Shaoqin Liu

ECS Meeting Abstracts • 2025

<jats:p> Electrochemically active bacteria can transport their metabolically generated electrons to anodes, or accept electrons from cathodes to synthesize high-value chemicals and fuels, via a process known as extracellular electron transfer (EET). Harnessing of this microbial EET process has led to various microbial bioelectrochemical systems such as bioenergy through microbial fuel cells (MFCs). Despite great progress that has been made in terms of the efficiency and applicability of MFCs in recent years, many issues are waiting to be tackled for practical applications of MFCs. The most important challenges included the relatively low power density and poor energy conversion efficiency of MFCs, which mainly arise from low extracellular electron transfer (EET) efficiency between microorganisms and electrode, and the cost of electrode materials. Thus, how to improve the electron transfer rate at the bacteria/electrode interface is an extremely important issue in MFCs. Herein, we designed and fabricated several nanostructured anodes to increase physical contact between electrode and outer-membrane proteins or microbial nanowires and promote efficient EET efficiency between microorganisms and electrode, leading to a steep improvement in MFC performance. For example, our group fabricated a three-dimensional graphene aerogel electrode coated with platinum nanoparticles. Benefited from the continuous 3D macroporous structure with suitable pore size, both the surface and interior of the electrode were covered with a thin biofilm of <jats:italic>S. oneidensis </jats:italic>MR-1 after pre-inoculation. The graphene aerogel scaffold decorated with highly conductive platinum nanoparticles resulted in an outstanding maximum power density of 1460 mW/m<jats:sup>2</jats:sup>, 5.3 folds of carbon cloth. The MFCs equipped with the graphene/FeS<jats:sub>2</jats:sub> NPs not only benefits bacterial adhesion and enrichment of electrochemically active<jats:italic> Geobacter </jats:italic>species on the electrode surface but also promotes efficient extracellular electron transfer, thus giving rise to a fast start-up time of 2 days, an unprecedented power density of 3220 mW m<jats:sup>-2</jats:sup> in the acetate-feeding and mixed bacteria-based MFCs and 310 mW m<jats:sup>-2</jats:sup> with simultaneous removal of 1319 ± 28 mg L<jats:sup>-1</jats:sup> chemical oxygen demand in effluents from a beer factory wastewater. The 3D hierarchical porous carbon foam anodes prepared by pyrolyzing nanoscale Fe-MIL-88b-NH<jats:sub>2</jats:sub> modified seitan composite deliver a maximum power density of 11.21 W m<jats:sup>-3</jats:sup> and current density of 23.11 A m<jats:sup>-3</jats:sup>, outperforming most previously reported 3D porous anodes. The characteristics of improved power generation and enhanced pollutant removal efficiency open door towards development of high-performance MFCs via rational anode design for practical application. </jats:p>

Divya Naradasu

Access Microbiology • 2022

<jats:p>Polymicrobial oral biofilms, which consist of fermentative-bacteria, are associated with periodontitis, gingivitis and cause systemic diseases<jats:sup>1</jats:sup>. Unlike aerobic-respiration, fermentation does not require electron acceptors like O2; and redox-cycling of biological electron-carriers, like NADH, drives the intracellular oxidation and reduction of organic-substrates<jats:sup>2</jats:sup>. Thus, the energy gain is potentially lower than that of respiratory metabolism; however, the high pathogenic activity in anaerobic conditions remained ambiguous<jats:sup>3</jats:sup>. Afew studies have shown that fermentative gut microbes are capable ofreducing external electron acceptors viaextracellular electron transfer (EET)<jats:sup>4-7</jats:sup>. EET, a phenomenon initially found in environmental-bacteria, where metabolically generated electrons are transferred to external electron-acceptors through an outer-membraneredoxprotein complex<jats:sup>8-9</jats:sup>. Thus, the pathogens colonization in the human microbiome may be supported by their EET capability and is important to explore such potentiality. Here, we electrochemically characterized oral-biofilm pathogens Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, to examine their EET ability with lactate/glucose. Both strains showed current production on an electrode surface, associated with consumption of substrate<jats:sup>10</jats:sup>. The addition of antibiotics that suppress the biosynthesis of membrane or protein showed a significant current decrease, demonstrating that current production reflects the cellular-activity. Further, transmission-electron-microscopy of 3,3‡-diaminobenzidine (DAB) stained cells revealed the presence of redox-enzymes on the cell-membrane suggesting a potential EET mechanism via membrane proteins9. These results could be a basis to reevaluate human oral pathogens from an electroactive point of view. The identified EET activity of the two strains can be utilized for an effective test for assessing the impact of antibacterial compounds on the pathogen cellular-activity on an electrode<jats:sup>11</jats:sup>.</jats:p>

Tahseena Naaz, Ankit Kumar, Anusha Vempaty et al.

Environmental Engineering Research • 0

<jats:p>Over the last two decades, scientific communities have been more interested in turning organic waste materials into bioenergy. Microbial fuel cells (MFC) can degrade organic wastewater and produce electrical power. Many constraints have limited the development of MFC. Among them, the anode biofilm development is one of the significant constraints that need to be improved. This review delineates the role of various biological components in the development of electroactive biofilm. The current article focuses on the numerous electron exchange methods for microbiome-induced electron transfer activity, the different proteins, and secretory chemicals involved in electron transfer. This study also focuses on several proteomics and genomics methodologies that have been adopted and developed to improve the extra electron transfer mechanism in electroactive bacteria. Recent advances and publications on synthetic biology and genetic engineering in investigating the direct and indirect electron transport phenomena have also been highlighted. This review helps the reader to understand the recent development in the genetic manipulations of the biofilm, electrode material modifications, EET mechanisms, and operational strategies for improving anode performance. This review also discusses the challenges in present technology and the future direction for improving biofilm production at the anode.</jats:p>

Alberto Hernández-Eligio, Leticia Vega-Alvarado, Xinying Liu et al.

Frontiers in Microbiology • 0

<jats:p>CsrA is a post-transcriptional regulator that controls biofilm formation, virulence, carbon metabolism, and motility, among other phenotypes in bacteria. CsrA has been extensively studied in γ-proteobacteria and firmicutes, However the cellular processes controlled for regulation in δ-proteobacteria remain unknown. In this work, we constructed and characterized the Δ<jats:italic>csrA</jats:italic> mutant strain in <jats:italic>Geobacter sulfurreducens</jats:italic> to determine the involvement of the CsrA protein in the regulation of biofilm and extracellular electron transfer. The Δ<jats:italic>csrA</jats:italic> mutant strain shows higher rates of insoluble Fe(III) reduction than the wild type using acetate as electron donor and the growth with fumarate and soluble (Fe(III)) was similar to wild type. Biofilm quantification and characterization by confocal laser scanning microscopy, showed that the Δ<jats:italic>csrA</jats:italic> mutant produces up to twice as much biofilm as the wild type strain and more than 95% viable cells. Transcriptome analysis by RNA-seq showed that in Δ<jats:italic>csrA</jats:italic> biofilms developed on an inert support, differentially expressed 244 genes (103 upregulated and 141 downregulated), including those related to extracellular electron transfer, exopolysaccharide synthesis, c-di-GMP synthesis and degradation. To validate the transcriptome data, RT-qPCR confirmed the differential expression of several selected genes in the Δ<jats:italic>csrA</jats:italic> strain. Also, current production in microbial fuel cells was performed and the Δ<jats:italic>csrA</jats:italic> strain produced 45–50% more current than the wild type. To identify the genes that changed expression in the Δ<jats:italic>csrA</jats:italic> strain in the graphite electrodes in an MFC, a transcriptome analysis was performed 181 genes changed their expression in the Δ<jats:italic>csrA</jats:italic> biofilms, of which 113 genes were differentially expressed only in MFC and 68 genes changed their expression as well as the transcriptome of biofilms grown on glass. <jats:italic>In silico</jats:italic> analysis of the 5′-UTR regions revealed that 76 genes that changed expression in the RNA-seq analysis have a consensus sequence for CsrA binding. To our knowledge this is the first report describing the involvement of CsrA in the regulation of extracellular electron transfer and biofilm in a member of the δ-proteobacteria.</jats:p>

O. O. Oluyide, J. K. Oloke, V. Adenigba et al.

Nigerian Journal of Biotechnology • 2025

The global energy crisis is caused by high energy demand and insufficient resources. Non-renewable energy sources are diminishing, while renewable energy sources are underutilized. An urgent search for alternative energy generation routes is necessary. A microbial fuel cell is a process that makes use of microorganisms like bacteria or fungi as biocatalysts that oxidize waste organic matter to release electrons which in turn are used to produce electricity. An MFC reactor is made of a cathode, an anode, and a substrate onto which microorganisms are fed so that electrons are released for bioelectricity generation .A two-chamber cathode was fabricated in this study. The chamber has a total volume of 120ml and a working volume of 100ml. The chamber was used to investigate the influence of substrate enrichment and type of electrode on electricity production by some selected bacteria (Pseudomonas Tawanensis (PT), Myroides Odoratimimus (MO), Sphingobacterium Mizutaii (SM). The substrate used is locust beans wastewater. The substrate was enriched with either sucrose or acetate. The electrodes include copper, aluminum, aluminum-zinc alloy, soft zinc, and zinc. To determine the most suitable enrichment sources (sucrose and acetate) a mixed culture of the three bacteria was inoculated in the substrate (locust bean wastewater) with a standard graphite electrode. Cellulose acetate was used as the membrane for the chamber in place of the cation exchange membrane. The setup was operated for 20 days. The effect of substrate enrichment and electrode use on bioelectricity and stability was later analyzed. The results from the mixed culture showed that the substrate enriched with sucrose generated a higher voltage (2.15x10-3 mA) when compared with an acetate-enriched substrate (this generated a voltage of 1.62x10-3 mA) with graphite as the electrode. Following this result, we selected sucrose as the enrichment source in the remaining experiment. Each bacterium used in this study generated electricity in the chamber containing sucrose-enriched substrate with each of the electrodes used. This implies that all the adopted electrodes are sufficient site for the formation of biofilm through which bioelectricity can be generated. However, the highest voltage (1.72mA) was recorded in the chamber containing Pseudomonas taiwanensis with zinc as the electrode in the chamber. We noted that in all the bacteria used in this study, bioeletricity generation was more stable and consistent with copper as the electrode of choice.

Sari Sekar Ningrum, Aidha Zulaika, Wike Handini et al.

Jurnal Penelitian Pendidikan IPA • 2023

Electricity consumption is increasing, causing fossil fuels to run out more quickly. Various efforts are needed to develop renewable energy, including generating electricity. One of the developments in renewable energy comes from biomass. There are various types of biomass developed, one of which is biomass of microorganisms which carry out metabolic activities by utilizing organic material to produce metabolites which include energy. Microbial fuel cell (MFC) is a technology that produces electrical energy with the help of microorganisms that degrade organic materials through catalytic reactions or bioelectrochemical mechanisms from microorganisms. In this research, bioelectricity produced from MFC was tested using Aspergillus Niger with sugarcane bagasse as a substrate. The voltage value obtained from observations carried out for 15 days obtained a voltage in the range of 1.3-4.2 mV

Abid Ali, M. I. Anis, S. S. Mohani et al.

Pakistan Journal of Engineering, Technology and Science • 2024

The exploration of sustainable and renewable energy sources parallels the computational modeling and simulation of biological systems, both driven by the increasing energy demands of modern society. One promising area of research is the utilization of microorganisms for electricity generation, leveraging their inherent metabolic processes. This study investigates two innovative approaches: Microbial Fuel Cells (MFCs) and Plant Microbial Fuel Cells (PMFCs). MFCs harness the electron transfer capabilities of certain bacteria to generate electricity directly from organic matter. This bio-electrochemical system offers a sustainable and environmentally friendly method of energy production. However, the performance of MFCs can be enhanced by incorporating plant-based systems, leading to the development of PMFCs. In this research, we introduce a novel PMFC design based on the Aloe vera plant, which demonstrates improved stability and increased bioelectricity generation compared to traditional PMFCs. We evaluate the impact of incorporating plants and compost on bioenergy production in PMFCs and present an automated testing framework for the electrical characterization of these systems. By harnessing the synergy between microorganisms and plant systems, this study aims to contribute to the ongoing efforts in developing clean and sustainable energy solutions. The proposed approaches not only address the depletion of fossil resources but also mitigate environmental degradation, aligning with the global sustainability goals.

Muhamad Maulana Azimatun Nur, Raden Herjun Desta K. H, Ryan Keane Mahardika Pratama et al.

International Journal of Marine Engineering Innovation and Research • 2024

⎯ This review investigates the role of microalgae in bioelectricity production through biophotovoltaic (BPV) systems, focusing on their dual benefits of generating renewable energy and treating wastewater while capturing CO 2 . The objective of this paper is to conduct a bibliometric analysis of publications from 2013 to 2024 to understand research trends, key contributors, and research hotspots in the field of microalgae-based BPV systems. Methods used include statistical analysis through VOSviewer to visualize the connections between articles and authors. The results show significant advancements in integrating of nanomaterials and microbial fuel cell technologies for bioelectricity generation, as well as ongoing challenges in scalability, voltage balance, and material optimization. This review provides insights into future research directions for improving BPV systems.

Shravan Kumar, N. Shenode, Yashavant Jeph et al.

International Journal for Research in Applied Science and Engineering Technology • 2024

Abstract: Microbial Fuel Cells (MFCs) have emerged as a compelling technological advancement that utilizes microbial metabolic processes to produce electricity from organic waste substrates. This review examines the latest advancements, prevailing challenges, and prospective developments of MFCs in relation to renewable energy generation and ecological sustainability. MFCs present a dual benefit by facilitating wastewater treatment while concurrently generating bioelectricity, thereby rendering them appealing for decentralized energy frameworks and waste management strategies. Recent progress in the fields of genetic engineering and synthetic biology has culminated in the development of optimized microbial strains and improved biofilm stability, which significantly enhances the efficiency of electron transfer. Innovations in electrode materials, including carbon nanotubes and graphene, have further augmented the performance metrics of these systems. Nevertheless, obstacles persist in augmenting power output, minimizing material costs, and scaling MFCs for larger industrial applications. This review also elucidates the environmental and economic implications of MFCs, particularly their capacity to mitigate carbon emissions and generate financial savings in the domain of wastewater treatment. Lastly, we delineate future research trajectories, concentrating on synthetic biology, hybrid renewable systems, and commercialization strategies that will catalyze the scalability and wider acceptance of MFC technology. The prospects for MFCs are indeed promising, providing innovative solutions to the pressing global challenges of energy production and waste management.

A. K. Lembon, P. Lestari, A. A. Ramadhani et al.

IOP Conference Series: Earth and Environmental Science • 2025

High reliance on petroleum and coal-based energy poses a significant challenge for environmental sustainability. To address this issue, it is crucial to explore renewable and sustainable energy alternatives. One promising solution is the use of microbial fuel cells (MFC), which are bio-electrochemical systems capable of generating electrical energy through conversion and catalyzation reactions by microorganisms under anaerobic conditions. MFCs can utilize acidic biomass substrates to produce bioelectricity, including waste from agricultural and domestic sectors. In Indonesia, cocoa and oranges are major agricultural commodities, but their production also leads to significant waste generation. Cocoa processing results in solid waste and cocoa fermentation wastewater, while high orange consumption leads to substantial peel waste. This study aimed to investigate the potential of using microbial fuel cells to produce energy from orange peel waste and cocoa fermentation wastewater. It is expected that the use of both wastes enhanced the production of electrical energy due to their high conductivity. The waste is converted into bioelectricity using MFCs with sustainable waste management technology. The dual chamber MFC system is connected by a salt bridge made of 0.1 M KCl and 12.5 g of agar powder. The electrode materials used Cu as the cathode (+) and Zn as the anode (-), cut into pieces measuring 9 x 4 cm. Solution testing consisted of voltage, current, temperature, pH, and organic acids. The solutions tested included 100% cocoa bean fermentation waste, 100% orange peel extract, cocoa bean fermentation wastewater, and various mixtures of orange peel extract and cocoa bean fermentation waste. The study results indicated that the most optimal MFC composition was achieved through the stability of the voltage and current values, resulting from the metabolism of a mixed substrate of cocoa bean fermentation waste and orange peel extract in equal proportions (50:50). Microbial metabolic activity through a fermentation process could break down complex compounds into simpler compounds, which then generating energy. The increase in voltage value is attributed to the lower pH solution, resulting in a larger electric current, particularly in waste mixtures with equal composition of ingredients.

Rojas-Flores Segundo, Cabanillas-Chirinos Luis, N. M. Otiniano et al.

Sustainability • 2025

Corn is one of the most widely produced cereals worldwide, generating large amounts of waste, represents an environmental and economic challenge. In regions such as Africa and rural areas of Peru, access to electricity is limited, affecting quality of life and economic development. This study proposes using microbial fuel cells (MFCs) to convert chicha de jora waste—a traditional fermented beverage made from corn—into electrical energy. Single-chamber MFCs with activated carbon (anode) and zinc (cathode) electrodes were used. A total of 100 ml of chicha de jora waste was added in each MFC, and three MFCs were used in total. The MFCs demonstrated the viability of chicha de jora waste as a substrate for bioelectricity generation. Key findings include a notable peak in voltage (0.833 ± 0.041 V) and current (2.794 ± 0.241 mA) on day 14, with a maximum power density of 5.651 ± 0.817 mW/cm2. The pH increased from 3.689 ± 0.001 to 5.407 ± 0.071, indicating microorganisms’ degradation of organic acids. Electrical conductivity rose from 43.647 ± 1.025 mS/cm to 186.474 ± 6.517 mS/cm, suggesting ion release due to microbial activity. Chemical oxygen demand (COD) decreased from 957.32 ± 5.18 mg/L to 251.62 ± 61.15 mg/L by day 18, showing efficient degradation of organic matter. Oxidation-reduction potential (ORP) increased, reaching a maximum of 115.891 ± 4.918 mV on day 14, indicating more oxidizing conditions due to electrogenic microbial activity. Metagenomic analysis revealed Bacteroidota (48.47%) and Proteobacteria (29.83%) as the predominant phyla. This research demonstrates the potential of chicha de jora waste for bioelectricity generation in MFCs, offering a sustainable method for waste management and renewable energy production. Implementing MFC technology can reduce environmental pollution caused by corn waste and provide alternative energy sources for regions with limited access to electricity.

Longxin Li, Xinyuan He, Huahua Li et al.

ACS Applied Bio Materials • 2024

As the core component of microbial fuel cells, the conductivity and biocompatibility of anode are hard to achieve simultaneously but significantly influence the power generation performance and the overall cost of microbial fuel cells. Stainless steel felt has a low price and high conductivity, making it a potential anode for the large-scale application of microbial fuel cells. However, its poor biocompatibility limits its application. This study provides a one-step binder-free modification method of a stainless steel felt anode with reduced graphene oxide to retain the high conductivity while greatly improving biocompatibility. The maximum power density achieved by reduced graphene oxide modified stainless steel felt was 951.89 mW/m2, 5.49 and 1.91 times higher than the unmodified stainless steel felt anode and reduced graphene oxide coated stainless steel felt by Nafion, respectively. The robust reduced graphene oxide modification markedly improved the biocompatibility by forming a uniform biofilm and utilizing the high conductivity of reduced graphene oxide to enhance the charge transfer rate. It led to 92.7 and 37.9% decreases in charge transfer resistance of reduced graphene oxide modified stainless steel felt compared to the unmodified one and the anode modified with reduced graphene oxide by Nafion, respectively. The excellent performance and green synthesis method of the anode validated its potential as a high-performance anode material for scaled-up microbial fuel cell applications.

Priya Dharshini Palanivel, Samsudeen Naina Mohamed, G. Mohanakrishna et al.

Journal of Chemical Technology &amp; Biotechnology • 2024

Microbial fuel cells (MFCs) are sustainable energy technologies that could resolve pollution challenges brought by various activities. It can meet energy demand by producing bioelectricity through catabolizing organic matter. Over the past two decades, research on many microbes have been used in MFCs, which intrigued researchers to explore the underlying electron transfer mechanism between microbe and anode. Electron transfer between electrode and microorganism occurs via different pathways: direct, indirect electron transfer and interspecies electron transfer. Shewanella and Geobacter are well‐known for microbe–electrode and microbe–microbe electron transfer. This review provides an overview of the significant varieties of microbes utilized in MFCs for simultaneous bioelectricity generation and wastewater treatment. Mechanisms of different modes of electron transfer involved during the oxidation of organic wastes in the anode section of MFCs are highlighted. Furthermore, this review also details some of the techniques to promote extracellular electron transfer efficiency which is important for the enhanced performance of MFC in terms of power, current generation and wastewater remediation. A perspective of challenges to be addressed for the effective functioning of these technologies, opportunities for MFC systems to be scaled up and associated techno‐economic analysis are discussed. © 2024 Society of Chemical Industry (SCI).

Rongdi An, Jiunian Guan, Gaoxiang Li et al.

Carbon Research • 2024

The electrode played an essential role in the operation of CW-MFC system due to its synergistic effect, and the development of electrode strategy has promoted the application of CW-MFC since 2012. In this paper, according to the material and the quantity, the electrode types in CW-MFC were distinctly divided into unified model, composited model, modified model, and multi-electrodes model combined with non-conductive or conductive particle. Different electrode strategies were provided to improve the performance of CW-MFC towards electricity generation, removal of pollutants, and control of greenhouse gas emission, and the coordination mechanism was further reviewed. Furthermore, the development process of the electrode strategy was summarized, and the low-cost, sustainable, and innovated electrode materials were emphatically recommended. For the scale-up application, multi-electrode model was systematically reviewed based on the optimizing of the material, shape, spacing distance, and connection type of electrode. This review may provide guidance to maximize the advantages of CW-MFC applications. Graphical Abstract

Arjan Dekker, A. ter Heijne, M. Saakes et al.

Environmental Science &amp; Technology • 2009

Scaling up microbial fuel cells (MFCs) is inevitable when power outputs have to be obtained that can power electrical devices other than small sensors. This research has used a bipolar plate MFC stack of four cells with a total working volume of 20 L and a total membrane surface area of 2 m(2). The cathode limited MFC performance due to oxygen reduction rate and cell reversal. Furthermore, residence time distribution curves showed that bending membranes resulted in flow paths through which the catholyte could flow from inlet to outlet, while leaving the reactants unconverted. The cathode was improved by decreasing the pH, purging pure oxygen, and increasing the flow rate, which resulted in a 13-fold power density increase to 144 W m(-3) and a volumetric resistivity of only 1.2 mOmega m(3) per cell. Both results are major achievements compared to results currently published for laboratory and scaled-up MFCs. When designing a scaled-up MFC, it is important to ensure optimal contact between electrodes and substrate and to minimize the distances between electrodes.

Karnapa Ajit, J. John, H. Krishnan

Environmental Science and Pollution Research • 2023

The cathode catalyst in microbial fuel cell (MFC) plays a crucial role in scaling up. Activity of biomass-derived activated carbon catalysts with appropriate precursor selection in a natural clay membrane-based MFC of 250 mL was studied. The performance of scaled up MFC of 1.5 L capacity with two different configurations was monitored. Rod-shaped particles with slit-type pores and amorphous graphitic nature with a surface area of 800.37 m2/g was synthesized. The intrinsic doping of heteroatoms N and P in the catalyst was with atomic weight percentages of 4.5 and 3.5, respectively and the deconvolution of N1 spectra confirmed pyridinic N and graphitic N content of 17.3% and 34.1% validating its suitability as a cathode catalyst. Electrochemical characterization of the catalyst coated SS mesh electrode confirmed that a loading of 5 mg/cm2 rendered higher catalytic activity compared to bare SS mesh. The maximum power density in catalyst modified cell was 0.91 W/m3 compared to 0.02 W/m3 as obtained in a plain stainless steel electrode cell at a COD removal efficiency of 93.3%. Series, parallel, and parallel-series combinations of 6 cells showed a maximum voltage of 4.15 V when connected in series and a maximum power density of 1.54 W/m3 when connected in parallel. System with multielectrode assembly achieved better power and current density (0.84 W/m3 and 1.97 A/m3) than the mixed parallel series circuitry (0.7 W/m3 and 0.57 A/m3). These performance results confirm that the catalyst is effective in both stacked and hydraulically connected system.

Pau Rodenas Motos, Gonzalo Molina, A. ter Heijne et al.

Journal of Chemical Technology &amp; Biotechnology • 2017

Abstract Background Bioelectrochemical systems (BESs) enable recovery of electrical energy through oxidation of a wide range of substrates at an anode and simultaneous recovery of metals at a cathode. Scale‐up of BESs from the laboratory to pilot scale is a challenging step in the development of the process, and there are only a few successful experiences to build on. This paper presents a prototype BES for the recovery of copper. Results The cell design presented here had removable electrodes, similar to those in electroplating baths. The anode and cathode in this design could be replaced independently. The prototype bioelectrochemical cell consisted of an 835 cm2 bioanode fed with acetate, and a 700 cm2 cathode fed with copper. A current density of 1.2 A/−2 was achieved with 48 mW m−2 of power production. The contribution of each component (anode, electrolytes, cathode and membrane) was evaluated through the analysis of the internal resistance distribution. This revealed that major losses occurred at the anode, and that the design with removable electrodes results in higher internal resistance compared with other systems. To further assess the practical applicability of BES for copper recovery, an economic evaluation was performed. Conclusion Analysis shows that the internal resistance of several lab‐scale BESs is already sufficiently low to make the system economic, while the internal resistance for scaled‐up systems still needs to be improved considerably to become economically applicable.© 2017 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Fei Zhang, Kristen S. Brastad, Zhen He

Environmental Science &amp; Technology • 2011

A novel osmotic microbial fuel cell (OsMFC) was developed by using a forward osmosis (FO) membrane as a separator. The performance of the OsMFC was examined with either NaCl solution or artificial seawater as a catholyte (draw solution). A conventional MFC with a cation exchange membrane was also operated in parallel for comparison. It was found that the OsMFC produced more electricity than the MFC in both batch operation (NaCl solution) and continuous operation (seawater), likely due to better proton transport with water flux through the FO membrane. Water flux from the anode into the cathode was clearly observed with the OsMFC but not in the MFC. The solute concentration of the catholyte affected both electricity generation and water flux. These results provide a proof of concept that an OsMFC can simultaneously accomplish wastewater treatment, water extraction (from the wastewater), and electricity generation. The potential applications of the OsMFC are proposed for either water reuse (linking to reverse osmosis for reconcentration of draw solution) or seawater desalination (connecting with microbial desalination cells for further wastewater treatment and desalination).

A. Heijne, Fei Liu, R. D. Weijden et al.

Environmental Science &amp; Technology • 2010

A metallurgical microbial fuel cell (MFC) is an attractive alternative for recovery of copper from copper containing waste streams, as the metal is recovered in its metallic form at the cathode, while the energy for metal reduction can be obtained from oxidation of organic materials at the anode with possible additional production of electricity. We studied the recovery of copper in an MFC using a bipolar membrane as a pH separator. Under anaerobic conditions, the maximum power density was 0.43 W/m(2) at a current density of 1.7 A/m(2). In the presence of oxygen, MFC performance improved considerably to a maximum power density of 0.80 W/m(2) at a current density of 3.2 A/m(2). Pure copper crystals were formed on the cathode, and no CuO or Cu(2)O was detected. Removal efficiencies of >99.88% were obtained. The cathodic recovery of copper compared to the produced electricity was 84% (anaerobic) and 43% (aerobic). The metallurgy MFC with the Cu(2+) reducing cathode further enlarges the application range of MFCs.

A. Rahmani, Nahid Navidjouy, M. Rahimnejad et al.

Environmental Technology • 2020

ABSTRACT Microbial fuel cells (MFCS) is a promising and expanding technology able to eliminate various pollutants of wastewater while converting its chemical energy into power energy using biocatalysts. The potential application of double-chamber microbial fuel cell (DC-MFC) for chemical oxygen demand (COD) removal and generated power from wastewater in the different conditions is investigated. DC-MFC is operated with anaerobic sludge as an active biocatalyst in an anode section, an aerobic cathode section and a Nafion117 membrane as a separator. The performance of the bioreactor is determined with different concentrations of chemical oxygen demand (COD) loadings in the MFC process, in terms of COD removal, power generation and columbic efficiencies. The results illustrated that COD removal efficiency increased at the high concentrations of organic matter. So that at COD concentration of 2000.0 mg/L the highest COD removal efficiency (84%) was obtained. But with increasing substrate initial concentration to 10000.0 mg/L the efficiency decreased to 79%. The important outputs of the system like the highest voltage, maximum generated power, current density, and energy efficiency with the 100,000 mg/L COD are 447 mV, 50.7 mW/m2, 570.0 mA/m2, and 18.6%, respectively. The optical density levels increased due to bacterial growth while pH severely decreased in the anode chamber when using high-concentration substrates in the MFC. GRAPHICAL ABSTRACT

I. Gajda, A. Stinchcombe, Irene Merino-Jimenez et al.

Frontiers in Energy Research • 2018

One of the challenges in Microbial Fuel Cell (MFC) technology is the improvement of the power output and the lowering of the cost required to scale up the system to reach usable energy levels for real life applications. This can be achieved by stacking multiple MFC units in modules and using cost effective ceramic as a membrane/chassis for the reactor architecture. The main aim of this work is to increase the power output efficiency of the ceramic based MFCs by compacting the design and exploring the ceramic support as the building block for small scale modular multi-unit systems. The comparison of the power output showed that the small reactors outperform the large MFCs by improving the power density reaching up to 20.4 W/m3 (mean value) and 25.7 W/m3 (maximum). This can be related to the increased surface-area-to-volume ratio of the ceramic membrane and a decreased electrode distance. The power performance was also influenced by the type and thickness of the ceramic separator as well as the total surface area of the anode electrode. The study showed that the larger anode electrode area gives an increased power output. The miniaturized design implemented in 560-units MFC stack showed an output up to 245 mW of power and increased power density. Such strategy would allow to utilize the energy locked in urine more efficiently, making MFCs more applicable in industrial and municipal wastewater treatment facilities, and scale-up-ready for real world implementation.

Dan Sun, Bin Xie, Jiahao Li et al.

SSRN Electronic Journal • 2022

In order to address the need for long-term, in-situ and inexpensive monitoring of dissolved oxygen (DO), a chitin-carrying microbial fuel cell (MFC) based DO sensor was developed using sediment anolyte, which had an extremely low cost of US$12.17 and comparable performance to certain commercial sensors. The MFC based DO sensor had a long lifetime of over half a year with chitin as the fuel, attributed to the syntrophic interactions between fermentative and exoelectrogenic microbes that were well developed for chitin degradation in anaerobic condition with sediment filling in the anode chamber. The use of sediment anolyte introduced hindered diffusion in the porous media, enabling the use of glass fiber as the separator to replace the ion exchange membrane and thus resulting in a much lower cost. Field tests of this MFC based DO sensor were conducted in fresh and saline waters respectively. Excellent performance was achieved with average deviations of <4.5% to three commercial methods of fiber optic sensor (HQ40d, HACH company, USA), Clark type sensor (Pro20i, YSI company, USA) and iodometry. This low-cost MFC sensor also showed a high reliability, with the same response of current generation to different DO levels in random 17-times tests, indicating its great market potentials for in-situ DO monitoring.

M. J. González-Pabón, F. Figueredo, D. Martínez-Casillas et al.

PLOS ONE • 2019

Microbial fuel cells (MFCs) can evolve in a viable technology if environmentally sound materials are developed and became available at low cost for these devices. This is especially important not only for the designing of large wastewater treatment systems, but also for the fabrication of low-cost, single-use devices. In this work we synthesized membranes by a simple procedure involving easily-biodegradable and economic materials such as poly (vinyl alcohol) (PVA), chitosan (CS) and the composite PVA:CS. Membranes were chemical and physically characterized and compared to Nafion®. Performance was studied using the membrane as separator in a typical H-Type MFCs showing that PVA:CS membrane outperform Nafion® 4 times (power production) while being 75 times more economic. We found that performance in MFC depends over interactions among several membrane characteristics such as oxygen permeability and ion conductivity. Moreover, we design a paper-based micro-scale MFC, which was used as a toxicity assay using 16 μL samples containing formaldehyde as a model toxicant. The PVA:CS membrane presented here can offer low environmental impact and become a very interesting option for point of need single-use analytical devices, especially in low-income countries where burning is used as disposal method, and toxic fluoride fumes (from Nafion®) can be released to the environment.

S. Chauhan, Amit Kumar, Soumya Pandit et al.

Membranes • 2023

The current study investigated the development and application of lithium (Li)-doped zinc oxide (ZnO)-impregnated polyvinyl alcohol (PVA) proton exchange membrane separator in a single chambered microbial fuel cell (MFC). Physiochemical analysis was performed via FT-IR, XRD, TEM, and AC impedance analysis to characterize thus synthesized Li-doped ZnO. PVA-ZnO-Li with 2.0% Li incorporation showed higher power generation in MFC. Using coulombic efficiency and current density, the impact of oxygen crossing on the membrane cathode assembly (MCA) area was evaluated. Different amounts of Li were incorporated into the membrane to optimize its electrochemical behavior and to increase proton conductivity while reducing biofouling. When acetate wastewater was treated in MFC using a PVA-ZnO-Li-based MCA, the maximum power density of 6.3 W/m3 was achieved. These observations strongly support our hypothesis that PVA-ZnO-Li can be an efficient and affordable separator for MFC.

Aryama Raychaudhuri, R. Sahoo, M. Behera

Water Science and Technology • 2021

Ceramic separators have recently been investigated as low-cost, robust, and sustainable separators for application in microbial fuel cells (MFC). In the present study, an attempt was made to develop a low-cost MFC employing a clayware ceramic separator modified with silica. The properties of separators with varying silica content (10%-40% w/w) were evaluated in terms of oxygen and proton diffusion. The membrane containing 30% silica exhibited improved performance compared to the unmodified membrane. Two identical MFCs, fabricated using ceramic separators with 30% silica content (MFCS-30) and without silica (MFCC), were operated at hydraulic retention time of 12 h with real rice mill wastewater with a chemical oxygen demand (COD) of 3,200 ± 50 mg/L. The maximum volumetric power density of 791.72 mW/m3 and coulombic efficiency of 35.77% was obtained in MFCS-30, which was 60.4% and 48.5%, respectively, higher than that of MFCC. The maximum COD and phenol removal efficiency of 76.2% and 58.2%, respectively, were obtained in MFCS-30. MFC fabricated with modified ceramic separator demonstrated higher power generation and pollutant removal. The presence of hygroscopic silica in the ceramic separator improved its performance in terms of hydration properties and proton transport.

Thirutamil Sachin A, Prajin Raja J, Ranjith S et al.

international journal of engineering technology and management sciences • 2025

<jats:p>Microbial Fuel Cells (MFCs) represent an innovative bioelectrochemical technology thatharnesses the metabolic activities of electroactive bacteria, particularly Shewanella oneidensisandGeobacter sulfurreducens, to generate electricity. These bacteria transfer electrons to an anodewhile breaking down organic matter, enabling sustainable energy production. This paper exploresthe principles behind MFCs, the electron transfer mechanisms of ShewanellaandGeobacter, andtheir practical applications. Experimental results demonstrate their potential for renewable energygeneration in wastewater treatment, agricultural applications, and remote sensing. The study alsodiscusses the challenges of scaling up MFCs, their environmental impact, and future prospects.</jats:p>

Yidan Hu, Yinghui Wang, Xi Han et al.

Frontiers in Bioengineering and Biotechnology • 0

<jats:p><jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> spp. were discovered in late 1980s as dissimilatory metal-reducing microorganisms that can transfer electrons from cytoplasmic respiratory oxidation reactions to external metal-containing minerals. In addition to mineral-based electron acceptors, <jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> spp. also can transfer electrons to electrodes. The microorganisms that have abilities to transfer electrons to electrodes are known as exoelectrogens. Because of their remarkable abilities of electron transfer, <jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> spp. have been the two most well studied groups of exoelectrogens. They are widely used in bioelectrochemical systems (BESs) for various biotechnological applications, such as bioelectricity generation <jats:italic>via</jats:italic> microbial fuel cells. These applications mostly associate with <jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> biofilms grown on the surfaces of electrodes. <jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> biofilms are electrically conductive, which is conferred by matrix-associated electroactive components such as <jats:italic>c</jats:italic>-type cytochromes and electrically conductive nanowires. The thickness and electroactivity of <jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> biofilms have a significant impact on electron transfer efficiency in BESs. In this review, we first briefly discuss the roles of planktonic and biofilm-forming <jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> cells in BESs, and then review biofilm biology with the focus on biofilm development, biofilm matrix, heterogeneity in biofilm and signaling regulatory systems mediating formation of <jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> biofilms. Finally, we discuss strategies of <jats:italic>Geobacter</jats:italic> and <jats:italic>Shewanella</jats:italic> biofilm engineering for improving electron transfer efficiency to obtain enhanced BES performance.</jats:p>

Tomás M. Fernandes, Leonor Morgado, David L. Turner et al.

Antioxidants • 0

<jats:p>Electrogenic microorganisms possess unique redox biological features, being capable of transferring electrons to the cell exterior and converting highly toxic compounds into nonhazardous forms. These microorganisms have led to the development of Microbial Electrochemical Technologies (METs), which include applications in the fields of bioremediation and bioenergy production. The optimization of these technologies involves efforts from several different disciplines, ranging from microbiology to materials science. Geobacter bacteria have served as a model for understanding the mechanisms underlying the phenomenon of extracellular electron transfer, which is highly dependent on a multitude of multiheme cytochromes (MCs). MCs are, therefore, logical targets for rational protein engineering to improve the extracellular electron transfer rates of these bacteria. However, the presence of several heme groups complicates the detailed redox characterization of MCs. In this Review, the main characteristics of electroactive Geobacter bacteria, their potential to develop microbial electrochemical technologies and the main features of MCs are initially highlighted. This is followed by a detailed description of the current methodologies that assist the characterization of the functional redox networks in MCs. Finally, it is discussed how this information can be explored to design optimal Geobacter-mutated strains with improved capabilities in METs.</jats:p>

Ruijie Wang, Xiaoshuai Wu, Chang Liu et al.

Catalysts • 0

<jats:p>The nanoporous carbon fiber materials derived from electrospun polyacrylonitrile (PAN) fibers doped with zeolitic imidazolate framework are developed here and applied in the microbe fuel cell anode for enhanced interfacial electron transfer. Zeolitic imidazolate fram-8 (ZIF-8) could introduce a large number of mesopores into fibers, which significantly promote indirect electron transfer mediated by flavins (IET). Moreover, it is noted that thinner fibers are more suitable for cytochromes-based direct electron transfer (DET). Furthermore, the enlarged fiber interspace strengthens the amount of biofilm loading but a larger interspace between thick fibers would hinder the formation of continuous biofilm. Consequently, the nanoporous carbon fiber derived from PAN/ZIF-8 composite with a 1:1 wt ratio shows the best performance according to its suitable mesoporous structure and optimal fiber diameter, which delivers a 10-fold higher maximum power density in microbial fuel cells compared to carbon fabric. In this work, we reveal that the proportion of IET and DET in the interfacial electron transfer process varies with different porous structures and fiber diameters, which may provide some insights for designing porous fiber electrodes for microbial fuel cells and also other devices of bioelectrochemical systems.</jats:p>

Maha A Abdulwahhab, Sarmad T Najim, Maha Allawi Abdulwahhab

Journal of Chemical Technology &amp; Biotechnology • 2023

<jats:title>Abstract</jats:title><jats:p>Over the past 20 years the scientific community has become interested in microbial fuel cell microbial fuel cell (MFC) technology, because it offers the potential for the direct conversion of organic waste into power generation through microbially catalysed anodic and microbial–enzymatic–abiotic cathodic electrochemical reactions. Several facts about the technology are taken into account in this evaluation. A brief history of abiotic to biological fuel cells is presented, as well as a presentation of microbial fuel cells and a description of the concept of a microbial fuel cell in a broader range of derivative technologies known as bio‐electrochemical systems with biofilm formation, aerobic and anaerobic digestion of organic materials contained in the substrates and how electrons transfer from the surface of the biofilm to the outer circle. Microbial electrolysis cells, and electro‐synthesis cells are briefly discussed. MFC can be improved through the understanding of previous studies by defining the method of work and the theoretical foundations on which they are built. Moreover, the wide range of criteria that is likely to restrict their performance can be determined by providing a brief explanation of components that make them up. Thermodynamic and biotic factors and the mechanism of operation of these bio‐electrochemical systems need to be considered. A review of the various components that make up the MFC will be proposed, allowing for the illumination of the several scientific locks that continue to limit the technology's effectiveness. This review will provide a discussion of the mechanism of MFCs and provide details about the action of electrically active bacteria in the anode chamber through the generation of electroactive biofilms and the conversion of part of the energy available in the substrates, and this is one of renewable energy which is highlighted by researchers. © 2023 Society of Chemical Industry (SCI).</jats:p>

Naoko Yoshida, Yasushi Miyata, Kasumi Doi et al.

Scientific Reports • 0

<jats:title>Abstract</jats:title><jats:p>Graphene oxide (GO) is reduced by certain exoelectrogenic bacteria, but its effects on bacterial growth and metabolism are a controversial issue. This study aimed to determine whether GO functions as the terminal electron acceptor to allow specific growth of and electricity production by exoelectrogenic bacteria. Cultivation of environmental samples with GO and acetate as the sole substrate could specifically enrich exoelectrogenic bacteria with<jats:italic>Geobacter</jats:italic>species predominating (51–68% of the total populations). Interestingly, bacteria in these cultures self-aggregated into a conductive hydrogel complex together with biologically reduced GO (rGO). A novel GO-respiring bacterium designated<jats:italic>Geobacter</jats:italic>sp. strain R4 was isolated from this hydrogel complex. This organism exhibited stable electricity production at &gt;1000 μA/cm<jats:sup>3</jats:sup>(at 200 mV vs Ag/AgCl) for more than 60 d via rGO while temporary electricity production using graphite felt. The better electricity production depends upon the characteristics of rGO such as a large surface area for biofilm growth, greater capacitance and smaller internal resistance. This is the first report to demonstrate GO-dependent growth of exoelectrogenic bacteria while forming a conductive hydrogel complex with rGO. The simple put-and-wait process leading to the formation of hydrogel complexes of rGO and exoelectrogens will enable wider applications of GO to bioelectrochemical systems.</jats:p>

Lei Zhou, Dandan Deng, Di Zhang et al.

Electroanalysis • 2016

<jats:title>Abstract</jats:title><jats:p>In this study, the petroleum hydrocarbon‐contaminated soil was used as both inoculation and carbon source simultaneously to enrich exoelectrogenic bacteria for using in microbial fuel cell system and it demonstrated working output power density at around 220 mW m<jats:sup>−2</jats:sup>. The feasible electrochemical properties have displayed by means of cyclic voltammetry and dual‐chamber MFCs experiments. Moreover, two species of exoelectrogens were isolated belonging to <jats:italic>Geobacter</jats:italic> sp. and <jats:italic>Ochrobactrum</jats:italic> sp., respectively. This work evaluates the capability of naturally occurring petroleum‐degrading species to produce electric current in bioelectrochemical system. To the best of our knowledge, this is the first time when ecological information on electroactive, petroleum‐degrading consortium is provided.</jats:p>

Sheng Tao Jiang, Yu Jiang Guan, Shu Li Bai

Advanced Materials Research • 2012

<jats:p>Different organics have different effects on the power generation of microbial fuel cell. A double-chamber Microbial Fuel Cell (MFC) was constructed to investigate organic matter degradation and power generation. Experiments were conducted using an initial phenol concentration of 500mg/L with different glucose concentrations (500 , 250 , and 100mg/L) as the MFC fuel . Results showed that maximum voltages decreased with the decrease of concentration of glucose and the maximum voltage was 434 mV. The cycle time were 170 , 146 ,141h respectively. Correspondingly , the maximal area power densities were 10.23 mw/m2,5.02mw/m<jats:sup>2</jats:sup>,3.15 mw/m<jats:sup>2</jats:sup>. phenol and COD removal rate reached 28%-33.3% and 31.1%-54.74% respectively after one cycle. However, maximum voltage was 201 mV when using 500 mg/L phenol as sole fuel. The results indicated that phenol could be used in the MFC for generating power while at the same time effectively accomplishing biodegradation. The MFC technology may provide a new method to offset operating costs, making advanced remediation measures for difficult to degrade organic materials more affordable for practical applications.</jats:p>

Gabriela Campos Mesquita, P. Soares, C. Moura et al.

Brazilian Dental Journal • 2017

This study assessed the epidemiological characteristics and management of the permanent teeth avulsion cases attended in a Brazilian dental trauma service from December 2005 to August 2016. A retrospective study was conducted of case records of 93 patients involving 139 avulsed teeth. Data included sex, age, trauma etiology, location of the accident, number and position of avulsed teeth, and presence and type of associated traumatic lesions. Management of the avulsed teeth was addressed as: time elapsed until teeth were retrieved from the accident's location; teeth's cleaning method and storage media; time elapsed until seeking treatment and replantation. The majority of the patients were children from 6-10 (31.2%) and 11-15 years old (26.9%). Male patients were more affected than female. Bicycle accident was the main etiological factor (31.2%). In 56 (60.2%) cases, traumatic lesions to neighboring teeth were present. In 55 (59.1%) cases, lesions to adjacent soft tissues were reported. In 82 (88.2%) cases, patients requested treatment at the same day of the accident. Sixty-four teeth (46.0%) were immediately retrieved and 28 (20.1%) were not found. Forty-two teeth (30.2%) were kept dry. Only one tooth (0.7%) was immediately replanted at the accident's site, while 51 teeth (36.7%) were not replanted. Numerous avulsed teeth were inappropriately managed and immediate replantation was not frequent. Public policies must be created to raise awareness towards the particularities of avulsion cases.

D. Otero, Bruna A. Bulsing, K. D. M. Huerta et al.

Brazilian Journal of Chemical Engineering • 2019

Different yeast strains from forests located in southern Brazil, with potential to produce carotenoids, were isolated. Three microorganisms were selected as potential carotenoid producers. Sporiodiobolus pararoseus, Rhodotorula mucilaginosa and Pichia fermentans were grown in Yeast Malt (YM) medium and the carotenoids produced identified as cryptoxanthin and β-carotene. In order to reduce production costs, agroindustrial residues were used in the formulation of medium A (parboiled rice water and crude glycerol) and medium B (parboiled rice water and sugar cane molasses). The highest carotenoid production was obtained with S. pararoseus. It reached 905.30 μ gL-1 (122.82 μg g-1) in YM medium, 820 μg L-1 (68.04 μg g-1) in medium B and 710 μg L-1 (86.46 μg g-1) in medium A. R. mucilaginosa exhibited the best performance in medium B (360 μg L-1 and 30.16 μg g-1) and a new microorganism P. fermentans reached 48% (medium A) and 78% (medium B) of the value found in YM medium. Therefore, the agroindustrial residues under evaluation, which replaced the commonly used nitrogen and carbon sources in culture media, enabled the isolated yeasts to yield

Leticia Pinheiro, M. R. S. Lima

Brazilian Political Science Review • 2018

The article examines the construction of the concept of autonomy in Latin America and discusses to what extent it can be applied to contemporary Brazilian foreign policy. The article first examines classical definitions of the concept, and then looks at the ways in which it has been used to analyze Brazilian foreign policy for over half a century. We then reaffirm the importance of agency and how power relations vary from one thematic area to another. In doing so, the [...]

H. P. V. Silva, Thaynnan Thómaz Silva Arruda, K. S. C. Souza et al.

Brazilian Oral Research • 2018

Considering that environmental risk factors substantially contribute to the etiology of orofacial clefts and that knowledge about the characteristics and comorbidities associated with oral clefts is fundamental to promoting better quality of life, this study aimed to describe the risk factors, main characteristics, and comorbidities of a group of patients with cleft lip and/or cleft palate (CL/P) from Rio Grande do Norte (RN), Brazil. Data were obtained from 173 patients with CL/P using a form from the Brazilian database on Orofacial Clefts. Most patients were male with cleft lip and palate and had a normal size and weight at birth; presented few neonatal intercurrent events; and had anemia and respiratory and cardiovascular diseases as main associated comorbidities. They also required timely surgical rehabilitation and multidisciplinary care to stimulate their neuropsychomotor development. In addition, a high frequency of familial recurrence and of parental consanguinity was evidenced in the studied population, especially for the cleft lip and cleft palate type. Other relevant findings were the considerable maternal exposure to alcohol, infections, smoking, and hypertension, as well as low supplementation with vitamins and minerals and deliberate consumption of analgesics, antibiotics, and antihypertensives during pregnancy. Characterization of the CL/P patient profile is essential for the planning of health services and integration among the health professionals involved in the diagnosis and treatment of these malformations. Our results reinforce the need for additional research to confirm the association between environmental factors and the development of orofacial clefts.

F. Timóteo, F. Korkes, W. Baccaglini et al.

International braz j urol • 2020

ABSTRACT Introduction Considering the lack of data on BC trends in Brazilian population, mainly as a result of the difficulty on gathering data, the present manuscript provides an overview of bladder cancer incidence, hospitalization, mortality patterns and trends using the Brazilian Data Center for The Public Health System (DATASUS). Materials and Methods All hospital admissions associated with BC diagnosis (ICD-10 C67) between 2008 and 2017 were analyzed. Distributions according to year, gender, age group, ethnicity, death, length of hospital stay, and costs were evaluated. Demographic data was obtained from the last Brazilian national census. Results From 2008 to 2017 there were 119,058 public hospital admissions related to BC. Patients were mostly white males aged 60 to 79 years-old. Mortality rates for patients who have undergone surgery was 6.75% on average, being 7.38% for women and 6.49% for men. Mortality rates were higher when open surgeries were performed compared to endoscopic procedures (4.98% vs 1.18%). Considering only endoscopic procedures, mortality rates were three times higher after urgent surgeries compared to elective ones (2.6% vs 0.6%). Over the years the cystectomy/transurethral bladder resection (C/T) ratio significantly decreased in all Brazilian Regions. In 2008, the C/T ratio was 0.19, while in 2017 it reduced to 0.08. Conclusions Despite BC relatively low incidence, it still represents a significant social economic burden in Brazil, as it presents with recurrent episodes that might require multiple hospitalizations and surgical treatment. The set of data collected might suggest that population access to health care has improved between 2008-2017.

Shaik Ashmath, Hao Wu, Shaik Gouse Peera et al.

Catalysts • 0

<jats:p>Pt supported on carbon (Pt/C) is deemed as the state-of-the-art catalyst towards oxygen reduction reactions (ORRs) in chemical and biological fuel cells. However, due to the high cost and scarcity of Pt, researchers have focused on the development of Earth-abundant non-precious metal catalysts, hoping to replace the traditional Pt/C catalyst and successfully commercialize the chemical and biological fuel cells. In this regard, electrocatalysts made of transition metals emerged as excellent candidates for ORRs, especially the electrocatalysts made of Fe and Co in combination with N-doped carbons, which produce potentially active M-N4-C (M=Co, Fe) ORR sites. At present, however, the transition metal-based catalysts are popular; recently, electrocatalysts made of rare earth metals are emerging as efficient catalysts, due to the fact that rare earth metals also have the potential to form rare earth metal-N4-C active sites, just like transition metal Fe-N4-C/Co-N4-C. In addition, mixed valance states and uniqueness of f-orbitals of the rare earth metals are believed to improve the redox properties of the catalyst that helps in enhancing ORR activity. Among the rare earth metals, Ce is the most interesting element that can be explored as an ORR electrocatalyst in combination with the N-doped carbon. Unique f-orbitals of Ce can induce distinctive electronic behavior to the catalyst that helps to form stable coordination structures with N-doped carbons, in addition to its excellent ability to scavenge the OH● produced during ORRs, therefore helping in catalyst stability. In this study, we have synthesized Ce/N-C catalysts by a metal–organic framework and pyrolysis strategy. The ORR activity of Ce/N-C catalysts has been optimized by systematically increasing the Ce content and performing RDE studies in 0.1 M HClO4 electrolyte. The Ce/N-C catalyst has been characterized systematically by both physicochemical and electrochemical characterizations. The optimized Ce/N-C-3 catalyst exhibited a half-wave potential of 0.68 V vs. RHE. In addition, the Ce/N-C-3 catalyst also delivered acceptable stability with a loss of 70 mV in its half-wave potential when compared to 110 mV loss for Pt/C (10 wt.%) catalyst, after 5000 potential cycles. When Ce/N-C-3 is used as a cathode catalyst in dual-chamber microbial fuel cells, it delivered a volumetric power density of ~300 mW m−3, along with an organic matter degradation of 74% after continuous operation of DCMFCs for 30 days.</jats:p>

Shaik Ashmath, Hyuk-Jun Kwon, Shaik Gouse Peera et al.

Nanomaterials • 0

<jats:p>Due to the high cost of presently utilized Pt/C catalysts, a quick and sustainable synthesis of electrocatalysts made of cost-effective and earth-abundant metals is urgently needed. In this work, we demonstrated a mechanochemically synthesized cobalt nanoparticles supported on N and S doped carbons derived from a solid-state-reaction between zinc acetate and 2-amino thiazole as metal, organic ligand in presence of cobalt (Co) metal ions ZnxCox(C3H4N2S). Pyrolysis of the ZnxCox(C3H4N2S) produced, Co/NSC catalyst in which Co nanoparticles are evenly distributed on the nitrogen and sulfur doped carbon support. The Co/NSC catalyst have been characterized with various physical and electrochemical characterization techniques. The Co content in the ZnxCox(C3H4N2S) is carefully adjusted by varying the Co content and the optimized Co/NSC-3 catalyst is subjected to the oxygen reduction reaction in 0.1 M HClO4 electrolyte. The optimized Co/NSC-3 catalyst reveals acceptable ORR activity with the half-wave potential of ~0.63 V vs. RHE in acidic electrolytes. In addition, the Co/NSC-3 catalyst showed excellent stability with no loss in the ORR activity after 10,000 potential cycles. When applied as cathode catalysts in dual chamber microbial fuel cells, the Co/NCS catalyst delivered satisfactory volumetric power density in comparison with Pt/C.</jats:p>