Mohammad Ranjbar, Mohammadreza Esmailbagi, Mahin Schaffie

Solid State Phenomena • 0

<jats:p>The objective of this study is to improve the understanding of copper sulfides dissolution and to use this knowledge for optimization of process parameters for commercial application of electrochemical bioleaching of chalcopyrite concentrates in stirred bioreactors. From the results of this study, the importance of the oxidation reduction potential (ORP) on the catalytic interaction between chalcopyrite and pyrite can be pointed out as the main parameters for successful bioprocessing of chalcopyrite concentrates. Under these conditions, the optimization of the average particle size of feed (D80) and adjusting the ORP in the range between 400-450 mV are important criteria for increasing the electrochemical bioleaching rate of chalcopyrite concentrates. It seems that the main reason for the increased copper recovery could be the control and prevention of chalcopyrite passivation resulting from improved galvanic interaction between copper sulfide minerals, here especially chalcopyrite and pyrite in the selected ORP range and the right particle size distribution of feed. At optimum conditions, the copper extraction from chalcopyrite flotation concentrate during 7 days of continuous electrochemical bioleaching operations in stirred tanks was about 95%, which should be high enough to justify the process economically.</jats:p>

Huajun Feng, Xueqin Zhang, Kun Guo et al.

Applied and Environmental Microbiology • 2015

<jats:title>ABSTRACT</jats:title> <jats:p> Fed batch bioelectrochemical systems (BESs) based on electrical stimulation were used to treat <jats:italic>p</jats:italic> -fluoronitrobenzene ( <jats:italic>p</jats:italic> -FNB) wastewater at high salinities. At a NaCl concentration of 40 g/liter, <jats:italic>p</jats:italic> -FNB was removed 100% in 96 h in the BES, whereas in the biotic control (BC) (absence of current), <jats:italic>p</jats:italic> -FNB removal was only 10%. By increasing NaCl concentrations from 0 g/liter to 40 g/liter, defluorination efficiency decreased around 40% in the BES, and in the BC it was completely ceased. <jats:italic>p</jats:italic> -FNB was mineralized by 30% in the BES and hardly in the BC. Microorganisms were able to store 3.8 and 0.7 times more K <jats:sup>+</jats:sup> and Na <jats:sup>+</jats:sup> intracellularly in the BES than in the BC. Following the same trend, the ratio of protein to soluble polysaccharide increased from 3.1 to 7.8 as the NaCl increased from 0 to 40 g/liter. Both trends raise speculation that an electrical stimulation drives microbial preference toward K <jats:sup>+</jats:sup> and protein accumulation to tolerate salinity. These findings are in accordance with an enrichment of halophilic organisms in the BES. <jats:named-content content-type="genus-species">Halobacterium</jats:named-content> dominated in the BES by 56.8% at a NaCl concentration of 40 g/liter, while its abundance was found as low as 17.5% in the BC. These findings propose a new method of electrical stimulation to improve microbial salinity resistance. </jats:p>

Shu-Hui Liu, Kun-Yan Lee

Journal of Power Sources • 2021

Ademola Adekunle, Vijaya Raghavan, Boris Tartakovsky

Journal of Power Sources • 2017

Chaeho Im, Minsoo Kim, Jung Rae Kim et al.

Frontiers in Microbiology • 0

<jats:p>Fossil resources must be replaced by renewable resources in production systems to mitigate green-house gas emissions and combat climate change. Electro-fermentation utilizes a bioelectrochemical system (BES) to valorize industrial and municipal waste. Current electro-fermentation research is mainly focused on microbial electrosynthesis using CO<jats:sub>2</jats:sub> for producing commodity chemicals and replacing petroleum-based infrastructures. However, slow production rates and low titers of metabolites during CO<jats:sub>2</jats:sub>-based microbial electrosynthesis impede its implementation to the real application in the near future. On the other hand, CO is a highly reactive gas and an abundant feedstock discharged from fossil fuel-based industry. Here, we investigated CO and CO<jats:sub>2</jats:sub> electro-fermentation, using a CO-enriched culture. Fresh cow fecal waste was enriched under an atmosphere of 50% CO and 20% CO<jats:sub>2</jats:sub> in N<jats:sub>2</jats:sub> using serial cultivation. The CO-enriched culture was dominated by <jats:italic>Clostridium autoethanogenum</jats:italic> (≥89%) and showed electro-activity in a BES reactor with CO<jats:sub>2</jats:sub> sparging. When 50% CO was included in the 20% CO<jats:sub>2</jats:sub> gas with 10 mA applied current, acetate and ethanol were produced up to 12.9 ± 2.7 mM and 2.7 ± 1.1 mM, respectively. The coulombic efficiency was estimated to 148% ± 8% without an electron mediator. At 25 mA, the culture showed faster initial growth and acetate production but no ethanol production, and only at 86% ± 4% coulombic efficiency. The maximum optical density (OD) of 10 mA and 25 mA reactors were 0.29 ± 0.07 and 0.41 ± 0.03, respectively, whereas it was 0.77 ± 0.19 without electric current. These results show that CO electro-fermentation at low current can be an alternative way of valorizing industrial waste gas using a bioelectrochemical system.</jats:p>

Jean Pierre Muhoza, Hongzhi Ma, Loissi Kalakodio et al.

International Journal of Waste Resources • 2017

Tekalign Tesfaye, Yohannes Shuka, Sisay Tadesse et al.

Scientific Reports • 0

Sadia Sikder, Md. Mostafizur Rahman

Case Studies in Chemical and Environmental Engineering • 2023

Kyle S. Jiang, Betar M. Gallant

ECS Meeting Abstracts • 2023

<jats:p> The lithium (Li) metal anode holds great promise for high energy-density rechargeable batteries due to its high gravimetric capacity (3860 mAh/g), an order of magnitude larger than graphite at a similar electrochemical potential (-3.040 V vs SHE for Li). However, limited Coulombic efficiency (CE), caused by the thermodynamic instability of conventional Li-ion electrolyte solvents and salts with Li that leads to unstable solid-electrolyte interphase (SEI) during repeated plating and stripping, has hindered the commercialization of Li metal batteries. Research efforts have focused on tuning the electrolyte composition to promote a stable SEI that simultaneously blocks continuous side reactions and electronic conductivity while facilitating Li<jats:sup>+</jats:sup> transport [1], with coin cells being by far the most preferred form factor for evaluating these electrolyte designs.</jats:p> <jats:p>Coin cells enable accessible and rapid testing of diverse electrolyte compositions. Their preparation requires no specialized equipment beyond an inert chemical environment, a crimping mechanism to seal the cell, and modest quantities of Li metal (~50 - 100 μm thickness) and electrolyte (~50 - 100 μL volume) [2]. Despite these attractive features, the procedures for preparing and techniques for measuring CE in coin cells are not fully standardized. In this presentation, we examine the impact on measured CE from preparation and testing procedures, including the internal coin cell stack consisting of components such as the electrodes, current collectors / spacers, and separators, and the cycling protocol. While the cycling protocol and cycling capacity are known to affect capacity loss mechanisms in Li metal batteries [3], we show that variances in CE can additionally be attributed to specific details of cell preparation. In particular, the working electrode area and stack thickness affect the pressure magnitude and uniformity inside the cell. We demonstrate that standardizing the procedures for preparing coin cells reduces variation due to nonuniformities and edge effects and hence improves the reproducibility of CE measurements.</jats:p> <jats:p>[1] Hobold, G. M., et al. <jats:italic>Nature Energy</jats:italic> <jats:bold>2021</jats:bold> <jats:italic>6</jats:italic> (10), 951-960.</jats:p> <jats:p>[2] Xiao, J., et al. <jats:italic>Nature Energy</jats:italic> <jats:bold>2020</jats:bold> <jats:italic>5</jats:italic> (8), 561-568.</jats:p> <jats:p>[3] Adams, B. D., et al. <jats:italic>Advanced Energy Materials</jats:italic> <jats:bold>2018</jats:bold> <jats:italic>8</jats:italic> (7), 1702097.</jats:p> <jats:p> <jats:inline-formula> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="815fig1.jpg" xlink:type="simple"/> </jats:inline-formula> </jats:p> <jats:p>Figure 1</jats:p> <jats:p/>

Yangyang Gao, Fengjun Yin, Weiqi Ma et al.

Bioelectrochemistry • 2020

Wulin Yang, Xu Wang, Moon Son et al.

Journal of Power Sources • 2020

Daniel Liu, Jimmy Kuo, Chorng-Horng Lin

Processes • 0

<jats:p>Certain bacteria can transfer extracellular electrons and are applied in microbial fuel cells (MFCs). In this study, we compared the extracellular electron transfer characteristics of 85 genomes from nine genera, namely Blautia, Bradyrhizobium, Desulfuromonas, Dialister, Geobacter, Geothrix, Shewanella, Sphingomonas, and Phascolarctobacterium, using the bioinformatic tools Prokka 1.14.6, Roary 3.13.0, Panaroo 1.3.4, PEPPAN 1.0.6, and Twilight. The unweighted pair-group method with arithmetic mean (UPGMA) clustering of genes related to extracellular electron transfer revealed a good genus-level structure. The relative abundance and hierarchical clustering analyses performed in this study suggest that the bacteria Desulfuromonas, Geobacter, Geothrix, and Shewanella have more extracellular electron transfer genes and cluster together. Further functional differences among the genomes showed that 66 genes in these bacteria were significantly higher in abundance than in the other five bacteria (p &lt; 0.01) based on PEPPAN followed by a Twilight analysis. Our work provides new potential insights into extracellular electron transfer in microorganisms.</jats:p>

Arpita Bose, Zhecheng Zhang

Open Access Government • 2025

<jats:sec> <jats:title>Role of extracellular electron transfer in the nitrogen cycle</jats:title> <jats:p>Extracellular electron transfer impacts the nitrogen cycle by enhancing microbial processes and connecting to other biogeochemical cycles. Understanding EET mechanisms provides insights into ecosystem functioning and potential advancements; Arpita Bose and Zhecheng (Robert) Zhang explain. Nitrogen is a fundamental element required by all living species. It can be found in amino acids, proteins, and nucleic acids. The nitrogen cycle promotes nitrogen transformation and transit across the environment, making it available for biological activity. Key steps in the cycle include nitrogen fixation (conversion of atmospheric nitrogen to ammonia), nitrification (oxidation of ammonia to nitrate), denitrification (reduction of nitrate to nitrogen gas), and anaerobic ammonium oxidation (anammox), which then converts ammonium and nitrite directly to nitrogen gas. Extracellular electron transfer (EET) is the mechanism by which microorganisms transmit electrons from their cells to accept electrons from external donors. This ability allows microorganisms to interact with insoluble substrates, which, in turn, influences a variety of biogeochemical cycles, including the nitrogen cycle. Understanding EET’s function sheds light on microbial ecology and environmental processes.</jats:p> </jats:sec>

M. BouDagher-Fadel

• 2018

1. Biology and history of larger benthic foraminiferaHistory and biological classification of foraminiferaEcology of the living larger foraminiferaPalaeontological and evolutionary history of the larger foraminiferaTaxanomic features used in larger foraminiferal classificationBiostratigraphic distribution over time of larger foaminiferaGeneral factors effecting the evolution of marine species in the mid to late Phanerozic2. The Palaeozoic larger benthic foraminifera: The Carboniferous and PermianMorphology and taxonomy of Palaeozoic larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of the fusulinidsPalaeogeographic distribution of the fusulinids3. The Mesozoic larger benthic foraminifera: the TriassicMorphology and taxonomy of Triassic larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Triassic foraminiferaPalaeogeographic distribution of Triassic foraminifera4. The Mesozoic larger benthic foraminifera: the JurassicMorphology and taxonomy of Jurassic larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Jurassic foraminiferaPalaeogeographic distribution of Jurassic foraminifera5. The Mesozoic larger benthic foraminifera: the CretaceousMorphology and taxonomy of Cretaceous larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Cretaceous foraminiferaPalaeogeographic distribution of Cretaceous foraminifera6. The Palaeogene larger benthic foraminiferaMorphology and taxonomy of Palaeogene larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Palaeogene foraminiferaPalaeogeographic distribution of Palaeogene foraminifera7. The Neogene larger benthic foraminiferaMorphology and taxonomy Neogene larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Neogene foraminiferaPalaeogeographic distribution of Neogene foraminifera8. SynthesisImportance of application of larger foraminifera in biostratigraphyImportance of larger foraminifera as marine environmental indicatorsThe significance of the larger foraminifera assemblages in the understanding of the global distribution of carbonate sediments and their value in contributing raw data to palaeoenvironmental and palaeoclimatic modelsAppendixNomenclature terminology and glossary

W. Prasidha, M. Taufiq

• 2021

This study was aimed at evaluating the effect of sodium acetate on the performance of aerated double chamber microbial fuel cells from tofu whey. Six different mass of sodium acetate was soluted in the anode chamber (0, 1, 2, 3, 4, and 5 gr). The value of open circuit voltage (OCV) was taken to analyze the performance. A double chamber microbial fuel cell (MFC) was developed to produce electricity from tofu whey and studied for 1680 hours (70 days). Anode and cathode were made by uncoated graphite rod. After 1680 hours, the electricity production characteristics were obtained. The results show that the highest OCV (274 mV) was reached by adding 5 gr of sodium acetate in the anode chamber. Furthermore, adding 5 gr sodium acetate in the anode chamber could provide more stable OCV then other (0, 1, 2, 3, and 4 gr sodium acetate). From the study can be concluded that adding the sodium acetate in the anode chamber can provide stable and higher OCV.

Z. H. E N H E, ‡ N O R B E R T W A G N E R, T. A N G E N E N T

• 0

Z H E N H E , ‡ N O R B E R T W A G N E R , § S H E L L E Y D . M I N T E E R , | A N D L A R G U S T . A N G E N E N T * , ‡ Department of Chemical Engineering and Environmental Engineering Science Program, Washington University in St. Louis, St. Louis, Missouri 63130, Institute for Technical Thermodynamics, German Aerospace Center, D-70569 Stuttgart, Germany, and Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103

Palash Pan, Nandan Bhattacharyya

Biofuels • 2024

Abstract Microbial fuel cells (MFCs) are indeed a promising technology with the potential to address energy shortages and environmental pollution simultaneously. MFC utilizes the metabolic activities of microbes to convert organic substrates into electrical energy. This study assesses the power production capabilities of an isolated bacterial strain from soil, Bacillus paramycoides NBPP1, using different configurations of MFCs. The organic waste from chicken butchery shop is used as nutrient and aluminum and graphite as anode and cathode respectively. The MFC achieved voltage in an open circuitof 662 mV, maximal density of power of 4 Wm−2, internal resistance of 898 Ω, and coulombic efficiency of 6.66% for dual chambers. For single chambers, the values were 649 mV, 570 Ω, 2.6 Wm−2, and 3.75% respectively. The COD removal efficiency was 57.14% for dual chambers and 47.16% for single chambers. The MFC also demonstrated LED illumination in a series circuit for a longer duration, with a maximum power density of 6.40 Wm−2. Additionally, the residual broth was found to be an effective organic fertilizer with adequate N, K, and sufficient P. This study highlights the sustainable resource utilization in MFC organic waste, which encompasses power generation, waste management, and the potential for organic fertilizer production.

M. Fernandez-Gatell, X. Sanchez‐Vila, J. Puigagut

• 2021

<p>Bioelectrochemical systems (BES) are devices that transform the chemical energy of organic and inorganic substrates into an electric current. BES represents a particularly interesting biosensor technology for monitoring the performance of &#160;remote/isolated wastewater treatment facilities (such as constructed wetlands). The work presented here aimed to assess the potential use of the electric signal produced by low-cost, membrane-less BES systems as an indicator of the operational conditions and treatment performance of natural-based wastewater treatment systems. For this purpose, several BES configurations and operation modes working under real domestic wastewater conditions were monitored.</p><p>Results showed that the electric current produced by the BES significantly correlates with key parameters in biological-based wastewater treatment systems such as microbial activity and biomass, water COD or solids accumulation. Therefore, our work demonstrates the feasibility of applying bioelectrochemical-based low-cost biosensors for the improvement and control of natural-based wastewater treatment systems.</p><p>&#160;</p><p>&#160;</p><p>Keywords: bioelectrochemical systems, wastewater, microbial activity, organic matter, low-cost, biosensor</p>

Dandan Liu

• 2018

Methane-producing Bioelectrochemical systems (BESs) is a promising technology converting renewable electricity into the form of storable methane. The objective of this thesis is to achieve efficient methane production in methane-producing BESs and investigate its applicability in full-scale powerto- gas projects. We focus on improving the biocathode performance by exploring suitable cathode materials and operational conditions, e.g. decreasing biocathode start-up time by using heat-treated stainless steel felt (Chapter 2), achieving high-rate methane production by using a granular activated carbon (Chapter 3). We also investigated the effect of intermittent electricity supply on performance of carbon-based biocathodes in methane-producing BESs (Chapter 4). We showed that integrating methane-producing BES into anaerobic digestion could be an attractive strategy to enhance the performance of anaerobic digestion in cold area (Chapter 5). Based on the results of this thesis, we evaluated the possible main issues by performing a techno-economic analysis of a full-scale methane-producing BESs (Chapter 6).

A. Tremouli, T. Kamperidis, G. Lyberatos

Molecules • 2021

Four multiple air–cathode microbial fuel cells (MFCs) were developed under the scope of using extracts from fermentable household food waste (FORBI) for the production of bioelectricity. The operation of the MFCs was assessed in batch mode, considering each cell individually. Τhe chemical oxygen demand (COD) efficiency was relatively high in all cases (>85% for all batch cycles) while the electricity yield was 20 mJ/gCOD/L of extract solution. The four units were then electrically connected as a stack, both in series and in parallel, and were operated continuously. Approximately 62% COD consumption was obtained in continuous stack operation operated in series and 67% when operated in parallel. The electricity yield of the stack was 2.6 mJ/gCOD/L of extract solution when operated continuously in series and 0.7 mJ/gCOD/L when operated continuously in parallel.

Uma Thanganathan

International Journal of Membrane Science and Technology • 0

<jats:p>Membrane electrode assemblies (MEAs) for a low temperature H2/O2 fuel cell were fabricated using glass composite membrane and Pt/C electrode were evaluated by various operating condition. The stability and durability of the cell and polarization characteristics of membrane electrode assembles (MEAs) were reported. Electrochemical performances on MEAs consist of PWA {(12-tungsto(VI) phosphoric acid, n-hydrate)}/P2O5(phosphoric acid)/SiO2 (TEOS, tetraethoxysilane) glass composite membrane electrolyte and Pt/C electrode have been demonstrated representing a major milestone towards developing a viable atmospheric low temperature H2/O2 fuel cell system. MEAs were showed good performances under various functions of the temperature and relative humidity. A maximum current density of 141 mA/cm2 was obtained at 35 °C with 30% relative humidity by using a PWA/P2O5/SiO2 (5/5/90 mol%) glass composite membrane and Pt/C (0.1 mg/cm2) electrode. Polarization curves were recorded and their results support the conclusions obtained from the electrochemical impedance spectroscopy (EIS).</jats:p>

Monalisa Ghosh, G Mohan Rao

ECS Meeting Abstracts • 2018

<jats:p> Vertically aligned and tree-like nanostructures of carbon are grown by using plasma enhanced chemical vapour deposition (PECVD) method using electron cyclotron resonance (ECR) plasma system. These nanostructures consist of a multiwalled carbon nanotube which is aligned perpendicular to the surface of the substrate with carbon films attached to it like “branches” of a tree giving the structure a tree like appearance. The thin film of these nanostructures is deposited in a ECR plasma system on a nickel seed layer with a microwave power of 500 W using acetylene and hydrogen gas in 2:1 ratios as the source gases, at a working pressure of 7x10<jats:sup>-4</jats:sup> mbar in presence of a negative substrate bias of 200 V <jats:sup>1</jats:sup>. As the material with its vertical alignment and tree-like morphology has a very high exposed surface area, this material was speculated to act as a high-performance electrode of electrochemical capacitors (EC) or supercapacitors. The unique three-dimensional morphology of the material gives a high surface area with less areal footprint of the material. </jats:p> <jats:p>The electrochemical performance of the material as electrode of EC has been studied by depositing the material of thickness 1 μm on circular stainless-steel substrates of diameter 12 mm (area 1.13 cm<jats:sup>2</jats:sup>). 1 M Na<jats:sub>2</jats:sub>SO<jats:sub>4 </jats:sub>solution in deionised water is used as the electrolyte for the EC with absorbed glass mat as the separator between the two nanostructured electrodes. The entire assembly is done inside Swagelok type cell for testing the electrochemical performance. The EC showed a specific capacity of 920 μF/cm<jats:sup>2</jats:sup> (9.2 mF/cc) at a scan rate 0.1 V/s which is higher than the reported values for vertically aligned carbon nanotube.<jats:sup>2–4</jats:sup> A rectangular cyclic voltammetry curve is observed even at a voltage of 1 V/s. The results indicate that this material is a promising candidate for electrode material of supercapacitor. </jats:p> <jats:p> <jats:bold>References</jats:bold> <jats:list list-type="simple"> <jats:list-item> <jats:p>M. Ghosh and G. M. Rao, <jats:italic>Carbon</jats:italic> <jats:bold>133</jats:bold>, 239–248 (2018).</jats:p> </jats:list-item> <jats:list-item> <jats:p>B. Hsia, J. Marschewski, S. Wang, J Bin In, C. Carraro, D. Poulikakos, C. P. Grigoropoulos and R. Maboudian <jats:italic>Nanotechnology</jats:italic>, <jats:bold>25,</jats:bold> 055401(9pp) (2014)</jats:p> </jats:list-item> <jats:list-item> <jats:p>T. Chen, H. Peng, M. Durstock, and L. Dai, <jats:italic>Sci. Rep.</jats:italic>, <jats:bold>4</jats:bold>, 1–7 (2014).</jats:p> </jats:list-item> <jats:list-item> <jats:p>C. L. Pint et al., <jats:italic>Carbon N. Y.</jats:italic>, <jats:bold>49</jats:bold>, 4890–4897 (2011)</jats:p> </jats:list-item> </jats:list> </jats:p> <jats:p> </jats:p> <jats:p> <jats:inline-formula> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="538fig1.jpeg" xlink:type="simple"/> </jats:inline-formula> </jats:p> <jats:p>Figure 1</jats:p> <jats:p/>

Hojin Choi, Hyeonseok Yoon

Nanomaterials • 0

<jats:p>The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, the latest trends in electrochemical capacitor research are also discussed through extensive analysis of the literature and by highlighting notable research examples (published mostly since 2013). Finally, a perspective on next-generation capacitor technology is also given, including the challenges that lie ahead.</jats:p>

Jianfeng LIU, Zhenhai Zhang

ECS Meeting Abstracts • 2017

<jats:p> Carbon dioxide is known as the main greenhouse gas, which is enormous produced during human activities. The electrochemical reduction of carbon dioxide not only reduce the amount of CO<jats:sub>2</jats:sub>, also produce CO<jats:sub>2</jats:sub> to CO, the intermediate for the production of some chemical and fuels. However, the electrochemical reduction process for CO<jats:sub>2</jats:sub> is inhibited due to the lack of a suitable catalyst with high energy efficiency and high conversion rate.<jats:sup>[1]</jats:sup> The catalysts with the precious metal catalysts, such as Ag, Au, and Zn, Ni received high energy efficiency during carbon monoxide production. Some researchers utilize these metal catalysts for CO<jats:sub>2</jats:sub> reduction process, and received the corresponding results.<jats:sup>[2]</jats:sup> However, the cost of the precious metal is another urgent issue. </jats:p> <jats:p> In my prior work, the nitrogen-doped graphene is applied as a non-metal catalyst for oxygen reduction reaction process in aidic and alkaline media, finally exhibit high current density and mass activity.<jats:sup>[3,4]</jats:sup> In this work, we also heat treated carbon with the goal of doping nitrogen into carbon, and apply this nitrogen-doped carbon as catalyst for CO<jats:sub>2</jats:sub> electrochemical reduction process. The nitrogen-doped carbon catalyst exhibit higher current density and higher overpotential than the corresponding carbon, that is to say, the doped nitrogen atoms play an important role for the reduction process. </jats:p> <jats:p>[1] C. E.Tornow, M. R. Thorson, S.Ma, A. A. Gewirth, P. J. Kenis, Journal of the American Chemical Society, 134(48), 19520, (2012). </jats:p> <jats:p>[2] A. Salehikhojin, H. R. M. Jhong, B. A. Rosen, W. Zhu, S. Ma, P. J. A. Kenis, J.phys.chem.c, 117(4), 1627, (2017). </jats:p> <jats:p>[3] J. Liu, D. Takeshi, D. Orejon, K. Sasaki, S. M. Lyth, Journal of The Electrochemical Society, 161(4), F544, (2014). </jats:p> <jats:p>[4] J Liu, K Sasaki, SM Lyth, ECS Transactions 58 (1), 1751 (2013) </jats:p>

Fábio Rodrigo Freitas, Elki Cristina Souza

DESAFIOS - Revista Interdisciplinar da Universidade Federal do Tocantins • 2024

Concerns over environmental protection have increased in recent years, leading to a search for new renewable energy sources for minimizing anthropological damage to both atmosphere and water bodies. Microbial Fuel Cells are inserted in such a context, since they can reduce the organic load of an effluent concomitantly with the production of bioelectricity. This study investigated three different sources of microorganisms, evaluating parameters such as carbon source concentration and temperature in energy efficiency. The electrical current generated by microbial activity in the oxidation of organic matter was monitored additionally with ionic conductivity and pH of the medium. Chemical Oxygen Demand was also determined towards an evaluation of the removal of organic matter. The Microbial Fuel Cell inoculated with Activated Sludge showed higher electrical current in comparison to other studies from the literature and a greater generation of electrical current and a high influence of conductivity on that efficiency was observed at 36 °C. As a conclusion, Microbial Fuel Cells can operate at both 4.0 gL-1 (COD mgO2 3,886.728) and 3.0 gL-1 (COD mgO2 3,124.573).

Na Chu, Yong Jiang, Donglin Wang et al.

Angewandte Chemie International Edition • 2023

Extensive study on renewable energy storage has been sparked by the growing worries regarding global warming. In this study, incorporating the latest advancements in microbial electrochemistry and electrochemical CO2 reduction, a super-fast charging biohybrid battery was introduced by using pure formic acid as an energy carrier. CO2 electrolyser with a slim-catholyte layer and a solid electrolyte layer was built, which made it possible to use affordable anion exchange membranes and electrocatalysts that are readily accessible. The biohybrid battery only required a 3-minute charging to accomplish an astounding 25-hour discharging phase. In the power-to-formate-to-bioelectricity process, bioconversion played a vital role in restricting both the overall Faradaic efficiency and Energy efficiency.The CO2 electrolyser was able to operate continuously for an impressive total duration of 164 hours under Gas Stand-By model, by storing N2 gas in the extraction chamber during stand-by periods. Additionally, the electric signal generated during the discharging phase was utilized for monitoring water biotoxicity. Functional genes related to formate metabolism were identified in the bioanode and electrochemically active bacteria were discovered. On the other hand, Paracoccus was predominantly found in the used air cathode. These results advance our current knowledge of exploiting biohybrid technology.

Ida Munfarida, Shinfi Wazna Auvaria

International Journal of Environmental, Sustainability, and Social Science • 2024

The increasing global demand for renewable energy and sustainable waste management solutions has inspired interest in microbial fuel cells (MFCs) as a dual-purpose technology for bioelectricity generation and waste treatment. This study explores the role of EM4, a consortium of effective microorganisms, in enhancing the voltage output and electrical conductivity of solid waste-powered MFCs. A batch system bioreactor assessed the impact of varying organic waste-to-zeolite ratios on MFC performance. The results demonstrated that a 1:1 ratio of organic waste to zeolite produced the highest electrical conductivity (3160 µS/cm) and the most substantial voltage output (777.5 mV) by day three of the experiment. Statistical analysis, including ANOVA and Kruskal-Wallis tests, revealed significant differences in voltage output across treatments, with a positive correlation between electrical conductivity and voltage production. These findings highlight the potential of integrating EM4 and conductive materials like zeolite to optimize bioelectricity generation in MFCs, contributing to the advancement of sustainable energy technologies.

Y. Kim, Hyeonaug Hong, Jaehyoung Yun et al.

Advanced Materials • 2020

Harvesting solar energy in the form of electricity from the photosynthesis of plants, algal cells, and bacteria has been researched as the most environment‐friendly renewable energy technology in the last decade. The primary challenge has been the engineering of electrochemical interfacing with photosynthetic apparatuses, organelles, or whole cells. However, with the aid of low‐dimensional nanomaterials, there have been many advances, including enhanced photon absorption, increased generation of photosynthetic electrons (PEs), and more efficient transfer of PEs to electrodes. These advances have demonstrated the possibility for the technology to advance to a new level. In this article, the fundamentals of photosynthesis are introduced. How PE harvesting systems have improved concerning solar energy absorption, PE production, and PE collection by electrodes is discussed. The review focuses on how different kinds of nanomaterials are applied and function in interfacing with photosynthetic materials for enhanced PE harvesting. Finally, the review analyzes how the performance of PE harvesting and stand‐alone systems have evolved so far and its future prospects.

Naoko Yoshida, Yuko Goto, Yasushi Miyata

C • 0

<jats:p>Graphene oxide (GO) has been shown to be reduced by several microorganisms. Recent studies of the growth of Geobacter species in the presence of GO and electricity production by recovery of electrons on the reduced form of GO (rGO) have indicated substantial benefits of GO and GO-respiring bacteria (GORB) in microbial electrochemical systems. In this study, we enriched GORB from a coastal sample to investigate the distribution and phylogenetic variety of GORB in seawater environments. X-ray photoelectron spectroscopy (XPS) and four-terminal probing revealed that the enriched microbial community (designated as CS culture) reduced GO and self-aggregated into a conductive hydrogel complex with rGO (the CS-rGO complex). In the process of GO reduction, certain bacterial populations grew in a manner that was dependent on GO respiration coupled with acetate oxidization. High-throughput sequencing of 16S rRNA as a biomarker revealed the predominance of Desulfomonas species at 92% of the total bacterial population in the CS culture. The CS-rGO complex produced electricity with acetate oxidization, exhibiting less than 1 Ω/cm3 of charge transfer resistance. Thus, these results suggested that Desulfomonas species could grow on rGO and produce electricity via the reduced form of GO.</jats:p>

Walaa Ibrahim Gabr

Alexandria Engineering Journal • 2015

Wei Tang, Xiao-Shuai Wu, Yan Qiao et al.

RSC Advances • 0

<p>Spherical mesopores with large pore width are more favorable to flavin mediated interfacial electron transfer in microbial fuel cells.</p>

Yu-tong Shi, Yang-Yang Yu, Zi‐Ai Xu et al.

Journal of Materials Chemistry A • 2019

Superior carbon belts from Spirogyra were explored for highly efficient extracellular electron transfer and microbial energy harvesting.

N. Quach, T. Viet, P. V. Toan et al.

Indonesian Journal of Electrical Engineering and Computer Science • 2021

This paper presents a model of an intelligent energy harvesting system from microbial fuel cells (MFCs) in the wastewater treatment process. The model consists of two direct current (DC/DC) converters connected in a cascade. One DC/DC converter is used to capture energy from MFC and store it in a supercapacitor. The other DC/DC converter is responsible for increasing the low output voltage to a higher voltage level. In the paper, the MFC is modeled by a DC voltage source instead of a real MFC that contains wastewater inside it. The experimental results demonstrate that the model of an intelligent energy harvesting system can increase the low output voltage of MFC up to 3.3 V and achieve intermittent output power at a high level that can use in practice.

Yong Yuan, Ting Liu, Peng Fu et al.

Journal of Materials Chemistry A • 0

<p>Sewage sludge amended with biomass was converted into highly conductive biochar, which was used as a high-performance anode and cathode for microbial fuel cells.</p>

Tole Sutikno, Tri Wahono, Hendril Satrian Purnama

Intellectual Journal of Energy Harvesting and Storage • 0

<jats:p>Energy harvesting technology research has progressed significantly in recent years due to the increasing demand for alternative energy sources. One of the most promising methods of supplying renewable energy has been successfully put on the road, known as energy harvesting technology. There are four energy harvesting technologies on the roadway: solar, piezoelectric, thermoelectric, and geothermal. This paper discusses the development of energy harvesting technology on roadway other than geothermal, examines the basic principles of energy harvesting technology on the roadway, and provides an analysis and comparison of these technologies. Energy harvesting technology from energy conversion factors, weaknesses, and advantages that are most likely to be applied on the roadway is piezoelectric.</jats:p>

Alistair J. McCormick, Paolo Bombelli, Robert W. Bradley et al.

Energy &amp; Environmental Science • 0

<p>In this review we focus on a specific sub-branch of light-harvesting bioelectrochemical systems called biophotovoltaic systems.</p>

Junki Saito, Kazuhito Hashimoto, Akihiro Okamoto

ECS Meeting Abstracts • 2016

<jats:p>Specific microbes are utilized for bioelectrode catalysis, at the anodic or cathodic electrode, in applications such as microbial fuel cells or electrosynthesis. In the anode chamber of microbial fuel cells (MFCs), microbial metabolism oxidizes organic compounds, and the electrons are transferred to the anode by extracellular electron transport (EET) processes. Despite numerous studies on the kinetics of EET to enhance the catalysis rate, the relevance with upstream reactions, including metabolism and intracellular electron transport chain, has scarcely been investigated. Herein, we investigate the rate-determining step for anodic current production (<jats:italic>j</jats:italic>) for the lactate oxidation of <jats:italic>Shewanella oneidensis</jats:italic> MR-1 by using riboflavin to specifically enhance the rate of EET via outer membrane <jats:italic>c</jats:italic>-type cytochromes (OM <jats:italic>c</jats:italic>-Cyts).<jats:sup>1</jats:sup> Microbial current production was measured in an anaerobic, three-electrode system poised at +0.4 V vs. SHE and kept at 303 K with 10 mM sodium lactate as a sole electron donor. Without the addition of flavin, <jats:italic>j</jats:italic> increases, saturates, and decreases as illustrated in Figure 1a. Upon the addition of 5µM riboflavin, <jats:italic>j</jats:italic> showed immediate increase in increasing and saturating current phases, though it increased sharper in the former (Figure 1b and c). In contrast, there was little effect of the riboflavin addition when <jats:italic>j</jats:italic> was decreasing (Figure 1d), suggesting that the RDS for <jats:italic>j</jats:italic> gradually shifted from EET to other upstream processes. Differential pulse (DP) voltammograms performed in each phases showed three peaks at approximately –230, –100, and +60 mV, which can be assigned to free riboflavin, bound riboflavin on OM <jats:italic>c</jats:italic>-Cyts, and the heme centers in OM <jats:italic>c</jats:italic>-Cyts, respectively.<jats:sup>2</jats:sup> Compared with the DP voltammogram when <jats:italic>j</jats:italic> was increasing, the peak current of the bound flavin showed a 50% decrease after <jats:italic>j</jats:italic> saturation, though the peak current of the heme centers was almost identical, indicating the dissociation of bound flavin from the OM <jats:italic>c</jats:italic>-Cyts. Given that flavin dissociation is induced by heme oxidation in OM <jats:italic>c</jats:italic>-Cyts,<jats:sup>2,3</jats:sup> the hemes in OM <jats:italic>c</jats:italic>-Cyts appear to become more oxidized after <jats:italic>j</jats:italic> saturation. These results further support the observation that the electron supply to OM <jats:italic>c</jats:italic>-Cyts from the upstream reactions gradually becomes slower than the EET rate. We will present the data for microbial growth, lactate consumption rate and voltammetric analysis in each phase, and the effect of trace metal removal from the medium to discuss the assignment of upstream reactions. </jats:p> <jats:p>Figure legend: </jats:p> <jats:p>Fig. 1. (a) A schematic image of the time course of current production. Area b, c, and d indicate the increasing, saturating, and decreasing current phase, respectively. (b–d) Current production in the presence (black lines) or absence (gray lines) of the addition of 5 µM riboflavin at the increasing (b), saturating (c), and decreasing (d) current phase, respectively. Arrows indicate the time points at which riboflavin was added. Microbes were added at t = 0 h. </jats:p> <jats:p>Reference </jats:p> <jats:p>1. Dan C., Daniel B. B., Daniel R. B., and Jeffrey A. G.The Mtr Respiratory Pathway Is Essential for Reducing Flavins and Electrodes in <jats:italic>Shewanella oneidensis</jats:italic>. <jats:italic>Journal of Bacteriology,</jats:italic> 192, 2: 467–474 (2010). </jats:p> <jats:p>2. Okamoto, A., Hashimoto, K., Nealson, K. H. and Nakamura, R. Rate enhancement of bacterial extracellular electron transport involves bound flavin semiquinones. <jats:italic>P Natl Acad Sci USA</jats:italic> 110, 7856-7861 (2013). </jats:p> <jats:p>3. Okamoto, A. et al. Cell-secreted Flavins Bound to Membrane Cytochromes Dictate Electron Transfer Reactions to Surfaces with Diverse Charge and pH. <jats:italic>Sci Rep-Uk</jats:italic> 4, e5628 (2014)</jats:p> <jats:p/> <jats:p> <jats:inline-formula> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="3243fig1.jpeg" xlink:type="simple"/> </jats:inline-formula> </jats:p> <jats:p>Figure 1</jats:p> <jats:p/>

Shuai Lou, Xinbai Jiang, Dan Chen et al.

RSC Advances • 0

<p>In this study, a membrane-free bio-contact coupled bioelectrochemical system (BC-BES) was established for the enhanced reductive transformation of <italic>p</italic>-nitrophenol (PNP).</p>

Geremia Sassetto, Maria Presutti, Agnese Lai et al.

ChemPlusChem • 0

<jats:p>This study uses a membrane‐less reactor to explore the bioelectrochemical remediation of real contaminated groundwater from chlorinated aliphatic hydrocarbons (CAHs) and nitrates. The research focuses on testing a column‐type bioelectrochemical reactor to stimulate in situ degradation of contaminants through the supply of electrons by a graphite granules biocathode. After a preliminary laboratory characterization and operation with a synthetic feeding solution, a field test is conducted in a real contaminated site, where the reactor demonstrates effective degradation of CAHs and inorganic anions. Notably, the cathodic potential promotes the reductive dechlorination of chlorinated species. Simultaneously, nitrate reduction, sulfate reduction, and methanogenesis occurr, influencing the overall coulombic efficiency of the process. The use of real groundwater, compared to the synthetic medium, significantly decreases the coulombic efficiency of reductive dechlorination, dropping from 2.43% to 0.01%. Concentration profiles along the bioelectrochemical reactor allow for a deeper description of the reductive dechlorination rate at different flow rates, as well as increase the knowledge about reduction and oxidation mechanisms. Scaling up the technology presents several challenges, including the optimization of coulombic efficiency and the management of competing microbial metabolisms. The study provides a valuable contribution toward advancing bioelectrochemical technologies for the bioremediation of complex contaminated sites.</jats:p>

Han Li, Ying Cui, Fei Wang et al.

PLOS ONE • 0

<jats:p>In this experiment, we took reflux sludge, sludge from an aeration tank, and soil from roots as microbial inoculating sources for an electrochemical device for denitrification with high-throughput sequencing on cathodic biofilms. The efficiency of nitrate nitrogen removal using different microbial inoculates varied among voltages. The optimal voltages for denitrification of reflux sludge, aeration tank sludge, and root soil were 0.7V, 0.5V, and 0.5V, respectively. Further analysis revealed that the respective voltages had a significant effect upon microbial growth from the respective inoculates. <jats:italic>Proteobacteria</jats:italic> and <jats:italic>Firmicutes</jats:italic> were the main denitrifying microbes. With the addition of low current (produced by the applied voltage), the Chao1, Shannon and Simpson indexes of the diversity of microorganisms in soil inoculation sources increased, indicating that low current can increase the diversity and richness of the microorganisms, while the reflux sludge and aeration tank sludge showed different changes. Low-current stimulation decreased microbial diversity to a certain extent. <jats:italic>Pseudomonas</jats:italic> showed a trend of decline with increasing applied voltage, in which the MEC (microbial electrolysis cell) of rhizosphere soil as inoculates decreased most significantly from 77.05% to 12.58%, while the MEC of <jats:italic>Fusibacter</jats:italic> showed a significant increase, and the sludge of reflux sludge, aeration tank and rhizosphere soil increased by 31.12%, 18.7% and 34.6%, respectively. The applied voltage also significantly increased the abundance of <jats:italic>Azoarcus</jats:italic> in communities from the respective inoculates.</jats:p>