Anirudh Bhanu Teja Nelabhotla, Carlos Dinamarca

Applied Sciences • 0

<jats:p>Anaerobic digestion (AD) is a widely used technique to treat organic waste and produce biogas. This article presents a practical approach to increase biogas yield of an AD system using a microbial electrosynthesis system (MES). The biocathode in MES reduces carbon dioxide with the supplied electrons and protons (H+) to form methane. We demonstrate that the MES is able to produce biogas with over 90% methane when fed with reject water obtained from a local wastewater treatment plant. The optimised cathode potential was observed in the range of −0.70 V to −0.60 V and optimised feed pH was around 7.0. With autoclaved feed, these conditions allowed methane yields of about 9.05 mmol/L(reactor)-day. A control experiment was then carried out to make a comparison between open circuit and MES methanogenesis. The highest methane yield of about 22.1 mmol/L(reactor)-day was obtained during MES operation that performed 10–15% better than the open circuit mode of operation. We suggest and describe an integrated AD-MES system, by installing MES in the reject water loop, as a novel approach to improve the efficiency and productivity of existing waste/wastewater treatment plants.</jats:p>

Dipankar Deb, Ravi Patel, Valentina E. Balas

Processes • 0

<jats:p>A microbial fuel cell (MFC) is a potentially viable renewable energy option which promises effective and commercial harvesting of electrical power by bacterial movement and at the same time also treats wastewater. Microbial fuel cells are complicated devices and therefore research in this field needs interdisciplinary knowledge and involves diverse areas such as biological, chemical, electrical, etc. In recent decades, rapid strides have taken place in fuel cell research and this technology has become more efficient. For effective usage, such devices need advanced control techniques for maintaining a balance between substrate supply, mass, charge, and external load. Most of the research work in this area focuses on experimental work and have been described from the design perspective. Recently, the development in mathematical modeling of such cells has taken place which has provided a few mathematical models. Mathematical modeling provides a better understanding of the operations and the dynamics of MFCs, which will help to develop control and optimization strategies. Control-oriented bio-electrochemical models with mass and charge balance of MFCs facilitate the development of advanced nonlinear controllers. This work reviews the different mathematical models of such cells available in the literature and then presents suitable parametrization to develop control-oriented bio-electrochemical models of three different types of cells with their uncertain parameters.</jats:p>

Silvia Bolognesi, Daniele Cecconet, Arianna Callegari et al.

Environmental Science and Pollution Research • 2021

<jats:title>Abstract</jats:title><jats:p>Despite solid wastes’ landfill disposal limitation due to recent European legislation, landfill leachate disposal remains a significant problem and will be for many years in the future, since its production may persist for years after a site’s closure. Among process technologies proposed for its treatment, microbial fuel cells (MFCs) can be effective, achieving both contaminant removal and simultaneous energy recovery. Start-up and operation of two dual-chamber MFCs with different electrodes’ structure, fed with mature municipal solid waste landfill leachate, are reported in this study. Influent (a mix of dairy wastewater and mature landfill leachate at varying proportions) was fed to the anodic chambers of the units, under different conditions. The maximum COD removal efficiency achieved was 84.9% at low leachate/dairy mix, and 66.3% with 7.6% coulombic efficiency (CE) at a leachate/dairy ratio of 20%. Operational issues and effects of cells’ architecture and electrode materials on systems’ performance are analyzed and discussed.</jats:p>

Azhan Ahmad, Monali Priyadarshani, Sovik Das et al.

Journal of Basic Microbiology • 2022

<jats:title>Abstract</jats:title><jats:p>Bioelectrochemical systems (BESs) are a unique group of wastewater remediating technology that possesses the added advantage of valuable recovery with concomitant wastewater treatment. Moreover, due to the application of robust microbial biocatalysts in BESs, effective removal of emerging contaminants (ECs) can be accomplished in these BESs. Thus, this review emphasizes the recent demonstrations pertaining to the removal of complex organic pollutants of emerging concern present in wastewater through BES. Owing to the recalcitrant nature of these pollutants, they are not effectively removed through conventional wastewater treatment systems and thereby are discharged into the environment without proper treatment. Application of BES in terms of ECs removal and degradation mechanism along with valuables that can be recovered are discussed. Moreover, the factors affecting the performance of BES, like biocatalyst, substrate, salinity, and applied potential are also summarized. In addition, the present review also elucidates the occurrence and toxic nature of ECs as well as future recommendations pertaining to the commercialization of this BES technology for the removal of ECs from wastewater. Therefore, the present review intends to aid the researchers in developing more efficient BESs for the removal of ECs from wastewater.</jats:p>

Parisa Ebrahimzadeh, Nahid Navidjouy, Hassan Khorsandi et al.

ChemElectroChem • 2024

<jats:title>Abstract</jats:title><jats:p>Bioelectrochemical systems (BES) is a new and expanding technology that can simultaneously convert chemical energy into electrical energy by removing nutrients. The present study investigated the BES in removing nitrogen compounds and produce electricity. To this end, a BES reactor with two chambers of cathode and anode and nafion 117 membrane was used as a separator between the two chambers. Then, the BES performance at different concentrations of COD and primary ammonium at different retention times was investigated to remove nitrogen compounds and organic matter. Voltage, current and power density were measured. The results showed that the maximum COD removal efficiency was 73.2 % for the substrate concentration of 2000 mg/L, which decreased to 72.6 % when the substrate concentration increased to 10000 mg/L. The maximum removal efficiency of nitrogen compounds was 83.4 % at COD 10000 mg/L and the initial ammonium concentration was 50 mg/L. The maximum voltage, current and power density in this phase were 391 mV, 460 mA/m<jats:sup>2</jats:sup>, 63/48 mW/m<jats:sup>2</jats:sup>, respectively. The results of the study showed that BES can be used as a suitable method to remove high amounts of ammonium in wastewater and organic materials and simultaneously produce electricity.</jats:p>

Shengjin Ke, Xuhui Jiang, Xi Zhang et al.

Journal of Physics: Conference Series • 2024

<jats:title>Abstract</jats:title> <jats:p>Bioelectrochemical systems (BESs) serve as an emerging renewable energy technology that presents great potential for wastewater treatment and energy recovery. Microbial desalination cell (MDC), as a type of BES, is capable of desalination while realizing wastewater treatment and recycling of electric energy, which has become a research hotspot in recent years. However, research that has been conducted tends to focus only on the desalination capacity of the MDC and pays less attention to its electricity generation performance. The electricity derived from the recovery of chemical energy in the wastewater by the system has also not been well utilized. In this study, a microbial reverse-electrodialysis cell (MRC), which is capable of obtaining the salt difference energy from high-salt wastewater, was constructed and coupled with an electrodialysis cell (EDC), ultimately constructing a new type of BES named MRC-EDC. It can synchronize the recovery of chemical energy and salt difference in high-salt wastewater, realizing the in-situ use of electric energy and wastewater desalination. The maximum power production performance of MRC-EDC reached 2.44 W m<jats:sup>−2</jats:sup>, which was 67.1% higher than that of conventional MFC. The COD removal rate of the system reached 34.16% after 10 h of operation, and the average desalination rate per hour was 5.15%. This study provides a reference for the construction of high-efficiency BESs.</jats:p>

Anagha Bindu, Sudipa Bhadra, Soubhagya Nayak et al.

Open Life Sciences • 2024

<jats:title>Abstract</jats:title> <jats:p>Bioelectrochemical biosensors offer a promising approach for real-time monitoring of industrial bioprocesses. Many bioelectrochemical biosensors do not require additional labelling reagents for target molecules. This simplifies the monitoring process, reduces costs, and minimizes potential contamination risks. Advancements in materials science and microfabrication technologies are paving the way for smaller, more portable bioelectrochemical biosensors. This opens doors for integration into existing bioprocessing equipment and facilitates on-site, real-time monitoring capabilities. Biosensors can be designed to detect specific heavy metals such as lead, mercury, or chromium in wastewater. Early detection allows for the implementation of appropriate removal techniques before they reach the environment. Despite these challenges, bioelectrochemical biosensors offer a significant leap forward in wastewater monitoring. As research continues to improve their robustness, selectivity, and cost-effectiveness, they have the potential to become a cornerstone of efficient and sustainable wastewater treatment practices.</jats:p>

N. Evelin Paucar, Chikashi Sato

Processes • 0

<jats:p>The world is facing serious threats from the depletion of non-renewable energy resources, freshwater shortages and food scarcity. As the world population grows, the demand for fresh water, energy, and food will increase, and the need for treating and recycling wastewater will rise. In the past decade, wastewater has been recognized as a resource as it primarily consists of water, energy-latent organics and nutrients. Microbial fuel cells (MFC) have attracted considerable attention due to their versatility in their applications in wastewater treatment, power generation, toxic pollutant removal, environmental monitoring sensors, and more. This article provides a review of MFC technologies applied to the removal and/or recovery of nutrients (such as P and N), organics (COD), and bioenergy (as electricity) from various wastewaters. This review aims to provide the current perspective on MFCs, focusing on the recent advancements in the areas of nutrient removal and/or recovery with simultaneous power generation.</jats:p>

Bhim Sen Thapa, Soumya Pandit, Sanchita Bipin Patwardhan et al.

Sustainability • 0

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

Emre Cevik, Mohammed A. Gondal, Noha Alqahtani et al.

Biotechnology and Bioengineering • 2023

<jats:title>Abstract</jats:title><jats:p>The power performance of the bio‐electrochemical fuel cells (BEFCs) depends mainly on the energy harvesting ability of the anode material. The anode materials with low bandgap energy and high electrochemical stability are highly desirable in the BEFCs. To address this issue, a novel anode is designed using indium tin oxide (ITO) modified by chromium oxide quantum dots (CQDs). The CQDs were synthesized using facile and advanced pulsed laser ablation in liquid (PLAL) technique. The combination of ITO and CQDs improved the optical properties of the photoanode by exhibiting a broad range of absorption in the visible to UV region. A systematic study has been performed to optimize the amount of CQDs and green Algae (Alg) film grown using the drop casting method. Chlorophyll (<jats:italic>a</jats:italic>, <jats:italic>b</jats:italic>, and total) content of algal cultures (with different concentrations) were optimized to investigate the power generation performance of each cell. The BEFC cell (ITO/Alg10/Cr3//Carbon) with optimized amounts of Alg and CQDs demonstrated enhanced photocurrent generation of 120 mA cm<jats:sup>−2</jats:sup> at a photo‐generated potential of 24.6 V m<jats:sup>−2</jats:sup>. The same device exhibited a maximum power density of 7 W m<jats:sup>−2</jats:sup> under continuous light illumination. The device also maintained 98% of its initial performance after 30 repeated cycles of light on–off measurements.</jats:p>

Fatemeh Poureshghi Oskouei, Nga Phuong Dong, Subhashis Das et al.

ECS Meeting Abstracts • 2022

<jats:p> Microbial fuel cells (MFCs) harness the metabolism of microorganisms, converting chemical energy into electrical energy. Improving both Anode and Cathode design is thus of great significance to enhance the MFC performance and its commercial application. For the performance improvement of MFCs, the anode becomes a breakthrough point due to its influence on bacterial attachment and extracellular electron transfer (EET). On the other hand, air cathodes have considerable influence on the maximum power of air-driven MFCs. The cathodes used in MFCs need to have high catalytic activity for oxygen reduction, but they should be inexpensive watertight,and easy to manufacture.</jats:p> <jats:p>As the first part of this work, carbon felt was electrochemically and chemically treated by electrolyzing in nitric acid and phosphate buffer followed by soaking in aqueous ammonia. The treated and untreated carbon felts were utilized as anodes in MFCs, and current production was compared while the cathode was stainless steel mesh (SS-316L) in both cases. The treated carbon felt displays strong interaction with the microbial biofilm of <jats:italic>Shewanella baltica 20</jats:italic> facilitating electron transfer from exoelectrogens to the anode. An MFC equipped with a treated carbon felt as anode has significantly lower charge-transfer resistance and achieves considerably better performance than one equipped with an untreated carbon felt anode. The enhanced electron transfer is attributed to newly generated carboxyl containing functional groups on the treated carbon felt.</jats:p> <jats:p>In the second part of the present study, SS-316L as a cathode was modified using phase inversion process to construct a poly vinylidenefluoride (PVDF) binder and an activated carbon catalyst according to the procedure reported previously.</jats:p> <jats:p>Finally, the MFC with treated carbon felt anode and PVDF air cathode was tested. The MFC with both modified anode and cathode achieves considerably better performance than one with a traditional carbon felt anode and SS-316L cathode. The maximum current density, power density, and energy recovery, and sensitivity of the biofilm to the heavy metals are significantly improved. </jats:p>

Xiaoqi Fan, Yun Zhou, Xueke Jin et al.

Carbon Energy • 2021

<jats:title>Abstract</jats:title><jats:p>For the performance improvement of microbial fuel cells (MFCs), the anode becomes a breakthrough point due to its influence on bacterial attachment and extracellular electron transfer (EET). On other level, carbon materials possess the following features: low cost, rich natural abundance, good thermal and chemical stability, as well as tunable surface properties and spatial structure. Therefore, the development of carbon materials and carbon‐based composites has flourished in the anode of MFCs during the past years. In this review, the major carbon materials used to decorate MFC anodes have been systematically summarized, based on the differences in composition and structure. Moreover, we have also outlined the carbon material‐based hybrid biofilms and carbon material‐modified exoelectrogens in MFCs, along with the discussion of known strategies and mechanisms to enhance the bacteria‐hosting capabilities of carbon material‐based anodes, EET efficiencies, and MFC performances. Finally, the main challenges coupled with some exploratory proposals are also expounded for providing some guidance on the future development of carbon material‐based anodes in MFCs.</jats:p>

Hindatu Yusuf, Mohamad Suffian Mohamad Annuar, Ramesh Subramaniam et al.

Chemical Engineering &amp; Technology • 2019

<jats:title>Abstract</jats:title><jats:p>Hydrophobic bacterial polyhydroxyalkanoates were rendered amphiphilic by grafting with poly(ethylene glycol) methacrylate, followed by compositing with carbon nanotubes. The polymer graft composite as an anode material encouraged superior biofilm surface growth; thus enhancing electrochemical activities in microbial fuel cells and resulting in higher current and power densities. The internal resistance of the cell was greatly reduced due to improved electron transfer from the biofilm to the anode.</jats:p>

Tahira Yaqoob, Malika Rani, Arshad Mahmood et al.

Materials • 0

<jats:p>MXene/Ag2CrO4 nanocomposite was synthesized effectively by means of superficial low-cost co-precipitation technique in order to inspect its capacitive storage potential for supercapacitors. MXene was etched from MAX powder and Ag2CrO4 spinel was synthesized by an easy sol-gel scheme. X-Ray diffraction (XRD) revealed an addition in inter-planar spacing from 4.7 Å to 6.2 Å while Ag2CrO4 nanoparticles diffused in form of clusters over MXene layers that had been explored by scanning electron microscopy (SEM). Energy dispersive X-Ray (EDX) demonstrated the elemental analysis. Raman spectroscopy opens the gap between bonding structure of as-synthesized nanocomposite. From photoluminence (PL) spectra the energy band gap value 3.86 eV was estimated. Electrode properties were characterized by applying electrochemical observations such as cyclic voltammetry along with electrochemical impedance spectroscopy (EIS) for understanding redox mechanism and electron transfer rate constant Kapp. Additionally, this novel work will be an assessment to analyze the capacitive behavior of electrode in different electrolytes such as in acidic of 0.1 M H2SO4 has specific capacitance Csp = 525 F/g at 10 mVs−1 and much low value in basic of 1 M KOH electrolyte. This paper reflects the novel synthesis and applications of MXene/Ag2CrO4 nanocomposite electrode fabrication in energy storage devices such as supercapacitors.</jats:p>

Elizabeth C. A. Trindade, Regina V. Antônio, Ricardo Brandes et al.

Journal of Applied Polymer Science • 2020

<jats:title>Abstract</jats:title><jats:p>Microbial fuel cells (MFC) are of great interest for new sources of renewable energies from the waste of biomass and debris. This work aimed was to develop an anode electrode of the carbon fiber‐embedded of bacterial cellulose/polyaniline (CF/BC/PANI) nanocomposite for MFC applications. For this purpose, carbon fiber was wrapped onto bacterial cellulose (BC) fibers network during the BC synthesis. The CF/BC/PANI was obtained by polyaniline polymerization on the BC nanofibers as a scaffold. To characterize the electrode, scanning electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction, and thermogravimetric analysis analysis were carried out. The electrical conductivity was determined by measuring the resistivity. MFC using the CF/BC/PANI electrode was monitored and the maximum current density generated was 0.009 mA/cm<jats:sup>2</jats:sup>. The results obtained from the CF/BC/PANI demonstrate great potential for the use as an MFC electrode, as well as a microenvironment favorable to a microbial biofilm formation.</jats:p>

Gopa Nandikes, Shaik Gouse Peera, Lakhveer Singh

Energies • 0

<jats:p>Microbial fuel cells (MFCs) are biochemical systems having the benefit of producing green energy through the microbial degradation of organic contaminants in wastewater. The efficiency of MFCs largely depends on the cathode oxygen reduction reaction (ORR). A preferable ORR catalyst must have good oxygen reduction kinetics, high conductivity and durability, together with cost-effectiveness. Platinum-based electrodes are considered a state-of-the-art ORR catalyst. However, the scarcity and higher cost of Pt are the main challenges for the commercialization of MFCs; therefore, in search of alternative, cost-effective catalysts, those such as doped carbons and transition-metal-based electrocatalysts have been researched for more than a decade. Recently, perovskite-oxide-based nanocomposites have emerged as a potential ORR catalyst due to their versatile elemental composition, molecular mechanism and the scope of nanoengineering for further developments. In this article, we discuss various studies conducted and opportunities associated with perovskite-based catalysts for ORR in MFCs. Special focus is given to a basic understanding of the ORR reaction mechanism through oxygen vacancy, modification of its microstructure by introducing alkaline earth metals, electron transfer pathways and the synergistic effect of perovskite and carbon. At the end, we also propose various challenges and prospects to further improve the ORR activity of perovskite-based catalysts.</jats:p>

Zhengying Guo, Peng Xu, Shiqing Zhou et al.

Sensors • 0

<jats:p>Excessive levels of heavy metal pollutants in the environment pose significant threats to human health and ecosystem stability. Consequently, the accurate and rapid detection of heavy metal ions is critically important. A AgNPs@CeO2/Nafion composite was prepared by dispersing nano-ceria (CeO2) in a Nafion solution and incorporating silver nanoparticles (AgNPs). The morphology, microstructure, and electrochemical properties of the modified electrode materials were systematically characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and cyclic voltammetry (CV). By leveraging the oxygen vacancies and high electron transfer efficiency of CeO2, the strong adsorption capacity of Nafion, and the superior conductivity of AgNPs, an AgNPs@CeO2/Nafion/GCE electrochemical sensor was developed. Under optimized conditions, trace Pb2+ in water was detected using square wave anodic stripping voltammetry (SWASV). The sensor demonstrated a linear response for Pb2+ within the concentration range of 1–100 μg·L−1, with a detection limit of 0.17 μg·L−1 (S/N = 3). When applied to real water samples, the method achieved recovery rates between 93.7% and 110.3%, validating its reliability and practical applicability.</jats:p>

Anh Vu Nguyen, Bin Lai, Lorenz Adrian et al.

Microbial Biotechnology • 2021

<jats:title>Summary</jats:title><jats:p><jats:italic>Pseudomonas putida</jats:italic> (<jats:italic>P. putida</jats:italic>) is a microorganism of interest for various industrial processes, yet its strictly aerobic nature limits application. Despite previous attempts to adapt <jats:italic>P. putida</jats:italic> to anoxic conditions via genetic engineering or the use of a bioelectrochemical system (BES), the problem of energy shortage and internal redox imbalance persists. In this work, we aimed to provide the cytoplasmic metabolism with different monosaccharides, other than glucose, and explored the physiological response in <jats:italic>P. putida</jats:italic> KT2440 during bioelectrochemical cultivation. The periplasmic oxidation cascade was found to be able to oxidize a wide range of aldoses to their corresponding (keto‐)aldonates. Unexpectedly, isomerization of the ketose fructose to mannose also enabled oxidation by glucose dehydrogenase, a new pathway uncovered for fructose metabolism in <jats:italic>P. putida</jats:italic> KT2440 in BES. Besides the isomerization, the remainder of fructose was imported into the cytoplasm and metabolized. This resulted in a higher NADPH/NADP<jats:sup>+</jats:sup> ratio, compared to glucose. Comparative proteomics further revealed the upregulation of proteins in the lower central carbon metabolism during the experiment. These findings highlight that the choice of a substrate in BES can target cytosolic and periplasmic oxidation pathways, and that electrode‐driven redox balancing can drive these pathways in <jats:italic>P</jats:italic>. <jats:italic>putida</jats:italic> under anaerobic conditions.</jats:p>

Pholoso Calvin Motsaathebe, Omolola Ester Fayemi

Nanomaterials • 0

<jats:p>Ascorbic acid (AA) is an essential vitamin in the body, influencing collagen formation, as well as norepinephrine, folic acids, tryptophan, tyrosine, lysine, and neuronal hormone metabolism. This work reports on electrochemical detection of ascorbic acid (AA) in oranges using screen-print carbon electrodes (SPCEs) fabricated with multi-walled carbon nanotube- antimony oxide nanoparticle (MWCNT-AONP) nanocomposite. The nanocomposite-modified electrode displayed enhanced electron transfer and a better electrocatalytic reaction towards AA compared to other fabricated electrodes. The current response at the nanocomposite-modified electrode was four times bigger than the bare electrode. The sensitivity and limit of detection (LOD) at the nanocomposite modified electrode was 0.3663 [AA]/µM and 140 nM, respectively, with linearity from 0.16–0.640 μM and regression value R2 = 0.985, using square wave voltammetry (SWV) for AA detection. Two well-separated oxidation peaks were observed in a mixed system containing AA and serotonin (5-HT); and the sensitivity and LOD were 0.0224 [AA]/µA, and 5.85 µΜ, respectively, with a concentration range from 23 to 100 µM (R2 = 0.9969) for AA detection. The proposed sensor outperformed other AA sensors reported in the literature. The fabricated electrode showed great applicability with excellent recoveries ranging from 99 to 107 %, with a mean relative standard deviation (RSD) value of 3.52 % (n = 3) towards detecting AA in fresh oranges.</jats:p>

Thomas Fudge, Isabella Bulmer, Kyle Bowman et al.

Water • 0

<jats:p>Traditional wastewater treatment methods have become aged and inefficient, meaning alternative methods are essential to protect the environment and ensure water and energy security worldwide. The use of microbial electrolysis cells (MEC) for wastewater treatment provides an innovative alternative, working towards circular wastewater treatment for energy production. This study evaluates the factors hindering industrial adoption of this technology and proposes the next steps for further research and development. Existing pilot-scale investigations are studied to critically assess the main limitations, focusing on the electrode material, feedstock, system design and inoculation and what steps need to be taken for industrial adoption of the technology. It was found that high strength influents lead to an increase in energy production, improving economic viability; however, large variations in waste streams indicated that a homogenous solution to wastewater treatment is unlikely with changes to the MEC system specific to different waste streams. The current capital cost of implementing MECs is high and reducing the cost of the electrodes should be a priority. Previous pilot-scale studies have predominantly used carbon-based materials. Significant reductions in relative performance are observed when electrodes increase in size. Inoculation time was found to be a significant barrier to quick operational performance. Economic analysis of the technology indicated that MECs offer an attractive option for wastewater treatment, namely greater energy production and improved treatment efficiency. However, a significant reduction in capital cost is necessary to make this economically viable. MEC based systems should offer improvements in system reliability, reduced downtime, improved treatment rates and improved energy return. Discussion of the merits of H2 or CH4 production indicates that an initial focus on methane production could provide a stepping-stone in the adoption of this technology while the hydrogen market matures.</jats:p>

Marie Abadikhah, Frank Persson, Anne Farewell et al.

ISME Communications • 2024

<jats:title>Abstract</jats:title> <jats:p>In microbial electrolysis cells (MECs), microbial communities catalyze conversions between dissolved organic compounds, electrical energy, and energy carriers such as hydrogen and methane. Bacteria and archaea, which catalyze reactions on the anode and cathode of MECs, interact with phages; however, phage communities have previously not been examined in MECs. In this study, we used metagenomic sequencing to study prokaryotes and phages in nine MECs. A total of 852 prokaryotic draft genomes representing 278 species, and 1476 phage contigs representing 873 phage species were assembled. Among high quality prokaryotic genomes (&amp;gt;95% completion), 55% carried a prophage, and the three Desulfobacterota spp. that dominated the anode communities all carried prophages. Geobacter anodireducens, one of the bacteria dominating the anode communities, carried a CRISPR spacer showing evidence of a previous infection by a Peduoviridae phage present in the liquid of some MECs. Methanobacteriaceae spp. and an Acetobacterium sp., which dominated the cathodes, had several associations with Straboviridae spp. The results of this study show that phage communities in MECs are diverse and interact with functional microorganisms on both the anode and cathode.</jats:p>

Dilan Akagunduz, Rumeysa Cebecioglu, Murat Ozdemir et al.

Water Science and Technology • 2021

<jats:title>Abstract</jats:title> <jats:p>In this study, hydrogen production was analyzed along with methane and carbon dioxide generation using paroxetine, venlafaxine, and o-desmethylvenlafaxine (ODV) as substrates in single-chamber microbial electrolysis cells (MECs). Combinations of all three drugs were examined at concentrations of 750 ng/mL and 170 ng/mL. At the beginning of MEC operations using a 750 ng/mL mixture of drugs, there was no hydrogen or methane, but carbon dioxide was detected. When the concentration of the drug mixture was reduced to 170 ng/mL, MECs produced hydrogen and methane gas. Removal of the drugs during MEC operations was also analyzed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Paroxetine, venlafaxine and ODV drugs were removed up to 99% by MECs. In conclusion, MECs could offer an alternative treatment method for wastewaters containing psychoactive pharmaceuticals with the added benefit of fuel hydrogen generation.</jats:p>

Hasika Suresh, Rhea Patel, Kundan Saha et al.

ECS Meeting Abstracts • 2024

<jats:p> Promoting extracellular electron transfer (EET) in bacteria has many widespread applications including wastewater treatment and environmental remediation. With the development of synthetic biology technologies that can alter microbial electron transfer routes and enhance their electrogenic capacity, there is a need for high throughput systems to identify the responsible genes and the consequent metabolic pathways in an expeditious way. Conventional platforms utilizing single electrodes, or electrochemical cells, and colorimetric detection suffer from low sensitivity and low throughput. Moreover, they require bulky equipment for readout and fluid handling. Moving towards a nuanced miniaturized electrochemical detection, we propose individually addressable microwells used to monitor electron flux from EET-capable bacteria with the ability to screen a large number of electroactive bacteria for various applications.</jats:p> <jats:p> <jats:bold>Materials and method</jats:bold> <jats:bold>: </jats:bold>The device is simple and fabricated with cost-effective electrodes. Carbon felt is used as the working electrode to improve bacterial entrapment and assist in capturing maximum electrons donated by the electroactive bacteria. Silver-silver chloride ink (Ag/AgCl) as the reference electrode will help maintain the potential of with respect to the working electrode. Conductive carbon ink as the counter electrode will promote current collection. The proposed device has the elements of a traditional three electrode system arranged in two different planes resulting in a 3D configuration of electrodes. The reference and counter electrode are on the bottom plane with acrylic wells housed right above each electrode pair, while the working electrode is used in the cross-bar architecture from the top plane as shown in <jats:bold>Figure 1(a).</jats:bold> The fabrication steps are illustrated in <jats:bold>Figure 1(b).</jats:bold> This system can be scaled to have 10000 microwells on a single platform with individual addressability of each micro-well array. With this layout, connections from the innermost wells can be drawn effortlessly without any signal damping from the surrounding wells. As a proof of concept, we have fabricated a 9 by 9 array (20cm by 20 cm) as shown in <jats:bold>Figure 1(a)</jats:bold>. Five strains of <jats:italic>Shewanella oneidensis</jats:italic> MR-1, the wild type organism and four modified strains overexpressing variants of MtrA (unmodified MtrA, IV-205, IV-261 and an empty vector), were screened for their current producing capacity [1].</jats:p> <jats:p> <jats:bold>Results:</jats:bold>A bacterial load of OD<jats:sub>600</jats:sub>= 0.065 was sufficient to give a reliable current signal. For each strain, the working electrode was biased at 0.205 V with respect to the reference electrode (Ag/AgCl), and the resulting chronoamperometry signal was recorded as shown in <jats:bold>Figure 1(c)</jats:bold>. The values obtained helped identify the current-producing capacity of each mutant. Among them, the highest peak current was given by mtr A<jats:sup>+</jats:sup> (20 μA), and IV – 261 gave a low peak current (2 μA) within 3 minutes, validating the difference in the genetic make-up and EET capabilities. Technical and biological replicates were also conducted for all the 5 strains. The average standard deviation for the technical and biological replicates (n=3, OD<jats:sub>600</jats:sub>=0.065) was 0.09 μA and 0.56 μA respectively. A similar current trend for the same set of strains was obtained by Ian et al., [1] using a traditional bioelectrochemical system, thus validating our platform’s functionality and integrity. This system allows for parallel screening of wild type and mutant variations of multiple electroactive bacteria as demonstrated. The high throughput feature enabled by this device can also find application to characterize mutants generated by directed evolution workflows. Additionally, mechanical and electrical multiplexing can further improve the electronic instrumentation and connections between the wells for parallel readout and will also minimize human intervention during the current measurements. Chronoamperometry measurements is an important technique to characterize EET. Thus, a low-cost system like ours will help do that in a shorter time frame with minimal bacterial inoculum and for a larger number of electroactive bacterial species. In conclusion, we aim to show that a 3D carbon felt platform is miniaturized, and can be scaled to understand and characterize EET from electroactive bacteria in a high throughput manner.</jats:p> <jats:p> <jats:bold>References</jats:bold> <jats:list list-type="roman-lower"> <jats:list-item> <jats:p>Ian J. Campbell, Joshua T. Atkinson, Matthew D. Carpenter, Dru Myerscough, Lin Su, Caroline M. Ajo-Franklin, and Jonathan J. Silberg Biochemistry 2022 61 (13), 1337-1350</jats:p> </jats:list-item> </jats:list> </jats:p> <jats:p> <jats:inline-formula> </jats:inline-formula> </jats:p> <jats:p>Figure 1</jats:p> <jats:p/>

N I I M Jamlus, M N Masri, S K Wee et al.

IOP Conference Series: Earth and Environmental Science • 2021

<jats:title>Abstract</jats:title> <jats:p>Electroactive bacteria can transfer electrons to electrodes to generate electricity in the microbial fuel cell (MFC). Electroactive bacteria can generate energy for growth via the oxidation of organic compounds and transfer electrons to the electrodes that serve as the terminal electron acceptor. In this study, electricity generation in a double chamber evaluated MFC by four newly isolated electroactive bacteria strains (ESPK 22, ESPK 26, KP20, and KP22). ESPK22 and ESPK26 were previously identified as gram-positive Bacillus genera, while KP20 and KP22 belong to gram-negative Klebsiella genera. Among all the strains tested, the gramnegative KP20 strain shows the highest electricity generation value is 222.08 mV and the lowest electricity generation was ESPK26 of 44.82 mV.</jats:p>

Najwa Najihah Mohamad Daud, Mohamad Nasir Mohamad Ibrahim, Asim Ali Yaqoob et al.

Fuel • 2024

Ashish Yewale, Ravi N. Methekar, Shailesh G. Agrawal

ECS Meeting Abstracts • 2018

<jats:p> Sustainability and resource management is one of the major concerns for scientific community now days. In this context, in many fields of research, the focus is centred on the re-utilization of used resources with no further damage to the environment. Microbial fuel cell (MFC) is one of the technologies, where electricity is generated from waste-water. MFC is an electrochemical device that converts organic matter directly into the electricity with high efficiency. MFCs offer certain advantages such as minimum sludge production, cost effective and operation at normal condition. Despite its wide range of potential applications and ease of feed stocks, commercialisation of this technology did not realized till now<jats:sup>1</jats:sup>. The major limitations for the commercialization are the scale up of the process<jats:sup>2</jats:sup> and continuous operations. To perform continuous operation for longer time, it is extremely important to understand the dynamics of the system. Dynamics of the system can be understood by performing exhaustive experiments and analysing the data thus obtained. But performing exhaustive experiments is a time consuming as well expensive task. The other approach is to model the system to understand the dynamics. </jats:p> <jats:p>In literature very few researcher worked on the modeling of continuous microbial fuel cell (CMFC). Although batch modeling of MFC have been reported earlier, a very few studies had focused on understanding the dynamics of the system. First dynamic study was carried out by Zhang et al<jats:sup>3</jats:sup>, and there model is based on electron transfer using mediator. Later, Picioreanu et al<jats:sup>4</jats:sup> modeled the bio-film development on the anode electrode in MFC. Marcus et al<jats:sup>5</jats:sup> and Pinto et al<jats:sup>6</jats:sup> developed 1-D model for multispecies electron donor and acceptor for bio-film anode based on the material balance, Ohm’s law and Nernst-Monod kinetics to describe the rate of electron donor oxidation. In 2017, Esfandyari et al<jats:sup>7</jats:sup>, developed batch process model considering direct electron transfer through bio-film to the electron acceptor. </jats:p> <jats:p>In this talk, we will present a continuous model developed for MFC and dynamic analysis of potential controlled variables. Dynamic analysis will provide deeper insights of the various physical phenomena of the microbial fuel cell. </jats:p> <jats:p>In present work, model presented by Esfandyari et al<jats:sup>7</jats:sup> which is a batch model is taken as the basis. Batch model developed in this work is validated with the work of Esfandyari<jats:sup>7</jats:sup> and Picioreanu et al<jats:sup>4</jats:sup> for typical dynamic responses. The batch model is then converted into the dual chamber continuous model. In continuous model, substrate (Lactate) and oxygen is continuously fed to the anode and cathode chamber respectively as shown in Figure 1. Coolant is supplied through the jacket to maintain the required operating temperature of the cell. Bacteria species <jats:italic>Shewanella</jats:italic> is used as the catalyst to oxidise electron donor. The electrons produced are then reaching the cathode electrode via external circuit producing the power. Protons migrate to the cathode through the proton exchange membrane. In the cathode chamber, transferred electrons and migrated protons are reacted with dissolved oxygen to produce water. To understand the dynamic of the MFC, the step change study of the important parameters i.e. substrate concentration, current produced and coolant flow have been simulated. The simulation result of this model is shown in Figure 2, where time variations of the current shows first order dynamic. The settling time observed to be approximately 20 days. It is also noted that the current obtained from the same size of fuel cell in continuous system is higher than the batch. </jats:p> <jats:p>Once the impact of pH is accounted into the model, the dynamic analysis with respective various potential manipulated variables i.e. pH of the solution, flow rate of the substrate and coolant flow rate will be studied to get further insight of the microbial fuel cell. The model, thus developed will be used as a system for devising an effective control and optimization strategies for the microbial fuel cell. </jats:p> <jats:p>References: <jats:list list-type="simple"> <jats:list-item> <jats:p>J. Chouler, G. Padgett, P. Cameron, K. Peruss, M. Titirici, I. Ieropoulos, and M. Lorenzo, Electrochimica Acta, <jats:bold>196</jats:bold>, 89-98,(2016)</jats:p> </jats:list-item> <jats:list-item> <jats:p>S. Choi, <jats:italic>Biosensors and Bioelectronic</jats:italic>, <jats:bold>69</jats:bold>, 8-25 (2015).</jats:p> </jats:list-item> <jats:list-item> <jats:p>X. Zhang and A. Halme, <jats:italic>B</jats:italic> <jats:italic>iotechnology Letters</jats:italic>, <jats:bold>17 </jats:bold>(8), 809-814 (1995).</jats:p> </jats:list-item> <jats:list-item> <jats:p>C. Picioreanua, I. Head, K. Katuri, M. van Loosdrecht, K. Scott, <jats:italic>Water Research</jats:italic>,<jats:bold>41</jats:bold>, 2921-2940 (2007).</jats:p> </jats:list-item> <jats:list-item> <jats:p>A. Marcus, C. Torres, B. Rittmann, <jats:italic>Biotechnology and Bioengineering</jats:italic>, <jats:bold>98 </jats:bold>(6), 1171-1182 (2007).</jats:p> </jats:list-item> <jats:list-item> <jats:p>R. Pinto, B. Srinivasan, M. Manuel, B. Tartakovsky, <jats:italic>Bioresource Technology</jats:italic>, <jats:bold>101</jats:bold>(14), 5256-5265 (2010).</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="2265fig1.jpeg" xlink:type="simple"/> </jats:inline-formula> </jats:p> <jats:p>Figure 1</jats:p> <jats:p/>

Jianfei Wang, Kexin Ren, Yan Zhu et al.

BioTech • 0

<jats:p>The microbial fuel cell has been considered a promising alternative to traditional fossil energy. It has great potential in energy production, waste management, and biomass valorization. However, it has several technical issues, such as low power generation efficiency and operational stability. These issues limit the scale-up and commercialization of MFC systems. This review presents the latest progress in microbial community selection and genetic engineering techniques for enhancing microbial electricity production. The summary of substrate selection covers defined substrates and some inexpensive complex substrates, such as wastewater and lignocellulosic biomass materials. In addition, it also includes electrode modification, electron transfer mediator selection, and optimization of operating conditions. The applications of MFC systems introduced in this review involve wastewater treatment, production of value-added products, and biosensors. This review focuses on the crucial process of microbial fuel cells from preparation to application and provides an outlook for their future development.</jats:p>

Rodrigo Valladares Linares, Jorge Domínguez-Maldonado, Ernesto Rodríguez-Leal et al.

Water • 0

<jats:p>The most important operational expense during wastewater treatment is electricity for pumping and aeration. Therefore, this work evaluated operational parameters and contaminant removal efficiency of a microbial fuel cell stack system (MFCSS) that uses no electricity. This system consists of (i) septic tank primary treatment, (ii) chamber for secondary treatment containing 18 MFCs, coupled to an energy-harvesting circuit (EHC) that stores the electrons produced by anaerobic respiration, and (iii) gravity-driven disinfection (sodium hypochlorite 5%). The MFCSS operated during 60 days (after stabilization period) and it was gravity-fed with real domestic wastewater from a house (5 inhabitants). The flow rate was 600 ± 100 L∙d−1. The chemical oxygen demand, biological oxygen demand, total nitrogen and total phosphorous were measured in effluent, with values of 100 ± 10; 12 ± 2; 9.6 ± 0.5 and 4 ± 0.2 mg∙L−1, and removal values of 86%, 87%, 84% and 64%, respectively. Likewise, an EHC (ultra-low energy consumption) was built with 6.3 V UCC® 4700 µF capacitors that harvested and stored energy from MFCs in parallel. Energy management was programmed on a microcontroller Atmega 328PB®. The water quality of the treated effluent complied with the maximum levels set by the Mexican Official Standard NOM-001-SEMARNAT-1996-C. A cost analysis showed that MFCSS could be competitive as a sustainable and energy-efficient technology for real domestic wastewater treatment.</jats:p>

Sameer Al‐Asheh, Marzieh Bagheri, Ahmad Aidan

Engineering in Life Sciences • 2022

<jats:title>Abstract</jats:title><jats:p>Removal efficiency of gold from a solution of pure tetrachloroaurate ions was investigated using microbial fuel cell (MFC) technology. The effects of type of catholyte solution and initial gold concentration on the removal efficiency were considered. Due to its presence at high levels in the gold wastewater, the effect of copper ions on the removal efficiency of the gold ions was also studied. The effects of pH and initial biomass concentration on the gold removal efficiency was also determined. The results showed that after 5 h contact time, 95% of gold removal efficiency from a wastewater containing 250 ppm of initial gold ions at ambient temperature using 80 g/L yeast concentration was achieved. After 48 h of the cell's operation under the same condition, 98.86% of AuCl<jats:sub>4</jats:sub><jats:sup>–</jats:sup> ions were successfully removed from the solution. At initial gold concentration in the waste solution of 250 ppm, pH 2, and initial yeast concentration of 80 g/L, 100% removal efficiency of the gold was achieved. On the other hand, the most suitable condition for copper removal was found at a pH of 5.2, where 53% removal efficiency from the waste solution was accomplished.</jats:p>

Choudhary Suresh Kumar, Yadav Rajesh

International Journal of Zoological Investigations • 2022

<jats:p>Water pollution is one of the major ecological challenge for all forms of life. The major cause of water pollution is rapid industrialization. Industries use water for various activities and during these activities; they generate an enormous volume of wastewater. The wastewater can be collected either in a local sewer system, treated by wastewater treatment plants, or directly released into the environment. In case of direct discharge of wastewater into the different water bodies, it adversely affects the life which is dependent on this for their water needs. Industrial wastewater contains various microorganisms, organic (chlorides, sulphates, oil and grease, hydrocarbons, pesticides, herbicides, phenol, aliphatic compounds), and chemical compounds (heavy metals, detergents, pesticides, nitrogen, and phosphorus) which are harmful to the environment as well as to humans. Bacteria are the most common microorganisms which are present in industrial wastewater, some of these are helpful in the treatment of wastewater and some are pathogenic which is responsible for various types of waterborne diseases. Thus, this study reviews various types of Bacteria present in industrial wastewater in terms of their roles within the wastewater treatment process.</jats:p>

Zabdiel A. Juarez, Víctor Ramírez, Carlos Hernández-Benítez et al.

Catalysts • 0

<jats:p>Wastewater treatment has become a priority in the global attempt to address environmental pollution. Conventional wastewater treatment processes are often limited by their high energy consumption, so it is necessary to develop new technologies. This work shows the results obtained using a passive aerated membraneless microbial fuel cell (PAML-MFC) system consisting of 10 individual units, designed to treat 1000 L/day of real wastewater, using granular activated carbon anodes and cathodes. The pilot-scale water treatment system under study combines design and materials to result in low-cost operation. After 300 days of treating real wastewater originally characterized by a chemical oxygen demand (COD) value of 500 mg/L on average, it was found that the PAML-MFC under study removed 60 to 80% of the COD contained in real wastewater. Under these conditions, the individual MFCs reached an average power density below 1 mW/m3.</jats:p>

Shelley D. Minteer

ECS Meeting Abstracts • 2023

<jats:p> Petroleum hydrocarbons are currently our major energy source and an important feedstock for the chemical industry. Beyond combustion, conversion of chemically inert hydrocarbons to more valuable chemicals is of considerable interest. However, two challenges hinder this conversion. One is the regioselective activation of inert carbon–hydrogen (C–H) bonds. The other is designing a pathway to realize this complicated conversion. This paper will discuss the use of alkane monoxygenases in bioelectrochemical systems for C-H activation, as well as enzyme cascades and hybrid catalytic cascades for the conversion of inert alkanes to complex organic molecules like imines with selectivity far beyond traditional homogeneous and heterogeneous catalysts. </jats:p>

Zhufan Lin, Xinyuan He, Huahua Li et al.

Processes • 0

<jats:p>The reverse polarity biocathode culture (RPBC) is a technology for the rapid preparation of biocathodes, which quickly enrich electroactive bacteria (EAB) in the microbial fuel cell (MFC) anode and then transform the electrode function from bioanode to biocathode by reversing bioelectrode polarity. However, the mechanism of RPBC is still unclear, and methods to regulate performance and ensure the long-term stability of cultured biocathodes have not been established. This study investigated the correlation between electrogenic bacteria and the target reducing EAB, from two aspects: energy supply and the formation of a composite biofilm. The results showed that electrogenic bacteria provided energy for the reducing EAB through interspecies electron transfer. This process could be regulated by changing the electrode potential and substrate concentration to obtain an optimized biocathode. In addition, the RPBC forms a composite biofilm of electrogenic bacteria and reducing EAB, which significantly improves the enrichment efficiency and the amount of reducing EAB (compared with a direct biocathode culture, respectively, shortening the enrichment time by 80%, increasing the electroactivity by 12.4 times, and increasing the nitrate degradation rate by 4.85 times). This study provides insights into regulating the performance and maintaining the long-term stability of RPBC-cultured biocathodes.</jats:p>

Nazla Fauziyah Octaviani, Nisa Kartika, Anggita Rahmi Hafsari

Indonesian Journal of Environmental Sustainability • 0

<jats:p>The uncontrolled nature of fossil fuels and their ecological consequences have moved emphasis to renewable energy and fuel cells, particularly in the transportation industry. The generation of energy from electrons generated from metabolic reactions aided by bacteria is studied in this paper. Microbial fuel cells (MFC) are an environmentally beneficial method of generating electricity while also purifying wastewater, with up to 50% chemical oxygen requirement elimination and power densities ranging from 420 to 460 MW/m2. This paper focuses on the technology that generates electricity by utilizing the metabolic power from electroactive bacteria as a renewable energy source. The method to collect data is a literature study. The result is seven species of electroactive bacteria potential from 7 articles, which can be used to generate MFC. In summary, using electroactive bacteria as MFC as a renewable energy source is possible because many sources of organic materials can be used as carbon sources for MFC, such as organic waste.</jats:p>

Tali Dotan, Yoo Kyung Go, Jesus Miguel Lopez Baltazar et al.

ECS Meeting Abstracts • 2025

<jats:p> Pyrolysis is the thermal decomposition of organic matter in the absence of oxygen <jats:sup>1</jats:sup>. This high-temperature process has been shown to produce carbon structures from photoresist since the 1990s. Using this technique, the photoresist is thermally reacted at high temperatures of 600 to 1100°C, forming a film with electrochemically active surfaces, providing glassy carbon-like properties. It has been demonstrated that better electrocatalytic behavior is obtained with carbon films prepared at the higher pyrolysis temperatures due to a differences in composition <jats:sup>1</jats:sup>. Additionally, pyrolysis has also been widely demonstrated for biowaste and various biomaterials. It is shown to be versatile, user-friendly, and has the potential for enhancement <jats:sup>1-3</jats:sup>.</jats:p> <jats:p>In this work, Shewanella Oneidensis bacterial biofilms are shown to provide conductive surfaces with properties that depend on the pyrolysis temperature in the range of 600 to 1100°C. The pyrolysis was carried out in a closed ceramic tube furnace under a 200mTorr vacuum at a heating rate of 5°C/ min. The pyrolysis process was characterized using thermogravimetric analysis and the resulting films were characterized by SEM, 4-point probe, Raman Spectroscopy, as well as by electrochemical characterization.</jats:p> <jats:p>This approach leverages the unique capabilities of S. oneidensis in metal ion reduction and nanoparticle biosynthesis, potentially allowing for the incorporation of catalytic nanoparticles within the electrode structure. The flexibility and distinctive properties of these biofilm-derived electrodes open up new possibilities for electrochemical CO<jats:sub>2</jats:sub> reduction and broader energy research applications, potentially contributing to the development of more efficient and selective catalytic systems for CO<jats:sub>2</jats:sub> utilization in a circular carbon economy.</jats:p> <jats:p>(1) Kim, J.; Song, X.; Kinoshita, K.; Madou, M.; White, R. Electrochemical Studies of Carbon Films from Pyrolyzed Photoresist. <jats:italic>J. Electrochem. Soc.</jats:italic> <jats:bold>1998</jats:bold>, <jats:italic>145</jats:italic> (7), 2314–2319.</jats:p> <jats:p>(2) Mohan, D.; Pittman, C. U.; Steele, P. H. Pyrolysis of Wood/Biomass for Bio-Oil: A Critical Review. <jats:italic>Energy Fuels</jats:italic> <jats:bold>2006</jats:bold>, <jats:italic>20</jats:italic> (3), 848–889.</jats:p> <jats:p>(3) Wang, G.; Dai, Y.; Yang, H.; Xiong, Q.; Wang, K.; Zhou, J.; Li, Y.; Wang, S. A Review of Recent Advances in Biomass Pyrolysis. <jats:italic>Energy Fuels</jats:italic> <jats:bold>2020</jats:bold>, <jats:italic>34</jats:italic> (12), 15557–15578. </jats:p>

Shuai Luo, Hongyue Sun, Qingyun Ping et al.

Energies • 0

<jats:p>Bioelectrochemical systems (BES) are promising technologies to convert organic compounds in wastewater to electrical energy through a series of complex physical-chemical, biological and electrochemical processes. Representative BES such as microbial fuel cells (MFCs) have been studied and advanced for energy recovery. Substantial experimental and modeling efforts have been made for investigating the processes involved in electricity generation toward the improvement of the BES performance for practical applications. However, there are many parameters that will potentially affect these processes, thereby making the optimization of system performance hard to be achieved. Mathematical models, including engineering models and statistical models, are powerful tools to help understand the interactions among the parameters in BES and perform optimization of BES configuration/operation. This review paper aims to introduce and discuss the recent developments of BES modeling from engineering and statistical aspects, including analysis on the model structure, description of application cases and sensitivity analysis of various parameters. It is expected to serves as a compass for integrating the engineering and statistical modeling strategies to improve model accuracy for BES development.</jats:p>

Jan‐Niklas Hengsbach, Mareike Engel, Marcel Cwienczek et al.

ChemElectroChem • 2023

<jats:title>Abstract</jats:title><jats:p>The concept of energy conversion into platform chemicals using bioelectrochemical systems (BES) has gained increasing attention in recent years, as the technology simultaneously provides an opportunity for sustainable chemical production and tackles the challenge of Power‐to‐X technologies. There are many approaches to realize the industrial scale of BES. One concept is to equip standard bioreactors with static electrodes. However, large installations resulted in a negative influence on various reactor parameters. In this study, we present a new single‐chamber BES based on a stirred tank reactor in which the stirrer was replaced by a carbon fiber brush, performing the functions of the working electrode and the stirrer. The reactor is characterized in abiotic studies and electro‐fermentations with <jats:italic>Clostridium acetobutylicum</jats:italic>. Compared to standard reactors an increase in butanol production of 20.14±3.66 % shows that the new BES can be efficiently used for bioelectrochemical processes.</jats:p>

Nhlanganiso Ivan Madondo, Emmanuel Kweinor Tetteh, Sudesh Rathilal et al.

Catalysts • 0

<jats:p>Conventional anaerobic digestion is currently challenged by limited degradability and low methane production. Herein, it is proposed that magnetic nanoparticles (Fe3O4-NPs) and bioelectrochemical systems can be employed for the improvement of organic content degradation. In this study, the effect of electrode configuration was examined through the application of a bioelectrochemical system and Fe3O4-NPs in anaerobic digestion (AD). A microbial electrolysis cell with cylindrical electrodes (MECC) and a microbial electrolysis cell (MEC) with rectangular electrodes were compared against the traditional AD process. Biochemical methane potential (BMP) tests were carried out using digesters with a working volume of 800 mL charged with 300 mL inoculum, 500 mL substrate, and 1 g Fe3O4-NPs. The electrodes (zinc and copper) of both digesters were inserted inside the BMPs and were powered with 0.4 V for 30 days at 40 °C. The MECC performed better, improving degradability, with enhanced methane percentage (by 49% &gt; 39.1% of the control), and reduced water pollutants (chemical-oxygen demand, total organic carbon, total suspended solids, turbidity, and color) by more than 88.6%. The maximum current density was 33.3 mA/m2, and the coulombic efficiency was 54.4%. The MECC showed a remarkable potential to maximize methane enhancement and pollution removal by adjusting the electrode configuration.</jats:p>

Yuman Guo, Yongqin Lv, Tianwei Tan

The Innovation Energy • 2024

<jats:p xml:lang="en">&lt;p&gt;Bioelectrochemical systems hold promise for the sustainable transformation of carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) using non-photosynthetic bacteria. Despite the progress made in developing electrodes and microbial platforms, significant challenges persist in optimizing electron transfer across the bio-abiotic interface. In this review, we delve into recent advances in fine-tuning bacteria-electrode interfaces to enhance bioelectrochemical CO&lt;sub&gt;2&lt;/sub&gt; conversion and to better understand the electron transfer mechanisms between CO&lt;sub&gt;2&lt;/sub&gt;-fixing microbes and electrodes. Notable achievements, such as single-atom catalyst design, heterologous expression of Mtr complexes, and multimodal characterization approaches, are discussed. However, electron transfer dynamics for many bacteria-electrode pairings remain incompletely understood, impeding the rational design of biosystems. Looking forward, a synergistic approach involving high-resolution characterization techniques, computational modeling, and targeted engineering of both microbial and electrode components is essential. Achieving finely tuned bio-abiotic interfaces at the molecular level holds the promise to revolutionize these bioelectrochemical platforms. With further optimization, scalable and sustainable CO&lt;sub&gt;2&lt;/sub&gt; conversion may become technically and economically viable.&lt;/p&gt; </jats:p>

Yang Liu, Hui Zhou, Weixiao Zhou et al.

Advanced Energy Materials • 2021

<jats:title>Abstract</jats:title><jats:p>Functional bioelectronic implants require energy storage units as power sources. Current energy storage implants face challenges of balancing factors including high‐performance, biocompatibility, conformal adhesion, and mechanical compatibility with soft tissues. An all‐hydrogel micro‐supercapacitor is presented that is lightweight, thin, stretchable, and wet‐adhesive with a high areal capacitance (45.62 F g<jats:sup>−1</jats:sup>) and energy density (333 μWh cm<jats:sup>−2</jats:sup>, 4.68 Wh kg<jats:sup>−1</jats:sup>). The all‐hydrogel micro‐supercapacitor is composed of polyaniline@reduced graphene oxide/Mxenes gel electrodes and a hydrogel electrolyte, with its interfaces robustly crosslinked, contributing to efficient and stable electrochemical performance. The in vitro and in vivo biocompatibility of the all‐hydrogel micro‐supercapacitor is evaluated by cardiomyocytes and mice models. The latter is systematically conducted by performing histological, immunostaining, and immunofluorescence analysis after adhering the all‐hydrogel micro‐supercapacitor implants onto hearts of mice for two weeks. These investigations offer promising energy storage modules for bioelectronics and shed light on future bio‐integration of electronic systems.</jats:p>