Microbial Fuel Cell For Generation Research Articles

Enhancing microbial fuel cell performance for distillery wastewater treatment and bioelectricity generation: harnessing niacin as a redox mediator.

The role of redox mediators in improving electron transport from electrochemically active bacteria to the anode is crucial for enhanced bioelectricity output from microbial fuel cells (MFCs), which makes the selection of an ideal mediator very important. This study aims at exploring a new redox mediator niacin (vit B3) for enhanced bioelectricity generation in MFC while treating distillery wastewater through facile modification of anode electrode by niacin doping (MFC-NME) and simple application of niacin to the anolyte (MFC-NAA). Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) of NME confirmed the effective adsorption of niacin onto the carbon felt surface. Notably, MFC-NME exhibited a significantly higher power density (PD) of 6.36 W/m3 compared to MFC-NAA (4.59 W/m3) and control MFC (3.49W/m3). The charge transfer resistance (RCT) in MFC-NME (1.73 Ω) and MFC-NAA (2.06 Ω) were lowered by more than half than that in control MFC (4.33 Ω), which underscores the efficacy of niacin as a redox mediator. SEM analysis revealed improved bacterial attachment over the bioanode in the MFC-NME as compared to that of MFC-NAA and control MFC. Removal of chemical oxygen demand (COD) was higher in MFC-NAA (85%) and MFC-NME (80%) than in control MFC (73%) suggesting that niacin in the anolyte supported greater organic matter removal due to enriched microbial activity. Niacin used in anode modification shows great potential for improved electron transfer and enhanced bioelectricity production and supports greater wastewater treatment performance. The modified bioanode NME exhibits excellent stability.

Effects of potassium-mediated electrical communication inhibition on nitrogen removal in microbial fuel cells

Potassium ion signaling mediates microbial communication in electroactive biofilms within microbial fuel cells (MFCs), but its role in nitrogen removal remains unclear. This study investigated the impact of inhibiting potassium signaling on nitrogen removal in MFCs using tetraethylammonium chloride (TEA) as an inhibitor. Results demonstrated that 5 mM and 10 mM TEA reduced the maximum power generation of MFCs from 77.95 mW/cm2 to 57.18 mW/cm2 and 48.23 mW/cm2, respectively. Correspondingly, total nitrogen (TN) removal efficiency was decreased from 46.57 ± 1.01% to 35.93 ± 0.63% and 38.97 ± 0.74%, respectively. This decline was attributed to inhibited potassium ion signaling, which compromised the electrochemical performance of the MFC and hindered the nitrogen removal process. The relative abundance of exoelectrogen Geobactor decreased from 15.37% to 5.17% and 8.05%, while the relative abundance of cathodic nitrifying bacteria Nitrosomonas decreased from 17.87% to 4.92% and 3.63% under 5 mM and 10 mM TEA. These findings underscore the crucial role of potassium ion signaling in enhancing the bioelectrochemical nitrogen removal process in MFCs.

Organic Waste for Bioelectricity Generation in Microbial Fuel Cells: Effects of Feed Physicochemical Characteristics

Food waste (FW), piggery waste (PW), and activated sludge (AS) were investigated as potential organic feeds for bioelectricity generation in laboratory-scale microbial fuel cells (MFCs). The MFCs fed by FW gained the highest maximum power density at 7.25 W/m3, followed by those fed by PW at 3.86 W/m3 and AS at 1.54 W/m3. The tCOD removal in the FW-, PW-, and AS-MFCs reached 76.9%, 63.9%, and 55.22%, respectively, within a 30-day retention time. Food waste, which resulted in the highest power density and tCOD removal, was selected for a series of following tests to investigate the effects of some physicochemical properties of organic feed on the performance of MFCs. The effect of feed particle size was tested with three controlled size ranges (i.e., 3, 1, and <1 mm) in MFCs. A smaller feed particle size provided a higher power density of 7.25 W/m3 and a tCOD removal of 76.9% compared to the MFCs fed with organic waste with a larger particle size. An increment in feed moisture from 70% to 90% improved the maximum power density from 7.2 to 8.5 W/m3, with a 17.5% enhancement, and improved the tCOD removal from 75.8% to 83.3%, with a 10.0% enhancement. A moderate C/N ratio of approximately 30/1 maximized the power density and COD removal (7.25 W/m3 and 81.73%) in the MFCs compared to C/N ratios of 20/1 (4.0 W/m3 and 64.14%) and 45/1 (4.38 W/m3 and 71.34%).

Three-dimensional biochar aerogel anode derived from expired yogurt for enhancing power efficiency and electron transfer at the bacteria-anode interface in microbial fuel cells

Microbial fuel cells (MFCs) are a promising and sustainable form of fuel cells that utilize electroactive microorganisms to generate electricity. However, the practical application of MFCs is limited by their low power density, inadequate biocompatibility, and suboptimal electrochemical properties. To overcome these challenges, we developed a three-dimensional high performance biochar aerogel anode (YP) made from a mixture of expired yogurt and polyvinyl alcohol (PVA) and investigated its effect on the performance of the MFC. The incorporation of PVA into the YP anodes resulted in improved electrolyte wettability and hydrophilic surfaces, thereby enhancing biocompatibility and bacterial adhesion, especially with Geobacter, reaching up to 89.6% coverage. The biofilm content reached 68.1 mg, which is 1.7 times that of carbon cloth, which improved the electron transfer efficiency at the bacteria-anode interface. Moreover, the mechanical strength of the YP anodes was increased, improving anode stability and durability. In addition, the aerogel anode exhibited impressive power density and current density values of 15.87 W m−3 and 43.76 A m−3, respectively. These values are 3.16 times and 3.60 times higher than the 5.03 W m−3 and 12.13 A m−3 of carbon cloth. This study makes a significant contribution to improving power generation in MFCs, optimizing electron transfer at the bacteria-anode interface, and paving the way for future practical applications of MFCs.

Enhancing bioelectricity generation from wastewater in microbial fuel cells using carbon nanomaterials

AbstractBACKGROUNDMicrobial fuel cells (MFCs) offer a promising approach for treating wastewater and generating electrical energy simultaneously. However, their implementation in wastewater treatment plants is hindered by the limited electricity generation, often attributed to the electrolyte's high resistance. This study aimed to improve bioelectricity generation in MFCs by adding nanomaterials to the electrolyte to enhance conductivity.RESULTSThree types of nanomaterials – carbon nanotubes (CNTs), graphitic carbon nitride (g‐C3N4), and reduced graphene oxide (r‐GO) – were synthesized and addition to the electrolyte at a concentration of 50 mg in 1.5 L. MFC performance was evaluated, employed a hydraulic retention time (HRT) of 140 h, and compared to a control with no nanomaterials added. The addition of nanomaterials significantly improved MFC performance. Compared to the control, the MFCs with CNTs, g‐C3N4, and r‐GO exhibited higher voltage: 1.301 V (CNTs), 1.286 V (g‐C3N4), 1.280 V (r‐GO) versus 0.570 V (control); increased power density: 14.11 mW m−3 (CNTs), 13.78 mW m−3 (g‐C3N4), 13.66 mW m−3 (r‐GO) versus 2.71 mW m−3 (control); enhanced areal power density: 21.06 mW m−2 (CNTs), 20.57 mW m−2 (g‐C3N4), 20.39 mW m−2 (r‐GO) versus 4.04 mW m−2 (control); and improved coulombic efficiency: 19.43% (CNTs), 19.19% (g‐C3N4), 19.11% (r‐GO) versus 8.54% (control).CONCLUSIONIncorporating nanomaterials into the MFC electrolyte significantly increased bioelectricity generation by 5.21 times and coulombic efficiency by 2.28 times compared to the control. This improvement is attributed to the high specific surface area of the nanomaterials, which facilitates the adhesion and growth of microorganisms around the anode, enhancing direct electron transfer. © 2024 Society of Chemical Industry (SCI).

Generation of Bioelectricity in Microbial Fuel Cell using Kitchen Waste Obtained from Dutse Urban, Nigeria

Microbial fuel cells (MFCs) have shown promise as a sustainable technology for wastewater treatment and energy recovery. In this study, cattle dung was used as an inoculum and kitchen waste (KW) from Dutse urban, Nigeria was used as a substrate for bioelectricity generation in MFC. The MFC was operated in a fed-batch mode over 37 days, spanning three cycles. During characterization, the chemical oxygen demand (COD) of the KW was found to be 30421 ± 124 mg/L, indicating a high concentration of organic pollutants. The MFC's performance was evaluated based on the voltage generated, with the first cycle reaching a peak of 254 mV, the second cycle 247 mV, and the third cycle 242 mV. Current and power densities during the three cycles decreased gradually from 66.84 mA/m² and 16.84 mW/m² in the first cycle to 63.68 mA/m² and 15.41 mW/m² in the third cycle respectively. Furthermore, there was a notable reduction in COD from the influent diluted from initial measured COD, from 1120 ± 63 mg/L to an effluent level of 226 ± 49 mg/L, indicating approximately 80% removal rate. The pH of the anolyte progressively dropped with each cycle, reflecting the metabolic activities of bacteria in the anode chamber. The findings underscore MFC's potential for organic waste management and electricity generation, with results outperforming some contemporary studies.

Enhancement of gaseous chlorobenzene biodegradation and power generation in a microbial fuel cell by bifunctional Acinetobacter sp. HY-99C

The efficient biodegradation of volatile chlorinated hydrocarbons using microbial fuel cells (MFCs) offers a feasible approach for purifying waste gas and alleviating energy crises. However, power generation is limited by poor pollutant biodegradation and slow electron transfer. The bifunctional bacterium Acinetobacter sp. HY-99C was screened and used to improve the performance of a conventional MFC. The inoculation of strain HY-99C into the conventional MFC promoted the formation of a compact biofilm with high metabolic activity and an enriched bifunctional genus (Acinetobacter), which resulted in the accelerated decomposition of chlorinated aromatic compounds into biodegradable organic acids. This led to efficient chlorobenzene removal and power generation from the MFC, with a chlorobenzene elimination capacity of 70.8 g m−3 h−1 and power density of 89.6 mW m−2, which are improved over those of previously reported MFCs. This study provides novel insights into enhancing pollutant removal and power generation in MFCs.

Enhancing microbial fuel cell performance with carbon powder electrode modifications for low-power sensors modules

Microbial Fuel Cell (MFC) is a promising technology for harnessing energy from organic compounds. However, the low power generation of MFCs remains a significant challenge that hinders their commercial viability. In this study, we reported three distinct modifications to the stainless-steel mesh (SSM), carbon cloth, and carbon felt electrodes using carbon powder (CP), a mixture of CP and ferrum, and a blend of CP with sodium citrate and ethanol. The MFC equipped with an SSM and CP anode showed a notable power density of 1046.89 mW.m-2. In comparison, the bare SSM anode achieved a maximum power density of 145.8 mW m-2. Remarkably, the 3D-modified SSM with a CP anode (3D-SSM-CP) MFC exhibited a substantial breakthrough, attaining a maximum power density of 1417.07 mW m-2. This achievement signifies a significant advancement over the performance of the unaltered SSM anode, underscoring the effectiveness of our modification approach. Subsequently, the 3D-SSM-CP electrode was integrated into single-chamber MFCs, which were used to power a LoRaWAN IoT device through a power management system. The modification methods improved the MFC performance while involving low-cost and easy fabricating techniques. The results of this study are expected to contribute to improving MFC's performance, bringing them closer to becoming a practical source of renewable energy.

Investigation of microbial fuel cell performance based on the nickel thin film modified electrodes

Microbial fuel cells (MFCs) are a self-sustaining and environmentally friendly system for the simultaneous was tewater treatment and bioelectricity generation. The type and material of the electrode are critical factors that can influence the efficiency of this treatment process. In this study, graphite plates and carbon felt were modified through the electrodeposition of nickel followed by the formation of a biofilm, resulting in conductive bio-anode thin film electrodes with enhanced power generation capacity. The structural and morphological properties of the electrode surfaces were characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy, elemental mapping, and field-emission scanning electron microscopy techniques. Maximum voltage, current density, and power generation were investigated using a dual-chamber MFC equipped with a Nafion 117 membrane and bio-nickel-doped carbon felt (bio-Ni@CF) and bio-nickel-doped graphite plate (bio-Ni@GP) electrodes under constant temperature conditions. The polarization and power curves obtained using different anode electrodes revealed that the maximum voltage, power and current density achieved with the bio-Ni@CF electrode were 468.0 mV, 130.72 mW/m2 and 760.0 mA/m2 respectively. Moreover, the modified electrodes demonstrated appropriate stability and resistance during successful runs. These results suggest that nickel-doped carbon-based electrodes can serve as suitable and stable supported catalysts and conductors for improving efficiency and increasing power generation in MFCs.

Metabolic regulation boosts bioelectricity generation in Zymomonas mobilis microbial fuel cell, surpassing ethanol production

Zymomonas mobilis (Z. mobilis), a bacterium known for its ethanol production capabilities, can also generate electricity by transitioning from ethanol production to electron generation. The purpose of this study is to investigate the ability of Z. mobilis to produce bioelectricity when utilized as a biocatalyst in a single-chamber microbial fuel cell (MFC). Given the bacterium's strong inclination towards ethanol production, a metabolic engineering strategy was devised to identify key reactions responsible for redirecting electrons from ethanol towards electricity generation. To evaluate the electroactivity of cultured Z. mobilis and its ethanol production in the presence of regulators, the reduction of soluble Fe(III) was utilized. Among the regulators tested, CuCl2 demonstrated superior effectiveness. Consequently, the MFC was employed to analyze the electrochemical properties of Z. mobilis using both a minimal and modified medium. By modifying the bacterial medium, the maximum current and power density of the MFC fed with Z. mobilis increased by more than 5.8- and sixfold, respectively, compared to the minimal medium. These findings highlight the significant impact of metabolic redirection in enhancing the performance of MFCs. Furthermore, they establish Z. mobilis as an active electrogenesis microorganism capable of power generation in MFCs.

Untreated vs. Treated Carbon Felt Anodes: Impacts on Power Generation in Microbial Fuel Cells.

This research sought to enhance the efficiency and biocompatibility of anodes in bioelectrochemical systems (BESs) such as microbial fuel cells (MFCs), with an aim toward large-scale, real-world applications. The study focused on the effects of acid-heat treatment and chemical modification of three-dimensional porous pristine carbon felt (CF) on power generation. Different treatments were applied to the pristine CF, including coating with carbon nanofibers (CNFs) dispersed using dodecylbenzene sulfonate (SDBS) surfactant and biopolymer chitosan (CS). These processes were expected to improve the hydrophilicity, reduce the internal resistance, and increase the electrochemically active surface area of CF anodes. A high-resolution scanning electron microscopy (HR-SEM) analysis confirmed successful CNF coating. An electrochemical analysis showed improved conductivity and charge transfer toward [Fe(CN)6]3-/4- redox probe with treated anodes. When used in an air cathode single-chamber MFC system, the untreated CF facilitated quicker electroactive biofilm growth and reached a maximum power output density of 3.4 W m-2, with an open-circuit potential of 550 mV. Despite a reduction in charge transfer resistance (Rct) with the treated CF anodes, the power densities remained unchanged. These results suggest that untreated CF anodes could be most promising for enhancing power output in BESs, offering a cost-effective solution for large-scale MFC applications.

Fabrication and Study of 3D Printed ABS-Carbon Composite Anodes for Single Chamber Microbial Fuel Cells

Microbial Fuel Cells (MFCs) are electrochemical devices that exploit microbes for wastewater treatment with simultaneous power production. Concerning reactor design, electrode materials and operation modes, great achievements have been reported with an emphasis on developing anode materials to improve overall MFC performance. Anode materials (carbon cloth, carbon veil, carbon sponges) and their properties such as biocompatibility, electrical conductivity, surface area and efficient transport of waste play a very important role in power generation in MFCs. Despite their low cost, they present structural-based disadvantages eg. Fragility, and low conductivity issues. Additive manufacturing of Fused Deposition Modelling (FDM) due to its tailoring properties, has employed various polymer-based materials such as Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) for manufacturing applications. In addition, carbon-based composites and hybrid materials eg. electrically conductive PLA and ABS have already been fabricated and are commercially available to exploit good electrical conductivity and structural rigidness. In this research, FDM was used to fabricate custom-sized electrodes made of a laboratory-produced electrically conductive ABS filament. A parametric study of conductivity and biocompatibility properties of these electrodes in correlation to 3D printer parameters was investigated and reported. Furthermore, treatment with a combination of thermal, mechanical, and chemical procedures was performed to improve the crucial parameters of anodes for MFCs.

Simultaneous Degradation of Penoxsulam with Power Generation in Microbial Fuel Cells

Simultaneous Degradation of Penoxsulam with Power Generation in Microbial Fuel Cells

Bioelectricity Generation from Microbial Fuel Cell utilizing Sewage Wastewater and Cow Urine from Dutse Metropolis Jigawa State

Microbial fuel cells (MFCs) are technologies that directly transform chemical energy into electrical energy by oxidizing organic matter using bacteria as biocatalysts. MFCs offer a potential technology for converting wastewater into useful energy source and at the same time serve as wastewater treatment facilities. This makes it superior to other wastewater treatment methods. This study focused on the utilization of MFCs to generate bioelectricity from sewage wastewater using cow urine as inoculum and identify the bacteria colonizing the anode electrode. The experiment were conducted using two-chambered MFC constructed using locally sourced materials. Wastewater was characterized using standard methods. The characteristics of the sewage wastewater are: 680 mg/L Chemical oxygen Demand (COD), 457 mg/L Biochemical oxygen Demand (BOD) and pH of 7.4. The maximum voltage, power and current density obtained were 196 mV, 18.26 mW/m2 and 97 mA/m2 respectively. The MFC shows a reduction in COD value by 82 % (680mg/L initial and 120 mg/L final).The identification of the anodic biofilms showed the presence of Bacillus spp and klebsiella spp based on their microscopic and biochemical characterization. The results of this study can contribute to improve understanding and optimizing electricity generation in MFC, Further study would be conducted in order to identify the microorganisms at molecular level.

Stimulation of electron transfer in electricigens by MnxCoySz heterostructure for the enhanced power generation of microbial fuel cell

Microbial fuel cells (MFCs) are an efficient approach to converting energy existing in waste into electricity. However, MFCs still face problems such as low electron transfer rate and low power density. Herein, the anode properties dominate the performance of MFC. This study manufactured a high-performance MnCo2S4–CoS1.097/carbon black carbon felt (T-MCS-CS/CB-CF) anode through a two-step hydrothermal method. T-MCS-CS/CB catalyst exhibited superior surface roughness and mesoporous structure. Besides, the excellent electrocatalytic activity of the T-MCS-CS/CB catalyst with the heterostructure resulted in the higher power output. After biofilm formation, T-MCS-CS/CB-CF anode exhibited lower Rct (9.29 Ω) than MnCo2S4-Co4S3/ carbon black carbon felt (MCS-CS/CB-CF (15.83 Ω)), carbon black carbon felt (CB-CF (29.52 Ω)) and CF anode (116.1 Ω), exhibiting higher electrochemical activity. T-MCS-CS/CB-CF anode enhanced extracellular electron transfer (EET) and improved the power density, which was 12.29 times higher (1299.27 mW/m2) than the bare CF (105.70 mW/m2). The relative abundance of Geobacter for T-MCS-CS/CB-CF (21.65 %) was 7.24 times higher than the control CF anode (2.99 %). Moreover, T-MCS-CS/CB modification enriched exoelectrogens/sulfate-reducing bacteria, Desulfovibrio, 4.69 % higher than the CF anode, which attributed to the introduction of CoS1.097. The excellent electrocatalytic activity, surface properties and biocompatibility of T-MCS-CS/CB-CF promoted the power output in MFC. This study provided an effective way of anodic electrocatalyst fabrication for enhancing the power generation of MFC.

Synthetic Biology Toolkit for a New Species of Pseudomonas Promissory for Electricity Generation in Microbial Fuel Cells.

Microbial fuel cells (MFCs) offer sustainable solutions for various biotechnological applications and are a crucial area of research in biotechnology. MFCs can effectively treat various refuse, such as wastewater and biodiesel waste by decomposing organic matter and generating electricity. Certain Pseudomonas species possess extracellular electron transfer (EET) pathways, enabling them to transfer electrons from organic compounds to the MFC's anode. Moreover, Pseudomonas species can grow under low-oxygen conditions, which is advantageous considering that the electron transfer process in an MFC typically leads to reduced oxygen levels at the anode. This study focuses on evaluating MFCs inoculated with a new Pseudomonas species grown with 1 g.L-1 glycerol, a common byproduct of biodiesel production. Pseudomonas sp. BJa5 exhibited a maximum power density of 39 mW.m-2. Also, the observed voltammograms and genome analysis indicate the potential production of novel redox mediators by BJa5. Additionally, we investigated the bacterium's potential as a synthetic biology non-model chassis. Through testing various genetic parts, including constitutive promoters, replication origins and cargos using pSEVA vectors as a scaffold, we assessed the bacterium's suitability. Overall, our findings offer valuable insights into utilizing Pseudomonas spp. BJa5 as a novel chassis for MFCs. Synthetic biology approaches can further enhance the performance of this bacterium in MFCs, providing avenues for improvement.

Synergistic effect of TiO2 nanostructured cathode in microbial fuel cell for bioelectricity enhancement

Nano-bedecking of electrode with nanoparticles is an effective method to improve power generation of microbial fuel cells (MFCs). In this study, different concentrations (0.25 mg cm−2, 0.50 mg cm−2, 0.75 mg cm−2 and 1.0 mg cm−2) of TiO2 nanoparticles of size 10–25 nm were overlaid on the carbon cloth (CC) using spray pyrolysis technique and used as catalytic cathode in a dual-chambered microbial fuel cell treating distillery wastewater. Results evidenced that TiO2 nanoparticles modified cathode increased the power generation and recorded a highest power and current density of 162.5 ± 2 mW m−2 and 1.4 ± 0.005 A m−2, respectively. Carbon cloth coated with 0.50 mg cm−2 TiO2 nanoparticles showed 2.8 and 7.3 times higher current and power density as compared to uncoated cathode. MFC operated at a hydraulic retention time (HRT) and organic loading rate (OLR) of 72 h and 59.2 g COD L−1 d−1 showed a maximum chemical oxygen demand (COD) removal of 72.3% which was 15.3% higher than the control MFC. Likewise, the coulombic efficiency of control and modified MFC was 33% and 44%, respectively. The maximum NO3−- N, NO2−- N and NH4+- N removal efficiency of 77.3%, 49.9% and 59.4% were observed for TiO2 nanoparticles modified electrode which was 19.3%, 11.4% and 10.5% higher than control. TiO2 modified cathode was effective in enhancing the bioelectricity generation in MFCs.

Anode Modification with Fe2O3 Affects the Anode Microbiome and Improves Energy Generation in Microbial Fuel Cells Powered by Wastewater.

This study investigated how anode electrode modification with iron affects the microbiome and electricity generation of microbial fuel cells (MFCs) fed with municipal wastewater. Doses of 0.0 (control), 0.05, 0.1, 0.2, and 0.4 g Fe2O3 per the total anode electrode area were tested. Fe2O3 doses from 0.05 to 0.2 g improved electricity generation; with a dose of 0.10 g Fe2O3, the cell power was highest (1.39 mW/m2), and the internal resistance was lowest (184.9 Ω). Although acetate was the main source of organics in the municipal wastewater, propionic and valeric acids predominated in the outflows from all MFCs. In addition, Fe-modification stimulated the growth of the extracellular polymer producers Zoogloea sp. and Acidovorax sp., which favored biofilm formation. Electrogenic Geobacter sp. had the highest percent abundance in the anode of the control MFC, which generated the least electricity. However, with 0.05 and 0.10 g Fe2O3 doses, Pseudomonas sp., Oscillochloris sp., and Rhizobium sp. predominated in the anode microbiomes, and with 0.2 and 0.4 g doses, the electrogens Dechloromonas sp. and Desulfobacter sp. predominated. This is the first study to holistically examine how different amounts of Fe on the anode affect electricity generation, the microbiome, and metabolic products in the outflow of MFCs fed with synthetic municipal wastewater.

Influence of environmental factors on electricity generation performance of electricity‐producing bacteria from oily sludge microbial fuel cells

AbstractElectricity‐generating bacteria are used as the biocatalysts of microbial fuel cells (MFCs). The power‐generating properties of electricity‐generating bacteria play an important role in organic matter degradation and electricity generation of MFCs. However, there are few electricity‐producing bacteria isolated from the anode biofilm of microbial fuel cells containing oily sludge. More importantly, the adaptability of nitrogen‐to‐phosphorus ratio, temperature and pH of the electricity‐generating bacteria were adjusted by controlled variable method. The results of this study showed that the isolated electricity‐producing bacteria (Citrobacter freundii) with a rod‐shaped cell, wrinkled surface, about 0.5–1.0 μm in length. The optimal nitrogen‐to‐phosphorus ratio, temperature and pH of MFCs are 5.67:1, 25°C, and pH = 7.5, Its maximum voltage and power density was up to 143.01 mV and 65 mW·m−3, respectively. Furthermore, the growth rate of the electricity‐producing bacteria is the highest. This lays the foundation for inoculating electricity‐generating bacteria into oily sludge MFCs to improve the oil removal and power generation performance.

Exploring the use of raw honey as a fuel source for microbial fuel cells

Microbial fuel cell (MFC) technologies are making headway in developing and expanding renewable energy through the conversion of organic matter to electricity. Various substrates can be used in the MFCs technology to enable energy generation, either pure substances or complex mixtures of organic materials. This study aims to consider the feasibility of raw honey as a fuel for mediator-less double-chamber MFC. The cell voltage was monitored in mediator-less double-chamber H2O2 cathode microbial fuel cell. The Mfensi clay partition and the raw honey were analyzed using FTIR-ATR. The results show the highest open-circuit voltage of 1414 mV with a maximum current density of 0.6540 A/m2 and a maximum power density of 247.0 W/m2. These results demonstrate that raw honey can be used for power generation in MFCs and for practical applications.