Víctor Salgado‐Dávalos, Sthefany Osorio‐Avilés, Sathish Kumar Kamaraj et al.

CLEAN – Soil, Air, Water • 2021

Abstract An economic and simple sediment microbial fuel cell (SMFC) design is evaluated to improve the recovery of energy from a river sediment, in terms of power density output (maximum power pick) normalized to the cathode surface. The organic matter content in the sediment is boosted by adding abundant, natural, and waste biomass (chitin) near the anode surface. The sluggish kinetics in the two‐electron reduction reaction of O 2 at the C‐cathode is replaced with an efficient four‐electron reduction reaction at the MnO 2 /C cathode. Five SMFCs composed of a common carbon fabric (CF) cathode and different unmodified anode materials, such as reticulate vitreous carbon (RVC: 10, 30, and 60 pore per inch, ppi), CF and commercial stainless‐steel (SS) mesh, are evaluated. The catholyte conductivity improved with Na 2 SO 4 . The results show that the power density output increased a 100‐fold when an MnO 2 /CF‐cathode is used with Na 2 SO 4 catholyte and the anolyte contained chitin. A microbial analysis of the SMFC sediment is performed. The bacterial groups identified, mainly Aminicenantia and Deltaproteobacteria , offer metabolic capacities to participate in the degradation of organic matter in the presence of chitin. Therefore, bacterial groups enriched in the anode biofilm produce electrical energy.

Xin Wang, Yujie Feng, Jia Liu et al.

Journal of Chemical Technology & Biotechnology • 2011

Abstract BACKGROUND: For a microbial fuel cell (MFC), the anode potential is an important electrochemical parameter for the growth, electron distribution and electrical activity of exoelectrogenic bacteria. RESULTS: The performance of a batch‐flow two‐chambered MFC was investigated operated at anode potentials of − 400, − 200, 0, + 200 and + 400 mV versus Ag/AgCl reference electrode. Glucose was used as substrate and ferricyanide as cathodic electron acceptor. At potentials from − 400 to + 200 mV, increasing maximum current outputs were obtained, ranging from 6.0 to 8.6 mA. However, the maximum current output decreased to 6.9 mA when the anode potential was further increased to + 400 mV. More positive potentials resulted in higher Coulombic efficiencies (CEs), with values increased from 64% (−400 mV) to 88% (+400 mV). Electrons deposited as H 2 and CH 4 resulted in lower CEs at more negative potentials (−400, − 200 and 0 mV). When + 400 mV was applied to the anode, the growth yield dropped from 0.25 ± 0.05 to 0.11 mol biomass mol −1 COD (chemical oxygen demand) with inhibition of electrical activity. CONCLUSIONS: The most positive anode potential reduced growth yield and inhibited bacterial growth, but electrical activity increased for potentials ranged from − 400 to + 200 mV. When the potential was increased to + 400 mV, growth yield was limited, affecting MFC performance. Copyright © 2011 Society of Chemical Industry

Sema Aslan, Peter Ó Conghaile, Dónal Leech et al.

Electroanalysis • 2017

Abstract Gluconobacter oxydans ( G. oxydans ) cells together with an osmium redox polymer (ORP) [Osmium (2,2’‐bipyridine)2(poly‐vinylimidazole)10Cl]Cl were combined with a glassy carbon paste electrode (GCPE) to form a bioanode for a microbial fuel cell (MFC) based on G. oxydans . Although there are G.oxydans / ORP combined bioanode in the literature, as far as it is known, this system is the first one where G.oxydans /ORP bioanode is combined with a cathode and a MFC is formed. After the optimization of experimental parameters, analytical characteristics of ORP/ G. oxydans /GCPE bioanode were investigated. ORP/ G. oxydans /GCPE showed two linear ranges for ethanol substrate as 1.0–30 mM (R 2 =0.902) and 30–500 mM (R 2 =0.997) and analytical range as 1.0–1000 mM. Limit of detection (3.0 s/m) and limit of quantification (10 s/m) values were calculated as 1.29 mM and 4.30 mM respectively where the RSD value was 1.16 % for n=5. Combining the developed bioanode in the presence of 5.0 mM K 3 Fe(CN) 6 mediator with a Pt wire cathode a double compartment MFC was obtained via a salt bridge. G. oxydans /GCPE bioanode based MFC had maximum power density of 0.133 μW cm −2 (at 33.5 mV), maximum current density as 8.73 μA cm −2 and OCP value of 156 mV. On the other hand, ORP/ G. oxydans /GCPE based MFC showed maximum power density as 0.26 μW cm −2 (at 46.8 mV), maximum current density as 15.079 μA cm ‐2 and OCP value of 176 mV.

Mohit Kumar, Soumya Pandit, Vinay Patel et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2022

Abstract Utilization of organic wastewater for hydrogen production has dual advantages of clean energy generation and bioremediation which is sustainable for a longer period. To maximize the energy recovery from starch rich wastewater, a two stage system comprising of thermophilic dark fermentation coupled with microbial fuel cell was employed. A single parameter optimization strategy was implemented for the operation of the batch system. The maximum cumulative hydrogen production obtained was 2.56 L L −1 with a 48 % reduction in COD under the optimal conditions of 35 g L −1 initial substrate concentration (COD), temperature 60 o C, and pH 6.5. The H 2 yield and H 2 production rate were 6.8 mol H 2 /kg COD reduced and 731.3 mL L −1 h −1 respectively. The effect of the organic loading rate (OLR) on H 2 production rate was studied in a continuous stirred tank reactor (CSTR). A maximum hydrogen production rate of 913 mL L −1 h −1 was observed at an OLR of 5.6 g L − 1 h −1 . Effluent recycle played an important role in the improvement of H 2 production. A maximum H 2 production rate of 1224 mL L −1 h −1 was observed at a recycle ratio of 0.6. Power density of 4.2 W m −3 was observed with MFC using the dark fermentative spent media neutralized with carbonate buffer at an optimal pH of 7. A total COD reduction of 86% was observed.

Segundo Rojas-Flores, Renny Nazario-Naveda, Santiago M. Benites et al.

Molecules • 2022

The excessive use of fossil sources for the generation of electrical energy and the increase in different organic wastes have caused great damage to the environment; these problems have promoted new ways of generating electricity in an eco-friendly manner using organic waste. In this sense, this research uses single-chamber microbial fuel cells with zinc and copper as electrodes and pineapple waste as fuel (substrate). Current and voltage peaks of 4.95667 ± 0.54775 mA and 0.99 ± 0.03 V were generated on days 16 and 20, respectively, with the substrate operating at an acid pH of 5.21 ± 0.18 and an electrical conductivity of 145.16 ± 9.86 mS/cm at two degrees Brix. Thus, it was also found that the internal resistance of the cells was 865.845 ± 4.726 Ω, and a maximum power density of 513.99 ± 6.54 mW/m2 was generated at a current density of 6.123 A/m2, and the final FTIR spectrum showed a clear decrease in the initial transmittance peaks. Finally, from the biofilm formed on the anodic electrode, it was possible to molecularly identify the yeast Wickerhamomyces anomalus with 99.82% accuracy. In this way, this research provides a method that companies exporting and importing this fruit may use to generate electrical energy from its waste.

Emilio Steven Corrales Navarro*, Melissa May Muñoz Boado

Research Square • 2023

Abstract The rapid consumption of fossil fuels has led to calls to switch from non-renewable to renewable energy sources. Microbial fuel cells are a promising technology that simultaneously treats wastewater and produces power. This study used the Taguchi Experimental method to optimize anode thickness and pH to obtain the maximum power density of an air-cathode microbial fuel cell (ACMFC). The graphene-sponge (G-S) anode thickness and chamber pH were selected as operating parameters, with their corresponding levels. The L 9 orthogonal array was selected for the experimental design. According to Taguchi Method, the optimum G-S anode thickness and chamber pH were obtained at 1.0 cm and 8.0, respectively. A confirmatory run was performed with the optimum conditions, and accordingly, maximum power density was observed at 707.75 mW·m −3 . Analysis of variance (ANOVA) was conducted to identify the percentage contributions of operating parameters in the process and was found to be 30.66% for pH and 69.34% for anode thickness.

Atit Jawre, Priyanshi Chauhan, Anket Patel et al.

Preprints.org • 2019

In these times electricity is big trouble of problem facing by the world. Therefore, there is necessitating for the property basis of energy that is employed for as bio-electricity. Many of the scientists and researchers are trying to find out the sustainable energy generates with the help of plant microbial fuel cell. Plant microbial fuel cell (P-MFCs) could be feasibility technology approach of bio-electricity generation which is mutualism interaction of the plants along with their rhizospheric bacteria. In the present study, Plant-microbial fuel cell was observed in grass e-table evaluated in term of bioelectricity generation from Cynodon dactylon (Dooba Ghas). This e-table was connected with electrode and different condition (physical and chemical) to detect the change in bioelectric potential. It was found that maximum voltage generated among all the conditions was 4.24 ±2V at 15 days by using Cynodon dactylon through P-MFCs. The potential difference generated through P-MFCs was measured using a multimeter. The generation of bioelectricity was observed under different conditions like exposure to light and shade condition measured for voltage was found to be significantly different parameters. The maximum recorded under light and shade conditions were 3.82 ±2 V and 4.25 ±2 V respectively at 15 days of incubation.

Zejie Wang, Taekwon Lee, Bongsu Lim et al.

Biotechnology for Biofuels • 2014

Abstract Background The microbial fuel cell represents a novel technology to simultaneously generate electric power and treat wastewater. Both pure organic matter and real wastewater can be used as fuel to generate electric power and the substrate type can influence the microbial community structure. In the present study, rice straw, an important feedstock source in the world, was used as fuel after pretreatment with diluted acid method for a microbial fuel cell to obtain electric power. Moreover, the microbial community structures of anodic and cathodic biofilm and planktonic culturewere analyzed and compared to reveal the effect of niche on microbial community structure. Results The microbial fuel cell produced a maximum power density of 137.6 ± 15.5 mW/m 2 at a COD concentration of 400 mg/L, which was further increased to 293.33 ± 7.89 mW/m 2 through adjusting the electrolyte conductivity from 5.6 mS/cm to 17 mS/cm. Microbial community analysis showed reduction of the microbial diversities of the anodic biofilm and planktonic culture, whereas diversity of the cathodic biofilm was increased. Planktonic microbial communities were clustered closer to the anodic microbial communities compared to the cathodic biofilm. The differentiation in microbial community structure of the samples was caused by minor portion of the genus. The three samples shared the same predominant phylum of Proteobacteria. The abundance of exoelectrogenic genus was increased with Desulfobulbus as the shared most abundant genus; while the most abundant exoelectrogenic genus of Clostridium in the inoculum was reduced. Sulfate reducing bacteria accounted for large relative abundance in all the samples, whereas the relative abundance varied in different samples. Conclusion The results demonstrated that rice straw hydrolysate can be used as fuel for microbial fuel cells; microbial community structure differentiated depending on niches after microbial fuel cell operation; exoelectrogens were enriched; sulfate from rice straw hydrolysate might be responsible for the large relative abundance of sulfate reducing bacteria.

Zhiguo Gao, Ping Xue, Haibo Wang et al.

Journal of The Electrochemical Society • 2023

Formaldehyde is a common organic pollutant in water with teratogenic and carcinogenic effects. This study reports that 200 mg l −1 formaldehyde in water can be effectively degraded with generating electricity by using microbial fuel cell (MFC) technology. A novel composite anode M-Co 3 O 4 -PEDOT-GF was prepared by modifying Co 3 O 4 nanoparticles (M-Co 3 O 4 ) derived from ZIF-67 and poly (3,4-ethylenedioxythiophene) (PEDOT) on the surface of Graphite felt (GF). The results showed that the MFC loading M-Co 3 O 4 -PEDOT-GF anode exhibited excellent electricity generation performance and formaldehyde degradation. The maximum voltage of the MFC was 549 mV, 46.0% increase than that of GF anode (376 mV), and higher than N-Co 3 O 4 -PEDOT-GF anode (488 mV) modified with commercial Co 3 O 4 (N-Co 3 O 4 ). The maximum power density of the MFC loading composite anode was 4177 mW m −2 , while that of MFC loading bare GF anode was 1562 mW m −2 . The dominant microorganisms were Pseudomonadales and Rhizobiales at the order level. The removal efficiency of formaldehyde by MFC loading M-Co 3 O 4 -PEDOT-GF anode was 89.2% in 152 h. The high efficiency of formaldehyde degradation was still maintained after 10 cycles. The results could be attributed to the composite anode with loose porous three-dimensional structure and good biological compatibility of PEDOT.

Ji Ho Ahn, Ji Hun Jeong, Tong Seop Kim

Volume 3: Coal, Biomass, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems • 2018

The demand for clean energy continues to increase as the human society becomes more aware of environmental challenges such as global warming. Various power systems based on high-temperature fuel cells have been proposed, especially hybrid systems combining a fuel cell with a gas turbine, and research on carbon capture and storage technology to prevent the emission of greenhouse gases is already underway. This study suggests a new method to innovatively enhance the efficiency of a molten carbonate fuel cell/micro gas turbine hybrid system including carbon capture. The key technology adopted to improve the net cycle efficiency is off-gas recirculation. The hybrid system incorporating oxy-combustion capture was devised, and its performance was compared with that of a post-combustion system based on a hybrid system. A molten carbonate fuel cell system based on a commercial unit was modeled. Externally supplied water for reforming was not needed as a result of the presence of the water vapor in the recirculated anode off-gas. The analyses confirmed that the thermal efficiencies of all the systems (MCFC stand-alone, hybrid, hybrid with oxy-combustion capture, hybrid with post-combustion capture) were significantly improved by introducing the off-gas recirculation. In particular, the largest efficiency improvement was observed for the oxy-combustion hybrid system. Its efficiency is over 57% and is even higher than that of the post-combustion hybrid system.

Jarina Joshi, Rocky Maharjan

ECS Meeting Abstracts • 2019

Microbial fuel cells (MFCs) are devices that can use microbial metabolism to degrade greenary waste from a wide range organic substrates. Alternatively, they produce electricity from microbial metabolism. Agricultural waste is a great problem in the low income country like Nepal. There are different techniques which is used for agriculture waste management. However, these techniques are time consuming and costly. Use of an efficiently designed microbial fuel cell is beneficial for proper management of organic waste of different composition. If there is production of value added products like electricity, will be the additional benefit. A significant amount of reduction in chemical oxygen demand (COD) was observed using MFC when 35% diluted solid greenery waste was used. Further, a maximum open circuit voltage of 222.7 mV was observed when MFC was operated with graphite felt electrode in anode. Vast enhancement in open circuit voltage was found when graphite felt electrode was coated with multiwalled carbon nano tubules/ polyaniline (MWCNT/PANI) was used as anode. Keyword: Microbial Fuel cell (MFC); cathode; graphite felt; Chemical Oxygen Demand (COD). References Rabaey, K., & Verstraete, W. (2005). Microbial fuel cells: Novel biotechnology for energy generation. Trends in Biotechnology , 23 (6) : 291–298. Hy Chiu, Ty Pai, MH Liu, CA Chang, FC Lo, TC Chang, HM Lo, CF Chiang, KP Chao, WY Lo, SW Lo and YL Chu (2016). Electricity Production from Municipal Solid Waste using Microbial Fuel Cells. Waste Management and Research. Pp 1-11.

Hui Cai, Juan Wang, Yunfei Bu et al.

Journal of Chemical Technology & Biotechnology • 2012

Abstract BACKGROUND: For a microbial fuel cell (MFC), the anode material plays a crucial role in power output. RESULTS: A dual‐chamber MFC was constructed using carbon cloth (CC) anodes treated by concentrated nitric acid (CC‐A) and heated in a muffle furnace (CC‐H), respectively. The experiment results showed that the stable maximum voltages were 0.42–0.46 V for CC, 0.52–0.58 V for CC‐A and 0.80 V for CC‐H under the condition of a 1000 Ω external resistance, which were much higher than those reported in the literature so far. Moreover, the maximum power density of the CC‐H anode (687 mW m −2 ) was larger than for the CC‐A anode (480 mW m −2 ) and the CC anode (333 mW m −2 ). Electrochemical impedance spectroscopy (EIS) results revealed that the internal resistance was 251 Ω for CC anode, 202 Ω for CC‐A anode and 162 Ω for CC‐H anode. Scanning electron microscopy (SEM) results indicated that the increase of power generation was attributed to the increase of bacteria counts attached to anodes. The power output of the MFC increased along with the increase of the N1s/C1s ratio, which was proved by X‐ray photoelectron spectroscopy (XPS) analysis. CONCLUSIONS: Carbon cloth anodes treated by concentrated nitric acid and high temperature resulted in improved power generation by a microbiol fuel cell. © 2012 Society of Chemical Industry

Girum Ayalneh Tiruye

Sewage - Recent Advances, New Perspectives and Applications • 2022

Microbial fuel cells (MFC) are emerging as a versatile eco-friendly bioelectrochemical system (BES) that utilizes microorganisms as biocatalysts to simultaneously convert chemical energy in the chemical bond of organic and inorganic substrates into bioelectricity and treat wastewater. The performance of MFC depends on the electroactive microorganisms, popularly known as exoelectrogens, the loading rate of organic substrate, pH, MFC configurations, hydraulic retention time, and temperature. In most cases, the performance of MFC can be evaluated by measuring chemical oxygen demand (COD) removal efficiency, Coulombic efficiency and MFC power density output. To date, the most common MFC’s reactor designs are single-chamber MFC, double-chambers MFC, and stacked-MFC configurations. Generally, considerable developments in MFC systems for waste treatment, renewable energy generation and resource recovery have been made in the last two decades, despite critical challenges of capital cost investment, and low efficiency for large scale applications are impeding MFC from commercialization. This mini-review chapter provides a comprehensive assessment of principles and configurations of MFC, treatment of domestic wastewater, energy generation, and resource recovery by MFC and challenges of MFC. I believe the information provided in this chapter will enlighten the current and future prospects of versatile applications of MFC during domestic wastewater treatment.

Tobias Junginger, Lucas Tardio Ascarrunz, Azariel Ruiz Valencia et al.

• 2025

The demand for energy-efficient groundwater remediation technologies has driven interest in Microbial Fuel Cells (MFCs) as a dual solution for contaminant degradation and energy production. Although laboratory-scale MFC studies have explored the interaction between microorganisms and electrode materials, the scalability of these systems for real-world applications in heterogeneous environments remains understudied. This study presents a highly controlled and monitored field-scale MFC design aimed at optimizing power output within a 1 x 1 x 6 m flow-through tank filled with porous medium and contaminated with diesel fuel. The system utilizes stainless steel electrodes with and without activated carbon filling and anaerobic bacteria to convert diesel into electrical energy through bioelectrochemical processes.Experimental parameters—including water conductivity, flow rate, and dissolved oxygen—were held constant, while electrode material, spacing, and external resistance were systematically varied to assess their effects on power enhancement. Stainless steel electrodes emerged as the most efficient, with activated carbon reaching stable power output faster than other materials. The optimized configuration generated a stable power output of 1.1 W, coupled with an estimated degradation of 800 mg of diesel over 173 days. Additionally, microbial analysis indicated that exoelectrogenic bacteria adapted to sustain higher power generation without altering environmental conditions adversely.This work demonstrates that electrode material and spatial arrangement are key to improving MFC power output and therefore remediation efficiencies in field-scale settings. The results advance the potential of MFCs as a sustainable technology for groundwater remediation and renewable energy generation, bridging the gap between lab-scale experimentation and practical environmental applications.

Matthew Ko, Elliot Padgett, Venkata Yarlagadda et al.

Journal of The Electrochemical Society • 2021

Achieving high power performance and durability with low Pt loadings are critical challenges for proton exchange membrane fuel cells. PtCo catalysts developed on new carbon black supports show promise by simultaneously providing good oxygen reduction kinetics and local oxygen transport. We investigate the role of nanoscale morphology in the performance of these catalysts supported on accessible (HSC-e and HSC-f) and conventional (Ketjen Black) porous carbons using 3D electron tomography, nitrogen sorption, and electrochemical performance measurements. We find that the accessible porous carbons have hollow interiors with mesopores that are larger and more numerous than conventional porous carbons. However, mesopore-sized openings (>2 nm width) are too rare to account for significant oxygen transport. Instead we propose the primary oxygen transport pathway into the interior is through 1–2 nm microporous channels permeating the carbon. The increased mesoporosity in the accessible porous carbons results in a shorter diffusion pathlength through constrictive, tortuous micropores in the support shell leading to lower local oxygen transport resistance. In durability testing, the accessible porous carbons show faster rates of electrochemical surface area loss, likely from fewer constrictive pores that would mitigate coarsening, but maintain superior high current density performance at end of test from the improved local oxygen transport.

Shaimaa Nghamish Mizil

Al-Mustansiriyah Journal of Science • 2017

In this study we tried to convert the chemical energy to electrical energy by using microbial fuel cell (MFC) consist of two chambers (anode and cathode) in presence of bacteria (Escherichia coli, pseudomonas aeroginosa ) and yeast (Saccharomyces cervesia) in the anode chamber to generate electrons. The system was started with glucose concentration 5gm/l in different pH value from (5-8). From the results we get the great generation of electricity with S. cervesia at pH 5 and the maximum voltage was 833mv. In case of bacteria that used in our experiment, the suitable pH for generation the electricity was (7).

Ademola Rabiu, Myalelo Nomnqa, Daniel Ikhuomoregbe

ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology • 2012

One of the attractions of high temperature polymer electrolyte membrane (PEM) fuel cell is the quality of the heat co-produced with power that could be recovered for use in a combined heat and power system. In this study, a one-dimensional model for a single PEM fuel cell was developed and implemented in Engineering Equations Solver (EES) environment to express the cell voltage as a function of current density among others. The single cell model was employed to investigate the energetic behaviour of a 1 kWe high temperature PEM fuel cell stack system, and the corresponding power and thermal efficiencies at different operating modes. A multiple parametric analyses using the built-in EES uncertainty propagation tool was used to determine the stack performance for the selected parameter range. The influence of the stack operating temperature, hydrogen utilization, the carbon monoxide content in the anode gas feed and the current density, on the efficiency of the fuel cell stack were studied at the required stack electrical output. The study showed that an increase in temperature increased the stack electrical power output whilst the thermal output decreased. The stack electrical power output was seen to increase with increase in the current density and hydrogen stoichiometry. It can be seen that ratio between the electrical power and thermal output increased as the current density increases. This ratio becomes unity at an operating current density of 0.3 A/cm2, representing the optimal operating current density of the stack. An increase in the hydrogen utilization has positive effects on both the cogeneration and thermal efficiency.

Lingling Gong, Mehran Abbaszadeh Amirdehi, Jayesh Sonawane et al.

ChemRxiv • 2022

Microfluidic microbial fuel cells (MFCs) hold great potential to reproduce core functions of bulk MFCs for study and optimization under precise conditions. Unlike most MFC types, those in a microfluidic format typically do not use a membrane to separate anode and cathode compartments, relying instead on the physics of laminar flow to maintain isolation of independent liquid streams. This lowers cost, device complexity, and should reduce internal resistance. However, to avoid solution crossover, which is likely to occur due to inevitable instabilities during long operational times, authors often separate electrodes by distances of several millimeters or more. This reverses benefits on internal resistance, undermining a prime advantage of microfluidic MFCs. This work demonstrates a facile method for the in-situ synthesis of a microscale membrane, supporting sub-milimeter electrode spacing. The membrane added only 68.5 Ω to the cell internal resistance and its synthesis resulted in no measurable changes to Rct at either electrode. However, the method to grow the membrane after device synthesis greatly reduced complexity in device fabrication. Overall, the reduced electrode spacing that was facilitated by the membrane lowered internal resistance from 25 k to 10 k and provide stable operation even under non-ideal flow conditions. Compared to a state-of-the-art membraneless MFC with 6 mm electrode spacing, the membrane MFC provided approximately 45% higher power density, 290% higher current density and 7 times higher acetate conversation efficiency. Membrane-enhanced flow stability also delivered continuous increases to power density with increased flow rate over baseline levels, rising to 30% higher for flow rate increases of 100 times.

Hegazy Rezk, Enas Taha Sayed, Mohammad Ali Abdelkareem et al.

International Journal of Energy Research • 2022

Summary Microbial fuel cell (MFC) is a promising technology since two important processes: wastewater treatment and electrical energy, can be obtained simultaneously. The performance of the MFC (maximum power density (MPD) and COD removal) depends mainly on substrate concentration, pH time, and initial COD. Therefore, the main target of this work is to simultaneously increase the MPD and COD removal by determining the optimal controlling parameters. The proposed methodology integrates fuzzy modelling and Harris Hawks optimization (HHO). Firstly, based on the experimental data set, an accurate fuzzy model is created to simulate the performance of MFC in terms of four controlling parameters. To prove the superiority of fuzzy model, the results are compared with response surface methodology (RSM) in terms of RMSE and coefficient of determination ( R 2 ). Secondly, using HHO, the optimal values of substrate concentration, co‐culture composition, pH, and time are determined. These four controlling parameters are used as decision variables during the optimization process, whereas the objective function is the simultaneous maximization of the MPD and COD removal. The obtained results proved that the optimal substrate concentration, pH, time, and initial COD values are 58.2%, 7, 14.4 days, and 32 × 10 −3 (mg/L) respectively. Under this condition, the integration between fuzzy and HHO, the overall performance of MFC has been improved by 10.37% and 19.13%, respectively, compared with the experimental and RSM.

Sreelakshmi Chandrasekharan, Kiruthika Sathiasivan, Jeyalakshmi Ramaswamy

Journal of Chemical Technology & Biotechnology • 2024

Abstract BACKGROUND The microbial fuel cell (MFC) is a potential cost‐effective technology for the energy‐neutral treatment of wastewater. However, the successful implementation of this technology in resource recovery is still limited. In this study, a microbial electrochemical cell was designed and operated for 30 days. Critical factors for removal and recovery of nitrogen and phosphorus as struvite from wastewater were assessed. RESULTS Optimization studies on critical factors such as the chemical oxygen demand (COD) of wastewater (500–2000 mg L −1 ) and cathode aeration rate (45–135 mL min −1 ) were conducted using a pure culture of Escherichia coli . The system yielded an average power density of 465 mW m −2 , average current density of 915 mA m −2 and phosphorus recovery at an extent of 40% as struvite. Additionally, a maximum reduction in the COD of 90% with an average coulombic efficiency of about 82% was obtained at a short interval of 30 days. Solubility studies of the recovered struvite for 12 h at different pH values from 4.5 to 9 showed a maximum solubility of 80% at pH 4.5 and a minimum of 3.5% at pH 9. CONCLUSION This study moves one step closer to applying MFC technology for nitrogen‐ and phosphorus‐rich wastewater treatment with concurrent struvite precipitation and electricity production. In this way, Sustainable Development Goals 2, 6 and 7 can be achieved through resource recovery, clean water and bioenergy. © 2024 Society of Chemical Industry (SCI).

Rudzani Sigwadi, Touhami Mokrani, Phumlani Msomi et al.

Preprints.org • 2021

To investigate the effect of acidic nanoparticles on proton conductivity, permeability and fuel cell performance, a commercial Nafion® 117 membrane was impregnated with zirconium phosphates (ZrP) and sulfated zirconium (S-ZrO2) nanoparticles. The tensile test, water uptake, methanol crossover, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermal gravimetric analysis (TGA) and Scanning Electron Microscopy (SEM) were used to assess the ca-pacity of nanocomposite membrane to function in a fuel cell. The modified Nafion® membrane obtained the higher water uptake and a lower water content angle than the commercial Nafion® 117 membrane, indicating that it has a greater impact on conductivity. Under strain rates of 40, 30 and 20 mm/min, the nanocomposite membranes demonstrate more stable thermal deterioration and higher mechanical strength, which offers tremendous promise for fuel cell applications. When compared to 0.113 S/cm and 0.013 S/cm, respectively, of commercial Nafion® 117 and Nafion® ZrP membranes, the modified Nafion® membrane with ammonia sulphate acid had the highest proton conductivity of 7.891 S/cm. When tested using a direct single cell methanol fuel cell, it had the highest power density of 183 m. cm-2 which is better than commercial Nafion® 117 and Nafion® ZrP membranes.

Susanta K. Das

ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology • 2010

In this study, we experimentally evaluated our newly designed high temperature PEM fuel cell (HTPEMFC) prototype performance at different operating conditions. In particular, we investigated the effects of operating temperature, pressure, air stoichiometry and CO poisoning in the anode fuel stream on the current-voltage characteristics of the HTPEMFC prototype. Experimental results obtained from the single HTPEM fuel cell show that the performance is quite steady with high CO-level reformate at high operating temperature which makes it possible to feed the reformate gas directly from the reformer to the stack without further CO removal. In order to develop design parameters for fuel reformer, experimental data of this type would be very useful. The results obtained from this study showed significant variations in current-voltage characteristics of HTPEMFC at different temperatures with different CO poisoning rates. The results are promising to understand the overall system performance development strategy of HTPEMFC in terms of current-voltage characteristics while fed with reformate with different CO ratios in the anode fuel stream.

Milad Kadivarian, Ali A. Dadkhah, Mohsen Nasr Esfahany

Water Science and Technology • 2019

Abstract While microbial fuel cells are being considered as a tool for energy saving in wastewater treatment facilities, such applications in oil refineries pose a challenge due to harder acclimation of microorganisms. In this research, the effect of heat pretreating mixed culture microorganisms (MCM), and cell cross section, on the performance of a novel cell design with two cross sections (single chamber microbial fuel cells, with circular: SCMFC_CC and rectangular: SCMFC_RC cross section) fed batched with refinery wastewater were investigated. First, using original and heat pretreated MCM, the performance of SCMFC_CC in terms of chemical oxygen demand (COD) removal and electricity production was investigated. Then, using only the heat pretreated MCM, the electricity production of SCMFC_RC was measured and compared with that of SCMFC_CC. Heat pretreatment of MCM improved maximum open circuit voltage (OCV) and maximum power density generated by 14% and 16%, respectively. However, heat pretreatment reduced COD removal by about 4%. The performance of SCMFC_CC in terms of maximum OCV and power density compared to SCMFC_RC was improved by 41% and 279%, respectively. Heat treatment of MCM increases the electricity generation of the cell, while reducing the performance of COD reduction due to decreasing the microorganism varieties in the MCM.

S. Zecevic, E. M. Patton, P. Parhami

3rd International Conference on Fuel Cell Science, Engineering and Technology • 2004

This paper describes a Direct Carbon-Air Fuel Cell (DCFC) which uses a molten hydroxide electrolyte. In DCFCs, carbon is electrochemically directly oxidized to generate the power without a reforming process. Despite its compelling cost and performance advantages, the use of molten metal hydroxide electrolytes has been ignored by DCFC researches, primarily due to the potential lack of invariance of the molten hydroxide electrolyte caused by its reaction with carbon dioxide. This paper describes the electrochemistry of DCFC based on molten hydroxide electrolyte and discusses means to overcome the historical carbonate formation. Furthermore, it describes the cell performance during the initial stage of a long term operation and discusses the causes for the initial cell performance degradation. To date, five successive generations of medium temperature DCFC prototypes have been built and tested at SARA Inc. to demonstrate the technology, all using graphite rods as their fuel source. The basic feature of the cell is a simple design in which the cathode is not traditional gas fed electrode type. It is a non-porous electrode structure made of an inexpensive Fe-Ti alloy and gaseous oxygen is introduced into the cell by bubbling humid air through the electrolyte. The cell successfully demonstrated delivering more than 50 A at 0.3 V with the current density exceeding 100 mA/cm2. Main feature of DCFC with hydroxide electrolyte is that the cell performance decreases over time mainly due to oxygen cathode polarization. There are three possible causes for this performance decay: Carbonate formation, electrolyte evaporation due to air bubbling, and corrosion products build up. In order to determine the right cause for the performance decay a series of experiments was carried out investigating various parameters involving cell temperature, water content in the melt, current density, carbonate content in the melt, melt level in the cell, air flow rate and intermittent on-off operation. DCFC was operating at constant current while cell voltage and electrode potentials were recorded over time. Results obtained indicated that the performance of DCFC with hydroxide electrolyte during initial 200 h is governed by the oxygen cathode performance that is mainly affected by corrosion products. The corrosion products catalyze decomposition of peroxide ions which are reacting species at the cathode resulting in an increase of cathode polarization over time. Effect of carbonate ions on the initial cell performance decay is insignificant as compared to the effect of corrosion product. Means to overcome the corrosion products issue were discussed.

Xin Hong Peng, Xi Zhang Chu, Peng Fei Huang et al.

Applied Mechanics and Materials • 2014

Poor energy output and high cost are the key factors to inhibit the development and application of microbial fuel cells (MFCs). Different types of modification techniques for anode material are suggested to improve power performance in MFCs. nanoFe 2 O 3 is characteristics of no toxicity, biocompatibility and low cost. In this work, stainless steel mesh (SSM), ultracapacitor activated carbon with SSM (AcM), Fe 2 O 3 added AcM (AMF) anodes are investigated to improve MFCs performance. The highest maximum power density (806 ± 26 mW·m - 2 ) is obtained in AMF anode, which is 11 % higher than that of AcM (730 ± 27 mW·m - 2 ), and 57 folds higher than that of SSM anode (12 ± 0.7 mW·m - 2 ). The semi-conducting properties of passive film on the anode surface play a rather important role in anodic reaction by Mott-Schottky analysis. Tafel test demonstrates that the exchange current density (8.36×10 - 4 A·m - 2 ) is improved by 20 % for AMF compared with AcM control (6.93×10 - 4 A·m - 2 ). These results show AcM is suitable as MFCs anode, and further addition of Fe 2 O 3 can increase the extracellular electron transfer in that way increase power production in MFCs.

Adriana Solares Basurto, Mateo Pérez Ruiz, María Angélica Luján Vega et al.

Eng • 2024

This research emphasizes the effect of using Eisenia foetida in vermicompost for power generation in microbial fuel cells (MFCs). By accelerating the organic decomposition, the bioenergy generation is improved. A vermicompost-microbial fuel cell employing electrogenic microorganisms was used to convert chemical energy into electrical energy. In this work, substrates of black soil, tree bark, leaves, eggshells, and ground tomatoes were used. The vermicompost MFC has a copper cathode and a stainless steel anode. In this study, the performance of MFCs was evaluated using different numbers of Eisenia foetida specimens, with three specimens (MFCW3), five specimens (MFCW5), and seven specimens (MFCW7). Our key findings show that by increasing the number of Eisenia foetida specimens does not bring higher power densities; as a result, the best power density was observed in MFCW3 and MFCW5 at the end of the fourth week, both presenting a total of five Eisenia foetida specimens with a power density of 192 mW m−2. Therefore, optimal results were found when 330 g of substrate and five Eisenia foetida specimens were used to achieve a maximum current density of 900 mW m−2 and a maximum power density of 192 mW m−2. This type of microbial fuel cell can be considered as an alternative for power generation with a significantly reduced environmental impact, considering the use of organic waste. It can be considered a game-changer in waste management and bioenergy projects.

Naveen Jain

Advances in Nonlinear Variational Inequalities • 2024

The quest for enhanced fuel cell efficiency is pivotal in advancing sustainable energy solutions. This paper investigates novel catalyst formulations aimed at improving the performance and longevity of fuel cells. Traditional catalysts, primarily based on precious metals such as platinum, present challenges related to cost and resource availability. In response, this study explores non-precious metal catalysts (NPMCs), composite materials, and nanostructured catalysts, which have shown promising results in recent research. Through rigorous experimental methods, including synthesis and characterization techniques, we evaluate the catalytic activity and efficiency of these novel formulations. The findings demonstrate significant improvements in power output and operational durability compared to conventional catalysts. Mechanistic insights into the reaction dynamics reveal how these new materials enhance performance metrics such as current density and voltage output. An economic analysis highlights the potential for scalability and cost-effectiveness of these innovative catalysts in commercial applications. This research underscores the critical role of catalyst design in optimizing fuel cell technology and sets the stage for future explorations aimed at overcoming existing limitations in the field. By leveraging advanced materials and formulations, we aim to contribute to the development of next-generation fuel cells with enhanced efficiency and practicality.

Kumar Sonu, Monika Sogani, Zainab Syed

ChemistrySelect • 2021

Abstract The present study aims at integrating Constructed Wetland using biochar as matrix with Microbial Fuel Cell (CW‐MFC) and evaluating its effect on textile wastewater (TW) treatment in the form of removal of COD, Color and TDS along with Bioelectricity generation. Two vertical down flow systems of CW‐MFC were investigated for TW treatment and system reusability (with and without corn cob biochar) in batch mode with retention time of 10 days for 10 cycles. The performance of CW‐MFC with the corn cob biochar (CW‐MFC−A) was better than the CW‐MFC without corn cob biochar (CW‐MFC−B) in terms of parameters of TW treatment, bioelectricity generation and matrix reusability. The maximum power density, COD removal efficiency, decolorization efficiency and TDS reduction as obtained with CW‐MFC−A (102.08 mW/m 2 ; 83 %; 90 %; 84 % respectively) were higher in comparison to the values obtained in CW‐MFC−B (78.24 mW/m 2 ; 66 %; 65 %; 67 % respectively). Furthermore, the germination assessment studies using the treated effluent from CW‐MFC−A resulted in 100 % germination of Vigna radiata seeds indicating the usefulness of corn cob biochar as wetland matrix for treatment of wastewaters.

Wolfgang Winkler, Mark Williams

ASME 2008 6th International Conference on Fuel Cell Science, Engineering and Technology • 2007

This study gives information of new opportunity fuels having increasing importance is all future energy scenarios. It compares the basic thermodynamic performance of fuel cells with various fuels — ammonia, methanol, hydrogen, carbon monoxide and carbon(s). For both oxygen ion conducting and proton conducting fuel cell, where applicable, its performance as a function of utilization is considered. The fuel cell itself will be considered as a reversible electrochemical reactor, generating power and mixing substances, but without further restrictions on its design. The thermodynamic state and the excess air are further parameters of variation. The consequences of the use of air and oxygen are considered as well. The principal reversible combustion of the fuel is the base of the operation of any fuel cell. The utilisation of the fuel changes the gas concentrations on the anode and cathode side depending on the ionic transport mechanism. The reversible SOFC model was used to describe the influence of the fuel utilisation, the thermodynamic state, and the operational parameters for the fuel H2 on the local Nernst voltage in previous publications. This work has been expanded to proton conducting cells and different opportunity and hydrocarbon fuels. Ammonia is quite different and at lower utilizations appears to be a superior fuel. Methanol is superior to methane over a wide utilization range. Hydrocarbons like methane have a smaller voltage decrease during utilization than hydrogen and carbon monoxide. Excess air larger than two has a small impact on voltage loss. Direct utilization of hydrocarbon fuels without reforming is a key development path toward higher efficiency.

Marcelinus Christwardana, Linda Aliffia Yoshi

International Journal of Renewable Energy Development • 2020

The Microbial fuel cells (MFCs) are electrochemical devices that can be utilized as biosensors, specifically Dissolved Oxygen (DO) biosensors. In this research, performance and techno-economic of MFC-based DO biosensors with two sizes, small and large, were evaluated and analysed to determine whether it is more economical to use a small or large reactor. MFC-based DO biosensors were also applied to an irrigation canal. When MFC immersed into distilled water with several variations of DO, the correlation between DO and current density produced equation with R2 values around 0.9989 and 0.9979 for SYMFC and LYMFC, respectively. The power density for SYMFC and LYMFC was 3.48 and 10.89 mW/m2, respectively, in DO 6. Higher power densities are correlated with the electrode surface area, especially the larger cathodic surface area. When applied to the irrigation canal, DO values measured using SYMFC and LYMFC have errors of around 3.39 and 4.42%, respectively, when compared to DO values measured using DO meters. LYMFC requires a capital cost of around $ 234.22 or 2.57 times higher than SYMFC, although it generates almost similar cost per mW/m2, $ 21.51 and $ 26.23 for LYMFC and SYMFC, respectively. The results concluded that yeast MFC -based DO biosensors with smaller sizes can achieve more economical compared to larger sizes.

Dani Permana, Herlian Eriska Putra, Oman Rohman et al.

Indonesian Journal of Biotechnology • 2024

A suitable wastewater treatment system is required due to the high organic compound content in tofu wastewater, which can harm the environment. Biological treatment methods are effective for treating tofu wastewater due to its characteristics. Microbial fuel cells (MFCs) represent one such biological treatment option, effectively removing organic contaminants while generating low‐power electricity through bioenergetic reactions. In MFCs, microorganisms are used as biocatalysts to degrade the organic compounds present in wastewater. This study aimed to assess the efficacy of Salt‐bridge microbial fuel cells (SB‐MFC) using various acclimatized microbe cultures for reducing organic compounds and generating energy from tofu wastewater. Tofu wastewater was sterilized prior to introduction into the reactor. Additional microbes, including the native microbe consortium from tofu wastewater, Escherichia coli, Saccharomycopsis fibuligera, and a mixed culture of E. coli and S. fibuligera, were then introduced as biocatalysts. Carbon electrodes were utilized as both the anode and cathode. The results indicate that the mixed culture of E. coli and S. fibuligera significantly reduced COD and BOD5 levels, with removal rates of 82.74% and 76.53%, respectively, after 48 h. Furthermore, the culture generated a voltage of 676 mV, a current of 2.53 mA, a power density of 428 mWatt/m2, and 4.789×10‐2 kWh of energy. This study contributes to the advancement of SB‐MFC by utilizing wastewater and a combination of bacteria and yeast as biocatalysts.

Peng Cheng, Rui Shan, Hao-Ran Yuan et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2018

Abstract Electron transfer from microorganisms to the electrode is the key process in microbial fuel cells (MFCs). In this study, a trehalose lipid was added to a Rhodococcus pyridinivorans-inoculated MFC to improve the power output by enhancing electron transfer. Upon trehalose lipid addition, the current density and maximum power density were increased by 1.83 times and 5.93 times, respectively. Cyclic voltammetry analysis revealed that the addition of trehalose lipid increased the electron transfer performance, while electrochemical impedance spectroscopy results proved a decrease in internal resistance. Microscopy images showed that the trehalose lipid-treated bacteria interacted more closely with various fagellum-like contacts, while in the pure trehalose lipid (200 mg/L), pores were obviously observed in the cell surface. Importance Improving the power output of microbial fuel cells by the addition of bio-surfactants have been proved to be a novel method. However, only rhamnolipid and sophorolipid are certified to be effective. Trehalose lipid is a common material in cosmetic and bio-medicine industry. Our research broaden the application of bio-surfactant in MFC and preliminarily explain the mechanism. Highlights Trehalose lipid enhanced MFC power generation Trehalose lipid decrease MFC internal resistance Pores were observed with the addition of trehalose lipid Addition of bio-surfactant is a promising way to increase MFC performance

Maha A. Allawi Abdulwahhab, Sarmad talib Najim

Research Square • 2023

Abstract This study compared the performance of microbial fuel cells (MFCs) using parchment paper as a separator to a CMI7000 proton exchange membrane. The MFCs were operated in two chambers with whey solution as the substrate. Parameters such as COD removal, internal resistance, power density, current density, and Columbic efficiency ratio (CE) were evaluated. The CMI7000 membrane exhibited the highest COD removal at 92%, while the parchment paper achieved removal percentages ranging from 72–91%. The internal resistance was lower for the parchment paper separator for the first run, the internal resistances were 68 and 84 for parchment paper and CMI7000, respectively. The maximum energy densities were 219 mW/m (5.74 mA/m) and 421 mW/m (8.24 mA/m) for parchment paper and CMI7000 membrane, respectively. The CE values for parchment paper were 36.32 and 33.5, while for the CMI7000 membrane, they were 42.73 and 32.0, for the two runs. Overall, the study demonstrated that the parchment paper separator performed reasonably well in terms of COD removal, internal resistance, energy density, and Columbic efficiency ratio compared to the CMI7000 membrane in microbial fuel cells.

Akanksha Mishra, Meenu Chhabra

Research Square • 2023

Abstract This present study investigated the effect of co-culturing the photobiont and mycobiont in the microbial fuel cell (MFC) cathode for lipid generation. Chlorella vulgaris provides oxygen and nutrients for the yeast Cystobasidium oligophagum JRC1 while latter provides CO 2 and quench oxygen for higher algae growth. Co-culture enhanced the lipid output of biomass by 28.33%. The total lipid yield and productivity with co-culture were 1.47 ± 0.18 g/L and 0.123 g/L/day respectively. The MFC attained open circuit voltage of 685 ± 11 mV. Synthetic wastewater was used at the anode with sodium acetate as a substrate. The power density of the system was 5.37 ± 0.21 mW m -2 with 75.88 ± 1.89% of COD removal. The total energy output (Lipid + Electrical energy) from the co-culture MFC was 11.5 ± 0.035 kWh m -3 which was 1.4-fold higher than algae alone.

Alok Tiwari, Niraj Yadav, Dipak A. Jadhav et al.

Environmental Engineering Research • 2024

The membrane employed in microbial fuel cells (MFC) stands as a pivotal component, comprising more than half of the overall construction cost of the assembled MFC. This study introduces a novel earthen membrane, crafted by inclusion of wood ash in different weight ratios, providing a low-cost substitute to the conventional Nafion 117 membrane. Among the fabricated membranes, X3, engineered with red soil and 20% wood ash exhibits superior performance. The inclusion of wood ash enhances proton transport and mitigates oxygen diffusion into the anode, while also augmenting the ion exchange capacity of the fabricated membrane. The MFC equipped with the X3 membrane (MX3) demonstrates the highest COD removal (93.89±0.73%) and coulombic efficiency (66.10±2.53%). Notably, MX3 achieves a remarkable power density (Pmax: 1450.09±151.3 mW/m3), surpassing all other microbial fuel cells and marking a 9.8-fold increase in comparison to the control MFC. This study underscores the potential of the X3 membrane as a novel and economically viable alternate to Nafion 117 membrane.

N. Samsudeen, Shivanand Chavan, T. K. Radhakrishnan et al.

Journal of Renewable and Sustainable Energy • 2016

The effect of chemically synthesized activated carbon (AC) on the performance of microbial fuel cell (MFC) was investigated in this study. Coconut fiber was used as a source material for synthesizing the AC. The AC with different ranges (5, 10, and 15 mg/cm2) was coated on the anode electrode surface to investigate and compare the performance of MFC with the control electrode (plain surface). The experimental results showed that the AC-5 (5 mg/cm2) coated electrode produced a peak power density (5.8 W/m3) which was higher than the control (plain) electrode (3.8 W/m3). The MFC performance in terms of power density and chemical oxygen demand (COD) removal efficiency was increased with increasing loading quantity of AC. When an AC-15 (15 mg/cm2) coated was electrode used in the MFC, the highest power density of 9.5 W/m3 with a COD removal efficiency of 74.8% was observed. Cyclic voltammetry analysis visualized the clear enhancement in electrochemical activity with an AC coated electrode. The effect of wastewater COD concentration on the performance was also investigated. The AC derived from coconut fibers can be considered as a biocompatible material to enhance MFC performance.

Deepak Lohani, Anupam Gautam

International Journal For Multidisciplinary Research • 2025

Wastewater treatment has traditionally been an energy intensive process, consuming between 950 and 2850 kJ/m3 of wastewater treated. By one account, wastewater contains 9.3 times more energy than is used to treat an equivalent volume, thus creating the desire to harness this energy through the use of a Microbial Fuel Cell (MFC). MFCs oxidize organic substrates, allowing simultaneous wastewater treatment and electricity generation. Previous research has primarily focused on the development of MFCs for electricity generation, mainly at the small, laboratory scale. Herein, an industrial-scale MFC process is proposed for the treatment of wastewater from a microbrewery based on a previously published model describing MFC operation. Through optimization and scale-out, a two chamber MFC process is developed for the treatment of wastewater with an inlet Chemical Oxygen Demand (COD).

Dena Z Khater, Rabab S Amin, Monera O Zhran et al.

Research Square • 2021

Abstract Mixed transition metal (Ni & Cu) oxides supported on graphene (NiO-CuO/G) electrocatalyst was fabricated and tested as an efficient and cost-effective cathode for oxygen reduction reaction (ORR) in microbial fuel cells (MFCs). The electrocatalytic activity and selectivity of the NiO-CuO/G for ORR were examined using linear sweep voltammetry measurements (LSV) on a rotating disc electrode (RDE) in pH-neutral electrolyte. In comparison with a benchmark platinum cathode, the NiO-CuO/G showed high selectivity towards the ORR. The analysis of Koutecky-Levich relationship suggests that the electrocatalyst follows the four-electron ORR pathway. NiO-CuO/G cathode in an air-cathode MFC exhibited a slightly lower power density 21.25 mWm − 2 compared to 50.4 mW m − 2 for Pt/C. Both scanning and transmission electron microscope analyses of anodic biofilm showed that a thick biofilm was successfully developed with a rod-like shape. Biochemical characterization of the communities showed that four genera named Escherichia coli ( E-coli ), Shewanella putrefaciens , Bacillus cereus and Bacillus Thuringiensis/mycoides , which belonging to GammaProteobacteria and Firmicutesphyla thatwerethe most abundant bacteria in the anodic biofilm. Our results revealed that NiO-CuO/G cathode demonstrates an enhanced electrocatalytic activity toward ORR in a pH-neutral solution; thus, the newly developed mixed transition metal oxides electrocatalyst can replace other expensive Pt-based catalysts for MFC application.

Sudhir V Ambekar, Makarand M Ghangrekar

Journal of Environmental Engineering and Science • 2022

Microbial fuel cells (MFCs) have proven to be an effective technology for treatment of waste water with the additional advantage of electricity generation. Although the power density obtained has increased manyfold over the past decade, the cost of treatment and cost of electricity generation need to be brought down to make the process feasible. In the present research, an attempt was made to use locally available, low-cost and effective materials for the construction of an MFC using novel anode architecture. The MFC was made using multiple membranes in a single cell. The special design of the anode proved to be very effective in obtaining a higher power density. A volumetric power density of 2002 mW/m 3 could be achieved without the use of any chemical catholyte. The corresponding coulombic efficiency obtained was 13.17%. When a chemical catholyte was used, the power density increased to 5201 mW/m 3 , an increase by more than 2.5 times. The corresponding coulombic efficiency of the MFC also increased to 29.16%. Such novel anode architecture could take this technology a step forward for practical implementation to harvest carbon dioxide neutral electricity from waste water. The performance of the MFC in the removal of chemical oxygen demand (COD) from waste water was found to be 93.9–97.75%, which is highly satisfactory. The removal efficiency was found to be independent of the initial COD of the substrate.

Jiaqi Lv, Weiye Wang, Qingliang Zhao et al.

Environmental Engineering Research • 2022

Microbial fuel cell powered electro-Fenton system (MFCⓅEFs) is a self-sustainable energy conversion process to degrade refractory pollutants utilizing green biomass energy. Most previous works usually employed innovative cathode to minimize electron transfer losses but neglected the development of high-efficiency anode to enhance electron generation. The synergy of polyaniline (PANI) and MnO<sub>2</sub> on electrode could improve charge accessibility and facilitate rapid electron transfer due to its superior conductivity and capacitance, which had not been applied to MFCⓅEFs as anode so far. In this study, a PANI-Mn/CF (carbon fiber loaded with polyaniline and MnO<sub>2</sub>) composite anode was introduced into MFCⓅEFs to enhance interface activity and realize more efficient electricity generation and pollutant degradation. Experimental results showed that a higher power density (5.49 times that of the original CF) and lower ohmic resistance (7.17 Ω) occurred in the MFCⓅEFs with PANI-Mn/CF anode, which consumed more sewage sludge (37.14% of TCOD removal), leading to achieving more effective pollutant degradation (93.03% of tetracycline hydrochloride removal). Overall, this study provided an innovative way of thinking and approach to efficient utilization of biomass waste and degradation of refractory pollutants with the merits of environmental sustainability.