Microbial Fuel Cell For Generation Research Articles

The Electricity Generation in Microbial Fuel Cells Using Reaeration Mechanism for Cathodic Oxygen Reduction

Electricity generation in microbial fuel cell (MFC) using reaeration mechanism to facilitate cathodic oxygen reduction is sustainable and economical. This study examined the effects of operational parameters of electrical load (Rext), organic load and cathode area (Sa) on MFC performance under reaeration rate (K2) of 0.5-1.5 d-1in cathode chamber. Two MFCs, consisting of MFC-A (with Rext10 Ω) and MFC-B (Rext1000 Ω), were operated in parallel and continuously fed with influent chemical oxygen demand (CODin) 324–561 mg/L to anode chamber; and in each MFC the Sa covering 184, 553, 992 and 1290 cm2 was tested. Results indicated that in MFC-A the current production increased with aqueous COD in anode chamber, in which the relationship between current and aqueous COD can be modeled with Monod kinetics. The estimated kinetic constants of maximum current Imax is 3 mA, and half-saturation constant of current Ks is 310 mg/L. The lowest dissolved oxygen (DO) of 1.9 mg/L occurred at highest CODin of 561 mg/L. In MFC-B, constant current of 0.4 mA and DO at 3.2-3.7 mg/L were maintained for all CODin. The Sa had insignificant influence on electricity generation in both MFCs. This study demonstrated the importance of electrical load, organic load, and their interactions among them in designing reaeration-assisted MFC for organic waste treatment.

Degradation of 2,4-Dichlorophenol by Bacillus Subtilis with Concurrent Electricity Generation in Microbial Fuel Cell

The growing critical and toxic wastewater contamination problems seek various sustainable and environmental friendly treatment methods to be further investigated. 2,4-dichlorophenol (2,4-DCP) is one of the recalcitrant and hazardous contaminants normally found in industrial wastewater and in some cases in domestic wastewater as well. This study explored the capability of bacteria Bacillus subtilis to degrade the 2,4-DCP in a double chamber microbial fuel cell (MFC) system. The MFC enables the removal of contaminants by bacteria with concurrent electricity generation through electron transfer mechanisms. B. subtilis is found to be a good exoelectrogenic bacterium for generating an optimum potential of 95 mV with 12 mA/m2 current density in MFC. B. subtilis was able to degrade ∼60% of 2,4-DCP into acceptable simpler metabolites, thus could be further utilized in treating hazardous phenolic contaminants while generating electricity through benign and sustainable wastewater treatment method.

Spontaneous arsenic (III) oxidation with bioelectricity generation in single-chamber microbial fuel cells

Arsenic is one of the most toxic elements commonly found in groundwater. With initial concentration of 200μgL−1, spontaneous As(III) oxidation is realized completely during 7 days operation in single-chamber microbial fuel cells (MFCs) in the present study, with the maximum power density of 752.6±17mWm−2. The product is less toxic and mobile As(V), which can be removed from aqueous solution more easily. High-throughput 16S rRNA gene pyrosequencing analysis indicates the existence of arsenic-resistant bacteria as Actinobacteria, Comamonas, Pseudomonas and arsenic-oxidizing bacteria as Enterobacter, with electrochemically active bacteria as Lactococcus, Enterobacter. They interact together and are responsible for As(III) oxidation and bioelectricity generation in MFCs. This study offers a potential attractive method for remediation of arsenic-polluted groundwater.

Inocula selection in microbial fuel cells based on anodic biofilm abundance of Geobacter sulfurreducens

Microbial fuel cells (MFCs) rely on microbial conversion of organic substrates to electricity. The optimal performance depends on the establishment of a microbial community rich in electrogenic bacteria. Usually this microbial community is established from inoculation of the MFC anode chamber with naturally occurring mixed inocula. In this study, the electrochemical performance of MFCs and microbial community evolution were evaluated for three inocula including domestic wastewater (DW), lake sediment (LS) and biogas sludge (BS) with varying substrate loading (Lsub) and external resistance (Rext) on the MFC. The electrogenic bacterium Geobacter sulfurreducens was identified in all inocula and its abundance during MFC operation was positively linked to the MFC performance. The LS inoculated MFCs showed highest abundance (18%±1%) of G. sulfurreducens, maximum current density [Imax=(690±30)mA·m−2] and coulombic efficiency (CE=29%±1%) with acetate as the substrate. Imax and CE increased to (1780±30)mA·m−2 and 58%±1%, respectively, after decreasing the Rext from 1000Ω to 200Ω, which also correlated to a higher abundance of G. sulfurreducens (21%±0.7%) on the MFC anodic biofilm. The data obtained contribute to understanding the microbial community response to Lsub and Rext for optimizing electricity generation in MFCs.

Anaerobic microbial fuel cell treating combined industrial wastewater: Correlation of electricity generation with pollutants

Microbial fuel cell (MFC) is a new technology that not only generates energy but treats wastewater as well. A dual chamber MFC was operated under laboratory conditions. Wastewater samples from vegetable oil industries, metal works, glass and marble industries, chemical industries and combined industrial effluents were collected and each was treated for 98h in MFC. The treatment efficiency for COD in MFC was in range of 85–90% at hydraulic retention time (HRT) of 96h and had significant impact on wastewater treatment as well. The maximum voltage of 890mV was generated when vegetable oil industries discharge was treated with columbic efficiency of 5184.7C. The minimum voltage was produced by Glass House wastewater which was 520mV. There was positive significant co-relation between COD concentration and generated voltage. Further research should be focused on the organic contents of wastewater and various ionic species affecting voltage generation in MFC.

Impact of Korean Ginseng (Panax Ginseng) on Power Generation of Microbial Fuel Cells

Impact of Korean Ginseng (Panax Ginseng) on Power Generation of Microbial Fuel Cells

Pharmaceutical Wastewater Treatment Associated with Renewable Energy Generation in Microbial Fuel Cell Based on Mobilized Electroactive Biofilm on Zeolite Bearer

Pharmaceutical Wastewater Treatment Associated with Renewable Energy Generation in Microbial Fuel Cell Based on Mobilized Electroactive Biofilm on Zeolite Bearer

Chemically Functionalized Conjugated Oligoelectrolyte Nanoparticles for Enhancement of Current Generation in Microbial Fuel Cells.

Water-soluble conjugated oligoelectrolyte nanoparticles (COE NPs), consisting of a cage-like polyhedral oligomeric silsesquioxanes (POSS) core equipped at each end with pendant groups (oligo(p-phenylenevinylene) electrolyte, OPVE), have been designed and demonstrated as an efficient strategy in increasing the current generation in Escherichia coli microbial fuel cells (MFCs). The as-prepared COE NPs take advantage of the structure of POSS and the optical properties of the pendant groups, OPVE. Confocal laser scanning microscopy showed strong photoluminescence of the stained cells, indicating spontaneous accumulation of COE NPs within cell membranes. Moreover, the electrochemical performance of the COE NPs is superior to that of an established membrane intercommunicating COE, DSSN+ in increasing current generation, suggesting that these COE NPs thus hold great potential to boost the performance of MFCs.

Catabolic and regulatory systems in Shewanella oneidensis MR-1 involved in electricity generation in microbial fuel cells.

Shewanella oneidensis MR-1 is a facultative anaerobe that respires using a variety of inorganic and organic compounds. MR-1 is also capable of utilizing extracellular solid materials, including anodes in microbial fuel cells (MFCs), as electron acceptors, thereby enabling electricity generation. As MFCs have the potential to generate electricity from biomass waste and wastewater, MR-1 has been extensively studied to identify the molecular systems that are involved in electricity generation in MFCs. These studies have demonstrated the importance of extracellular electron-transfer (EET) pathways that electrically connect the quinone pool in the cytoplasmic membrane to extracellular electron acceptors. Electricity generation is also dependent on intracellular catabolic pathways that oxidize electron donors, such as lactate, and regulatory systems that control the expression of genes encoding the components of catabolic and electron-transfer pathways. In addition, recent findings suggest that cell-surface polymers, e.g., exopolysaccharides, and secreted chemicals, which function as electron shuttles, are also involved in electricity generation. Despite these advances in our knowledge on the EET processes in MR-1, further efforts are necessary to fully understand the underlying intra- and extracellular molecular systems for electricity generation in MFCs. We suggest that investigating how MR-1 coordinates these systems to efficiently transfer electrons to electrodes and conserve electrochemical energy for cell proliferation is important for establishing the biological basis for MFCs.

Employing a Flexible and Low-Cost Polypyrrole Nanotube Membrane as an Anode to Enhance Current Generation in Microbial Fuel Cells.

The flexible and low-cost polypyrrole nanotube membrane is demonstrated as a promising anode in microbial fuel cells, which significantly enhances the extracellular electron transfer between Shewanella oneidensis MR-1 and the electrode, owing to the large active surface area and high electrical conductivity.

Optimization of Pt-Pd alloy catalyst and supporting materials for oxygen reduction in air-cathode Microbial Fuel Cells

ABSTRACT In this study, Pt-Pd alloy catalyst was fabricated on carbon papers via electro-deposition as an alternative catalyst for oxygen reduction in air-cathode Microbial Fuel Cells (MFCs). Effects of electro-deposition cycles and supporting materials (graphene and carbon nanotubes (CNTs)) on oxygen reduction reaction (ORR) activity of the Pt-Pd electrode and power generation in MFCs were investigated. The structural and electrochemical properties of the Pt-Pd catalyst were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Results showed that the Pt-Pd electrode showed a good ORR activity. A MFC with a Pt-Pd cathode of 15 deposition cycles produced a maximum power density of 1274 mWm −2 , comparable to that with a conventional Pt/C cathode (0.5 mg Pt cm −2 ). CNT as the supporting material further increased ORR activity of the Pt-Pd electrode and power generation capacity in MFCs, while graphene as the supporting material did not produce positive effects. XRD results confirmed the presence of Pt/Pd elements on the electrode. SEM results showed that decoration using CNT reduced Pt-Pd particle size and promoted them even dispersion on the carbon paper. The Pt-Pd electrode attained a comparable performance to the Pt/C electrode when controlling an optimum deposition cycles and using CNT as the supporting materials, which demonstrates the potential of replacing Pt as an oxygen reduction catalyst in MFCs due to high oxygen reduction activity and relatively low cost.

Performance and stability of different cathode base materials for use in microbial fuel cells

Metal supporting materials are increasingly being used as base materials for microbial fuel cell (MFC) cathodes. However, the potential for corrosion may limit their use as base materials of MFCs during scale-up and long-term operation. In this study, the electrochemical performance, power generation in MFCs, hydrostatic pressure tolerance, and stability of activated carbon (catalyst) cathodes with carbon cloth or different size metal mesh as base materials are investigated. Electrochemical testing results show that the finest stainless steel mesh (250 × 250 openings per inch) outperforms carbon cloth cathodes by 10–40% at current densities ranging from 6 to 11.2 A m−2 over the typical cathode operating range of 0.1 V–0 V. When tested in MFCs, however, carbon cloth based cathodes out perform all stainless steel mesh cathodes by as much as 34%, reaching 1.72 W m−2; probably due to the corrosion and salt build-up on the surface of the stainless steel mesh cathodes. Carbon cloth cathodes also maintained high static pressure heads of 1.9 m. The high electrochemical performance, hydrostatic pressure tolerance, and corrosion resistance of carbon cloth suggest that carbon fiber based materials may be more suitable than metal based materials for use as MFC cathodes base material for some applications.

Deciphering electron-shuttling characteristics of thionine-based textile dyes in microbial fuel cells

Prior studies indicated that OH and/or NH2 substituent containing auxochrome compounds (e.g., 2-aminophenol and 1-amino-2-naphthol) could act as electron shuttles (ESs) to stimulate wastewater decolorization and bioelectricity generation in microbial fuel cells (MFCs). This study provided first-attempt to disclose how and why thionine-associated textile dyes (i.e., azure A and azure C) could also own such redox-mediating capabilities in MFCs. Due to the presence of iminium part as mediating group, N(CH3)2 or N(CH3)H substituent could effectively mediate electron transport compared to NH2 substituent for bioelectricity generation in MFCs. For dye-laden wastewater treatment, the presence of electron-mediating textile dyes (e.g., thionine, azure A and azure C) in MFCs is promising to stimulate biodegradation of organics and bioelectricity generation. With such ESs as stimulants, using MFC as operation strategy would be cost-effective for wastewater treatment as oxidation of organic pollutants could be automatically accelerated.

Improving performance of microbial fuel cell while controlling methanogenesis by Chaetoceros pretreatment of anodic inoculum

Loss of substrate due to methanogenesis reduces Coulombic efficiency (CE) of the microbial fuel cell (MFC) significantly. Hexadecatrienoic acid present in the marine algae Chaetoceros inhibits the growth of methanogenic archaea. Influence of Chaetoceros pre-treated mixed anaerobic sludge on the electrogenic activity of MFC was evaluated. A MFC inoculated with Chaetoceros pre-treated mixed anaerobic sludge demonstrated maximum CE of 45.18%, with volumetric power density of 21.43W/m3 and current density of 93A/m3. Cyclic voltammetry indicated higher electron discharge on the anode surface due to suppression of methanogenesis. Tafel analysis also showed a higher exchange current density and a lower Tafel slope and charge transfer resistance, indicating advantage of this pre-treatment method in reducing the cell internal losses. A 60% reduction in specific methanogenic activity was observed in anaerobic sludge pre-treated with Chaetoceros; emphasizing significance of this pretreatment for suppressing methanogenesis and its utility for enhancing electricity generation in MFC.

Carbon Nanotube Composite Electrode Coated with Polypyrrole for Microbial Fuel Cell Application.

Microbial fuel cells (MFCs) are bio-electrochemical system that can convert biomass spontaneously into electricity through the metabolic activity of microorganisms. We constructed MFCs of polypyrrole (PPy) coated carbon nanotube (CNT) composite as an electrode material and Shewanella oneidensis as the biocatalyst to increase power density. The PPy-coated CNT were synthesized by the in-situ chemical polymerization of pyrrole on CNT, and the electrochemical properties and performance of the modified electrode as an anode in MFC were then investigated. Treatment with 0.1 wt% Ge-132 on the acid-treated MWNTs helped to form better PPy-MWNT composite. The PPy-CNT/CF anode showed a noteworthy 38% power production improvement when compared to plain CF anode. The PPy-CNT composite could be a very efficient and promising electrode material for electricity generation of MFC.

Enhancing organic matter removal, biopolymer recovery and electricity generation from distillery wastewater by combining fungal fermentation and microbial fuel cell

For enhancing organic matter removal from cereal-based distillery stillage two-stage treatment consisting of fermentation by Aspergillus awamori followed by microbial fuel cell (MFC) is proposed. Considerable reduction in total and soluble chemical oxygen demand (COD) up to 70% and 40%, respectively, along with 98% reduction of suspended solids (SS) has been achieved during fungal pretreatment. The process generated chitosan, a useful fermentation byproduct from fungal mycelia, as 0.6–0.7g/l of settled sludge with mycelium (3.8% solids). Prior treatment of wastewater with fungal strain enhanced the power generation in MFC by 2.9 times at an organic loading rate of 1.5kgCOD/m3day, demonstrating soluble COD reduction of 92% in MFC. While treating distillery wastewater, this two-stage integrated biological process demonstrated overall 99% COD removal and almost complete removal of SS, delivering ample scope for scale-up and industrial application to offer effective solution for distillery wastewater treatment.

Conductive Polymer/Graphene Supported Platinum Nanoparticles as Anode Catalysts for the Extended Power Generation of Microbial Fuel Cells

Platinum (Pt) nanoparticles anchored over reduced graphene oxide (rGO) and rGO/conductive polyaniline (PANI) composites were synthesized and exploited as anode catalysts in microbial fuel cells (MFC). PANI bridges rGO and Pt nanoparticles through the electrostatic interaction/π–π stacking force/hydrogen bonding and Pt–N bond, respectively, and increased the intrinsic stability of rGO/PANI/Pt composite. The electrocatalytic performances of rGO/PANI/Pt exhibited the better oxidation current and lower internal resistance over the prepared rGO/PANI and rGO/Pt composites as evidenced from the cyclic voltammetric and electrochemical impedance techniques, respectively. By the combined efforts of active support, high electrical conductivity, and number of catalytic active sites, the prepared rGO/PANI/Pt nanocomposite exhibited a maximum MFC power density of 2059 mW/m2 with the concrete life durability. Thus, the proposed approach has paved new dimensions in not only the preparation of rGO-supported conductive pol...

Anode modification with formic acid: A simple and effective method to improve the power generation of microbial fuel cells

The physicochemical properties of anode material directly affect the anodic biofilm formation and electron transfer, thus are critical for the power generation of microbial fuel cells (MFCs). In this work, carbon cloth anode was modified with formic acid to enhance the power production of MFCs. Formic acid modification of anode increased the maximum power density of a single-chamber air-cathode MFC by 38.1% (from 611.5±6mW/m2 to 877.9±5mW/m2). The modification generated a cleaner electrode surface and a reduced content of oxygen and nitrogen groups on the anode. The surface changes facilitated bacterial growth on the anode and resulted in an optimized microbial community. Thus, the electron transfer rate on the modified anodes was enhanced remarkably, contributing to a higher power output of MFCs. Anode modification with formic acid could be an effective and simple method for improving the power generation of MFCs. The modification method holds a huge potential for large scale applications and is valuable for the scale-up and commercialization of microbial fuel cells.

Controlling methanogenesis and improving power production of microbial fuel cell by lauric acid dosing.

Methanogens compete with anodophiles for substrate and thus reduce the power generation and coulombic efficiency (CE) of the microbial fuel cell (MFC). Performance of a baked clayware membrane MFC inoculated with mixed anaerobic sludge pretreated with lauric acid was investigated in order to enhance power recovery by controlling methanogenesis. In the presence of lauric acid pretreated inoculum, MFC produced maximum volumetric power density of 4.8 W/m(3) and the CE increased from 3.6% (for untreated inoculum) to 11.6%. Cyclic voltammetry (CV) and electro-kinetic evaluation indicated a higher bio-catalytic activity at the anode of the MFC inoculated with lauric acid pretreated sludge. With the lauric acid pretreated inoculum a higher catalytic current of 114 mA, exchange current density of 40.78 mA/m(2) and lower charge transfer resistance of 0.00016 Ωm(2) were observed during oxidation at the anode. Addition of lauric acid significantly achieved suppression of methanogenesis and enhanced the sustainable power generation of MFC by 3.9 times as compared with control MFC inoculated with sludge without any pretreatment.

Which determines power generation of microbial fuel cell based on carbon anode, surface morphology or oxygen-containing group?

To clarify the role of carbon surface nature in the power generation of microbial fuel cell (MFC) based on carbon anode, three carbon felt samples, obtained by simple water cleaning (CCF), heating (HCF) and oxidation with ammonium persulfate (ACF), were characterized with SEM, BET, FTIR, cyclic voltammetry and acid titration, and their performances as anode of MFC were investigated with polarization curve measurement, chronoamperometry and chronopotentiometry. It is found that the power output of MFC depends on the morphology rather than the oxygen-containing group concentration of the carbon felt surface. CCF, HCF and ACF have their surface oxygen-containing groups of 1.52, 0.8 and 0.45 mM m−2 and specific surface areas of 0.33, 0.65 and 1.19 m2 g−1, but yield their maximal power densities of 606, 858 and 990 mW m−2, respectively. This study suggests that intensive attention should be paid to the design of surface morphology in order to improve power generation of MFC.