Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Xuanye Leng, Siyu Chen, Samantha R. McCuskey et al.
Advanced Electronic Materials · 2024
Abstract Bioelectrochemical systems (BES) have garnered significant attention for their applications in renewable energy, microbial fuel cells, biocatalysis, and bioelectronics. In BES, bioelectrodes are used to facilitate extracellular electron transfer among microbial biocatalysts. This study is focused on enhancing the efficiency of these processes through microcompartmentalization, a technique that strategically organizes and segregates microorganisms within the electrode, thereby bolstering BES output efficiency. The study introduces a deoxyribonucleic acid (DNA)‐based reduced graphene oxide (rGO) aerogel engineered as a bioanode to facilitate microorganism compartmentalization while providing an expanded biocompatible surface with continuous conductivity. The DNA‐rGO aerogel is synthesized through the self‐assembly of graphene oxide and DNA, with thermal reduction imparting lightweight structural stability and conductivity to the material. The DNA component serves as a hydrophilic framework, enabling precise regulation of compartment size and biofunctionalization of the rGO surface. To evaluate the performance of this aerogel bioanode, measurements of current generation are conducted using Shewanella oneidensis MR‐1 bacteria as a model biocatalyst. The bioanode exhibits a current density reaching up to 1.5 A·m⁻ 2 , surpassing the capabilities of many existing bioanodes. With its abundant microcompartments, the DNA‐rGO demonstrates high current generation performance, representing a sustainable approach for energy harvesting without reliance on metals, polymers, or heterostructures.
D. Nosek, A. Cydzik‐Kwiatkowska
Journal of Ecological Engineering · 2022
In recent years, much research has focused on energy recovery from biomass as an alternative to fossil fuel usage. Microbial fuel cells (MFCs), which produce electricity via microbial decomposition of organic matter, are of great interest. The performance of an MFC depends on the electrode material; most often, carbon materials with good electrical conductivity and durability are used. To increase the power output of an MFC, the anode material can be modified to reduce the internal resistance and increase the anode surface area. Therefore, this study determined how modifying a carbon felt anode with reduced graphene oxide (rGO) and a combination of rGO with iron (III) oxide (rGO-Fe) affected electricity generation in an MFC fueled with wastewater. A mixed microbial consor tium was used as the anode biocatalyst . The MFC-rGO-Fe produced significantly higher voltages than other cells (average 109.4 ± 75.1 mV in the cycle). Power density curves indicated that modifying the anode with rGO-Fe increased the power of the MFC to 4.5 mW/m 2 , 9.3- and 3.9-times higher than that of the control MFC and the MFC-rGO, respectively. Anode modification reduced the internal resistance of the cells from 1029 Ω in the control MFC to 370 and 290 Ω in the MFC-rGO and MFC-rGO-Fe, respectively. These results show that a mixture of rGO with iron (III) oxide positively affects electricity production and can be successfully used for anode modification in the MFCs fueled with wastewater.
Lizhen Zeng, Lixia Zhang
RSC Advances · 2025
A novel multilayer nanoflake structure of manganese oxide/graphene oxide (γ-MnO2/GO) was fabricated via a simple template-free chemical precipitation method, and the modified carbon felt (CF) electrode with γ-MnO2/GO composite was used as an anode material for microbial fuel cells (MFCs). The characterization results revealed that the γ-MnO2/GO composite has a novel multilayer nanoflake structure and offers a large specific surface area for bacterial adhesion. The electrochemical analyses demonstrated that the γ-MnO2/GO composite exhibited excellent electrocatalytic activity and enhanced the electrochemical reaction rate and reduced the electron transfer resistance, consequently facilitating extracellular electron transfer (EET) between the anode and bacteria. The maximum power density of MFC equipped with the γ-MnO2/GO composite-modified carbon felt anode was 1.13 ± 0.09 W m−2, which was 119% higher than that of the pure commercial carbon felt anode under the same conditions. Thus, the results demonstrate that the multilayer γ-MnO2/GO nanoflake composite-modified carbon felt anode is a promising anode material for high-performance MFC applications.
V. Fedina, A.A. Kovaleva, S. Alferov
XI Международная конференция молодых ученых: биоинформатиков, биотехнологов, биофизиков, вирусологов, молекулярных биологов и специалистов фундаментальной медицины — 2024 : сб. тез. · 2024
Biofuel cells are an actively developing technology that involves the use of living systems to generate electricity. In this work, membrane fractions of Gluconobacter oxydans bacteria were applied on electrodes modified with graphene oxide. The modification of graphite felt leads to an increase in its electrochemical properties, due to which the process of electron transfer between the electrode and the biocatalyst is increased.
Xinmin Liu, Zhaoxin Zhou, Ning Liu et al.
Environmental Technology · 2024
ABSTRACT A novel graphene oxide-modified resin (graphene oxide-macroporous adsorption resin) was prepared and used as a multifunctional carrier in an anaerobic fluidized bed microbial fuel cell (AFB-MFC) to treat phenolic wastewater (PW). The macroporous adsorption resin (MAR) was used as the carrier, graphene oxide was used as the modified material, the conductive modified resin was prepared by loading graphene oxide (GO) on the resin through chemical reduction. The modified resin particles were characterized by scanning electron microscopy (SEM), Raman spectroscopy (RS), specific surface area and pore structure analysis. Graphene oxide-macroporous adsorption resin special model was established using the Amorphous Cell module in Materials Studio (MS), and the formation mechanism of graphene oxide-macroporous adsorption resin was studied using mean square displacement (MSD) of the force module. Molecular dynamics simulation was used to study the motion law of molecular and atomic dynamics at the interface of graphene oxide-macroporous adsorption resin composites. The strong covalent bond between GO and MAR ensures the stability of GO/MAR. When the modified resin prepared in 3.0 mg/mL GO mixture was used in the AFB-MFC, the COD removal of wastewater was increased by 9.1% to 72.44%, the voltage was increased by 84.04% to 405.8 mV, and power density was increased by 765.44% to 242.67 mW/m2. GRAPHICAL ABSTRACT
Elitsa Chorbadzhiyska, Ivo Bardarov, Yolina Hubenova et al.
Catalysts · 2020
In this study, graphite–metal oxide (Gr–MO) composites were produced and explored as potential anodic catalysts for microbial fuel cells. Fe2O3, Fe3O4, or Mn3O4 were used as a catalyst precursor. The morphology and structure of the fabricated materials were analyzed by scanning electron microscopy and X-ray diffraction, respectively, and their corrosion resistance was examined by linear voltammetry. The manufactured Gr–MO electrodes were tested at applied constant potential +0.2 V (vs. Ag/AgCl) in the presence of pure culture Pseudomonas putida 1046 used as a model biocatalyst. The obtained data showed that the applied poising resulted in a generation of anodic currents, which gradually increased during the long-term experiments, indicating a formation of electroactive biofilms on the electrode surfaces. All composite electrodes exhibited higher electrocatalytic activity compared to the non-modified graphite. The highest current density (ca. 100 mA.m−2), exceeding over eight-fold that with graphite, was achieved with Gr–Mn3O4. The additional analyses performed by cyclic voltammetry and electrochemical impedance spectroscopy supported the changes in the electrochemical activity and revealed substantial differences in the mechanism of current generation processes with the use of different catalysts.
Danielle T. Bennett, Anne S. Meyer
Applied and Environmental Microbiology · 2025
ABSTRACT Shewanella oneidensis ( S. oneidensis ) has the capacity to reduce electron acceptors within a medium and is thus used frequently in microbial fuel generation, pollutant breakdown, and nanoparticle fabrication. Microbial fuel setups, however, often require costly or labor-intensive components, thus making optimization of their performance onerous. For rapid optimization of setup conditions, a model reduction assay can be employed to allow simultaneous, large-scale experiments at lower cost and effort. Since S. oneidensis uses different extracellular electron transfer pathways depending on the electron acceptor, it is essential to use a reduction assay that mirrors the pathways employed in the microbial fuel system. For microbial fuel setups that use nanoparticles to stimulate electron transfer, reduction of graphene oxide provides a more accurate model than other commonly used assays as it is a bulk material that forms flocculates in solutions with a large ionic component. However, graphene oxide flocculates can interfere with traditional absorbance-based measurement techniques. This study introduces a novel image analysis method for quantifying graphene oxide reduction, showing improved performance and statistical accuracy over traditional methods. A comparative analysis shows that the image analysis method produces smaller errors between replicates and reveals more statistically significant differences between samples than traditional plate reader measurements under conditions causing graphene oxide flocculation. Image analysis can also detect reduction activity at earlier time points due to its use of larger solution volumes, enhancing color detection. These improvements in accuracy make image analysis a promising method for optimizing microbial fuel cells that use nanoparticles or bulk substrates. IMPORTANCE Shewanella oneidensis ( S. oneidensis ) is widely used in reduction processes such as microbial fuel generation due to its capacity to reduce electron acceptors. Often, these setups are labor-intensive to operate and require days to produce results, so use of a model assay would reduce the time and expenses needed for optimization. Our research developed a novel digital analysis method for analysis of graphene oxide flocculates that may be utilized as a model assay for reduction platforms featuring nanoparticles. Use of this model reduction assay will enable rapid optimization and drive improvements in the microbial fuel generation sector.
Wu Hao, Sang-Hun Lee, Shaik Gouse Peera
Nanomaterials · 2023
Current study provides a novel strategy to synthesize the nano-sized MnO nanoparticles from the quick, ascendable, sol-gel synthesis strategy. The MnO nanoparticles are supported on nitrogen-doped carbon derived from the cheap sustainable source. The resulting MnO/N-doped carbon catalysts developed in this study are systematically evaluated via several physicochemical and electrochemical characterizations. The physicochemical characterizations confirms that the crystalline MnO nanoparticles are successfully synthesized and are supported on N-doped carbons, ascertained from the X-ray diffraction and transmission electron microscopic studies. In addition, the developed MnO/N-doped carbon catalyst was also found to have adequate surface area and porosity, similar to the traditional Pt/C catalyst. Detailed investigations on the effect of the nitrogen precursor, heat treatment temperature, and N-doped carbon support on the ORR activity is established in 0.1 M of HClO4. It was found that the MnO/N-doped carbon catalysts showed enhanced ORR activity with a half-wave potential of 0.69 V vs. RHE, with nearly four electron transfers and excellent stability with just a loss of 10 mV after 20,000 potential cycles. When analyzed as an ORR catalyst in dual-chamber microbial fuel cells (DCMFC) with Nafion 117 membrane as the electrolyte, the MnO/N-doped carbon catalyst exhibited a volumetric power density of ~45 mW m2 and a 60% degradation of organic matter in 30 days of continuous operation.
Asim Ali Yaqoob, Albert Serrà, Showkat Ahmad Bhawani et al.
Polymers · 2022
Although regarded as environmentally stable, bioelectrochemical fuel cells or, microbial fuel cells (MFCs) continue to face challenges with sustaining electron transport. In response, we examined the performance of two graphene composite-based anode electrodes—graphene oxide (GO) and GO–polymer–metal oxide (GO–PANI–Ag)—prepared from biomass and used in MFCs. Over 7 days of operation, GO energy efficiency peaked at 1.022 mW/m2 and GO–PANI–Ag at 2.09 mW/m2. We also tested how well the MFCs could remove heavy metal ions from synthetic wastewater, a secondary application of MFCs that offers considerable benefits. Overall, GO–PANI–Ag had a higher removal rate than GO, with 78.10% removal of Pb(II) and 80.25% removal of Cd(II). Material characterizations, electrochemical testing, and microbial testing conducted to validate the anodes performance confirmed that using new materials as electrodes in MFCs can be an attractive approach to improve the electron transportation. When used with a natural organic substrate (e.g., sugar cane juice), they also present fewer challenges. We also optimized different parameters to confirm the efficiency of the MFCs under various operating conditions. Considering those results, we discuss some lingering challenges and potential possibilities for MFCs.
Yuanfeng Liu, Tingli Ren, Zijing Su et al.
Journal of Materials Chemistry A · 2023
Weak biofilm colonization and sluggish extracellular electron transfer (EET) between the biofilm and anode are major obstacles to achieving high power density in microbial fuel cells (MFCs).
Wenxian Guo, Meiqiong Chen, Xiaoqing Liu et al.
Chemistry – A European Journal · 2021
Abstract A simple, cost‐effective strategy was developed to effectively improve the electron transfer efficiency as well as the power output of microbial fuel cells (MFCs) by decorating the commercial carbon paper (CP) anode with an advanced Mo 2 C/reduced graphene oxide (Mo 2 C/RGO) composite. Benefiting from the synergistic effects of the superior electrocatalytic activity of Mo 2 C, the high surface area, and prominent conductivity of RGO, the MFC equipped with this Mo 2 C/RGO composite yielded a remarkable output power density of 1747±37.6 mW m −2 , which was considerably higher than that of CP‐MFC (926.8±6.3 mW m −2 ). Importantly, the composite also facilitated the formation of 3D hybrid biofilm and could effectively improve the bacteria–electrode interaction. These features resulted in an enhanced coulombic efficiency up 13.2 %, nearly one order of magnitude higher than that of the CP (1.2 %).
Yuyang Wang, Huan Yang, Jing Wang et al.
Coatings · 2023
Microbial fuel cells (MFCs) have exhibited potential in energy recovery from waste. In this study, an MFC reactor with a polyaniline–sodium alginate–graphene oxide (PANI–SA–GO)/carbon brush (CB) hydrogel anode achieved maximum power density with 4970 mW/m3 and produced a corresponding current density of 4.66 A/m2, which was 2.72 times larger than the MFC equipped with a carbon felt film (CF) anode (1825 mW/m3). Scanning electron microscopy indicated that the PANI-SA-GO/CB composite anode had a three-dimensional macroporous structure. This structure had a large specific surface area, providing more sites for microbial growth and attachment. When the charging-discharging time was set from 60 min to 90 min, the stored charge of the PANI-SA-GO/CB hydrogel anode (6378.41 C/m2) was 15.08 times higher than that of the CF (423.05 C/m2). Thus, the mismatch between power supply and electricity consumption was addressed. This study provided a simple and environment-friendly modification method and allowed the prepared PANI–SA–GO/CB hydrogel anode to markedly promote the energy storage and output performance of the MFC.
Praveena Gangadharan, Indumathi M. Nambi, Jaganathan Senthilnathan et al.
RSC Advances · 2016
In the present study, a low molecular heterocyclic aminopyrazine (Apy)–reduced graphene oxide (r-GO) hybrid coated carbon cloth (r-GO–Apy–CC) was employed as an active and stable bio-electro catalyst in a microbial fuel cell (MFC).
M. Al-badani, Peng Chong, Heng-Siong Lim
International Journal of Green Energy · 2023
ABSTRACT Microbial fuel cells (MFCs) have attracted much interest as an alternative energy conversion technology and as a system for recovering and treating wastewater. MFC is a powerful technique for generating energy from various sources, including natural organic matter and renewable biomass. It has several possible applications, including power generation for many small electronic devices, wastewater treatment, and biosensors. However, the restricted power output of MFCs is the most significant impediment to their widespread use and up-scaling in practical applications. The anode electrode is the most critical component of an MFC, where poor anode electrode performance leads to poor MFC efficiency. Therefore, efforts have been made to modify electrodes to improve their performance. While power density is an essential metric in determining MFC efficiency, other parameters such as Coulombic efficiency, current density, cell voltage, and the removal rate of chemical oxygen demand (COD) should also be considered to evaluate the performance of MFC. This study reviews the most recent electrode modification techniques through anode treatments with metal oxides, conductive polymers, carbon nanotubes, and other chemical compounds as well as through cathode modifications. Different modified MFCs are compared in terms of their power density and the type of bacteria and membrane used.
Sri Sathya Sandilya Garimella, Sai Vennela Rachakonda, Sai Sowmya Pratapa et al.
Annals of Microbiology · 2024
Microbial fuel cells (MFCs), which use bacterial electron transport mechanisms to generate energy, have become a viable technology for renewable energy production. This review investigates the evolutionary and functional connections between bacterial energy transduction mechanisms and mitochondrial electron transport chains, building on the endosymbiont theory of eukaryotic cell evolution. The conserved features and similarities between prokaryotic and eukaryotic electron transport pathways were elucidated, highlighting their common origins and roles in cellular bioenergetics. This discussion explores the essential mechanisms governing the movement of electrons and ions across biological membranes, crucial for generating energy and maintaining electrochemical gradients in bacteria and mitochondria. Capitalizing on these insights, we explore the applications of electrogenic bacteria in MFCs for renewable electricity generation. Optimal conditions for enhancing bacterial electron transfer to electrode surfaces are identified, paving the way for improved MFC performance. Potential large-scale implementations of MFCs in wastewater treatment, biosensing, and bioremediation of contaminated environments are discussed, underscoring their versatility and environmental benefits. The importance of investigating bioenergetic mechanisms at both the cellular and molecular scales of fully harnessing the capabilities of microbial energy conversion systems is highlighted in this review. By bridging the gap between fundamental cellular processes and sustainable technologies, we aim to advance renewable energy solutions that harness the remarkable capabilities of electrogenic microorganisms.
Akshat Sharma, Lara Đelević, Katharina Herkendell
Energy Technology · 2024
The adoption of microbial fuel cell (MFC) technology hinges on the development of efficient proton‐exchange membranes (PEMs), which significantly influences fuel cell performance and cost. PEMs have a critical role in preventing oxygen crossover, maintaining electrochemical neutrality, and supporting microorganisms within MFCs. Nafion, the current industry‐standard PEM, grapples with environmental, cost, and performance issues. Although improvements to Nafion have been reported using additives, immersion in heteropolyacids, different pretreatment methods, and UV irradiation, many of the challenges still remain. Herein, the recent developments in the area of alternative PEMs are reviewed and analyzed. Among them, sulfonated aromatic hydrocarbons, particularly sulfonated polyether ether ketone, have emerged as top contenders in terms of scale up and commercial viability. At the same time, membranes based on polyvinyl alcohol, ionic liquids, and natural materials are also being actively researched for various MFC applications. Since most studies are short term and lab scale, there is a need evaluate long‐term stability and economic cost of PEMs in terms of standardized parameters such as power‐to‐cost and normalized energy recovery. Additionally, for emerging low‐energy‐density MFC applications like biosensors and in vivo power sources, PEM properties and design need to be tailored carefully.
Huajun Feng, Yuxiang Liang, K. Guo et al.
Environmental Science & Technology Letters · 2016
Titanium has been widely used as a dimensionally stable anode in the electrolysis industry because of its excellent corrosion resistance, conductivity, and scalability. However, because of its poor biocompatibility and poor performance as a bioanode, it has drawn little attention in the field of microbial fuel cells (MFCs). This study reports an efficient way to convert a titanium electrode into a high-performance anode for MFCs, in situ growth of titanium dioxide nanotubes (TNs) on its surface. After TN modification, the titanium surface became rougher, more hydrophilic, and more conducive for anodic biofilm formation. The maximal current density achieved on this TN-modified titanium electrode was 12.7 A m–2, which was 190-fold higher than that of the bare titanium electrode and even higher than that of the most commonly used carbon felt electrode. Therefore, the high conductivity, corrosion resistance, and current density make the TN-modified titanium electrode a promising and scalable anode for MFCs.
Zejie Wang, B. Lim
Environmental Engineering Research · 2019
Sediment microbial fuel cells (SMFCs) illustrated great potential for powering environmental sensors and bioremediation of sediments. In the present study, array anodes for SMFCs were fabricated with graphite rods as anode material and stainless steel plate as electric current collector to make it inconvenient to in situ settle down and not feasible for large-scale application. The results demonstrated that maximum power of 89.4 μW was obtained from three graphite rods, twice of 43.3 μW for two graphite rods. Electrochemical impedance spectroscopy revealed that three graphite rods resulted in anodic resistance of 61.2 Ω, relative to 76.0 Ω of two graphite rods. It was probably caused by the parallel connection of the graphite rods, as well as more biomass which could reduce the charge transfer resistance of the biofilm anode. The presently designed array configuration possesses the advantages of easy to enlarge the surface area, decrease in anodic resistance because of the parallel connection of each graphite rod, and convenience to berry into sediment by gravity. Therefore, the as prepared array node would be an effective method to fabricate large-scale SMFC and make it easy to in situ applicate in natural sediments.
Wenbin Liu, Leiming Lin, Ying Meng et al.
Environmental Science: Nano · 2021
Microbial fuel cell with titanium dioxide nanotube array cathode was first demonstrated as a promising approach for uranium recovery and separation from groundwater.
Weihua He, Xiaoyuan Zhang, Jia Liu et al.
Environmental Science: Water Research & Technology · 2016
A new type of scalable MFC was developed based on using alternating graphite fiber brush array anode modules and dual cathode modules in order to simplify construction, operation, and maintenance of the electrodes. The modular MFC design was tested with a single (two-sided) cathode module with a specific surface area of 29 m2 m−3 based on a total liquid volume (1.4 L; 20 m2 m−3 using the total reactor volume of 2 L), and two brush anode modules. Three different types of spacers were used in the cathode module to provide structural stability, and enhance air flow relative to previous cassette (combined anode–cathode) designs: a low-profile wire spacer; a rigid polycarbonate column spacer; and a flexible plastic mesh spacer. The best performance was obtained using the wire spacer that produced a maximum power density of 1100 ± 10 mW m−2 of cathode (32 ± 0.3 W m−3 based on liquid volume) with an acetate-amended wastewater (COD = 1010 ± 30 mg L−1), compared to 1010 ± 10 mW m−2 for the column and 650 ± 20 mW m−2 for the mesh spacers. Anode potentials were unaffected by the different types of spacers. Raw domestic wastewater produced a maximum of 400 ± 8 mW m−2 under fed batch conditions (wire-spacers), which is one of the highest power densities for this fuel. Over time the maximum power was reduced to 300 ± 10 mW m−2 and 275 ± 7 mW m−2 for the two anode compartments, with only slightly less power of 250 ± 20 mW m−2 obtained under continuous flow conditions. In fixed-resistance tests, the average COD removal was 57 ± 5% at a hydraulic retention time of 8 h. These results show that this modular MFC design can both simplify reactor construction and enable relatively high power generation from even relatively dilute wastewater.
Thorben Muddemann, Dennis Haupt, Bolong Jiang et al.
Processes · 2019
This contribution describes the effect of the quality of the catalyst coating of cathodes for wastewater treatment by microbial fuel cells (MFC). The increase in coating quality led to a strong increase in MFC performance in terms of peak power density and long-term stability. This more uniform coating was realized by an airbrush coating method for applying a self-developed polymeric solution containing different catalysts (MnO2, MoS2, Co3O4). In addition to the possible automation of the presented coating, this method did not require a calcination step. A cathode coated with catalysts, for instance, MnO2/MoS2 (weight ratio 2:1), by airbrush method reached a peak and long-term power density of 320 and 200–240 mW/m2, respectively, in a two-chamber MFC. The long-term performance was approximately three times higher than a cathode with the same catalyst system but coated with the former paintbrush method on a smaller cathode surface area. This extraordinary increase in MFC performance confirmed the high impact of catalyst coating quality, which could be stronger than variations in catalyst concentration and composition, as well as in cathode surface area.
Tianjiao Guo, Chunyan Zhang, Jingkai Zhao et al.
Scientific Reports · 2019
Abstract A Chemical absorption-bioelectrochemical reduction (CABER) system is based on Chemical absorption-biological reduction (CABR) system, which aims at NO removal and has been studied in many of our previous works. In this paper, we applied polypyrrole (PPy) on the electrode of bioelectrochemical reactor (BER) of CABER system, which induced a much higher current density in the cyclic voltammetry (CV) curve for the electrode itself and better NO removal rate in the system. In addition, a Microbial Electrolysis Cell (MEC) is constructed to study its strengthening mechanism. Results shows that PPy-MEC has a greater Faraday efficiency and higher reduction rate of Fe(III)EDTA and Fe(II)EDTA-NO in the solution when compared to original Carbon MEC, which confirms the advantage of PPy-modified electrode(s) in the CABER system. The results of this study are reported for illustration of potential of CABER technology and design of low-cost high-efficiency NO x control equipment in the future.
Xiaolin Zhang, Xiaojing Li, Xiaodong Zhao et al.
RSC Advances · 2019
The great potential of bioelectrochemical systems (BESs) in pollution control combined with energy recovery has attracted increasing attention.
Angela Cantillo-González, Javiera Anguita, Claudia Rojas et al.
Micromachines · 2022
Bioelectrochemical systems (BESs) have been extensively studied for treatment and remediation. However, BESs have the potential to be used for the enrichment of microorganisms that could replace their natural electron donor or acceptor for an electrode. In this study, Winogradsky BES columns with As-rich sediments extracted from an Andean watershed were used as a strategy to enrich lithotrophic electrochemically active microorganisms (EAMs) on electrodes (i.e., cathodes). After 15 months, Winogradsky BESs registered power densities up to 650 μWcm−2. Scanning electron microscopy and linear sweep voltammetry confirmed microbial growth and electrochemical activity on cathodes. Pyrosequencing evidenced differences in bacterial composition between sediments from the field and cathodic biofilms. Six EAMs from genera Herbaspirillum, Ancylobacter, Rhodococcus, Methylobacterium, Sphingomonas, and Pseudomonas were isolated from cathodes using a lithoautotrophic As oxidizers culture medium. These results suggest that the tested Winogradsky BES columns result in an enrichment of electrochemically active As-oxidizing microorganisms. A bioelectrochemical boost of centenarian enrichment approaches, such as the Winogradsky column, represents a promising strategy for prospecting new EAMs linked with the biogeochemical cycles of different metals and metalloids.
Manoj Kumar, Rajesh Singh
Environmental Science: Water Research & Technology · 2020
In the present study, we investigated the role of constructed wetlands (CWs) integrated with a bioelectrochemical system (BES), which can concurrently treat wastewater effectively with energy recovery.
Jing Wang, Ming Li, Fangtai Liu et al.
Journal of Nanomaterials · 2016
We proposed a self-connected carbon nanofiber design for electrode in microbial bioelectrochemical system. This design was realized by direct growth of carbon nanofibers (CNFs) onto stainless steel (SSM) via a chemical vapor deposition process without addition of any external catalysts. In the CNFs-SSM composite electrode, the SSM acted as the conductive network and ensured efficient substrate and proton transfer, and the CNFs layer served as highly porous habitats for thick biofilm propagation. The current generated by the CNFs-SSM was 200 times higher than the bare SSM under the same experimental conditions. This provided a simple and promising method for preparation of electrode material with high performance and low-cost in bioelectrochemical system.
Hui Wang, Ying Du, XiangHua Wang et al.
Fuel Cells · 2024
ABSTRACT Refractory organic pollutant removal can be enhanced by a bioelectrochemical system via the addition of electron donors/acceptors. In this study, a single‐chamber soil microbial fuel cell (MFC) was constructed, and electricity production and atrazine removal efficiency were assessed using different co‐substrates and phosphate buffer concentrations. The co‐substrates compensated for the lack of soil organic matter and provided a sufficient carbon source for microorganisms to facilitate MFC electricity generation and efficient atrazine removal. The maximum voltage (94 mV), power density (39.41 mW m −2 ), removal efficiency (85.30%), and degradation rate (1.68 mg kg −1 d −1 ) were highest in the soil MFCs with sodium acetate when compared with the other groups. Phosphate buffer significantly alleviated the dramatic soil pH change. The electricity generation and atrazine removal efficiency increased with the buffer concentration (0–0.10 g L −1 ). The maximum voltage (144 mV) and power density (89.35 mW m −2 ) were highest, total internal resistance (652 Ω) was lowest, and atrazine removal efficiency (90.95%) and degradation rate (1.54 mg kg −1 d −1 ) were determined in the soil MFCs with the phosphate buffer concentration of 0.10 g L −1 , and. These results indicate that the co‐substrate and phosphate buffer can enhance the electricity generation of soil MFCs and atrazine removal.
Philipp Arbter, Niklas Widderich, Tyll Utesch et al.
Microbial Cell Factories · 2022
Abstract Background Electro-fermentation (EF) is an emerging tool for bioprocess intensification. Benefits are especially expected for bioprocesses in which the cells are enabled to exchange electrons with electrode surfaces directly. It has also been demonstrated that the use of electrical energy in BES can increase bioprocess performance by indirect secondary effects. In this case, the electricity is used to alter process parameters and indirectly activate desired pathways. In many bioprocesses, oxidation-reduction potential (ORP) is a crucial process parameter. While C. pasteurianum fermentation of glycerol has been shown to be significantly influenced electrochemically, the underlying mechanisms are not clear. To this end, we developed a system for the electrochemical control of ORP in continuous culture to quantitatively study the effects of ORP alteration on C. pasteurianum by metabolic flux analysis (MFA), targeted metabolomics, sensitivity and regulation analysis. Results In the ORP range of −462 mV to −250 mV, the developed algorithm enabled a stable anodic electrochemical control of ORP at desired set-points and a fixed dilution rate of 0.1 h −1 . An overall increase of 57% in the molar yield for 1,3-propanediol was observed by an ORP increase from −462 to −250 mV. MFA suggests that C. pasteurianum possesses and uses cellular energy generation mechanisms in addition to substrate-level phosphorylation. The sensitivity analysis showed that ORP exerted its strongest impact on the reaction of pyruvate-ferredoxin-oxidoreductase. The regulation analysis revealed that this influence is mainly of a direct nature. Hence, the observed metabolic shifts are primarily caused by direct inhibition of the enzyme upon electrochemical production of oxygen. A similar effect was observed for the enzyme pyruvate-formate-lyase at elevated ORP levels. Conclusions The results show that electrochemical ORP alteration is a suitable tool to steer the metabolism of C. pasteurianum and increase product yield for 1,3-propanediol in continuous culture. The approach might also be useful for application with further anaerobic or anoxic bioprocesses. However, to maximize the technique's efficiency, it is essential to understand the chemistry behind the ORP change and how the microbial system responds to it by transmitted or direct effects.
Manoj Kumar, Rajesh Singh
Environmental Science: Water Research & Technology · 2020
In this study, two-phase continuous vertical flow constructed wetlands were installed with a pre-cleaner bioelectrochemical system for the removal of NH 4 + -N (60.41–85.78%), NO 3 − -N (25.55–35.18%), TN (57.80–84.65%), TKN (37.24–70.08%), PO 4 3− -P (38.89–63.40%), SO 4 2− (49.53–76.06%), and COD (25.83–74.70%) from municipal wastewater.
Young Eun Song, Changman Kim, Jiyun Baek et al.
Sustainable Energy & Fuels · 2020
The high CODH activity appears to have a synergistic effect with an electrode-assisted electron transfer, and thus maximize the conversion of acetate and VFAs from electrosynthesis with CO.
Anna Weimer, Jens Krömer, Bin Lai et al.
Microbial Biotechnology · 2025
ABSTRACT Mediator‐based extracellular electron transfer (EET) in a bioelectrochemical system is a unique approach to regulate the microbial redox and energy metabolism of Pseudomonas putida KT2440, which enables a new‐to‐nature high product yield under anaerobic conditions. Previous studies identified respiratory complex III in the inner membrane as a key redox protein involved in mediator (ferricyanide) interactions, but the exact mechanism through which the mediator crosses the outer membrane to extract electrons from membrane‐bound redox proteins and transfer them to the anode remains unclear. In this study, we demonstrated the critical role of the TonB‐dependent system, a widespread transportation system in gram‐negative bacteria, in the mediator‐based EET process. Transcriptomic analyses revealed significant upregulation of TonB‐dependent receptors in response to ferricyanide exposure, suggesting their involvement in mediator uptake. Deletion of the TonB complex resulted in a > 50% decrease in the mediator reduction rate and current output, confirming the role of the TonB‐dependent system in mediator transport. Additionally, increasing passive diffusion through the overexpression of the general porin OprF increased cell permeability and the mediator reduction rate, but it failed to compensate for the absence of TonB‐dependent transport. These findings suggest that both systems act in a complementary manner: the TonB‐dependent system is likely the primary mechanism for periplasmic mediator uptake, whereas OprF is likely involved mainly in mediator efflux. Further bioelectrochemical system experiments demonstrated that, with a functional TonB‐dependent system, OprF overexpression increased current output, glucose consumption, and 2‐ketogluconate production, suggesting a viable strategy for enhancing the efficacy of mediator‐based EET. This work reveals the major mediator transport mechanism in P. putida and deepens the understanding of the mediator‐based EET pathway, laying the basis for future rational engineering of EET kinetics and facilitating the integration of mediator‐based electron transfer into industrial biotechnology to push its process boundaries.
Christy M. Dykstra, Spyros G. Pavlostathis
Biotechnology and Bioengineering · 2017
ABSTRACT Bioelectrochemical systems (BESs) may be used to upgrade anaerobic digester biogas by directly converting CO 2 to CH 4 . The objective of this study was to evaluate gas (N 2 , CO 2 , CH 4 , and H 2 ) and carbon transport within a methanogenic BES. Four BES configurations were evaluated: abiotic anode with abiotic cathode (AAn‐ACa), bioanode with abiotic cathode (BAn‐ACa), abiotic anode with biocathode (AAn‐BCa), and bioanode with biocathode (BAn‐BCa). Transport of N 2 , a gas commonly used for flushing anoxic systems, out of the anode headspace ranged from 3.7 to 6.2 L/d‐atm‐m 2 , normalized to the proton exchange membrane (PEM) surface area and net driving pressure (NDP). CO 2 was transported from the cathode to the anode headspace at rates from 3.7 to 5.4 L/d‐atm‐m 2 . The flux of H 2 from cathode to anode headspace was 48% greater when the system had a biocathode (AAn‐BCa) than when H 2 was produced at an abiotic cathode (BAn‐ACa), even though the abiotic cathode headspace had 75% more H 2 than the AAn‐BCa biocathode at the end of 1 day. A 7‐day carbon balance of a batch‐fed BAn‐BCa BES showed transient microbial carbon storage and a net transport of carbon from anode to cathode. After a 7‐day batch incubation, the CH 4 production in the biocathode was 27% greater on a molar basis than the initial CO 2 supplied to the biocathode headspace, indicating conversion of CO 2 produced in the anode. This research expands the current understanding of methanogenic BES operation, which may be used in improving the assessment of BES performance and/or in the development of alternative BES designs and mathematical models. Biotechnol. Bioeng. 2017;114: 961–969. © 2016 Wiley Periodicals, Inc.
M. Zeppilli, A. Mattia, M. Villano et al.
Fuel Cells · 2017
Abstract Here, an innovative three‐chamber bioelectrochemical system configuration is proposed to combine COD, CO 2 and NH 4 + removal into a single device. In the proposed process, while COD oxidation and CO 2 reduction occurred, respectively, in the anodic and cathodic chamber, the consequent current generation promoted the migration of target ionic species towards an intermediate accumulation chamber, across cation and anion exchange membranes, respectively. Under this configuration, COD removal proceeded in the anode chamber with an average removal rate of 841 mgCOD L −1 d −1 while the cathode was able to remove 2.1 gCO 2 L −1 d −1 and produce 60 meq L −1 d −1 of CH 4 . Around 90% of the removed CO 2 was contained in the concentrated spill (at around 20 g L −1 of bicarbonate), which was recovered from the intermediate accumulation chamber and also contained the removed nitrogen as ammonium ion (around 32% removal and around 4‐fold concentration with respect to the anode influent). Methane generation allowed a partial recovery of energy of overall energy consumption costs of both COD and CO 2 removal. This study confirms the possibility to combine three processes into a single bioelectrochemical device.
Gowthami Palanisamy, Sadhasivam Thangarasu, Tae Hwan Oh
Polymers · 2023
Microbial fuel cells (MFCs) provide considerable benefits in the energy and environmental sectors for producing bioenergy during bioremediation. Recently, new hybrid composite membranes with inorganic additives have been considered for MFC application to replace the high cost of commercial membranes and improve the performances of cost-effective polymers, such as MFC membranes. The homogeneous impregnation of inorganic additives in the polymer matrix effectively enhances the physicochemical, thermal, and mechanical stabilities and prevents the crossover of substrate and oxygen through polymer membranes. However, the typical incorporation of inorganic additives in the membrane decreases the proton conductivity and ion exchange capacity. In this critical review, we systematically explained the impact of sulfonated inorganic additives (such as (sulfonated) sSiO2, sTiO2, sFe3O4, and s-graphene oxide) on different kinds of hybrid polymers (such as PFSA, PVDF, SPEEK, SPAEK, SSEBS, and PBI) membrane for MFC applications. The membrane mechanism and interaction between the polymers and sulfonated inorganic additives are explained. The impact of sulfonated inorganic additives on polymer membranes is highlighted based on the physicochemical, mechanical, and MFC performances. The core understandings in this review can provide vital direction for future development.
Axel Rous, G. Santa-Catalina, E. D. Quéméner et al.
bioRxiv (Cold Spring Harbor Laboratory) · 2023
The production of nitrogen fertilizers in modern agriculture is mostly based on the Haber-Bosch process, representing nearly 2% of the total energy consumed in the world. Low-energy bioelectrochemical fixation of N2 to microbial biomass was previously observed but the mechanisms of microbial interactions in N2-fixing electroactive biofilms are still poorly understood. The present study aims to develop a new method of enrichment of autotrophic and diazotrophic bacteria from soil samples with a better electron source availability than using H2 alone. The enrichment method was based on a multi-stage procedure. The first enrichment step was specifically designed for the selection of N2-fixing bacteria from soil samples with organic C as electron and carbon source. Then, a polarized cathode was used for the enrichment of autotrophic bacteria using H2 (hydrogenotrophic) or the cathode as electron source. This enrichment was compared with an enrichment culture of pure diazotrophic hydrogenotrophic bacteria without the use of a microbial electrochemical system. Interestingly, both methods showed comparable results for N2 fixation rates at day 340 of the enrichment with an estimated average of approximately 0.2 mgNfixed/L.d. Current densities up to −15 A/m2 were observed in the polarized cathode enrichments and a significant increase of the microbial biomass on the cathode was shown between 132 and 214 days of enrichment.These results confirmed an enrichment in autotrophic and diazotrophic bacteria on the polarized cathode. It was hypothesied that autotrophic bacteria were able to use either the H2 produced at the cathode or directly the cathode through direct electron transfer (DET) as more biomass was produced than with H2 alone. Finally, the analysis of the enriched communities suggested that Desulforamulus ruminis mediated microbial interactions between autotrophic anaerobic and heterotrophic aerobic bacteria in polarized cathode enrichment. These interactions could play a key role in the development of biomass in these systems and on N2 fixation. Based on these findings, a conceptual model on the functioning of mixed cultures N2-fixing electroactive biofilms was proposed.
D. Pant, Suman Bajracharya, G. Mohanakrishna et al.
Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1 · 2016
Microbial Electrosynthesis (MES) comprises electro-reduction of carbon dioxide (CO2) to multi-carbon organic compounds by chemolithotrophs using electrons from a cathode. Reduction of CO2 to chemicals through microbial electrocatalysis was investigated by using a mixed culture of acetogenic and carboxydotrophic bacteria forming a microbial biofilm supported on a carbon based electrode, as biocathode, in a two chamber reactor. The biofilm was developed after a start-up phase with fructose and later on, growing on bicarbonate as substrate at sufficiently negative cathode potential (hydrogen evolution) in a couple of subsequent fed-batch operations. CO2 reduction could occur via direct electron transfer from the electrode or indirectly via mediators or via hydrogen at more reductive potential. Predominantly, Acetic acid was produced along with other volatile fatty acids (VFAs) while applying − 1.1 V/Ag/AgCl cathode potential, along with hydrogen evolution. At the initial stage of fed-batch operation, higher carbon recovery up to 60% was observed from bicarbonate (dissolved CO2) to acetic acid while after accumulation of acetate, the recovery rate went down to 12% as acetate degradation/conversion started or other unmeasured products formed. Maximum acetate production rate achieved during the operation was 40 g m− 2 day− 1 corresponding to coulumbic efficiency of 41%. Microbial analysis of catholyte at the end of the experiment showed that the bacterial community was dominated by Cellulomonas, Stappia and Pseudomonas spp. These results suggest that the mixed culture enriched with acetogenic bacteria can catalyze the electro-reduction of CO2 into a number of chemicals like VFAs through direct or indirect electron transfer mechanisms. While using gaseous CO2 as carbon source, the dissolution and mass transfer of CO2 to the biocatalyst limit the biological reduction process. In addition, the bacterial attachment and retention of reducing equivalent specially hydrogen also restrict the process at the cathode. In order to deal with these issues, a gas diffusion cathode (GDC) (VITO Core™) and a flow-through porous carbon felt cathode were separately tested in MES for CO2 reduction. In principal, the porous activated carbon with hydrophobic binder layer in GDC creates a three-phase interface that makes CO2 and reducing equivalents available to the bacteria. Flow-through graphite felt cathode retains the suspended biomass and electrochemically produced hydrogen when the catholyte is forced to flow through it. An enriched inoculum of acetogenic bacteria, isolated from wastewater sludge was used as biocatalyst. The cathode potentials were maintained at − 0.9 to − 1.1 V vs Ag/AgCl to facilitate CO2 reduction also via the hydrogen evolved at the cathode. On average, CO2 reduction to acetate was achieved with the production rate ∼35 to 43 mg/L/d supplying 20% (v/v) CO2 gas mixture in both the reactors. In the reactors without GDCs or modified cathode, CO2 reduction was never steady for a long period of operation. Acetate was the primary product of CO2 reduction but ethanol and butyrate were also produced concurrently at pH lower than 6. The highest acetate production rate reached in GDC reactor was ∼550 mg/L/d supplying 80% (v/v) CO2 mixture over the GDC. In conclusion, gas diffusion and flow-through cathodes were useful to develop stable CO2 reducing biocathodes and also to operate in continuous mode. Keywords: Microbial electrosynthesis, CO2 reduction, Gas diffusion cathode, Flow-through biocathode, Biocathode, Autotrophic Bioproduction.
Kengo Sasaki, Daisuke Sasaki, Yota Tsuge et al.
Biotechnology for Biofuels · 2021
Abstract Background It is desirable to improve the anaerobic digestion processes of recalcitrant materials, such as cellulose. Enhancement of methane (CH 4 ) production from organic molecules was previously accomplished through coupling a bioelectrochemical system (BES); however, scaling-up BES-based production is difficult. Here, we developed a two-stage process consisting of a BES using low-cost and low-reactive carbon sheets as the cathode and anode, and a fixed film reactor (FFR) containing conductive material, i.e., carbon fiber textiles (CFTs) (:BES → FFR). By controlling the cathodic current at 2.7 μA/cm 2 without abiotic H 2 production, the three-electrode BES system was operated to mimic a microbial electrolysis cell. Results The thermophilic BES (inlet pH: 6.1) and FFR (inlet pH: 7.5) were operated using hydraulic retention times (HRTs) of 2.5 and 4.2 days, respectively, corresponding to a cellulose load of 3555.6 mg-carbon (C)/(L day). The BES → FFR process achieved a higher CH 4 yield (37.5%) with 52.8 vol% CH 4 in the product gas compared to the non-bioelectrochemical system (NBES) → FFR process, which showed a CH 4 yield of 22.1% with 46.8 vol% CH 4 . The CH 4 production rate (67.5 mM/day) obtained with the BER → FFR process was much higher than that obtained using electrochemical methanogenesis (0.27 mM/day). Application of the electrochemical system or CFTs improved the yields of CH 4 with the NBES → FFR or BES → non-fixed film reactor process, respectively. Meta 16S rRNA sequencing revealed that putative cellulolytic bacteria (identified as Clostridium species) were present in the BES and NBES, and followed (BES→ and NBES→) FFR. Notably, H 2 -consuming methanogens, Methanobacterium sp. and Methanosarcina sp., showed increased relative abundances in the suspended fraction and attached fraction of (BES→) FFR, respectively, compared to that of (NBES→) FFR, although these methanogens were observed at trace levels in the BES and NBES. Conclusions These results indicate that bioelectrochemical preprocessing at a low current effectively induces interspecies H 2 transfer in the FFR with conductive material. Sufficient electrochemical preprocessing was observed using a relatively short HRT. This type of two-stage process, BES → FFR, is useful for stabilization and improvement of the biogas (CH 4 ) production from cellulosic material, and our results imply that the two-stage system developed here may be useful with other recalcitrant materials.
Diya Novarina, Eko Swistoro, M. Firdaus et al.
PENDIPA Journal of Science Education · 2018
ABSTRACT[Innovation of microbial fuel cell stack system using cow rumen waste substrate and its implementation as a learning media]. The aims of this study are to: 1) describe the difference of Electric Motion (GGL), 2) describe the difference of electric power per unit area of the anode (Pa) which is produced between the series design MFC type series, parallel, mixed type 1 and mixed type 2, and 3) describe the significant difference of learning outcomes between the PBL learning model using MFC media with PBL learning model by using the electrical kit medium on dynamic electrical concept in SMA Muhammadiyah 4 Bengkulu. The free variable of this research are MFC stack system design (series, parallel, mixed types 1 and 2) and the dependent variable is GGL and electric power per unit of anode surface area. The results are obtained difference GGL and Pa between series design, parallel, mixed types 1 and 2 by comparison are 3: 1: 1,5: 2 whereas Pa ratio is 1: 10: 6: 2 with maximum GGL is obtained in series design of 3,29 V and Pa maximum in parallel circuit 21,76 mW / m2. Implementation of MFC series as a learning media used Problem Based Learning model on physics learning Implementation of MFC circuit with research design using one group pretest-posttest design. The testing of hypothesis with t-test shows tcount 2.739> ttable 2,001 and 95% significant level so it can be concluded there are significant differences in learning outcomes of PBL learning model by using MFC media with PBL learning model by using media Electric Kit on dynamic electrical concept in SMA Muhammadiyah 4 Bengkulu. Keywords: Stack Microbial Fuel Cell (MFC) Sistem; Rumen Cow Liquid Waste; Learning Media.
Shujie Fan, M. Mahmoud, Biao Wen et al.
BioResources · 2018
The bioelectric activity of two lab scale microbial fuel cell (MFC) designs, MFCI (1,500 cm3) and MFCII (12,000 cm3) were examined using old corrugated containerboard (OCC) discharge for simultaneous effective treatment with greater power production. The decrease of MFC internal resistance (MFC-Rin) resulted in increased generated power output. The different parameters used in MFC included electrode conducting area (ECA), cathodic redox solution (CRS), MFC volume capacity, and MFCs connections. The generated current densities (CD) and power densities output (PD) at variables of external resistances (Rex) that ranged from 10 Ω to 20,000 Ω were calculated to estimate the MFC-Rin. In MFCI, using potassium ferri-cyanide as CRS, the change of ECA from 16 cm2 to 64 cm2 decreased the MFCI-Rin from 130 Ω to 110 Ω, and it was further decreased to 65 Ω when manganese dioxide was used as the CRS. Using Rex 100 Ω, MFCII exhibited lower Rin 18.46%, enhanced voltage 37.5%, and greater chemical oxygen demand removal 4.77% compared with MFCI. Series and parallel connections between four MFCI increased the generated PD by 286% and 258%, respectively, compared with that obtained by single MFCI.
K R S Pamintuan, J A A Clomera, K V Garcia et al.
IOP Conference Series: Earth and Environmental Science · 2018
Plant-microbial fuel cells (PMFCs) are a sub-branch of a class of promising bioelectrochemical systems which are capable of simultaneously supplying biomass and renewable energy from photosynthesis and root exudation. In this study, the possibility of power amplification through stacking was tested. Ipomoea aquatica and Pistia stratiotes were used as model plants in this study because their biomass is valued as food for humans and livestock, respectively. In a brief 7-day experiment, maximum power densities of 6.35 mW / m2 for I. aquatica and 3.54 mW/m2 for P. stratiotes were obtained from aquatic PMFC assemblies. No significant difference in voltage was observed between the two plants, although the current and power output of I. aquatica were significantly higher than that of P. stratiotes. Connecting three cells in series resulted to three times higher voltage but the same current, and connecting three cells in parallel resulted to three times higher current but the same voltage for both plants. Power was also amplified by stacking. There is no significant difference in the power produced by the cells connected in series or parallel. Power density remained constant due to the increase in surface area of electrodes used upon stacking. These results are consistent with the rules of electric circuits and would become a valuable tool in the computational design of larger systems with numerous cells that can supply a large part of our electricity demands. For future studies, assemblies with more cells are recommended to establish the upper limit of the validity of the series/parallel models and can be tested with other plants.