrome C oxidase and respiratory complex I, which could be associated with the exoelectrogenic capacity of the microorganisms. Finally, the metagenomic information indicates that the biofilm can synthesize rhamnose, sialic acid, and alginate molecules, which could possibly be associated with the formation and consolidation of the microbial biofilm.

Metabolic cross-feeding interactions modulate the dynamic community structure in microbial fuel cell under variable organic loading wastewaters.

The efficiency of microbial fuel cells (MFCs) in industrial wastewater treatment is profoundly influenced by the microbial community, which can be disrupted by variable industrial operations. Although microbial guilds linked to MFC performance under specific conditions have been identified, comprehensive knowledge of the convergent community structure and pathways of adaptation is lacking. Here, we developed a microbe-microbe interaction genome-scale metabolic model (mmGEM) based on metabolic cross-feeding to study the adaptation of microbial communities in MFCs treating sulfide-containing wastewater from a canned-pineapple factory. The metabolic model encompassed three major microbial guilds: sulfate-reducing bacteria (SRB), methanogens (MET), and sulfide-oxidizing bacteria (SOB). Our findings revealed a shift from an SOB-dominant to MET-dominant community as organic loading rates (OLRs) increased, along with a decline in MFC performance. The mmGEM accurately predicted microbial relative abundance at low OLRs (L-OLRs) and adaptation to high OLRs (H-OLRs). The simulations revealed constraints on SOB growth under H-OLRs due to reduced sulfate-sulfide (S) cycling and acetate cross-feeding with SRB. More cross-fed metabolites from SRB were diverted to MET, facilitating their competitive dominance. Assessing cross-feeding dynamics under varying OLRs enabled the execution of practical scenario-based simulations to explore the potential impact of elevated acidity levels on SOB growth and MFC performance. This work highlights the role of metabolic cross-feeding in shaping microbial community structure in response to high OLRs. The insights gained will inform the development of effective strategies for implementing MFC technology in real-world industrial environments.

CNT@Ti3C2TxMXene Nanocomposite Catalysts as Anodes to Improve the Electricity Production Performance of Microbial Fuel Cells

CNT@Ti3C2TxMXene Nanocomposite Catalysts as Anodes to Improve the Electricity Production Performance of Microbial Fuel Cells

Electricity production and nutrient recovery from waste activated sludge via microbial fuel cell and subsequent struvite crystallization: Effect of low temperature thermo-alkaline pretreatment

Microbial fuel cell (MFC) and subsequent struvite crystallization are available low-carbon environmental- friendly techniques for resource utilization of waste activated sludge (WAS). In this study, low temperature thermo-alkaline pretreatment (LTTAP) was innovatively proposed for enhancing MFC electricity generation and subsequent struvite crystallization from WAS. The results indicated that LTTAP at 75 °C and pH 10 not only substantially shortened the start-up time of MFC to 3–4 days, but also significantly increased maximum power density to 5.38 W/m3. Moreover, thermo-alkaline pretreated WAS effectively exhibited stable and high output voltage over long period, compared to unpretreated WAS. Furthermore, pretreated WAS can provide an effective pH buffering function for MFC operation. In addition, about 90 % of phosphate in the pretreated WAS supernatant was recovered by struvite crystallization. The findings herein provided a new route for enhancing electricity production and nutrient recovery from WAS, which can realize the full-scale applicationof WAS resource utilization.

Enhancing microbial fuel cell performance with free-standing three-dimensional N-doped porous carbon anodes

Microbial fuel cells (MFCs) utilize microorganisms as catalysts to transform the chemical energy to electrical power. However, the practical application of MFCs is currently impeded by low power output, which is caused by insufficient microbial colonization on the anode, slow extracellular electron transfer at the microbe-anode interface, and low oxygen reduction reaction catalytic efficiency at the cathode. Herein, a three-dimensional (3D) hierarchical porous anode of Carbonization-CTS-MF/rGOtempreture (CCMF/rGOT) by pyrolyzing crosslinked composite of melamine formaldehyde resin (MF), chitosan (CTS) and graphene oxide (GO). The macroporous anode provides a biocompatible surface for exoelectrogens and 3D electron transfer pathways. In addition, an appropriate balance of graphitic-N and pyrrolic-N content optimizes both conductivity and the number of active sites, thereby synergistically enhancing extracellular electron transfer (EET) efficiency. Therefore, the power density of CCMF/rGO1000 anode is 11.28 W/m3, which surpasses the CCMF1000 anode without 3D reduced graphene oxide (rGO) conductive network (10.04 W/m3), and traditional carbon cloth anode (4.36 W/m3). Moreover, the anode runs stably for more than 200 days with a maximum operating voltage of 0.69 V, which achieves chemical oxygen demand (COD) removal rate of 95.4 %. This work provides a promising strategy to prepare a free-standing 3D anode with enriched exoelectrogens and enhanced EET to improve the MFCs performance.

Impact of biocatalytic behavior of Shewanella sp. through electron transfer processes on effective treatment of beer brewing wastewater in a microbial fuel cell and power generation

AbstractThis study examines the performance of a microbial fuel cell (MFC) utilizing Shewanella bacteria through electrochemical impedance spectroscopy (EIS). Exo‐electrogen bacteria are key agents in an MFC. Shewanella sp. as a common exo‐electrogen bacteria can transfer electrons from the cell surface through different electron transfer mechanisms. In this work, EIS was used to probe the effects of biofilms of Shewanella sp. and the solution of 10% V/V Shewanella on the MFC performance. This research investigates the effects of both microbial biofilms and Shewanella bacterial solutions on MFC efficacy. Findings revealed that biofilm formation on the anode surface significantly reduces anode charge transfer resistance, thereby enhancing power generation. Notably, a 10% Shewanella solution resulted in a 25% higher power density compared to the biofilm. Furthermore, the MFC demonstrated up to 80% chemical oxygen demand removal efficiency in treating brewery wastewater. The study underscores the viability of Shewanella bacterial solutions as an efficient alternative to biofilms, emphasizing their role in improving MFC performance and wastewater treatment efficiency.

Promoting Electricity Production and Cr (VI) Removal Using a Light–Rutile–Biochar Cathode for Microbial Fuel Cells

Microbial fuel cell (MFC) technology holds significant promise for the production of clean energy and treatment of pollutants. Nevertheless, challenges such as low power generation efficiency and the high cost of electrode materials have impeded its widespread adoption. The porous microstructure of biochar and the exceptional photocatalytic properties of rutile endow it with promising catalytic potential. In this investigation, we synthesized a novel Rutile–Biochar (Rut-Bio) composite material using biochar as a carrier and natural rutile, and explored its effectiveness as a cathode catalyst to enhance the power generation efficiency of MFCs, as well as its application in remediating heavy metal pollution. Furthermore, the impact of visible light conditions on its performance enhancement was explored. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis validated the successful fabrication of rutile composites loaded with biochar. The maximum current density and power density achieved by the MFCs were 153.9 mA/m2 and 10.44 mW/m2, respectively, representing a substantial increase of 113.5% and 225% compared to the control group. In addition, biochar-supported rutile MFCs showed excellent degradation performance of heavy metal pollutants under light conditions. Within 7 h, the Cr6+ degradation rate reached 95%. In contrast to the blank control group, the removal efficiency of pollutants exhibited increases of 630.8%. The cyclic degradation experiments also showcased the remarkable stability of the system over multiple cycles. This study successfully integrated natural rutile and biochar to fabricate highly efficient cathode photocatalyst composites, which not only enhanced the power generation performance of MFCs but also presented an environmentally sustainable and economically viable method for addressing heavy metal pollution.

Bifunctional electrode materials: Enhancing microbial fuel cell efficiency with 3D hierarchical porous Fe3O4/Fe-N-C structures

The rational development of high-performance anode and cathode electrodes for microbial fuel cells (MFCs) is crucial for enhancing MFC performance. However, complex synthesis methods and single-performance electrode materials hinder their large-scale implementation. Here, three-dimensional hierarchical porous (3DHP) Fe3O4/Fe-N-C composites were prepared via the hard template method. Notably, Fe3O4/Fe-N-C-0.04-600 demonstrated uniformly dispersed Fe3O4 nanoparticles and abundant Fe-Nx and pyridinic nitrogen, showing excellent catalytic performance for oxygen reduction reaction (ORR) with a half-wave potential (E1/2) of 0.74 V (vs. RHE), surpassing Pt/C (0.66 V vs. RHE). Moreover, Fe3O4/Fe-N-C-0.04-600 demonstrated favorable biocompatibility as an anode material, enhancing anode biomass and extracellular electron transfer efficiency. Sequencing results confirmed its promotion of electrophilic microorganisms in the anode biofilm. MFCs employing Fe3O4/Fe-N-C-0.04-600 as both anode and cathode materials achieved a maximum power density of 831.8 ± 27.7 mW m−2, enduring operation for 38 days. This study presents a novel approach for rational MFC design, emphasizing bifunctional materials capable of serving as anode materials for microorganism growth and as cathode catalysts for ORR catalysis.

Vanadium (V) reduction and the performance of electroactive biofilms in microbial fuel cells with Shewanella putrefaciens

The electron transfer ability of biofilms significantly influences the electrochemical activity of microbial fuel cells (MFCs). However, there is limited understanding of pentavalent vanadium (V(V)) bioreduction and microbial response characteristics in MFCs. In this study, the effect of gradient concentrations of V(V) on the performance of EABs with Shewanella putrefaciens in MFCs was investigated. The results showed that as V(V) concentration increased (0–100 mg/L), the voltage output, power densities, polarization, and electrode potential decreased. V(V) was found to act as an electron acceptor and was reduced during MFCs operation, with a yield of 83.16% being observed at 25 mg/L V(V). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) indicated declining electrochemical performance of the MFCs with escalating V(V) concentration. The content of protein and polysaccharide from extracellular polymeric substances (EPS) in anodic biofilms increased to 66.75 and 49.15 mg/L at 75 mg/L V(V), respectively. Three-dimensional fluorescence spectroscopy confirmed increased humic substances in EPS extraction with V(V) exposure. The functional genes narG, nirK, and gor involved in V(V) reduction were upregulated with rising V(V) concentration through quantitative polymerase chain reaction (qPCR) analysis. Additionally, riboflavin, cytochrome c, nicotinamide adenine dinucleotide (NADH), and electron transport system activity (ETSA), key indicators for assessing electron transfer behavior, exhibited a negative correlation with various V(V) concentrations, decreasing by 31.81%, 57.14%, 67.39%, and 51.41%, respectively, at a concentration of 100 mg/L V(V) compared to the blank control. These findings contribute valuable insights into the response of EABs to V(V) exposure, presenting potential strategies for enhancing their effectiveness in the treatment of vanadium-contaminated wastewater.

Investigation of bioelectricity generation potential of pharmaceutical wastewater through microbial fuel cells operation

Pharmaceutical wastewater (PWW) as an industrial wastewater presents a potential hazard to natural water systems. This wastewater contains organic matter, which is toxic to the various life forms of the system. PWW is one of the major health problems nowadays, not only for aquatic life but also for human beings and the environment. There are several methods such as filtration, advanced oxidation, coagulation and biological membranes been used for the treatment of PWW, however, all of these methods are limited in their results and applications. In this present study, Microbial Fuel Cells (MFCs) represent a new method for treating wastewater, generating electricity, and reducing COD simultaneously. A novel H-type MFC connected with a graphite electrode has been designed for bioelectricity generation, COD reduction as well as PWW treatment. The treatment of PWW showed adequate bioelectricity generation such as Voltage, Current, and Power, of about 775 mV, 0.421 mA, and 583.70 mW at 100 Ω respectively. The percentage of the COD removed ranged from 95.2-96.7% and 12-34% at the different process variables. This study established bioelectricity generation and bio-treatment of PWW.

Exploring and evaluating the relationship between Saccharomyces cerevisiae biofilm maturation on carbon felt anodes and microbial fuel cell performance

Microbial fuel cells (MFCs) hold great promise as sustainable bioenergy sources, with their performance intricately linked to the formation and characteristics of biofilms. This study delves into the bio-electrochemical perspective of biofilms in MFCs, aiming to elucidate their pivotal role in MFC functionality. The investigation focused on a yeast-based MFC operated through 48 h per cycle, with cycle 5 marking the maturation stage of biofilm formation. During this phase, voltage stability was observed, with a stationary phase voltage of 38.9±2.6 mV. Notably, cycle 5 exhibited a significant boost in power density, reaching 8.82 mW m-2, accom­panied by the lowest internal resistance of 100 Ω. Furthermore, the electron transfer rate constant from cycle 5 is 1.14±0.02 s-1, 57 times higher than the initial, underscoring biofilm's catalytic potential. Additionally, cyclic voltammetry unveiled non-linear relationships between redox reaction peak current and scan rate, with a consistent DEp of ~219 mV at 100 mV s-1. Importantly, elemental analysis disclosed incorporating diverse elements (Na, Al, Si, P, S, Cl, K, Ca, Cr, and Fe) into the carbon felt, signifying their association with biofilm development. These findings offer critical insights into optimizing MFC performance through biofilm modulation, advancing sustainable bioenergy technologies.

Effects of Retention Time, pH, Temperature and Type of Fruit Wastes on the Bioelectricity Generation Performance of Microbial Fuel Cell during the Biotreatment of Pharmaceutical Wastewater: Experimental Study, Optimization and Modelling

Effects of Retention Time, pH, Temperature and Type of Fruit Wastes on the Bioelectricity Generation Performance of Microbial Fuel Cell during the Biotreatment of Pharmaceutical Wastewater: Experimental Study, Optimization and Modelling

Enhancing microbial fuel cell performance for distillery wastewater treatment and bioelectricity generation: harnessing niacin as a redox mediator.

The role of redox mediators in improving electron transport from electrochemically active bacteria to the anode is crucial for enhanced bioelectricity output from microbial fuel cells (MFCs), which makes the selection of an ideal mediator very important. This study aims at exploring a new redox mediator niacin (vit B3) for enhanced bioelectricity generation in MFC while treating distillery wastewater through facile modification of anode electrode by niacin doping (MFC-NME) and simple application of niacin to the anolyte (MFC-NAA). Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) of NME confirmed the effective adsorption of niacin onto the carbon felt surface. Notably, MFC-NME exhibited a significantly higher power density (PD) of 6.36 W/m3 compared to MFC-NAA (4.59 W/m3) and control MFC (3.49W/m3). The charge transfer resistance (RCT) in MFC-NME (1.73 Ω) and MFC-NAA (2.06 Ω) were lowered by more than half than that in control MFC (4.33 Ω), which underscores the efficacy of niacin as a redox mediator. SEM analysis revealed improved bacterial attachment over the bioanode in the MFC-NME as compared to that of MFC-NAA and control MFC. Removal of chemical oxygen demand (COD) was higher in MFC-NAA (85%) and MFC-NME (80%) than in control MFC (73%) suggesting that niacin in the anolyte supported greater organic matter removal due to enriched microbial activity. Niacin used in anode modification shows great potential for improved electron transfer and enhanced bioelectricity production and supports greater wastewater treatment performance. The modified bioanode NME exhibits excellent stability.

Phosphomolybdic acid functionalized nano silica for enhanced anti-biofouling effect in polymer electrolyte membranes for microbial fuel cell application

Microbial fuel cells (MFCs) represent a promising technology for simultaneous electricity generation and wastewater treatment. In this study, a single-chambered MFC was fabricated utilizing a novel polymer electrolyte membrane synthesized from sulfonated polyether ether ketone grafted with styrene sulfonic acid (SPEEK/SSA) as the base polymer, and silica decorated with phosphomolybdic acid (SPMA) as a functionalized nanofiller. Various concentrations of SPMA (2.5 %, 5 %, 7.5 %, and 10 %) were incorporated into the SPEEK/SSA membranes and characterized physicochemically. The SPEEK/SSA membrane with 5 wt% SPMA demonstrated the highest proton conductivity (3.75×10−2 S cm−1) and ion exchange capacity (1.68 meq g−1). This PEM also exhibited superior tensile strength (20 MPa) and excellent chemical durability, as evidenced by Fenton's reagent test. Performance evaluation revealed that this membrane achieved a maximum power density of 196.6 mW m−2 at a maximum of 180 mA m−2 current density. Additionally, antibiofouling tests indicated that the 5 % SPMA-incorporated membrane possessed significant antibacterial properties against both gram-positive and gram-negative bacteria and exhibited high biofilm inhibition. The wastewater treatment efficacy of the MFC with the 5 % SPMA membrane was confirmed by a chemical oxygen demand (COD) removal efficiency of 81.49 %, indicating its potential for effective wastewater treatment. Phylogenetic analysis through 16S rRNA sequencing identified major bacterial phyla including Proteobacteria, Bacteroidetes, Chloroflexi, and Firmicutes, with predominant genera such as Pseudomonas and Acidovorax. This study emphasises the potential of nanocomposite membranes to enhance the performance and durability of MFCs while mitigating biofouling, thereby paving the way for future research and development in this field.

The effect of inoculum source of different pollution levels on the performances of microbial fuel cell biosensors

Selection of inoculum sources is a key factor in constructing microbial fuel cells (MFCs), and the property of inoculum sources is greatly affected by the degree of environmental pollution. However, limited attention has been paid to how these differences affect the response of MFC biosensors. Here the effects of inoculum sources with varying pollution levels on the performances of constructed MFCs were evaluated, and the microbial communities were analyzed before and after inoculation. The results showed significant differences in the detection of biochemical oxygen demand (BOD) and toxicity (Cu2+) among the five groups of MFC biosensors. Combined with the data of the microbial community, the results indicated that the increase rate of the initial start-up voltage is related to the abundance of original electroactive bacteria (EAB) in the inoculum source. The higher the abundance of EAB, the faster increase rate in the initial start-up voltage and the shorter start-up time. The difference in the detection range of the BOD should be related to the ability of the microbial communities to withstand the organic shock loads. The microbial community's tolerance to Cu2+ was affected by the original water quality of the inoculum source. The high metal ion content leads to low sensitivity of MFC biosensor to Cu2+ ion. Enterobacteriaceae were abundant in all the five groups of MFCs, indicating that the dominant bacteria can be enriched in MFC anode biofilms with the inoculum sources of different pollution levels. The microbial community compositions of the anode biofilms were affected by the inoculum sources of different pollution levels, which in turn resulted in the differences in MFCs performances.

Leveraging microbial synergy: Predicting the optimal consortium to enhance the performance of microbial fuel cell using Subspace-kNN

Microbial Fuel Cells (MFCs) are a sophisticated and advanced system that uses exoelectrogenic microorganisms to generate bioenergy. Predicting performance outcomes under experimental settings is challenging due to the intricate interactions that occur in mixed-species bioelectrochemical reactors like MFCs. One of the key factors that limit the MFC's performance is the presence of a microbial consortium. Traditionally, multiple microbial consortia are implemented in MFCs to determine the best consortium. This approach is laborious, inefficient, and wasteful of time and resources. The increase in the availability of soft computational techniques has allowed for the development of alternative strategies like artificial intelligence (AI) despite the fact that a direct correlation between microbial strain, microbial consortium, and MFC performance has yet to be established. In this work, a novel generic AI model based on subspace k-Nearest Neighbour (SS-kNN) is developed to identify and forecast the best microbial consortium from the constituent microbes. The SS-kNN model is trained with thirty-five different microbial consortia sharing different effluent properties. Chemical oxygen demand (COD) reduction, voltage generation, exopolysaccharide (EPS) production, and standard deviation (SD) of voltage generation are used as input features to train the SS-kNN model. The proposed SS-kNN model offers an accuracy of 100% during training period and 85.71% when it is tested with the data obtained from existing literature. The implementation of selected consortium (as predicted by SS-kNN model) improves the COD reduction capability of MFC by 15.67% than that of its constituent microbes which is experimentally verified. In addition, to prevent the effects of climate change and mitigate water pollution, the implementation of MFC technology ensures clean and green electricity. Consequently, achieving sustainable development goals (SDG) 6, 7, and 13.

Enhancing microbial fuel cell performance through algal oxygenation: A novel approach for sustainable energy generation

Enhancing microbial fuel cell performance through algal oxygenation: A novel approach for sustainable energy generation

Sustainable Use of the Fungus Aspergillus sp. to Simultaneously Generate Electricity and Reduce Plastic through Microbial Fuel Cells

The improper disposal of plastic waste has become a significant problem, with only a small amount recycled and the rest ending up in landfills or being burned, leading to environmental pollution. In addition, the cost of electric energy has risen by over 100% in the last 20 years, making it unaffordable for remote areas to access this service due to high installation costs, leaving people living far from major cities without electricity. This study proposes an innovative solution to these issues using microbial fuel cell (MFC) technology to simultaneously reduce plastic waste and generate electric energy by utilizing the fungus Aspergillus sp. As a substrate for 45 days. The MFCs reached maximum values of 0.572 ± 0.024 V and 3.608 ± 0.249 mA of voltage and electric current on the thirty-first day, with the substrate operating at a pH of 6.57 ± 0.27 and an electrical conductivity of 257.12 ± 20.9 mS/cm. Furthermore, it was possible to reduce the chemical oxygen demand by 73.77% over the 45 days of MFC operation, while the recorded internal resistance was 27.417 ± 9.810 Ω, indicating a power density of 0.124 ± 0.006 mW/cm2. The initial and final transmittance spectra, obtained using FTIR (Fourier Transform Infrared), showed the characteristic peaks of polyethylene (plastic), with a noticeable reduction in the final spectrum, particularly in the vibration of the C-H compound. After 45 days of fungus operation, the plastic surface used as a sample exhibited perforations and cracks, resulting in a thickness reduction of 313.56 µm. This research represents an initial step in using fungi for plastic reduction and electric energy generation in an alternative and sustainable manner.

PERFORMANCE ASSESSMENT OF A SINGLE CHAMBER MICROBIAL FUEL CELL (MFC)

Microbial fuel cells (MFCs) represent renewable energy technology with potential applications in electricity generation. This study aimed to construct and evaluate the performance of a single-chamber MFC using soil samples. Two MFCs were built for this purpose: one to assess performance by monitoring the variation of voltage and current over time, and the other to examine the effect of cathode surface area on MFC performance. Microbial fuel cells are important due to their potential to generate renewable energy, treat wastewater, remediate contaminated environments, serve as biosensors, and be scalable and integrated with other technologies, making them a promising solution for addressing various environmental and energy challenges. Notable results included recording maximum currents and voltages of 2.2 mA and 0.6 V, respectively, which elucidated the non-linear relationship between current and voltage. Additionally, it was found that the cathode surface area has a direct impact on the current produced. The polarization curve, illustrating current density as a function of voltage, was also analyzed. Another significant finding was a coulombic efficiency of 92.6%. Furthermore, connecting the MFCs in series achieved a voltage of 1.363 V. These results indicate substantial progress in the field. This study contributed to the advancement of MFC technology and its potential for practical applications in renewable energy generation, wastewater treatment, and environmental sustainability.