Efficiency Of Microbial Fuel Cells Research Articles

Effects of aeration coupled with microbial fuel cell on nitrogen removal and electricity production for biogas slurry

Microbial fuel cell (MFC) can be used as a potential technology for degradation of organic contaminant. In order to improve the efficiency of MFC treating the biogas slurry (BS), a comparison between the pretreatments of aerobic static culture and aeration was studied. The nitrogen and chemical oxygen demand (COD) removal and electricity production capacity of BS-MFC was investigated. The results showed that the total degradation rate of NH4+-N in BS after the aeration coupled with MFC treatment reached 95.70 %, which was 12.97 % higher than that of the aerobically statically cultivated BS. The coulombic efficiency (CE) of the aeration-treated BS participating the reaction in MFC was always higher than that of the aerobically cultivated group. The relative abundance of Chloroflexi, which plays an important role in nitrogen metabolism, accounted for a smaller proportion in the MFC reaction effluent after aeration treatment. While, the denitrification bacteria Patescibacteria was slightly enhanced. The aeration-treated BS also stimulated the growth of electrochemically active microorganisms Gammaproteobacteria in the MFC system. The results of this study showed that pretreatment of the BS with aeration was more favorable to improve the efficiency of the BS-MFC, which provided informative suggestions for the improvement of MFC.

The influence of benzene on the composition, diversity and performance of the anodic bacterial community in glucose-fed microbial fuel cells.

Bioelectrochemical systems offer unique opportunities to remove recalcitrant environmental pollutants in a net positive energy process, although it remains challenging because of the toxic character of such compounds. In this study, microbial fuel cell (MFC) technology was applied to investigate the benzene degradation process for more than 160 days, where glucose was used as a co-metabolite and a control. We have applied an inoculation strategy that led to the development of 10 individual microbial communities. The electrochemical dynamics of MFC efficiency was observed, along with their 1H NMR metabolic fingerprints and analysis of the microbial community. The highest power density of 120 mW/m2 was recorded in the final period of the experiment when benzene/glucose was used as fuel. This is the highest value reported in a benzene/co-substrate system. Metabolite analysis confirmed the full removal of benzene, while the dominance of fermentation products indicated the strong occurrence of non-electrogenic reactions. Based on 16S rRNA gene amplicon sequencing, bacterial community analysis revealed several petroleum-degrading microorganisms, electroactive species and biosurfactant producers. The dominant species were recognised as Citrobacter freundii and Arcobacter faecis. Strong, positive impact of the presence of benzene on the alpha diversity was recorded, underlining the high complexity of the bioelectrochemically supported degradation of petroleum compounds. This study reveals the importance of supporting the bioelectrochemical degradation process with auxiliary substrates and inoculation strategies that allow the communities to reach sufficient diversity to improve the power output and degradation efficiency in MFCs beyond the previously known limits. This study, for the first time, provides an outlook on the syntrophic activity of biosurfactant producers and petroleum degraders towards the efficient removal and conversion of recalcitrant hydrophobic compounds into electricity in MFCs.

Effect of Using Various Cathode Materials (Carbon Felt, Ni-Co, Cu-B, and Cu-Ag) on the Operation of Microbial Fuel Cell

Wastewater has high potential as an energy source. Therefore, it is important to recover even the smallest part of this energy, e.g., in microbial fuel cells (MFCs). The obtained electricity production depends on the process rate of the electrodes. In MFC, the microorganisms are the catalyst of anode, and the cathode is usually made of carbon material. To increase the MFC efficiency it is necessary to search the new cathode materials. In this work, the electricity production from yeast wastewater in membrane-less microbial fuel cells with a carbon felt, Ni-Co, Cu-B, and Cu-Ag cathodes has been analyzed. In the first place, the measurements of the stationary potential of the electrodes (with Cu-Ag catalyst obtained by the electrochemical deposition technique) were performed. Next, the analysis of the electric energy production during the operation of the membrane-less microbial fuel cell (ML-MFC). The highest parameters were obtained for the Ni-Co and Cu-Ag catalysts. The cell voltage of 607 mV for Ni-Co and 605 mV for Cu-Ag was obtained. Additionally, the power of 4.29 mW for both cathodes - Ni-Co and Cu-Ag was obtained. Moreover, Ni-Co and Cu-Ag allow the shortest time of COD reduction. Based on the test results (with selected MFC design, wastewater, temperature, etc.), it can be concluded that of all the analyzed electrodes, Cu-Ag and Ni-Co electrodes have the best parameters for use as cathodes in ML-MFC. However, based on the results of this study, it can be concluded that all the tested electrodes can be used as cathode material in MFC.

Techniques for obtaining and mathematical modeling of polarization curves in microbial fuel cells

Over the past years the performance of microbial fuel cells (MFCs) has significantly improved. However it is still necessary to increase the efficiency in order to make their scaling-up viable. Obtaining polarization curves (PCs) is considered a widely accepted methodology to characterize the electrical efficiency of MFCs. Through PCs it is possible to identify the main potential losses that limit the system, as well as irreversibilities of energy production, so that better operational and constructive conditions can be proposed. This work reviews techniques for obtaining PCs from MFCs, as well as for the interpretation of these curves. It also provides a discussion about the mathematical modeling strategies of PCs as a methodology for obtaining insights into electrochemical phenomena and their effects on MFCs performance. Thus, this study seeks to contribute to the discussion on MFCs characterization for the improvement of these devices and regarding the establishment of better conditions for reproducibility and comparison of polarization data. Furthermore, it hopes to serve as a reference for researchers who want to perform, interpret and model PCs from their own MFC systems.

Improving MFC efficiency in power generation and COD removal by using protic ionic liquid in MWCNT-CS-2-aminothiazole-SO3H nanoparticle-infused sulfonated PES

This study exhibits a novel nanofiller, functionalized multi-walled carbon nanotube (MWCNT)/chitosan (CS) by 2-aminothiazole/SO3H. This synthesized nanofiller was incorporated with a fabricated sulfonated polyethersulfone (SPES) to manufacture a composite proton exchange membrane (PEM), SPES/MWCNT-CS-2-aminothiazole-SO3H. The composite membranes were fabricated by different percentage amounts of nanofiller (0.1 wt%, 0.5 wt%, 1.0 wt%, 1.5 wt%). The trait comparison of SPES/MWCNT-CS-2-aminothiazole-SO3H, SPES, and Nafion 117 membrane is performed to investigate their application in the microbial fuel cell (MFC). The fabricated composite membrane SPES/MWCNT-CS-2-aminothiazole-SO3H 0.5 wt% illustrated superior water uptake (WU) of 90.41 %. Moreover, the maximum power density (PD) (66.04 mW.m−2) was produced by SPES/MWCNT-CS-2-aminothiazole-SO3H 0.5 wt%, which demonstrated a considerable increase (approximately 20 times) compared to SPES (3.19 mW.m−2). Furthermore, the power density generated by the Nafion 117 membrane was 15.78 mW.m−2. In addition, the statistics in MFC usage presented that prepared composite membrane combined with MWCNT-CS-2-aminothiazole-SO3H 0.5 wt% had the optimum chemical oxygen demand (COD) removal, and the coulombic efficiency (CE), with 90.46 % and 80.68 %, respectively. Due to the high efficiency and remarkable power generation achieved by the MFC with SPES/MWCNT-CS-2-aminothiazole-SO3H 0.5 wt%, this modified membrane can be considered as a promising cost-effective alternative separator in MFC.

Boosting power output in microbial fuel cells with microwave-assisted synthesis of hierarchical bimetallic anodes for enhanced extracellular electron transport

Microbial fuel cells (MFCs) are a promising technology that can generate electricity from various organic waste sources using bacteria as catalysts. However, the low power density of MFCs due to the inefficient extracellular electron transport (EET) remains a major challenge for MFCs. To address this challenge, researchers have been developing new anodes that can enhance the EET efficiency of MFCs. In this study, we report the fabrication of an efficient anode by embedding FeCo bimetallic nanoparticles on carbon cloth (FexCoy@CC) using a microwave-assisted synthesis and calcination process. We find that the Fe1Co1@CC anode demonstrates excellent electrocatalytic activity for electron transfer between bacteria and the anode. Furthermore, in mixed bacterial culture-based MFCs, the Fe1Co1@CC anode shows exceptional electrochemical performances, achieving a high-power density of 3220 mW m−2, a current density of 6.98 A m−2, and a Coulombic efficiency of 16.74 %. The remarkable performance is attributed to the high electronic conductivity provided, the enrichment of electrochemically active Geobacter species, and the EET efficiency enhancement of microbial redox reactions through FeCo bimetallic nanoparticles. This facile and cost-effective method demonstrates great potential for improving the performance of MFCs, which could lead to more efficient and sustainable wastewater treatment and green energy production.

Synergistic advancements in sewage-driven microbial fuel cells: novel carbon nanotube cathodes and biomass-derived anodes for efficient renewable energy generation and wastewater treatment

Microbial fuel cells (MFCs) offer a dual solution of generating electrical energy from organic pollutants-laden wastewater while treating it. This study focuses on enhancing MFC performance through innovative electrode design. Three-dimensional (3D) anodes, created from corncobs and mango seeds via controlled graphitization, achieved remarkable power densities. The newly developed electrode configurations were evaluated within sewage wastewater-driven MFCs without the introduction of external microorganisms or prior treatment of the wastewater. At 1,000°C and 1,100°C graphitization temperatures, corncob and mango seed anodes produced 1,963 and 2,171 mW/m2, respectively, nearly 20 times higher than conventional carbon cloth and paper anodes. An advanced cathode composed of an activated carbon-carbon nanotube composite was introduced, rivaling expensive platinum-based cathodes. By optimizing the thermal treatment temperature and carbon nanotube content of the proposed cathode, comparable or superior performance to standard Pt/C commercial cathodes was achieved. Specifically, MFCs assembled with corncob anode with the proposed and standard Pt/C cathodes reached power densities of 1,963.1 and 2,178.6 mW/m2, respectively. Similarly, when utilizing graphitized mango seeds at 1,100°C, power densities of 2,171 and 2,151 mW/m2 were achieved for the new and standard cathodes, respectively. Furthermore, in continuous operation with a flow rate of 2 L/h, impressive chemical oxygen demand (COD) removal rates of 77% and 85% were achieved with corncob and mango seed anodes, respectively. This work highlights the significance of electrode design for enhancing MFC efficiency in electricity generation and wastewater treatment.

Improving power output in microbial fuel cells with free-standing CoCx/Co@CC composite anodes

Microbial fuel cells (MFCs) are being recognized as a promising solution for sustainable energy generation and wastewater treatment. Despite their potential, MFCs face certain challenges that must be overcome, such as the problem of low power output caused by inefficient extracellular electron transfer (EET). In this study, we develop a nanoporous CoCx/Co@CC composite anode using microwave-assisted and high-temperature calcination methods to enhance EET efficiency and bacterial adhesion in MFCs. Compared with pure carbon cloth (CC) anodes, MFCs with CoCx/Co@CC anodes exhibit a 1.24-fold increase in power density, with a maximum output of 2693 mW m−2. The improved performance can be attributed to the lower charge transfer resistance (Rct) and higher redox activity of the CoCx/Co@CC anode. Cobalt's multiple valence states enhance its ability to transfer electrons between microorganisms and electrodes, ultimately increasing the overall redox activity. The CoCx/Co@CC anode also promotes the growth and enrichment of exoelectrogens, with Geobacter being enriched up to 75 % at the anode, compared with 46 % at the CC electrode. These findings demonstrate the potential of CoCx/Co@CC anodes for improving the EET efficiency of MFCs, which can have significant implications for sustainable energy and wastewater treatment.

Biofilm metagenomic characteristics behind high coulombic efficiency for propanethiol deodorization in two-phase partitioning microbial fuel cell

Hydrophobic volatile organic sulfur compounds (VOSCs) are frequently found during sewage treatment, and their effective management is crucial for reducing malodorous complaints. Microbial fuel cells (MFC) are effective for both VOSCs abatement and energy recovery. However, the performance of MFC on VOSCs remains limited by the mass transfer efficiency of MFC in aqueous media. Inspired by two-phase partitioning biotechnology, silicone oil was introduced for the first time into MFC as a non-aqueous phase (NAP) medium to construct two-phase partitioning microbial fuel cell (TPPMFC) and augment the mass transfer of target VOSCs of propanethiol (PT) in the liquid phase. The PT removal efficiency within 32 h increased by 11–20% compared with that of single-phase MFC, and the coulombic efficiency of TPPMFC (11.01%) was 4.32–2.68 times that of single-phase MFC owing to the fact that highly active desulfurization and thiol-degrading bacteria (e.g., Pseudomonas, Achromobacter) were attached to the silicone oil surface, whereas sulfur-oxidizing bacteria (e.g., Thiobacillus, Commonas, Ottowia) were dominant on the anodic biofilm. The outer membrane cytochrome-c content and NADH dehydrogenase activity improved by 4.15 and 3.36 times in the TPPMFC, respectively. The results of metagenomics by KEGG and COG confirmed that the metabolism of PT in TPPMFC was comprehensive, and that the addition of a NAP upregulates the expression of genes related to sulfur metabolism, energy generation, and amino acid synthesis. This finding indicates that the NAP assisted bioelectrochemical systems would be promising to solve mass-transfer restrictions in low solubility contaminates removal.

Comparative performance of sustainable anode materials in microbial fuel cells (MFCs) for electricity generation from wastewater

Microbial fuel cells (MFCs) are a promising technology to generate electricity from wastewater and reduce the organic content. Whilst there has been a significant enhancement in MFC efficiency arising from the introduction of novel materials and cell designs, challenges remain with respect to the performance, cost, and sustainability of anode materials. This paper reports the development of single chamber MFCs with a focus on novel, cost-effective, and recycled carbon-based anode materials, including Recycled Water Filter Block/Powder (RWFB/RWFP), Recycled Chopped Carbon Fibre (RCCF), Carbon Felt (CF) and Graphite Flexible powder (GFG). Anodes prepared from GFG were shown to provide high power density (342.8 mW/m2), followed by RCCF, CF, RWFP, RWFB and CF (77.6, 71.8, 59.0 and 57.9 mW/m2, respectively). Chemical Oxygen Demand (COD) reduction was measured initially and at day 30, with GFG anodes observed to remove 83% of the initial load, compared to RCCF, RWFB, RWFP and CF anodes, where COD reductions of 69%, 61%, 65% and 73% were observed, respectively. Electrochemical analysis and biofilm imaging confirmed recycled materials were colonised by microorganisms and performed to high standards. GFG offers significant promise as an anode material, with excellent performance supported by a reduction in capital cost of up to 90% in comparison to CF. The use of recycled carbon material as MFC anodes shows promise, but requires additional work to improve the stability and durability of systems to permit scale-up.

A new electro-active bacterium, Paraclostridium sp. AKS46, converts waste efficiently into electricity in microbial fuel cell

Microbial fuel cell (MFC) has gained importance for its ability to convert waste into energy. Exoelectrogens are the essential component of MFC that plays an important role in determining the efficiency of MFC. Therefore, the current study aimed at isolating efficient exoelectrogen(s) with significant biodegradation ability. Based on iron reduction ability, the current study isolated a bacterium that exhibited a high level of current generation and significant COD reduction (58–70%) of the medium/waste used in MFC. The maximum current density achieved in the 80 ml capacity of two electrodes MFC by the new isolate was 632 mA/m2. The ribotyping analysis identified this isolate as a member of the Paraclostridium genera and named Paraclostridium sp. AKS46. Further study revealed that this new isolate is capable of forming a biofilm on the anode, and the result showed a positive correlation of this biofilm formation with the current generation. Field emission-scanning electron microscopy (SEM), energy dispersive X-ray-SEM, Fourier transform infrared spectroscopy, gas chromatography-mass spectroscopy, and high-performance liquid chromatography analysis of the AKS46 reveal multiple electron transfer routes to the electrode surface. Furthermore, this new isolate was found to be capable of utilizing diverse carbon sources and thus generated current efficiently using different household wastes in MFC. Hence, the present study isolated an efficient exoelectrogen, Paraclostridium sp. AKS46, which can generate a high level of electricity with a significant reduction of COD of diverse wastes. Thus the new isolate has the potential to be used in MFC for sustainable development.

Benchmark and strategy development for microbial fuel cells in industrial wastewater treatment

The chemical energy hidden in wastewater can be extracted, turning an energy‐intensive treatment process into an energy‐independent one. However, conventional aerobic treat‐ ment is very energy intensive, and anaerobic treatment requires a post‐treatment step to meet stringent discharge requirements. Therefore, Microbial Fuel Cells (MFCs) have attracted a lot of attention because of their ability to extract electrical energy directly from wastewater during the treatment process. Since combustion losses can be avoided, theoretically the greatest energy value can be obtained from the organic load. However, most MFC research is currently still taking place on a laboratory scale in the treatment of synthetic or municipal wastewater. Commercialization of MFC technology will require large‐scale plants, for which a suitable MFC design and operation concepts must first be identified, since neither configuration nor operating system has been clearly established yet. In addition, no specific concepts and application fields currently exist for the treat‐ ment of industrial wastewater.Consequently, with regard to MFCs in industrial wastewater treatment, the aim of this work is to develop a benchmark that serves for modeling the required overall efficiency of MFCs and to identify the most relevant key factors in order to derive enhancement strate‐ gies. By providing an overview of current MFCs in industrial wastewater treatment and developing a benchmark, the targets for long‐term operation of MFCs can be established allowing critical factors for design and operation to be identified. The resulting enhance‐ ment strategies were validated and the overall evaluation with the developed benchmark allowed an assessment regarding the commercialization potential.Compared to the first MFC design (MFC 1.0), the enhanced MFC design (MFC 2.0) increased the power density by a factor of up to 11 and extended the long‐term stability to one year by increasing the specific cathode surface area and reducing the electrode spacing in conjunction with avoiding fiber clogging on the anode side. In addition to using beneficial brewery wastewater with high content of easily degradable organic acids and high conductivity, the performance of the MFC was further stabilized and improved by changing the operating mode to continuous operation and reducing the hydraulic re‐ tention time to 6 h, resulting in a mean organic removal rate of 6.5 ± 1.9 kg/(m3 · d). Although the overall energy efficiency is low compared to anaerobic treatment, the enor‐ mous wastewater treatment potential forms the basis for MFCs to become an alternative to conventional treatment technologies if self‐sufficient treatment is targeted. Due to the wide range of operating conditions and the modularity of stack systems, MFCs can become a promising option especially for industrial wastewater treatment.

Electricity Production from Yeast Wastewater in Membrane-Less Microbial Fuel Cell with Cu-Ag Cathode

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

Over-expressing NadA quinolinate synthase in Escherichia coli enhances the bioelectrochemistry in microbial fuel cells.

The microbial fuel cell (MFC), which converts biomass energy into electricity through microbial metabolism, is one of the important devices for generating new bioenergy. However, low power production efficiency limits the development of MFCs. One possible method to solve this problem is to genetically modify the microbial metabolism pathways to enhance the efficiency of MFCs. In this study, we over-expressed the nicotinamide adenine dinucleotide A quinolinate synthase gene (nadA) in order to increase the NADH/+ level in Escherichia coli and obtain a new electrochemically active bacteria strain. The following experiments showed an enhanced performance of the MFC, including increased peak voltage output (70.81 mV) and power density (0.29 μW/cm2), which increased by 361% and 20.83% compared to the control group, respectively. These data suggest that genetic modification of electricity producing microbes could be a potential way to improve MFC performance.

Exploring the potential of metal oxides as cathodic catalysts in a double chambered microbial fuel cell for phenol removal and power generation

Detection of high phenol concentrations in industrial wastewater contributed to the need for more efficient wastewater treatment approaches. This study compared and investigated the different metal oxides as cathodic catalysts in a double chambered microbial fuel cell (MFC) for simultaneous phenol removal and bioelectricity generation. Metal oxides such as copper (II) oxide (CuO), manganese dioxide (MnO2) and tin (IV) oxide (SnO2) were synthesized and loaded on a carbon (C) plate, respectively, for application as cathode in the MFC. Results revealed that total chemical oxygen demand and phenol removal efficiency of MFC depleted in the order of CuO/C (96.69 and 100 %) > β-MnO2/C (90.93 and 94.41 %) > α-MnO2/C (84.69 and 90.17 %) > SnO2/C (80.25 and 84.84 %) > bare C (70.48 and 77.06 %) cathode due to the deterioration in the oxygen reduction reaction reactivity. Besides, the solution pH was crucial in determining the catalyst's surface charge properties. At pH 8, higher solution conductivity and stronger electrostatic attraction between positively charged CuO and anionic phenol molecules were favourable for the complete phenol removal. This phenomenon contributed to a 1.77-fold higher maximum power density attained at pH 8 (29.24 mW m−2) than that of pH 11 (16.52 mW m−2) due to more electrons could be utilized for electricity generation. This study provided valuable information on the facile fabrication of cost-effective cathodic catalysts in a double chambered MFC for wastewater treatment and bioelectricity generation.

Impact of Self-Fabricated Graphene–Metal Oxide Composite Anodes on Metal Degradation and Energy Generation via a Microbial Fuel Cell

Microbial fuel cells (MFCs) are thought to be ecologically friendly, despite electron transport and generation challenges. In order to address this, the efficiency of MFCs was investigated using two different anode electrodes made from biomass: graphene oxide (GO) and graphene oxide-metal oxide (GO-MO) (GO-ZnO). After 18 days of operation, the maximum power density for GO was 0.69 mW/m2, whereas the maximum power density for GO-ZnO was 1.05 mW/m2. Furthermore, the ability of MFCs to transform the soluble metal ions (Cd2+, Cr3+, Pb2+, and Ni2+) into an insoluble state was investigated, which is a secondary use of MFCs with significant benefits. In the soluble state of metal ion transformation into an insoluble state, the rate of GO-ZnO was higher (92.71%) than that of GO (81.20%). The outcomes of material, analytical, and biological tests undertaken to validate the efficiency of anodes are presented. It has been shown that using innovative materials as electrodes in MFCs is a potential method for improving electron transport. Furthermore, as an organic substrate, food waste seems to be a viable alternative to more traditional options. In light of these discoveries, we investigate various unanswered issues and possibilities for MFCs. Organic substrate evaluation trials were also included in the present results to demonstrate that organic waste may be a reliable source of MFC performance. This article also has a thorough discussion of food waste oxidation, as well as challenges and future recommendations.

Applications of Nanomaterials in Microbial Fuel Cells: A Review.

Microbial fuel cells (MFCs) are an environmentally friendly technology and a source of renewable energy. It is used to generate electrical energy from organic waste using bacteria, which is an effective technology in wastewater treatment. The anode and the cathode electrodes and proton exchange membranes (PEM) are important components affecting the performance and operation of MFC. Conventional materials used in the manufacture of electrodes and membranes are insufficient to improve the efficiency of MFC. The use of nanomaterials in the manufacture of the anode had a prominent effect in improving the performance in terms of increasing the surface area, increasing the transfer of electrons from the anode to the cathode, biocompatibility, and biofilm formation and improving the oxidation reactions of organic waste using bacteria. The use of nanomaterials in the manufacture of the cathode also showed the improvement of cathode reactions or oxygen reduction reactions (ORR). The PEM has a prominent role in separating the anode and the cathode in the MFC, transferring protons from the anode chamber to the cathode chamber while preventing the transfer of oxygen. Nanomaterials have been used in the manufacture of membrane components, which led to improving the chemical and physical properties of the membranes and increasing the transfer rates of protons, thus improving the performance and efficiency of MFC in generating electrical energy and improving wastewater treatment.

Removal of Diclofenac Sodium from Wastewater in Microbial Fuel Cell by Anode Modified with MnCo2O4

Microbial fuel cell (MFC) with a modified anode is one of the new methods to increase MFC efficiency. This study synthesized an anode modified with cobalt manganese oxide (MnCo2O4@CF) on carbon felt (CF) by easy hydrothermal method and binder-free. Chemical oxygen demand (COD) was measured with and without diclofenac (DCF). According to SEM results, MnCo2O4 was uniformly dispersed on the anode electrode surface. Moreover, the maximum power density in COD (1000 mg/L), 48 h. condition without DCF (726 mA/m2) was 165 ± 0.012 mW/m2 and with DCF concentration of 20 mg/L, it was 308 ± 0.013 mW/m2 (992 mA/m2). In addition, in the presence of 10 mg/L DCF concentration, the maximum COD removal efficiency was 82% ± 1.93 at 48 h. COD removal efficiency without DCF was 94.67% ± 0.02 at 72 h. After 72 h, the maximum removal efficiency of COD and DCF in the carbon anode was 41% ± 1.15 and 9.5% ± 0.23, respectively. Moreover, the maximum DCF removal efficiency using a MnCo2O4 anode was 56% ± 0.55, at 48 h; the initial COD concentration was 500 mg/L, and the DCF concentration was 20 mg/L. This research showed that coating the anode with MnCo2O4 could lead to the increased growth of microorganisms on the surface of the anode, decreased load transfer resistance, increased power density, and more removal of COD and DCF. As a result, the performance of fuel cells with modified anode and removal of DCF increased compared to anode with CF-MFC. Thus, the performance of fuel cells with modified anode and removal of DCF increased compared to anode with CF-MFC.

Biomass-Derived Carbon Anode for High-Performance Microbial Fuel Cells

Although microbial fuel cells (MFCs) have been developed over the past decade, they still have a low power production bottleneck for practical engineering due to the ineffective interfacial bioelectrochemical reaction between exoelectrogens and anode surfaces using traditional carbonaceous materials. Constructing anodes from biomass is an effective strategy to tackle the current challenges and improve the efficiency of MFCs. The advantage features of these materials come from the well-decorated aspect with an enriched functional group, the turbostratic nature, and porous structure, which is important to promote the electrocatalytic behavior of anodes in MFCs. In this review article, the three designs of biomass-derived carbon anodes based on their final products (i.e., biomass-derived nanocomposite carbons for anode surface modification, biomass-derived free-standing three-dimensional carbon anodes, and biomass-derived carbons for hybrid structured anodes) are highlighted. Next, the most frequently obtained carbon anode morphologies, characterizations, and the carbonization processes of biomass-derived MFC anodes were systematically reviewed. To conclude, the drawbacks and prospects for biomass-derived carbon anodes are suggested.

Application of Microbial Fuel Cell (MFC) for Pharmaceutical Wastewater Treatment: An Overview and Future Perspectives

Pharmaceutical wastewater (PWW) is rapidly growing into one of the world’s most serious environmental and public health issues. Existing wastewater treatment systems carry numerous loopholes in supplying the ever-increasing need for potable water resulting from rises in population, urbanization, and industrial growth, and the volume of wastewater produced is growing each day. At present, conventional treatment methods, such as coagulation, sedimentation, oxidation, membrane filtration, flocculation, etc., are used to treat PWW. In contrast to these, the application of microbial fuel cells (MFCs) for decontaminating PWW can be a promising technology to replace these methods. MFC technologies have become a trending research topic in recent times. MFCs have also garnered the interest of researchers worldwide as a promising environmental remediation technique. This review extensively discusses the flaws in standalone conventional processes and the integration of MFCs to enhance electricity production and contaminant removal rates, especially with respect to PWW. This article also summarizes the studies reported on various antibiotics and wastes from pharmaceutical industries treated by MFCs, and their efficiencies. Furthermore, the review explains why further research is needed to establish the actual efficiency of MFCs to achieve sustainable, environmentally friendly, and cost-effective wastewater treatment. A brief on technoeconomic impacts has also been made to provide a glimpse of the way these technologies might replace present-day conventional methods.