Arianna Callegari, Silvia Bolognesi, Daniele Cecconet

Water • 2019

Nitrate groundwater contamination is an issue of global concern that has not been satisfactorily and efficiently addressed, yet. In this study, a 2-stage, sequential bioelectrochemical system (BES) was run to perform autotrophic denitrification of synthetic groundwater. The system was run at a 75.6 mgNO3−-N L−1NCC d−1 nitrate loading rate, achieving almost complete removal of nitrate (>93%) and Total Nitrogen (TN) (>93%). After treatment in the first stage reactor values of effluent nitrate compatible with the EU and USA limits for drinking water (<11.3 and 10 mgNO3−-N L−1, respectively) were achieved. Nitrite and nitrous oxide were observed in the first stage’s effluent, and were then successfully removed in the second stage. The observed nitrate removal rate was 73.4 ± 1.3 gNO3−-N m−3NCC d−1, while the total nitrogen removal rate was 73.1 ± 1.2 gN m−3NCC d−1. Specific energy consumptions of the system were 0.80 ± 0.00 kWh m−3, 18.80 ± 0.94 kWh kgNO3−-N−1 and 18.88 ± 0.95 kWh kgN−1. Combination of two denitrifying BES in series herein described proved to be effective.

Xiyao Shou, Ping Chun Shih

• 2025

Despite significant advancements in bioelectrochemical systems over the past decade, scaling up these devices remains a major challenge, limiting their practical application. This study explores the structural and functional integration of biophotovoltaic (BPV) cells onto a tensegrity strut. Tensegrity structures, composed of interconnected struts and cables, offer high stability and low material use, combined with BPV cells that utilize Synechocystis sp.PCC 6803 to generate photocurrent under both day and night conditions. We also explored the interactions of other artificial microbial consortiums comprising P.putida KT2440 (Pp), S.oneidensis MR-1 (So), and Synechocystis sp. PCC 6803 (Ss). Results indicate positive interactions between Ss and So, Pp and So using the MIMIC library developed by the UCL CSSB group (2022). Among different BPV configurations, the liquid-based BPV system containing Synechocystis sp. (Ss) achieved the highest electrical output equal to 0.45mW/m² while the hydrogel-based BPV cells maintained an average open circuit potential of 0.80V over three days. On the architectural scale, BPV cells are arranged on tensegrity struts in a rotational symmetric configuration to allow sun exposure and were evaluated by assessing elastic deformation simulated in Karamba3D software, leading to a 26% increase in structural stiffness. Additionally, the integration of BPV cells within the struts induces vibration, reduces cell sedimentation, and promotes cell growth. The above findings guide future research toward optimizing microbial consortia across BPV configurations, scaling production, and exploring novel bio-integrated applications.

S. Spiess, J. Kucera, T. Vaculovič et al.

Frontiers in Microbiology • 2023

Metal recycling is essential for strengthening a circular economy. Microbial leaching (bioleaching) is an economical and environmentally friendly technology widely used to extract metals from insoluble ores or secondary resources such as dust, ashes, and slags. On the other hand, microbial electrolysis cells (MECs) would offer an energy-efficient application for recovering valuable metals from an aqueous solution. In this study, we investigated a MEC for Zn recovery from metal-laden bioleachate for the first time by applying a constant potential of −100 mV vs. Ag/AgCl (3 M NaCl) on a synthetic wastewater-treating bioanode. Zn was deposited onto the cathode surface with a recovery efficiency of 41 ± 13% and an energy consumption of 2.55 kWh kg−1. For comparison, Zn recovery from zinc sulfate solution resulted in a Zn recovery efficiency of 100 ± 0% and an energy consumption of 0.70 kWh kg−1. Furthermore, selective metal precipitation of the bioleachate was performed. Individual metals were almost completely precipitated from the bioleachate at pH 5 (Al), pH 7 (Zn and Fe), and pH 9 (Mg and Mn).

A. Fathy, Hegazy Rezk, Dalia Yousri et al.

Sustainability • 2023

In this research work, the best operating conditions of microbial electrolysis cells (MECs) were identified using artificial intelligence and modern optimization. MECs are innovative materials that can be used for simultaneous wastewater treatment and bio-hydrogen production. The main objective is the maximization of bio-hydrogen production during the wastewater treatment process by MECs. The suggested strategy contains two main stages: modelling and optimal parameter identification. Firstly, using adaptive neuro-Fuzzy inference system (ANFIS) modelling, an accurate model of the MES was created. Secondly, the optimal parameters of the operating conditions were determined using the jellyfish optimizer (JO). Three operating variables were studied: incubation temperature (°C), initial potential of hydrogen (pH), and influent chemical oxygen demand (COD) concentration (%). Using some measured data points, the ANFIS model was built for simulating the output of MFC considering the operating parameters. Afterward, a jellyfish optimizer was applied to determine the optimal temperature, initial pH, and influent COD concentration values. To demonstrate the accuracy of the proposed strategy, a comparison with previous approaches was conducted. For the modelling stage, compared with the response surface methodology (RSM), the coefficient of determination increased from 0.8953 using RSM to 0.963 using ANFIS, by around 7.56%. In addition, the RMSE decreased from 0.1924 (using RSM) to 0.0302 using ANFIS, whereas for the optimal parameter identification stage, the optimal values were 30.2 °C, 6.53, and 59.98 (%), respectively, for the incubation temperature, the initial potential of hydrogen (pH), and the influent COD concentration. Under this condition, the maximum rate of the hydrogen production is 1.252 m3H2/m3d. Therefore, the proposed strategy successfully increased the hydrogen production from 1.1747 m3H2/m3d to 1.253 m3H2/m3d by around 6.7% compared to RSM.

Basil Mansoor, Sumreen Ashraf, Umar Rehman et al.

ECWS-7 2023 • 2023

: The microalgae-microbial fuel cell (mMFC) enables us to perform secondary and tertiary treatment of domestic wastewater while simultaneously producing green electricity. In this work, the treatment of wastewater and producing electricity using a dual-chambered mMFC were demonstrated. Furthermore, the electricity produced by the mMFC was utilized to drive microbial electrolysis cell (MEC) for hydrogen synthesis. Primary domestic wastewater was treated in the anodic compartment of mMFC. Chemical oxygen demand (COD) removal of 67.2 and 54% was achieved in the anodic compartment of batch and continuous mode, respectively. Wetland-treated water was filled in the cathodic compartment, and Scenedesmus sp. was used as a catholyte. The overall voltage of 1.85 V was used to run a 1-L MEC. Industrial wastewater was treated with a COD removal of 73% in the MEC and biohydrogen was produced at a rate of 9.8 ± 0.2 mL L − 1 d − 1 .

Valentin Nenov, Lyubka Atanasova, Hyusein Yemendzhiev et al.

Processes • 2024

Bio-electrochemical systems have increasingly become the focus of research due to their potential in environmental biotechnology, particularly in the domains of waste utilization and energy recovery. A prominent method within this domain is the transformation of organic matter into hydrogen via microbial electrolysis cells (MECs). This study offers a thorough analysis of MEC performance, employing exergy analysis and incorporating relevant data from the existing literature. The findings of this research indicate a relationship between process efficiency and effective electron transfer originating from biological oxidation to the cathode reaction, facilitating hydrogen generation. The assessment performed revealed that the exergy efficiency of the process varies by a wide range, depending on conditions such as substrate type and concentration, applied external voltage, and the presence of specific inhibitors. This interplay between substrate concentration, overall efficiency, and energy requirement underlines the complex dynamics of optimizing MEC performance. Our insights provide understanding of the challenges in bio-electrochemical systems, offering implications for their sustainable and efficient use in environmental biotechnology. The theoretical analysis involved assessing the utilization of glucose and glycerol, along with the evaluation of electrical energy consumption and hydrogen yield. Our results demonstrate that a higher applied voltage is associated with greater exergy efficiency. Furthermore, after comparing the use of glucose and glycerol as substrates, our study supports the preferential application of glucose for enhanced efficiency.

Heng Yang, Shenyu Tan, Yu Huang et al.

Water • 2024

In this study, a constructed wetland–Fe3O4/granular activated carbon anode microbial electrolysis cell (CW-FMEC) was constructed to enhance denitrification in low COD/N ratio wastewater. The introduction of Fe3O4 boosted the expression of functional genes involved in the denitrification pathway, and the abundance of narG, nirS, and nosZ increased by 99.29%, 70.54%, and 132.18%, respectively, compared to CW. In addition, the content of c-type cytochromes (c-Cyts) and EPS were also enhanced in the CW-FMEC. The microbial communities study displayed that Thauera, Dechloromonas, and Arenimonas became the main genera for denitrification. The denitrification performance at different COD/N ratios was investigated in depth. Under optimal working circumstances, the CW-FMEC had an excellent nitrate removal rate (88.9% ± 1.12%) while accumulating nearly no NO2−-N or NH4+-N in the effluent. This study provides a new direction for the development of CW-MEC and accelerates its implementation.

Sha Long, Xuran Liu, Jun Xiao et al.

Environmental Science & Technology • 2024

Triclocarban (TCC), as a widely used antimicrobial agent, is accumulated in waste activated sludge at a high level and inhibits the subsequent anaerobic digestion of sludge. This study, for the first time, investigated the effectiveness of microbial electrolysis cell-assisted anaerobic digestion (MEC-AD) in mitigating the inhibition of TCC to methane production. Experimental results showed that 20 mg/L TCC inhibited sludge disintegration, hydrolysis, acidogenesis, and methanogenesis processes and finally reduced methane production from traditional sludge anaerobic digestion by 19.1%. Molecular docking revealed the potential inactivation of binding of TCC to key enzymes in these processes. However, MEC-AD with 0.6 and 0.8 V external voltages achieved much higher methane production and controlled the TCC inhibition to less than 5.8%. TCC in the MEC-AD systems was adsorbed by humic substances and degraded to dichlorocarbanilide, leading to a certain detoxification effect. Methanogenic activities were increased in MEC-AD systems, accompanied by complete VFA consumption. Moreover, the applied voltage promoted cell apoptosis and sludge disintegration to release biodegradable organics. Metagenomic analysis revealed that the applied voltage increased the resistance of electrode biofilms to TCC by enriching functional microorganisms (syntrophic VFA-oxidizing and electroactive bacteria and hydrogenotrophic methanogens), acidification and methanogenesis pathways, multidrug efflux pumps, and SOS response.

Yusen Zhu, Meixin Guo, Xuejiao Qi et al.

Research Square • 2023

Abstract Microbial electrolysis cell (MEC) is a new way to enhance degradation of food waste anaerobic digestate and recover methane. Through long-term operation, the start-up method, organic load, and methane production mechanism of the digestate have been optimized. At an organic load of 4000 mg/L, MEC increased methane production by 3–4 times and COD removal by 20.3% compare with anaerobic digestion (AD). The abundance of bacteria Fastidiosipila and Geobacter , which participated in the acid degradation and direct electron transfer in the MEC, increased dramatically than that in the AD. The dominant methanogenic archaea in the MEC and AD was Methanobacterium (44.4–56.3%) and Methanocalculus (70.05%), respectively. Geobacter and Methanobacterium dominated the MEC by direct electron transfer of organic matter into synthetic methane intermediates. MEC showed a perfect COD removal efficiency of the digestate, meanwhile CH 4 as a clean energy was obtained. Thus, MEC was a promising technology for deep energy from digestate.

Lorenzo Cristiani, Marco Zeppilli, Cristina Porcu et al.

Molecules • 2020

Here, a 12-liter tubular microbial electrolysis cell (MEC) was developed as a post treatment unit for simultaneous biogas upgrading and ammonium recovery from the liquid effluent of an anaerobic digestion process. The MEC configuration adopted a cation exchange membrane to separate the inner anodic chamber and the external cathodic chamber, which were filled with graphite granules. The cathodic chamber performed the CO2 removal through the bioelectromethanogenesis reaction and alkalinity generation while the anodic oxidation of a synthetic fermentate partially sustained the energy demand of the process. Three different nitrogen load rates (73, 365, and 2229 mg N/Ld) were applied to the inner anodic chamber to test the performances of the whole process in terms of COD (Chemical Oxygen Demand) removal, CO2 removal, and nitrogen recovery. By maintaining the organic load rate at 2.55 g COD/Ld and the anodic chamber polarization at +0.2 V vs. SHE (Standard Hydrogen Electrode), the increase of the nitrogen load rate promoted the ammonium migration and recovery, i.e., the percentage of current counterbalanced by the ammonium migration increased from 1% to 100% by increasing the nitrogen load rate by 30-fold. The CO2 removal slightly increased during the three periods, and permitted the removal of 65% of the influent CO2, which corresponded to an average removal of 2.2 g CO2/Ld. During the operation with the higher nitrogen load rate, the MEC energy consumption, which was simultaneously used for the different operations, was lower than the selected benchmark technologies, i.e., 0.47 kW/N·m3 for CO2 removal and 0.88 kW·h/kg COD for COD oxidation were consumed by the MEC while the ammonium nitrogen recovery consumed 2.3 kW·h/kg N.

Rahul Gautam, Uttam Kumar Ghosh

Global NEST International Conference on Environmental Science & Technology • 2023

The energy consumption around the world has increased significantly and depleting reserves posing a major concern. The green energy sources are the need of the hour to counter the fuel scarcity and souring prices. Hydrogen production through a microbial electrolysis cell (MEC) is an effective and green technology. It is a bio-electrochemical system where microbial oxidation of organic feed at anode and reduction of protons to Hydrogen at cathode takes place. To derive hydrogen evolution reaction (HER) over the cathode, an external applied voltage of 0.2V is required which is very nominal in comparison to the voltage required for water electrolysis. In the present study, the reactor digestate derived biochar biocatalyst was evaluated for its impact in the process parameter enhancements. The bio-catalyzed membrane-less single chambered MEC (BC-SC-MEC) in a batch mode at an applied voltage of 0.8 V had resulted into higher COD removal efficiency and hydrogen production rates at 30 ± 2 °C (Fig.1). The COD removal of 78%, with Coulombic efficiency of 60% and cathodic hydrogen recovery of 52 % were reported in BC-SC-MEC, while SC-MEC resulted into COD removal of 72%, coulombic efficiency of 55% and cathodic hydrogen recovery of 48% were reported. These results support the claim of boosted hydrogen production in the bio-catalyzed MEC for enhanced energy recovery.

Devi Radhika, Archana Shivakumar, Deepak Kasai et al.

Energies • 2022

Microbial electrolysis cells (MECs) have been explored for various applications, including the removal of industrial pollutants, wastewater treatment chemical synthesis, and biosensing. On the other hand, MEC technology is still in its early stages and faces significant obstacles regarding practical large-scale implementations. MECs are used for energy generation and hydrogen peroxide, methane, hydrogen/biohydrogen production, and pollutant removal. This review aimed to investigate the aforementioned uses in order to better understand the different applications of MECs in the following scenarios: MECs for energy generation and recycling, such as hydrogen, methane, and hydrogen peroxide; contaminant removal, particularly complex organic and inorganic contaminants; and resource recovery. MEC technology was examined in terms of new concepts, configuration optimization, electron transfer pathways in biocathodes, and coupling with other technologies for value-added applications, such as MEC anaerobic digestion, combined MEC–MFC, and others. The goal of the review was to help researchers and engineers understand the most recent developments in MEC technologies and applications.

S. A. Hussain, M. Perrier, B. Tartakovsky

RSC Advances • 2018

This study describes a new approach for achieving stable long-term performance and maximizing removal of chemical oxygen demand (COD) in a Microbial Electrolysis Cell (MEC) by periodic disconnection of the MEC power supply.

Uttam Ghosh, Rahul Gautam

Global NEST International Conference on Environmental Science & Technology • 2023

The microbial electrolysis cell is gaining advantage over the other biological hydrogen production techniques as it requires less energy for hydrogen generation as compared to the water electrolysis process. The present study aims to assess the aptness of Agro-Industry Waste (AIW) fed membrane-less single chambered Microbial Electrolysis Cell (SC-MEC) for the biohydrogen production in batch mode under applied voltage of 1 V at 30 ± 2 °C (Fig.1). The performance of the reactor was assessed through volume of hydrogen per gram of COD removed, columbic efficiency, cathodic hydrogen recovery and COD removal efficiency. The highest COD removal of 71% was reported with columbic efficiency of around 45%. These results demonstrated an energy-efficient approach for biohydrogen production from AIW coupled with waste mitigation.

René Alejandro Flores-Estrella, Uriel de Jesús Garza-Rubalcava, Andreas Haarstrick et al.

Processes • 2019

In this work, a mathematical description of a Microbial Electrolysis Cell (MEC) is proposed, taking into account the global mass balances of the different species in the system and considering that all the involved microorganisms are attached to the anodic biological film. Three main biological reactions are introduced, which were obtained from the solution of partial differential equations describing the spatial distribution of potential and substrate in the biofilm. The simulation of the model was carried out using numerical methods, and the results are discussed.

Kenan Dalkilic, Aysenur Ugurlu

Research Square • 2022

Abstract The aim of study was to enhance the biogas production from cattle manure in a combined microbial electrolysis cell and anaerobic digestion system (MEC + AD). The MEC + AD reactor were operated on semi continuous mode under different voltage applications and different organic loading rates ranging from 6 g VS/L.d to 30 g VS/L.d. The study was carried out in two parts. In the first part, MEC + AD and conventional anaerobic reactors were compared in terms of biogas production. In the second part, MEC + AD reactor was operated under different voltage applications (0.3, 0.6, and 1.0 V) and organic loading rates. MEC + AD system exhibited 28–52% better biogas production performances (2.03 L/L/d; CH 4 :75.5% vs 1.43 L/L/d; CH 4 : 70.4%) compared to control reactor in all sets due to voltage application. In the second part, biogas productions of MEC + AD reactor changed between 3.08 L/L/d and 5.13 L/L/d (75–77.8% CH 4 ) depending on the organic loading rates and applied voltages. Higher voltages (0.6 and 1.0 V) showed better methane production performances especially at high OLRs with respect to lower voltages. Consequently, MEC + AD reactor could be operated efficiently at extreme operational conditions (HRT of 2 days and OLR of 30 g VS/L/d) that conventional anaerobic reactors can not be operated.

René Alejandro Flores-Estrella, Victor Alcaraz-Gonzalez, Andreas Haarstrick

Energies • 2022

The aim of this work is to propose a methodology to obtain an effectiveness factor for biofilm in a microbial electrolysis cell (MEC) system and use it to reduce a partial differential equation (PDE) biofilm MEC model to an ordinary differential equation (ODE) MEC model. The biofilm mass balances of the different species are considered. In addition, it is considered that all the involved microorganisms are attached to the anodic biological film. Three effectiveness factors are obtained from partial differential equations describing the spatial distributions of potential and substrate in the biofilm. Then, a model reduction is carried out using the global mass balances of the different species in the system. The reduced model with three uncertain but bounded effectiveness factors is evaluated numerically and analyzed in the sense of stability and parametric sensibility to demonstrate its applicability. The reduced ODE model is compared with a validated model taken from the literature, and the results are in good agreement. The biofilm effectiveness factor in MEC systems can be extended to the reduction of PDE models to obtain ODE models that are commonly used in optimization and control problems.

Bachira Abada, Amina Saidi

Journal of Renewable Energies • 2024

This study focuses on micro-electrochemical screening to select microbial strains capable of directly transfer electrons to the working electrode dependent on specific enzymatic machinery. The main objective of this work is to select and identify promising strains for allow the bioelectrolysis production of hydrogen. To achieve this goal, microbial composites (artificial biofilms), have been developed using Escherichia coli CGE1 from LCPME. CNRS Fransh, Pseudomonas putrifisciens (CIP 69.13) (CIP, Collection Institut Pasteur, Fransh). Shewanella oneidensis MR-1 (ATCC 700550), and Thiobacillus denitrificans, from (ATCC, American Type Culture Collection), each one enclosed in a matrix carbon nanotubes and protamine matrix, forming an artificial biofilm on buckypaper. Cyclic Voltammetry (CV) measurements were performed over a potential range of +0.4 to -0.7V at 5mV/s under 30°C, using a saturated KCl Ag/AgCl reference electrode and a stainless-steel grid counter electrode. For E. coli and P. putrifisciens, the measurement focused on the oxidation of 20mM glucose, while the former bacteria were growth with and without O2. For S. oneidensis and T. denitrificans the focus was on the reduction of fumarate and 20 mM of NaNOH3+, respectively. As results, E. coli and P. putrifisciens species show no notable electrochemical activity, with no signal of glucose oxidation, due to the absence of type C cytochromes in the cytoplasmic membrane, unlike S. oneidensis and T. denitrificans, that demonstrate a direct electron transfer.

Bart De Gusseme, Maarten Soetaert, Tom Hennebel et al.

Microbial Biotechnology • 2012

Summary Diclofenac is one of the most commonly detected pharmaceuticals in wastewater treatment plant (WWTP) effluents and the receiving water bodies. In this study, biogenic Pd nanoparticles (‘bio‐Pd’) were successfully applied in a microbial electrolysis cell (MEC) for the catalytic reduction of diclofenac. Hydrogen gas was produced in the cathodic compartment, and consumed as a hydrogen donor by the bio‐Pd on the graphite electrodes. In this way, complete dechlorination of 1 mg diclofenac l −1 was achieved during batch recirculation experiments, whereas no significant removal was observed in the absence of the biocatalyst. The complete dechlorination of diclofenac was demonstrated by the concomitant production of 2‐anilinophenylacetate (APA). Through the addition of −0.8 V to the circuit, continuous and complete removal of diclofenac was achieved in synthetic medium at a minimal HRT of 2 h. Continuous treatment of hospital WWTP effluent containing 1.28 µg diclofenac l −1 resulted in a lower removal efficiency of 57%, which can probably be attributed to the affinity of other environmental constituents for the bio‐Pd catalyst. Nevertheless, reductive catalysis coupled to sustainable hydrogen production in a MEC offers potential to lower the release of micropollutants from point‐sources such as hospital WWTPs.

Gerasimos Kanellos, Asimina Tremouli, Georgios Arvanitakis et al.

Preprints.org • 2023

This study deals with the computational analysis of the kinetic processes of a microbial electrolysis cell assisted-anaerobic digestion (MEC-AD) treating raw-waste activated sludge (WAS), comparatively with a conventional AD, as well as the effect of the Organic Loading Rate (OLR) on the system’s performance. The aim was to derive a single kinetic and mathematical model for the study of the MEC-AD, using the ADM1 framework, which can be utilized to extract the effect of an applied potential on the kinetics of AD. The experimental data were obtained from the long-term, continuous operation of two identical reactors (an AD and a MEC-AD), which were operated at different OLRs (1.1, 1.7 and 2.9 gCOD/(L*d)). The results showed that the MEC-AD yielded improved biomass yields, substrate consumption kinetics and 1st order disintegration kinetics, with a predominant contribution to disintegration of complex particulates, comparatively with the AD. Moreover, it enabled operation at higher OLRs (achieving the highest divergence from the AD at the OLR of 4.14 gCOD/(L*d)), therefore accelerating sludge treatment, as well as an improved performance at an increased solids retention time (SRT). These findings can serve as a quantitative guide for the effects of the operating parameters on the raw-WAS-fed MEC-AD performance.

Bu Qing, Md Tabish Noori, Booki Min

Research Square • 2024

Abstract Microbial electrolysis cells (MEC) can produce hydrogen (H 2 ) at a low energy expense, but H 2 production rate is often limited by poor microbe-electrode interaction. This study aimed to enhance the interaction of microbes with a cathode electrode modified with an iron-sulfide (FeS) catalyst in MECs to achieve an efficient hydrogen evolution reaction (HER) and to optimize performance at different substrate concentrations, ranging from 1 g/L to 3 g/L of glucose. The electrochemical analysis revealed FeS a highly active catalyst for HER, surpassing the performance of a 10% platinum (Pt-C)-modified cathode. At 2g/L glucose, MECs with a FeS-modified cathode (MEC-FeS) produced hydrogen at the highest yield of 7.01 mol H 2 /mol glucose, and the hydrogen production rate was 1.96 ± 0.09 m 3 /m 3 •d. The control operations of MEC with a pristine cathode and dark fermentation resulted in a reduced hydrogen yield of 5.83 ± 0.25 mol H 2 /mol glucose and 2.12 ± 0.1 mol H 2 /mol glucose, respectively. Moreover, the MEC-FeS achieved a high energy efficiency of 78 ± 5% when compared to the MEC without catalyst (60 ± 5%) and the dark fermentation (24 ± 1%). This study suggests that the utilization of FeS as a cathode catalyst in MECs can ensure high-rate hydrogen generation with optimal substrate concentration, paving the way for efficient upscaling and field application.

Cong Wang, Dongdong Chang, Qi Zhang et al.

Research Square • 2023

Abstract Lignocellulose pretreated by pyrolysis can be transformed into clean energy (such as bioethanol) via microbial fermentation, which is significant for waste recycling, environmental protection, and energy security. However, acids, aldehydes, and phenols present in the bio-oil exert inhibitory effects on microorganisms, which challenges the downstream utilization and conversion of lignocellulosic pyrolysate. In this study, we constructed a microbial electrolysis cell system for bio-oil detoxification and efficient ethanol production (C 2 H 5 O) using evolved Escherichia coli . In the bio-oil media with electricity, E. coli -H exhibited significant levoglucosan consumption and ethanol production abilities compared to the control. Finally, 0.54 g ethanol/g levoglucosan was produced by E. coli -H in the undetoxified bio-oil media with 1.0%(w/v) levoglucosan, reaching 95% of the theoretical yield. This design aimed to solve bioethanol production and utilization challenges, as evident in related studies. This research provides a practical method for bioethanol production from lignocellulosic substrates and a scientific basis and technical demonstration for its industrialized application.

Wei Yang, Yi Peng, Yudong Zhang et al.

ACS Sustainable Chemistry & Engineering • 2019

Microbial fuel cell (MFC) has been attracting extensive interest, because it can be used for electricity generation and concurrently wastewater treatment. Yet, the MFC performance has remained limi...

Ravinder Kumar, L. Singh, A. Zularisam et al.

International Journal of Energy Research • 2018

Microbial fuel cells (MFCs) are emerging as a versatile renewable energy technology. This is particularly because of the multidimensional applications of this eco‐friendly technology. The technology depends on the electroactive bacteria, popularly known as exoelectrogens, to simultaneously produce electric power and treat wastewater. Electrode modifications with nanomaterials such as gold nanoparticles and iron oxide nanoparticles or pretreatment methods such as sonication and autoclave sterilization have shown promising results in enhancing MFC performance for electricity generation and wastewater treatment. The MFC technology has been also investigated for the removal of various heavy metals and toxic elements, and to detect the presence of toxic elements in wastewater. In addition, the MFCs can be modified into microbial electrolysis cells to generate hydrogen energy from various organic matters. This article provides a comprehensive and state‐of‐the‐art review of possible applications of the MFC technology. This also points out the various challenges that limit MFC performance. Finally, this article identifies the strategies to improve MFC performance for different applications. Copyright © 2017 John Wiley & Sons, Ltd.

M. I. Din, M. Iqbal, Zaib Hussain et al.

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects • 2020

A microbial fuel cell is an efficient, cost-effective, and green methodology for electricity production and wastewater treatment. A single chambered microbial fuel cell (SCMFC) was designed to gene...

Loubna Ezziat, A. Elabed, S. Ibnsouda et al.

Frontiers in Energy Research • 2019

Being constituents of the effluents of many industries, heavy metals cause severe environmental pollution due to their recalcitrance and persistence in the environment. Conventional remediation strategies used to treat heavy metals loaded wastewater are neither economical nor environmentally friendly. To overcome these challenges, the rise of a new process that combines energy conservation and recovery was mandatory. Microbial fuel cells have been recognized as an emerging technology to mitigate environmental pollution; it provides a solution to wastewater treatment and the removal and/or recovery of heavy metals. Microbial fuel cells can be defined as bioelectrochemical systems that utilize the catalytic activity of microorganisms organized in biofilms to oxidize organic or inorganic compounds by producing electric current thus providing a new opportunity for sustainable energy production and bioremediation. The removal of metals, such as chromium, vanadium, arsenic, copper, silver and gold has been studied using both single and double chambered MFCs. The fact that some heavy metals have high redox potential makes it possible to utilize them as effective electron acceptors instead of oxygen in the cathodic chamber of microbial fuel cells. Biotic/Abiotic cathode chambers can not only remove but also recover heavy metals. However, a number of challenges such us: low production rates and limited efficiencies make the application of this technology restricted to lab scale only. In this chapter, we review the treatment of metal-containing effluents using microbial fuel cells. We’ll first summarize the principle of metal removal/recovery in microbial fuel cells, and then provide an overview of literature that attempted to treat metal loaded effluents in both single and double chambered microbial fuel cells while discussing power output, heavy metal removal efficiency and mechanisms involved in the process. Furthermore, the primary challenges and opportunities for scaling-up of microbial fuel cells and their future applications in the treatment of heavy metals contaminated wastewater will be outlined.

Sami G. A. Flimban, I. M. Ismail, Taeyoung Kim et al.

Energies • 2019

Microbial fuel cell (MFC) technology offers an alternative means for producing energy from waste products. In this review, several characteristics of MFC technology that make it revolutionary will be highlighted. First, a brief history presents how bioelectrochemical systems have advanced, ultimately describing the development of microbial fuel cells. Second, the focus is shifted to the attributes that enable MFCs to work efficiently. Next, follows the design of various MFC systems in use including their components and how they are assembled, along with an explanation of how they work. Finally, microbial fuel cell designs and types of main configurations used are presented along with the scalability of the technology for proper application. The present review shows importance of design and elements to reduce energy loss for scaling up the MFC system including the type of electrode, shape of the single reactor, electrical connection method, stack direction, and modulation. These aspects precede making economically applicable large-scale MFCs (over 1 m3 scale) a reality.

I. Das, M. Ghangrekar, R. Satyakam et al.

Journal of Hazardous, Toxic, and Radioactive Waste • 2020

Abstract Scaling up of a microbial fuel cell (MFC) is a challenging task and researchers are still struggling to achieve acceptable results when treating real wastewater at the field scale. In this...

W. Tan, Siewhui Chong, Hsu-Wei Fang et al.

Processes • 2021

Microbial fuel cell (MFC) technology has attracted a great amount of attention due to its potential for organic and inorganic waste treatment concomitant with power generation. It is thus seen as a clean energy alternative. Modifications and innovations have been conducted on standalone and hybrid/coupled MFC systems to improve the power output to meet the end goal, namely, commercialization and implementation into existing wastewater treatment plants. As the energy generated is inversely proportional to the size of the reactor, the stacking method has been proven to boost the power output from MFC. In recent years, stacked or scale-up MFCs have also been used as a power source to provide off-grid energy, as well as for in situ assessments. These scale-up studies, however, encountered various challenges, such as cell voltage reversal. This review paper explores recent scale-up studies, identifies trends and challenges, and provides a framework for current and future research.

Jamile Mohammadi Moradian, Zhen Fang, Yang‐Chun Yong

Bioresources and Bioprocessing • 2021

Biomass is one of the most abundant renewable energy resources on the earth, which is also considered as one of the most promising alternatives to traditional fuel energy. In recent years, microbial fuel cell (MFC) which can directly convert the chemical energy from organic compounds into electric energy has been developed. By using MFC, biomass energy could be directly harvested with the form of electricity, the most convenient, wide-spread, and clean energy. Therefore, MFC was considered as another promising way to harness the sustainable energies in biomass and added new dimension to the biomass energy industry. In this review, the pretreatment methods for biomass towards electricity harvesting with MFC, and the microorganisms utilized in biomass-fueled MFC were summarized. Further, strategies for improving the performance of biomass-fueled MFC as well as future perspectives were highlighted.

Hridoy Roy, T. Rahman, Nishat Tasnim et al.

Membranes • 2023

A microbial fuel cell (MFC) is a system that can generate electricity by harnessing microorganisms’ metabolic activity. MFCs can be used in wastewater treatment plants since they can convert the organic matter in wastewater into electricity while also removing pollutants. The microorganisms in the anode electrode oxidize the organic matter, breaking down pollutants and generating electrons that flow through an electrical circuit to the cathode compartment. This process also generates clean water as a byproduct, which can be reused or released back into the environment. MFCs offer a more energy-efficient alternative to traditional wastewater treatment plants, as they can generate electricity from the organic matter in wastewater, offsetting the energy needs of the treatment plants. The energy requirements of conventional wastewater treatment plants can add to the overall cost of the treatment process and contribute to greenhouse gas emissions. MFCs in wastewater treatment plants can increase sustainability in wastewater treatment processes by increasing energy efficiency and reducing operational cost and greenhouse gas emissions. However, the build-up to the commercial-scale still needs a lot of study, as MFC research is still in its early stages. This study thoroughly describes the principles underlying MFCs, including their fundamental structure and types, construction materials and membrane, working mechanism, and significant process elements influencing their effectiveness in the workplace. The application of this technology in sustainable wastewater treatment, as well as the challenges involved in its widespread adoption, are discussed in this study.

M. Azizul Moqsud

Revolutionizing Energy Conversion - Photoelectrochemical Technologies and Their Role in Sustainability • 2024

Living plants can generate electricity with the help of the microbial fuel cell. This is a sustainable way to generate electricity as there is no chance of environmental pollution. In this chapter, plant microbial fuel cells will be discussed thoroughly including their design and mechanism for sustainable power generation through plant microbial fuel cells. This plant microbial fuel cell can provide the necessary bioenergy and the potential food supply at the same time. If we could get green energy and food together, then it would certainly increase the chance of the probable supply of the two important demands of the world, which are shortages of green energy and food for humanity.

Gakai Peter Kingori

Preprints.org • 2025

Microbial fuel cells (MFCs) are promising technologies for generating bioelectricity from organic waste through microbial catalysis. However, the high cost of membranes used in MFCs remains one of the major concerns limiting their widespread application. In this study, a low-cost and readily available bio-membrane fabricated from onion skin was developed and applied as the membrane component in MFCs. By using Shewanella oneidensis MR-1 as the model exoeletrogen, the onion skin membrane equipped MFC delivered even higher bioelectricity output (~133 mW/m2) compared to that equipped with the costly Nafion membrane (~74 mW/m2). This research demostrated that it is possible to use onion membrane as a cost-effective alternative to Nafion membrane for bioelectrochemical systems.

Rizki Deva Maharani

• 2019

Pengembangan fuel cell yaitu sel elektrokimia berbasis mikroba atau Microbial Fuel Cell (MFC) berbahan bakar hidrogen murni. Microbial Fuel Cell (MFC) adalah bioreaktor pengubah energi kimia senyawa organik menjadi energi listrik pada kondisi anaerob dengan reaksi katalitik mikroorganisme untuk dihasilkan tegangan dan arus listrik. Reaktor MFC dibuat dengan bentuk dua chamber yang keduanya dihubungkan dengan jembatan garam. Jembatan garam difungsikan sebagai jalan pada proses transfer elektron. Kompartemen anoda menghasilkan arus listrik yang menjadi penetrasi dalam membran plasma yang kemudian terjadi transfer elektron mikroorganisme dan membawa elektron ke permukaan elektroda. Materi organik yang digunakan adalah air buangan yang mengandung mikroba, karena mikroba sebagai sumber enegi utama untuk mereduksi energi yang nantinya menghasilkan sel bahan bakar. Hal ini menjadi energi alternatif sekaligus penanggulangan air buangan Jenis air buangan yang dapat digunakan sebagai substrat mikroba pada sistem MFC bisa berasal dari limah industri maupun limbah domestik.

Rahsaan Simon

• 2024

As renewable-energy technologies are garnering much attention due to the necessary mitigation of climate change, the requirement for a fuel cell utilizing a clean source of dihydrogen input appears to be of the utmost importance. The following work hypothesizes a hybrid fuel cell utilizing both microbial and technological means for clean in-situ hydrogen production and subsequent energy production at potentially higher rates than standardized microbial fuel cells and with a negative carbon footprint.

Dominic Gervasio, J. Parker Evans, Barry Pryor

Preprints.org • 2020

The construction of optimized biological fuel cells requires a cathode which combines the longevity of a microbial catalyst with the power density of an enzymatic catalyst. Laccase secreting fungi were grown directly on the cathode of a biological fuel cell to facilitate the exchange of inactive enzymes with active enzymes with the goal of extending the lifetime of laccase cathodes. Additionally, a functionally graded coating was developed to increase enzyme loading at the cathode. Directly incorporating the laccase producing fungus at the cathode extends the operational lifetime of laccase cathodes while eliminating the need for frequent replenishment of the electrolyte. Additionally, the hybrid microbial-enzymatic cathode addresses the issue of enzyme inactivation by using the natural ability of fungi to exchange inactive laccases at the cathode with active laccases. Finally, enzyme adsorption was increased through the use of a functionally graded coating containing an optimized ratio of titanium dioxide nanoparticles and single walled carbon nanotubes. The hybrid microbial-enzymatic fuel cell combines the higher power density of enzymatic fuel cells with the longevity of microbial fuel cells and demonstrates the feasibility of a self-regenerating fuel cell in which inactive laccases are continuously exchanged with active laccases.

Li Zhao, Jacob Brouwer, John Naviaux et al.

ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology • 2014

Microbial fuel cells (MFCs) are promising for simultaneous treatment of wastewater and energy production. In this study, a mathematical model for microbial fuel cells with air cathodes was developed and demonstrated by integrating biochemical reactions, Butler–Volmer expressions and mass/charge balances. The model developed is focused on describing and understanding the steady-state polarization curves of the microbial fuel cells with various levels and methods of anode-biofilm growth with air cathodes. This polarization model combines enzyme kinetics and electrochemical kinetics, and is able to describe measured polarization curves for microbial fuel cells with different anode-biofilm growth. The MFC model developed has been verified with the experimental data collected. The simulation results provide insights into the limiting physical, chemical and electrochemical phenomena and their effects on cell performance. For example, the current MFC data demonstrated performance primarily limited by cathode electrochemical kinetics.

Luke T. Wagner, Niloofar Hashemi, Nastaran Hashemi

ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology • 2013

Microbial fuel cells (MFCs) have been a potential green energy source for a long time but one of the problems is that either the technology must be used on a large scale or special equipment have been necessary to keep the fuel cells running such as syringe pumps. Paper-based microbial fuel cells do not need to have a syringe pump to run and can run entirely by themselves when placed in contact with the fluids that are necessary for it to run. Paper-based microbial fuel cells are also more compact than traditional MFCs since the device doesn’t need any external equipment to run. The goal of this paper is to develop a microbial fuel cell that does not require a syringe pump to function. This is done by layering chromatography paper with wax design printed onto it. This restricts the fluids to a specific flow path allowing it to act like the tubes in a typical microbial fuel cell device by delivering the fluids to the chamber. The fluids are picked up by tabs that sit in the fluid and use capillary attraction to flow up the tab and into the device. The fluids are directed to the chambers where the chemical and biological processes take place. These flows are then directed out of the device so that they are taken to a waste container and out of the system. Our microliter scale paper-based microbial fuel cell creates a significant current that is sustained for a period of time and can be repeated. A paper-based microbial fuel cell also has a fast response time. These results mean that it could be possible for a set of paper-based microbial fuel cells to create a power density capable of powering small, low power circuits when used in series or parallel. In this paper, we discuss the fabrication and experimental results of our paper-based microbial fuel cell. Also there will be a discussion of how paper-based microbial fuels cells compare to the traditional microbial fuel cells and how they could be used in the future.

Ransford Kingsley Asiedu, Rejoice Ayeley Ayi, Gilbert Blah Quarshie et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2025

Abstract Hydrogen, a source of renewable energy, unfortunately relies largely on fossil fuel technologies for its production. However, recent studies have shown that microbial technologies could be used to facilitate green hydrogen production. Based on these findings, this work primarily focused on utilizing farm soil, wastewater, anaerobic sludge and cow dung for the production of green hydrogen. A double chambered Microbial Electrolysis Cell (MEC) was coupled with a single chambered Microbial Fuel Cell (MFC) for this work. In this experiment, the fuel cell produced an average potential difference of 118.9 ± 0.001 mV over a period of 312 hours (13 days). The electrolysis cell also produced an average potential difference of 56.8 ± 0.003 mV over the same period of time. The two chambers of the MEC which facilitated the electrolysis process were separated by a locally made Proton Exchange Membrane. Hydrogen gas was produced at an average rate of about 6.9 ± 0.012 mL/day with the highest being 65.5 ± 0.012 mL on day 9. Also, an average current of 0.22 ± 0.006 μA flowed through the entire system and the total amount of hydrogen gas produced at the end of the experiment was approximately 96.8 ± 0.012 mL . Based on this work, it is evident that green hydrogen can be produced by means of coupling microbial electrolysis cells with microbial fuel cells and utilizing farm soil, wastewater, anaerobic sludge and cow dung.

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Fuel • 2023