Double-chamber Microbial Fuel Cells Research Articles

Investigating the bacterial consortia properties of electrogenic anodic biofilm in a double-chamber microbial fuel cell: electrochemical, physical, biochemical and molecular characterization

This work evaluated the electrochemical, physical, biochemical, and molecular characterization of electrogens from a graphite felt anode when zinc oxide on activated carbon (ZnO/AC) was used as a cathodic electrocatalyst in a double-chambered microbial fuel cell (DCMFC). The electrochemical polarization behavior of the DCMFC showed that ZnO/AC had a higher power density (PDmax) of 89 mW m−2 with a corresponding cell current density (CD) of 248 mA m−2 and a voltage output of 395 mV, which was higher than those of the blank electrode used as a benchmark (PDmax of 68 mW m−2 at a CD of 161 mA m−2 and a voltage of 421 mV). Furthermore, scanning electron microscopy and transmission electron microscopy revealed that the morphology and interior properties of the strains varied among the rods (bacilli), spirals (vibrios), and spheres (diplococci, staphylococci and streptococci). In addition, biochemical characterization via the Vitek2 compact system and molecular analysis via 16 S rRNA and 18 S rRNA gene sequencing revealed the occurrence of nine prevalent species that were correlated with Sphingobacterium spiritivorum, Ochrobactrum anthropicus, Pseudomonas mendocina, Stenotrophomonas maltophilia, Leuconostoc mesenteroides, Staphylococcus equorum, Bacillus subtilis HQ334981.1, Kocuria kristinae KC581674.1 and Saccharomyces cerevisiae NR111007.1. Consequently, the present study outlines different characterization strategies for electrogenic microbes that play an important role in the overall performance of DCMFC for scaling up and managing existing environmental pollution for sustainable energy generation.

A comparative analysis of organic substrates from industrial wastewater streams for enhanced electricity production using a double chamber microbial fuel cell (DCMFC)

This study investigates the startup sequence of a Double Chamber Microbial Fuel Cell (DCMFC) for the treatment of diverse industrial wastewater streams, including biorefinery, dairy, and mixed sources. It presents a comprehensive startup and calibration procedure for the essential electrical components, utilizing MATLAB-SIMULINK to establish typical resistance calibration curves and correlate measured electrical parameters with expected values. This approach enables a robust experimental startup protocol for the DCMFC under psychrophilic and thermophilic conditions. The study explores the impact of fundamental operating parameters on determining the experimental Hydraulic Retention Time (HRT) of the DCMFC. Specifically, it examines the effects of catholyte type (Phosphate PO43−buffer) and three distinct organic substrates: dairy wastewater, biorefinery wastewater, and mixed substrates (50% v/v dairy).Electricity production is evaluated in terms of voltage yield (mV), Columbic efficiency (CE) (%), and overall growth yield (Y). The study also assesses the COD (Chemical Oxygen Demand) mass balance component's influence on COD removal efficiency to establish a viable operating HRT during the startup phase. Key findings include startup experimental voltage yields of 145.2 mV for biorefinery, 85 mV for mixed wastewater, and an impressive 357 mV for dairy wastewater. Columbic efficiencies of 0.92%, 0.77%, and 0.02% were respectively achieved. Furthermore, the study reveals a viable experimental HRT, ranging from 72 to 96 hours, for both biorefinery/mixed and dairy/mixed wastewater sources, facilitating startup electricity generation and efficient removal of organic contaminants. These findings contribute to the advancement of sustainable wastewater treatment and bioelectricity generation, offering valuable insights for practical applications.

The effect of ammonia concentration on the treatment of bio electrochemical leachate using MFCs technology.

Microbial fuel cells (MFCs) have garnered attention in bio-electrochemical leachate treatment systems. The most common forms of inorganic ammonia nitrogen are ammonium ([Formula: see text]) and free ammonia. Anaerobic digestion can be inhibited in both direct (changes in environmental conditions, such as fluctuations in temperature or pH, can indirectly hinder microbial activity and the efficiency of the digestion process) and indirect (inadequate nutrient levels, or other conditions that indirectly compromise the microbial community's ability to carry out anaerobic digestion effectively) ways by both kinds. The performance of a double-chamber MFC system-composed of an anodic chamber, a cathode chamber with fixed biofilm carriers (carbon felt material), and a Nafion 117 exchange membrane is examined in this work to determine the impact of ammonium nitrogen ([Formula: see text]) inhibition. MFCs may hold up to 100mL of fluid. Therefore, the bacteria involved were analysed using 16S rRNA. At room temperature, with a concentration of 800mg L-1 of ammonium nitrogen and 13,225mg L-1 of chemical oxygen demand (COD), the study produced a considerable power density of 234 mWm-3. It was found that [Formula: see text] concentrations above 800mg L-1 have an inhibitory influence on power output and treatment effectiveness. Multiple routes removed the most nitrogen ([Formula: see text]-N: 87.11 ± 0.7%, NO2 -N: 93.17 ± 0.2% and TN: 75.24 ± 0.3%). Results from sequencing indicate that the anode is home to a rich microbial community, with anammox (6%), denitrifying (6.4%), and electrogenic bacteria (18.2%) making up the bulk of the population. Microbial fuel cells can efficiently and cost-effectively execute anammox, a green nitrogen removal process, in landfill leachate.

BIOELECTRICITY OF COCOA POD WASTE AS A SUBSTRATE IN A DOUBLE CHAMBER MICROBIAL FUEL CELL

Currently, the utilization of cocoa pod has not been maximized, resulting in waste and foul odors that disturb the environment. However, cocoa pod contain a relatively high amount of cellulose compounds that serve as an energy source or nutrition for bacteria to carry out metabolic activities, thus holding the potential to be used as a substrate in microbial fuel cells (MFC). Based on this, the aim of this research is to investigate the bioelectricity generated by a MFC using cocoa pod husk as a substrate, including voltage, current, and power density, in order to determine the potential of cocoa pod husk waste as an electrical energy source. In this study, a double chamber MFC consists of an anode chamber with copper electrodes and a cathode chamber with zinc electrodes, separated by a salt bridge. The bacteria used were Saccharomyces cerevisiae, and the substrate was made from cocoa pod husk waste. Bioelectricity testing involved measuring the voltage, current, and power density produced by the MFC over several minutes. The measurement results for maximum voltage, maximum current generated, and maximum electrical power (at 6 days) from the reactor were as follows: 36.0 mV, 0.19 mA, and 456 mW/m2, respectively.

Self-Driven Electrokinetic Remediation of Cd Contamination Soil by Using Double-Chamber Microbial Fuel Cell

Green and sustainable techniques are in great demand for the remediation of heavy metal-contaminated soil. Cadmium ion (Cd2+) in soil could be extracted under the internal electric field and participating on the surface of the electrode. Here, we proposed a sediment microbial fuel cell (SMFC) for the electrokinetic remediation of cadmium (Cd) contamination soil. Within the 7 weeks of SMFC operation, the removal efficiency for total Cd could be up to 70.04 ± 0.45%, which was significantly higher than that obtained by open circuit SMFC. The maximum output power density was 71.00 ± 0.82 mW m−2 with a current density of 0.60 ± 0.03 A m−2. Results obtained by electrochemical impedance showed that the inter resistance of SMFC was 944 ± 14 Ω. High-throughput sequencing revealed that the Alpha-, Beta- and Gammaproteobacteria increased to 67.85%–80.99% in the SMFC. The relative abundance of Cd2+/Zn2+-exporting ATPase, participating in Cd2+ reduction, in SMFC varied from 25.83% to 30.68%, which were significantly higher than that of control (11.21% to 19.94%). Our findings have presented an effective energy-saving method for the remediation of heavy metal-contaminated soils.

Production potential of cow dung for the generation of electric current using microbial fuel cell

Production potential of cow dung for the generation of electricity was investigated using microbial fuel cell (MFC). Cow dung was collected from FUTA farm and Ilesha Garage farm in Akure. Voltage and current was measured per day for 21 days and the electrode used for the set up are carbon-carbon and carbon-aluminium electrode. Proximate, physico-chemical and mineral composition were determined using standard methods. Isolation and identification of microorganisms present in the cow dung were determined before and after generation of voltage and current using microbiological techniques. The microorganisms isolated were Providencia alcalifaciens, P. rettgeri, P. stuartti, Escherichia coli, E. fergusonii, Morganella morganii, Staphylococcus haemolyticus, S. aureus, Micrococcus luteus, Fusarium solani, Saccharomyces cerevisiae and Mucor mucedo. The highest voltage 0.737±0 mV and electric current 1.265±0 mA were generated from FUTA cow dung. The pH ranged between 7.3 to 9.9 and the temperature ranged between 25 ˚C to 33 ˚C during generation of voltage and current. This study has shown that cow dung is a potential substrate for generation of electric current using fabricated double chamber MFC.

Electrochemical Insight into the Use of Microbial Fuel Cells for Bioelectricity Generation and Wastewater Treatment

Microbial fuel cell (MFC) technology is anticipated to be a practical alternative to the activated sludge technique for treating domestic and industrial effluents. The relevant literature mainly focuses on developing the systems and materials for maximum power output, whereas understanding the fundamental electrochemical characteristics is inadequate. This experimental study uses a double-chamber MFC having graphite electrodes and an anion-exchange membrane to investigate the electrochemical process limitations and the potential of bioelectricity generation and dairy effluent treatment. The results revealed an 81% reduction in the chemical oxygen demand (COD) in 10 days of cell operation, with an initial COD loading of 4520 mg/L. The third day recorded the highest open circuit voltage of 396 mV, and the maximum power density of 36.39 mW/m2 was achieved at a current density of 0.30 A/m2. The electrochemical impedance spectroscopy analysis disclosed that the activation polarization of the aerated cathode was the primary factor causing the cell’s resistance, followed by the ohmic and anodic activation overpotentials.

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.

ISOLATION AND CHARACTERIZATION OF CELLULOSE DEGRADING MICROORGANISMS GENERATING ELECTRICITY USING MICROBIAL FUEL CELL

Global warming and the accumulation of organic waste constitute a serious environmental problem. Therefore, microbial fuel cells (MFC) are an eco-friendly device that have significant capability for the production of electricity using biodegradable waste as fuel. Microorganisms used as catalysts in the anode compartment, execute a principal function in operating MFCs. The present study was conducted to isolate and to screen potential bioelectricity generating microorganisms from dumpsite soil samples and also to construct a domestic dual-chambered microbial fuel cell (MFC). Streptomyces fimicarius was found to be the best isolate for the degradation of cellulose and the production of bioelectricity. The bacterial isolate was identified based on morphological characteristics, biochemical characteristics and molecular identification using 16S rRNA. Double-chambered MFC was constructed by using two polypropylene plastic containers of 1.4 L volume each. The two chambers were joined by using an agar salt bridge and carbon rods were utilized as electrodes. The generation of electricity by the isolate was compared using glucose and cellulose as sole carbon source in a minimal medium. The maximum voltage was found to be 322 mV in the presence of cellulose used as substrate after 5 days of incubation at room temperature and last for 10 days.

Insights into the development of microbial fuel cells for generating biohydrogen, bioelectricity, and treating wastewater

Bio-electrochemical systems, such as microbial fuel cells (MFCs), serve as greener alternatives to conventional fuel energy. Despite the burgeoning review works on MFCs, comprehensive discussions are lacking on MFC designs and applications. This review paper provides insights into MFC applications, substrates used in MFC and the various design, technological, and chemical factors affecting MFC performance. MFCs have demonstrated efficacy in wastewater treatment of at least 50% and up to 98%. MFCs have been reported to produce ∼30 W/m2 electricity and ∼1 m3/d of biohydrogen, depending on the design and feedstock. Electricity generation rates of up to 5.04 mW/m−2–3.6 mW/m−2, 75–513 mW/m−2, and 135.4 mW/m−2 have been found for SCMFCs, double chamber MFCs, and stacked MFCs with the highest being produced by the single/hybrid single-chamber type using microalgae. Hybrid MFCs may emerge as financially promising technologies worth investigating due to their low operational costs, integrating low-cost proton exchange membranes such as PVA-Nafion-borosilicate, and electrodes made of natural materials, carbon, metal, and ceramic. MFCs are mostly used in laboratories due to their low power output and the difficulties in assessing the economic feasibility of the technology. The MFCs can generate incomes of as much as $2,498.77 × 10−2/(W/m2) annually through wastewater treatment and energy generation alone. The field application of MFC technology is also narrow due to its microbiological, electrochemical, and technological limitations, exacerbated by the gap in knowledge between laboratory and commercial-scale applications. Further research into novel and economically feasible electrode and membrane materials, the improvement of electrogenicity of the microbes used, and the potential of hybrid MFCs will provide opportunities to launch MFCs from the laboratory to the commercial-scale as a bid to improve the global energy security in an eco-friendly way.

Recovery of microbial fuel cells with high COD molasses wastewater and analysis of the microbial community

The microbial fuel cell (MFC) is a green technology that can be used to simultaneously degrade organics and generate energy. In this work, a double-chamber microbial fuel cell (DCMFC) was used to treat molasses wastewater with different concentrations, in batch tests. The results demonstrated that when the COD of the influent wastewater was low (3630 mg/L), the MFC system ran stably for 12 h, the maximum power density reached 3.28 W/m3, the internal resistance was 94 Ω, and a total COD removal efficiency of 88.5% was obtained at the end of the cycle. However, as the influent increased to 9060 mg/L, the performance of the MFC significantly declined due to the accumulation of volatile fatty acids (VFAs) and low pH. Interestingly, 10 days later the MFC system began to recover: output voltage increased from 209 to 535 mV, VFA declined from 2428.25 to 0 mg/L, and pH increased from 4.83 to 6.98. The microbial diversity of the biofilm on the anode was also investigated using high-throughput sequencing technology in order to clarify the effect of microbials on the treatment efficiency. The dominant microbial genera, such as Azospirillum, Sulfuricurvum, Syntrophomonas and Curvibacter, are highly related to the electron transfer and VFA degradation. In addition, Geobacter found on the carbon felt was responsible for electricity generation. These results demonstrate that MFCs could be an efficient way to treat molasses wastewater, because of its great self-recovery capability.

Co-substrates' influence on bioelectricity production in an azo dye-based microbial fuel cell

Co-substrates have been known to influence bioelectricity output during dye degradation. This preliminary research is focused on understanding the variations of bioelectricity output when co-substrates glucose and nitrogen sources were added along with Congo red azo dye in a double-chambered microbial fuel cell (MFC). A novel bacterial consortium capable of azo dye degradation was added as the inoculant to the double-chambered MFC. Differences in bioelectricity output were noted when glucose alone, ammonium nitrate and ammonium phosphate alone were added as co-substrates with Congo red dye. MFC with 25 mg L−1 ammonium nitrate peaked 0.032V and 0.003A open circuit (OC) output after 8 h hydraulic retention time (HRT). This was followed by observing effects of glucose alone and glucose combined with nitrogen sources over 8 h. Peak voltage and current of 0.11V and 0.012A, respectively were achieved at 3 h HRT by experimental model with glucose alone as co-substrate.

The system design of the peat-based microbial fuel cell as a new renewable energy source: The potential and limitations

The microbial fuel cell (MFC) is considered as a renewable, non-toxic, reliable, clean, efficient, and also an alternative source for bioenergy. It provides numerous opportunities to improve sustainable applications in various sites, ranging from industrial to home. The low power output of microbial fuel cells is one of the important factors that hinder their commercialization. Power outputs must be improved to contribute to the commercialization of MFCs. In this study, organic peat material was used as a substrate for a double chamber MFC. In addition, since Clostridium bacteria were detected in the organic peat material, an additional bacterial strain was not used. In this MFC application, where graphite is used as both anode and cathode electrodes, 1 mol/L NaOH solution was employed as the cathode chamber solution. This peat-based MFC provided the highest electrical power density of 438.116 mW/m2. The most important limiting factor of the peat-based MFC was the spreading of the NaOH solution throughout the cell due to the rupture of the proton exchange membrane after 9 h of operation.

Recent advance in microbial fuel cell reactor configuration and coupling technologies for removal of antibiotic pollutants

Microbial fuel cell (MFC) technology, as a biological treatment model that can convert antibiotic pollutants into electrical energy, has attracted extensive attention in recent years. Reactor configuration and coupling process play an important role in the treatment of antibiotic wastewater by the MFC, which will affect microbial activity, pollutant removal, and electricity generation. In this review, recent advances of reactor configuration (single chamber, double chamber, and cylinder) and coupling technology (wetland-MFC, sediment-MFC and membrane-MFC, and so on) of the MFC on treating of antibiotics are summarized, and their characteristics in the aspects of pollutant removal and power output are analyzed. Finally, through comparing removal quantity (mg antibiotics per day), the double chamber MFC as the individual treatment unit and the membrane-MFC exhibit better removal quantity.

Waste to energy conversion utilizing nanostructured Algal‐based microbial fuel cells

AbstractIncreasing environmental pollution along with the depletion of energy resources are critical challenges. Microbial fuel cells (MFCs), a simple fuel cell that converts chemical energy into bioelectricity by the catalytic activities of living microbes, are evolving as a multipurpose renewable energy technology. The power generation via the MFCs depends on harvesting free electrons from the electroactive microorganisms, popularly known as exoelectrogens, to simultaneously produce electricity and treat wastewater. In the present work, nanostructured bio‐electrochemical systems are designed to exploit the usability of algae biomass collected from high rate algal pond system (HRAP) either as algal‐living cells or as dry biomass for bioelectricity production via several approaches (i.e., the algae will act as bioanode, biocathode, or nutrient substrate). The obtained results indicated that a higher electric current is produced when microalgae living cells are exploited as bio‐cathode in a double‐chamber‐microbial fuel cell (DCMFC) with a net power density (250 mW/m2) combined with high‐efficiency removal of COD reached 44.8%. Overall, the study's findings suggested that living algal cells from HRAP support high power output from a DMFC when they are exploited as biocathode, hence, the system introduced the opportunity to redesign the high rate algal ponds in the wastewater treatment plants in a way to produce energy plus the main assigned tasks which are the removal of wastes.

The performance of a cyanobacterial biomass-based microbial fuel cell (MFC) inoculated with Shewanella oneidensis MR-1

Cyanobacterial biomass is a rich renewable resource for direct bioelectricity generation in biomass-based microbial fuel cells (MFCs). In this study, the performance of a double chamber MFC with Anabaena vaginicola cyanobacterial biomass as the anodic substrate was investigated. The anode chamber was inoculated with a pure culture of Shewanella oneidensis MR-1, and different MFC experiments using pretreated and untreated cyanobacterial biomass substrate with 5 or 20 mg/L riboflavin were conducted. Pretreatment of the biomass and addition of 20 mg/L riboflavin led to the highest current density (366 mA/m3), maximum power density (144 mW/m3), chemical oxygen demand removal efficiency (65%), and coulombic efficiency (5.7%). Increasing the concentration of riboflavin improved bioelectricity generation (1.4–1.7-fold increase in maximum power density), confirming its effectiveness as a redox mediator, and its role in the extracellular electron transfer process of the S. oneidensis MR-1 biofilm. Moreover, pretreating the biomass also enhanced the conversion efficiency of biomass to bioelectricity. This indicated that pretreatment of the biomass influenced the utilization of biomass by S. oneidensis MR-1 cells. These findings can help increasing the potential of using renewable substrates for more efficient bioenergy generation in pure culture MFCs.

Removal of Cd and Ni with enhanced energy generation using biocathode microbial fuel cell: Insights from molecular characterization of biofilm communities

The present study explores the potential of using biocathode for enhanced energy recovery from wastewater and removal of toxic metals Cd and Ni from aqueous solutions in a double chamber Microbial Fuel Cell (MFC) overcoming the challenge of their less favoured removal owing to low redox potential. Wetland sediment was used as inoculum both in anode and cathode chambers. Power density generated by biocathode MFC from diluted distillery wastewater was 722 mW/m3, which was 10 times that produced by the abiotic MFC. At 10 mgL−1 concentration, 92% Ni and 87% Cd were removed, while at 25 mgL−1 concentration, removal increased by 70% when biocathode was used. Microbial characterization of biofilms, using 16S metagenomic sequencing revealed that diversity of microbial communities developed on the anode and cathode biofilms were quite different though inoculum source was the same. Metal tolerant γ-proteobacteria, exopolysaccharide producing and metal chelating genera like Ochrobactrum and Halomonas were abundant in cathodic biofilm that seem involved in Ni and Cd removal. Anodic biofilm was mostly dominated by the orders Clostridiales and Burkholderiales (class β-proteobacteria), and the fermentor genus Achromobacter was dominant. The novel approach of using biocathode in the MFC, thus significantly improved the removal of Ni and Cd from single as well as mixed metal solutions along with remarkable increase in energy recovery without any use of expensive catalysts, and characterisation of the biofilm at anode and cathode indicated how the microbial communities originating from same inoculum differed in their composition perform different roles of electricity production and metal removal in the MFC.

Sustained energy production from wastewater in microbial fuel cell: effect of inoculum sources, electrode spacing and working volume.

The present study was aimed at producing enhanced and sustained bioelectricity from distillery wastewater in a doublechamber microbial fuel cell (MFC) by changing inter-electrode distance, inoculum and reactor volume. Using double chamber MFC with 1 L working volume, when the distance between the electrodes was kept shorter (1cm), it generated power density of 1.74W/m3, which was 42.5% higher than that of MFC with electrode spacing of 10cm (1W/m3). Using inoculum from different sources viz. garden soil (MFC-GS), wetland sediment (MFC-WS) and sludge from wastewater treatment plant (MFC-S), the highest open circuit voltage (OCV) of 0.84V and power density of 2.74W/m3 were produced by MFC-WS, which also showed sustained electricity production (1.68W/m3) from the wastewater during a 10-day experiment. Relatively lower power density was generated from MFC-S (1.42W/m3), while that from MFC-GS was the lowest (0.94W/m3). Bioelectricity generation and overall performance were then assessed using a smaller reactor size. Smaller working volume of MFC (250ml) favoured greater production of power density (3.2W/m3) than that with 1 L working volume (2.96W/m3) with electrode distance of 1cm. The present study was novel in selecting a suitable mixed-microbial inoculum out of the diverse sources screened and reducing resistance by sharply narrowing down inter-electrode distance and reactor volume, which led to significantly enhanced and sustained electricity generation fromdoublechamber MFC.

Characterization of a biosurfactant producing electroactive Bacillus sp. for enhanced Microbial Fuel Cell dye decolourisation

A biosurfactant producing Gram positive bacterium isolated from anodic biofilm of textile wastewater fed MFC was identified as Bacillus sp. MFC (Accession number: MT322244). Scanning Electron Microscopy of the bacterium showed appendages, the bacterium forms biofilm on Congo red agar medium. The obtained results showed that the addition of 5 mg/l endogenous biosurfactant to the bacterial cells resulted in 19-fold increase in bacterial surface-bound exopolysaccharides (EPS) and 1.94-fold increase in biofilm. However, when the biosurfactant concentration increased to 20 and 40 mg/l, EPS and biofilm decreased and the cells lost their colony forming ability. The dielectric properties of the bacterial cells showed increase in conductivity and relative permittivity with increasing biosurfactant concentrations. The shape of the voltammogram currents peak, their location and Electrochemical impedance spectroscopy (EIS) suggest the involvement of biofilm as direct electron transfer pathway. The average voltage obtained was 0.65 V as compared to 0.45 V for the control MFC. Decolourization was tested for Congo red in a double chamber Microbial Fuel Cell (MFC), the results showed 2-fold increase in decolourization when biosurfactant is added post biofilm formation. The results confirm that Bacillus sp. MFC possess electrogenic properties and that adding low concentrations of endogenous biosurfactant to 24 h biofilm accelerates electron transfer by inducing perforations in the cell wall and increasing EPS as an electron transfer transient medium. Therefore, MFC performance can be enhanced.

Enhanced sludge stabilization coupled with microbial fuel cells (MFCs)

This study presents research results on electricity production from waste activated sludge using MFCs during stabilization process. Different MFC configurations equipped with various electrodes were used. Voltage measurements were continuously done during 35 days of MFC operation. Experimental results showed that bioelectricity generation was linked to volatile solids (VS) and protein reductions as a fraction of extracellular polymeric substances (EPS). Double chamber MFC reactor equipped with graphite electrodes had better power and current densities as 312.98 mW/m2 and 39.07 μA/cm2 while single chamber MFC equipped with titanium electrodes revealed better power and current densities as 97.60 mW/m2 and 17.63 μA/cm2, respectively. Molecular results indicated that power outputs of MFCs effected by diverse microbial communities in anode biofilms. Although organic matter degradation is reported as 35%–55% VS reduction for digesters, this research provided a promising approach for sludge stabilization with enhanced degrading of organic matters up to 75% by using MFCs.