Payel Choudhury, Ria Majumdar, Tarun Kanti Bandyopadhyaya

Journal of Electrochemical Science and Engineering • 2021

To investigate the performance of microbial fuel cell (MFC) with a single-chamber membrane, Pseudomonas aeruginosa is used as a bio catalyst for various synthetic wastewaters rich in carbohydrate and is compared with real dairy wastewater in this experiment. Therefore, the choice of appropriate carbon, nitrogen, NaCl, inoculum content, temperature, and pH process parameters are used for preparing synthetic wastewater was agreed upon by one-variable-at-a time approach. Maximum levels of voltage generation attained from the synthetic wastewater was 485 mV when supple­mented with 1.5 % of lactose as a source of carbon, 0.3 % of ammonium chloride as a decent nitrogen source, 0.03 % of NaCl, inoculum concentration of 3 %, the temperature at 37 oC and pH 7. On the other hand, the maximum voltage attained with real dairy wastewater was 561 mV with high chemical oxygen demand (COD) value of 801 mg l-1. The maximum power density obtained from dairy wastewater was 73.54 mW m-2. Thus, High voltage achieved for MFC operating with real dairy wastewater suggests that it can be used not only for the industrial application to generate more renewable power, but also for the wastewater treatment carried out at the same time.

Aritro Banerjee, Rajnish Kaur Calay, Subhashis Das

Water • 2023

Microbial fuel cells (MFC) are emerging technologies that can produce electricity while treating wastewater. A series of tests were carried out to evaluate the efficiency of this technology for treating dairy wastewater (DWW). The experiments used Shewanella baltica as an exoelectrogen in a small single MFC to treat simulated DWW. The impacts of various operational factors, specifically pH, hydraulic retention time (HRT), and chemical oxygen demand (COD) in the influent to the anode chamber, were investigated, and the effect of these variables on the output performance of the cell was evaluated. The best performance of the MFC was found when the pH, HRT, and COD were 8, 6.66 h, and 20,632 mg/L, respectively, in the scaled experimental setup. Under these conditions, the maximum power density and percentage removal of COD in terms of wastewater treatment ability were found to be 138 mW/m2 and 71%, respectively. It may be concluded that MFCs are suitable treatment technologies for treating dairy wastewater while potentially simultaneously generating power.

Syarif Hidayat, Dini Widyani Aghnia, Edwan Kardena et al.

Jurnal Presipitasi : Media Komunikasi dan Pengembangan Teknik Lingkungan • 2020

wastewater into direct electrical energy. In this study, the applied external resistance in the MFC reactor was optimized to determine its optimum conditions in generating electrical energy and removing organic compounds in wastewater. The MFC reactor's performance was evaluated by cell potential, power density, Coulombic efficiency (CE), and organic removal efficiency. The purpose of measuring these parameters is to determine the MFC reactor's performance in producing electrical energy and removing organic compounds for each experiment variation. Biochemical tests were carried out to choose the type of microorganisms in the anode electrode. This measurement is essential for the optimization of environmental conditions for subsequent experiments. MFC reactor with 100 Ω was selected as an optimum condition since it produced the highest power density and efficiency organic removal. In this condition, the CE value was 57%, slightly lower than the MFC reactor with an external resistance of 50 Ω, 65%. Based on biochemical tests, microorganisms that grow on the anode electrode were closed to the Clostridium (Clostridium sp1 and Clostridium sp2), a type of bacteria that belongs to the class of the exoelectrogen. The results showed that the applied external resistance influenced the performance of the MFC reactor. Thus the selection of the proper external resistance is an essential factor in the MFC reactor's operation.

Nurettin Çek, Ahmet Erensoy, Namık Ak et al.

International Journal of Chemical Reactor Engineering • 2022

Abstract Microbial fuel cells (MFCs) can be used to produce clean energy from organic wastes. Various biomasses for MFCs can be used as biofuel materials. Moss ( Bryophyta ) is a source of biomass materials and can be used as an alternative fuel for microbial fuel cells. In this study, moss-enriched MFCs were produced by using moss as a biofuel source and aluminum and silver as an electrode. As a result of the good electrochemical performance of the metal electrodes (aluminum and silver), higher power density than previous studies involving moss was obtained, with the highest power density in this study being 20 mW/m 2 . Moreover, in this study, bacterial activity, biofilm formation, soil utilization, pH change, and corrosion were investigated in MFCs and the effects of MFC on power density were discussed. The addition of soil increased the corrosion rate and internal resistance while reducing the power density. As a result of the addition of soil, the power density dropped to 16.13 mW/m 2 . The corrosion rate was lower than industrial corrosion. Changes in pH confirmed that organic material dissolved and chemical reactions took place. Scanning electron microscope (SEM)-Energy dispersive spectroscopy (EDS) analyzes showed the presence of Bacillus and Coccus bacteria species on the electrode surfaces. These bacteria were acted as biocatalysts by forming a biofilm on the electrode surfaces.

Zia Ullah, Sheikh Zeshan

Water Science and Technology • 2019

Abstract The microbial fuel cell (MFC) provides new opportunities for energy generation and wastewater treatment through conversion of organic matter into electricity by electrogenic bacteria. This study investigates the effect of different types and concentrations of substrates on the performance of a double chamber microbial fuel cell (DCMFC). Three mediator-less laboratory-scale DCMFCs were used in this study, which were equipped with graphite electrode and cation exchange membrane. The MFCs were fed with three different types of substrates (glucose, acetate and sucrose) at a chemical oxygen demand (COD) concentration of 1,000 mg/L. The selected substrate (acetate) was studied for three different concentrations of 500, 2,000 and 3,000 mg/L of COD. Results demonstrated that acetate was the best substrate among the three different substrates with maximum power density and COD removal of 91 mW/m2 and 77%, respectively. Concentration of 2,000 mg/L was the best concentration in terms of performance with maximum power density and COD removal of 114 mW/m2 and 79%, respectively. The polarization curve shows that ohmic losses were dominant in DCMFCs established for all three substrates and concentrations.

Ganjar Samudro, Tsuyoshi Imai, Yung-Tse Hung

Water • 2021

One of the important factors in enhancing the performance of microbial fuel cells (MFCs) is reactor design and configuration. Therefore, this study was conducted to evaluate the regressors and their operating parameters affecting the double anode chamber–designed dual-chamber microbial fuel cell (DAC-DCMFC) performance. Its primary design consists of two anode chamber compartments equipped with a separator and cathode chamber. The DAC-DCMFCs were parallelly operated over 8 days (60 days after the acclimation period). They were intermittently pump-fed with the different organic loading rates (OLRs), using chemically enriched sucrose as artificial wastewater. The applied OLRs were adjusted at low, medium, and high ranges from 0.4 kg.m−3.d−1 to 2.5 kg.m−3.d−1. The reactor types were type 1 and type 2 with different cathode materials. The pH, temperature, oxidation-reduction potential (ORP), optical density 600 (OD600), chemical oxygen demand (COD), and total organic carbon (TOC) were measured, using standard analytical instruments. In general, the power production achieved a maximum of 866 ± 44 mW/m2, with a volumetric power density of 5.15 ± 0.26 W/m3 and coulombic efficiency of 84%. Two-stage COD and TOC removal at medium OLR achieved a range of 60–80%. Medium OLR is the recommended level to enhance power production and organic removal in DAC-DCMFC. The separated anode chambers into two parts in a dual anode chamber microbial fuel cell adjusted by various organic loadings expressed a preferable comprehension in the integrated MFCs for wastewater treatment.

Binjal Pradhan, Ranjan Pradhan

European Scientific Journal, ESJ • 2020

Comparative measurement of electricity produced by inherent eletrogens in benthic mud that were maintained at different operating pH using microbial fuel cell was studied. A two-chamber microbial fuel cell model with proton exchange membrane was adopted for this study applying electrogene sourced from benthic mud collected from local lake and pond in Ontario. The objective of this study is to investigate the effects of different pH of 6, 7 and 8 maintained within the anode cell in a microbial biofuel cell (MFC) containing microbial communities found in a benthic mud medium over 192 hours. The outcomes of the study demonstrated that in acidic conditions, there was an initial decrease in output whereas an alkaline condition allowed for the acclimatization and eventual increase of electric current and microbial activity of the study period. MFC operated at pH 7 generated consistently higher electric power during the study duration exhibiting ideal conditions for the inherent exoelectrogenic bacteria. On average 249.8 mV of electricity were measured from the MFC with pH 7. The average current density calculated to be 9.76 (±2.02) X 10-5 µA/cm2 . The average power density during the study period was calculated to be 2.49 (± 0.77) X 10-5 µW/cm2

Pimprapa Chaijak, Panisa Michu, Junjira Thipraksa

Trends in Sciences • 2023

Melanoidin is the main cause of the dark brown color of the palm oil mill effluent (POME) that form under the Maillard reaction. In this study, the constructed wetland integrated with microbial fuel cell (CW-MFC) has been developed for melanoidin removal from the POME and simultaneously electricity generation as a by-product. The macrophyte Dieffenbachia sp. has been used as a biocatalyst on the cathode electrode and the oxidoreductase-producing bacterium Bacillus lichenformis with laccase and manganese peroxidase activity has been used as an anodic biocatalyst. The maximal melanoidin removal, chemical oxygen demand (COD) removal, enzyme activity, and power output were monitored. The maximal laccase and manganese peroxidase activities of 1.60 ± 0.10 U/mL and 1.45 ± 0.05 U/mL were found during melanoidin degradation. In addition, the maximal melanoidin removal of 93.59 ± 0.10% and 95.12 ± 0.15% were achieved respectively. When the maximal power density of 0.18 ± 0.01 mW/m3 was generated. This study gained new knowledge about using the CW-MFC system as a biological treatment process of the melanoidin content in the POME and simultaneously generated electrical energy as a by-product. HIGHLIGHTS The coupling process of constructed wetland and the microbial fuel cell is promising for the melanoidin removal of the POME The maximal melanoidin removal of 93.59 % was gained The maximal power output of 0.18 mW/m3 was generated from this system GRAPHICAL ABSTRACT

Ademola Adekunle, Vijaya Raghavan, Boris Tartakovsky

Batteries • 2019

This study describes a novel approach for real-time energy harvesting and performance diagnostics of a solid anolyte microbial fuel cell (SA-MFC) representing a prototype smart biobattery. The biobattery power output was maximized in real time by combining intermittent power generation with a Perturbation-and-Observation algorithm for maximum power point tracking. The proposed approach was validated by operating the biobattery under a broad range of environmental conditions affecting power production, such as temperature (4–25 °C), NaCl concentration (up to 2 g L−1), and carbon source concentration. Real-time biobattery performance diagnostics was achieved by estimating key internal parameters (resistance, capacitance, open circuit voltage) using an equivalent electrical circuit model. The real time optimization approach ensured maximum power production during 388 days of biobattery operation under varying environmental conditions, thus confirming the feasibility of biobattery application for powering small electronic devices in field applications.

M. Behera, S. S. R. Murthy, M. M. Ghangrekar

Water Science and Technology • 2011

The performance of dual chambered mediator-less microbial fuel cell (MFC) operated under batch mode was evaluated under different operating temperatures, ranging between 20 and 55 °C, with step increase in temperature of 5 °C. Synthetic wastewater with sucrose as carbon source having chemical oxygen demand (COD) of 519–555 mg/L was used in the study. Temperature was a crucial factor in the performance of MFCs for both COD removal and electricity production. The MFC demonstrated highest COD removal efficiency of 84% and power density normalized to the anode surface area of 34.38 mW/m2 at operating temperature of 40 °C. Higher VSS to SS ratio was observed at the operating temperature between 35 and 45 °C. Under different operating temperatures the observed sludge yield was in the range of 0.05 to 0.14 g VSS/g COD removed. The maximum Coulombic and energy efficiencies were obtained at 40 °C, with values of 7.39 and 13.14%, respectively. Internal resistance of the MFC decreased with increase in operating temperature. Maximum internal resistance of 1,150 Ω was observed when the MFC was operated at 20 °C; whereas the minimum internal resistance (552 Ω) was observed at 55 °C.

Yu Zhao, Xiao Bin Wang, Peng Li et al.

Advanced Materials Research • 2012

Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), power density and anode potential are used to characterize the mediator microbial fuel cell at different methylene blue (MB) concentrations. At lower MB concentration between 9.98×10-3 mmol/L and 1.66×10-1 mmol/L, the increased power density is enabled by using high mediator concentrations. Higher peak power density of 159.6 mw/m2 is observed compared with the peak power density of 36.0 mw/m2. But MB at too high concentration is disadvantageous to the perform of MFC. At the MB concentration of 2.50×10-1 mmol/L, the peak power output is just 128.4 mw/m2, which is lower than 159.6 mw/m2 at MB concentration of 1.66×10-1 mmol/L.

Marie Douma, Musong Katche, Nicole Telem et al.

American Journal of Electrical Power and Energy Systems • 2025

The increasing demand for sustainable electricity generation necessitates the exploration of innovative technologies. Biomass technology is emerging as a promising alternative to address the energy crisis for low-power devices and reduce reliance on fossil fuels. One of the methods to generate energy from this biomass is by using microbial fuel cells (MFC). However, the efforts made with this technology are still mainly limited at the laboratory scale, limiting its interest and its utilization for electrical power generation. This paper presents the real-life implementation and feasibility of a dual-chamber microbial fuel cell fabricated with concrete. 15 dual-chamber reactors were manufactured, with a volume of 0.5 liters for each chamber. Inside the anodic chamber, a carbon foam measuring 4.5 x 4.5 cm² was placed and used as the anode electrode. Two different electrode materials were used for the cathode electrodes. Six reactors used 4.5 x 4.5 cm<sup>2</sup> carbon foam while the other 9 used graphite rods of 5 mm diameter and 15 cm long. The anode chamber was inoculated with a mixture of 25% cow dung and 75% tap water and then sealed airtight. Each cathode chamber was filled with 0.5 liters of saline solution. After 7 days of manipulation, the Open Circuit Voltage (OCV) obtained from this investigation ranged from 0.415 V to 0.732 V. That reflects the successful conversion of chemical energy of this waste in the concrete-based microbial fuel cell reactor into electrical energy. The average maximum power density obtained using graphite rod cathodes was 14.15 mW/m² while an average of 20.21 mW/m² was obtained from the MFCs using carbon foam cathodes. When the MFCs were stacked together in series, a total voltage of 8.5 V was observed.

Huong V. H. Tran, Eojin Kim, Bonyoung Koo et al.

Preprints.org • 2020

To obtain an accurate and reproducible experimental results in microbial fuel cell (MFC), it is important to know ‘anode maturation biofilm’ to produce a stable and maximum performance. For this purpose, four single chamber MFCs were tested in this study. The linear sweep voltammetry (LSV) polarization tests illustrated that maximum power densities of three MFCs became stable after 9 weeks. Although there were variations afterwards, such variations were negligible. Average maximum power densities from the 9th to the 17th week were 2,990 mW/m2 (MFC-4), 2,983 mW/m2 (MFC-2), 2,368 mW/m2 (MFC-3) and 837 mW/m2 (MFC-1). Polarization resistance shows that MFC-1 had much larger anode resistance (36.6-85.4 Ω) than the other MFCs (1.7-11.6 Ω). Anodic cyclic voltammetry (CV) shows that current production increased over time and MFC-1 had much smaller current production (24.4 mA) than the other MFCs (31.0-34.9 mA) at 17th week. The increased current production indicates anode biofilm became more mature over time, but overall cell performance did not increased accordingly. Possibly due to the bad inoculation, MFC-1 showed the lowest performance. However, its performance was restored to the initial performance and anode resistance was reduced by 47% at 17th week. This study shows that the optimum anode maturation time is 9 weeks and that bioanode performance is a key factor for MFC performance. This study also shows than LSV polarization and CV tests are accurate and non-destructive measurement methods for diagnosing anode performance.

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Global NEST Journal • 2017

<p>This study investigates the feasibility of using cathode catalyst (Iron phthalocyanine (FePc) combined multi walled carbon nano tubes (MWCNT) and compares the oxygen reduction rate under different conductivity of catholite solution (50 mM, 100mM) in double chamber Microbial Fuel Cell. Microbial fuel cell (MFC) research is going on for few decades to increase the power density and improve the removal efficiency. Iron phthalocyanine (FePc) combined multi walled carbon nano tubes (MWCNT) cathode catalyst showed the highest power density (9.34 w/m2) in 100 mM PBS than 50 mM (7.58 W/m2). The electrodes are characterized by scanning electron microscopy (SEM) and the electrocatylitic activity of the catalyst coated electrodes were examined by cyclic voltammetry(CV). The high power density indicates a potential alternative to precious platinum metal catalyst in treatment as well as electricity production Microbial Fuel cell.</p>

Kumar Sonu, Monika Sogani, Zainab Syed et al.

Research Square • 2024

Abstract The increasing trend in global atmospheric temperature caused by a spike in atmospheric concentrations of carbon dioxide must be addressed as soon as feasible to avoid approaching the point of zero return. Innovative technologies based on the concepts of plant microbial fuel cell (PMFC) may help in this direction by sequestering CO 2 while creating a massive amount of biomass. In the present study, the Aloe vera plant was employed to generate Cleaner and viable bioenergy in a PMFC. The carbonized Ipomoea carnea had a synergistic effect on power production and plant Growth. The highest power output of the PMFC with a carbonized Ipomoea carnea anode was 260 mW/m 2 , which was 186.1 mW/m 2 more than the carbon rod anode. Within 35 working days, high biomass was identified in the carbonized Ipomoea carnea anode, allowing for increased generation bioelectricity.

Akiyama Shingo, Kiyoharu Nakagawa

• 2020

In this study, the effect of the mesopores of Marimo nano carbon (MNC) on power generation performance for anode material of direct glucose fuel cell was investigated. Three types of MNC with different mesopore distributions were used for the catalyst support material, Pt was used as loaded metal. In the glucose fuel cell performance test, MNC having many pores of about 35 nm showed the highest maximum output density of 0.72 mW cm-2 at 5 wt% metal loading and 0.3 M Glucose aqueous solution. The pores of about 30 nm may promote ion diffusion and rapid mass transport of reactants and products. These results indicated that MNC was an effective material as anode material for direct glucose fuel cell.

En Ren Zhang, Yong Cai Zhang

Advanced Materials Research • 2011

The electrochemical interaction between bacteria and electrode should be further strengthened at the present stage in order to develop microbial fuel cells (MFCs) to practical power sources. Developing effective anode materials is an alternative to achieving this goal. In this study, the redox activity of polyaniline (PAn) in neutral pH solution was improved by doping ionic liquid (IL) into the synthesized PAn; and the current output of MFC could be enhanced by using IL doped polyaniline (PAnIL) film as anode material. Both cyclic voltermmeter (CV) measurement and MFC operation showed that PAnIL electrochemically synthesized in solution with 30%(v/v) IL addition exhibited the best performance.

Hamed Farahani, Mostafa Ghasemi, Mehdi Sedighi et al.

Sustainability • 2024

The culture medium composition plays a critical role in optimizing the performance of microbial fuel cells (MFCs). One under-investigated aspect of the medium is the impact of the Wolf vitamin solution. This solution, known to contain essential vitamins like biotin, folic acid, vitamin B12, and thiamine, is believed to enhance bacterial growth and biofilm formation within the MFC. The influence of varying Wolf vitamin solution concentrations (2, 4, 6, 8, and 10 mL) on microbial fuel cell (MFC) performance is investigated in this study. Python 3.7.0 software is employed to enhance and anticipate the performance of MFC systems. Four distinct machine-learning algorithms, namely adaptive boosting (AdaBoost), extreme gradient boosting (XGBoost), categorical boosting algorithm (CatBoost), and support vector regression (SVR), are implemented to predict power density. In this study, a data split of 80% for training and 20% for testing was employed to optimize the artificial intelligence (AI) model. The analysis revealed that the optimal concentration of Wolf mineral solution was 5.8 mL. The corresponding error percentages between the experimental and AI-predicted values for current density, power generation, COD removal, and coulombic efficiency were found to be remarkably low at 0.79%, 0.5%, 1.89%, and 1.27%, respectively. These findings highlight the significant role of Wolf mineral solution in maximizing MFC performance and demonstrate the exceptional precision of the AI model in accurately predicting MFC behavior.

Maksudur R. Khan, M.S.A. Amin, M.T. Rahman et al.

pjct • 2013

Electricity generation from the readily biodegradable organic substrate (glucose) accompanied by decolorization of azo dye was investigated using a two-chamber microbial fuel cell (MFC). Batch experiments were conducted to study the effect of dye and substrate concentration on MFC performance. Electricity generation was not significantly affected by the azo dye at 300 mg/L, while higher concentrations inhibited electricity generation. The chemical oxygen demand (COD) removal and decolorization of dye containing wastewater used in the MFC were studied at optimum operation conditions in anode and cathode, 57% COD removal and 70% dye removal were achieved. This study also demonstrated the effect of different catholyte solutions, such as KMnO 4 and K 2 Cr 2 O 7 on electricity generation. As a result, KMnO 4 solution showed the maximum electricity generation due to its higher standard reduction potential.

Yang Song, Munir H. Nayfeh, Siu-Tung Yau

RSC Advances • 2014

The performance of a yeast MFC is improved by applying a dc voltage V appl to its anode without causing extra energy to be spent on the MFC.

Umair Fazal, AN Tabish, Samina Akbar et al.

Research Square • 2023

Abstract Discharge of wastewater containing traces of cow dung from a dairy farm poses significant threat to the environment, which necessitates the effluent treatment. Microbes present in organic rich dairy effluent containing traces of cow dung produced electricity. The performance of Microbial Fuel Cell(MFC) was analyzed by drawing I-V curves and performing electrochemical impedance spectroscopy (EIS). The MFC produced maximum power density of 203 mWm -2 at a current density of 1191 mAm -2 . The Chemical Oxygen Demand (COD) removal efficiency was found to be 81% after 10 days of MFC operation. Decrease in anode polarization resistance confirmed the formation of biofilm at anode surface.

Linlin Liu, William Varroy, Marc-Antoine Bansept et al.

ChemRxiv • 2024

In this work, we present a new “all-graphite” concept in microfluidic fuel cells, applied to microbial fuel cells (MFCs). The all-graphite microfluidic MFCs were fabricated by milling channels directly into the electrodes. Two such electrode channels were affixed face-to-face with separation by an ion exchange membrane to form a complete MFC. Three such MFCs were fabricated with simple straight channels having different channel heights and activated with pure culture anaerobic Geobacter sulfurreducens electroactive biofilm. After the proof-of-principle and correlation between the channel height and electroactive biofilm thickness, we demonstrated improvements on power and current outputs using a fourth design, which featured a high surface area provided by pillars. A high acetate conversion efficiency of more than 80% and low internal resistance of 1.2 kΩ were achieved using the pillar MFC. Additionally, a high-power density of 4.7 W m-2 was obtained with a straight channel MFC.

Charitha Basnayaka, Maheshi Somasiri, Ahmed Ahsan et al.

Research Square • 2024

Abstract Marine photosynthetic Microbial fuel cells (mpMFCs) can utilize marine photosynthetic microorganisms to drive electrical energy generating electrochemical reactions. Due to improved ionic mobility and superior electrical conductivity of sea water, it is a suitable electrolyte for operating bio-electrochemical devices at operating elevated salinities. This study examined the use of seawater as a conducting medium in two-chambered MFCs to enhance power production in conjunction with a marine photosynthetic bio-cathode as an alternative to the abiotic chemical cathode. Using a modified BG11 seawater medium as catholyte, marine cyanobacteria were grown and maintained in the MFC cathode compartment. After a significant quantity of biomass had formed, it was harvested for use as the substrate for anode microorganisms. Isolated marine cyanobacteria from photosynthetic biocathode were identified using 16s rRNA and Sanger DNA sequencing. In electrochemical characterization, mMFC, maximum power density (P max ) was 147.84 mW/m 2 and maximum current density (J max ) reached 1311.82 mA/m 2 . In mpMFC, P max was 104.48 mW/m 2 and J max was 1107.27 mA/m 2 . P max was 53.14 mW/m 2 and J max was 501.81 mA/m 2 in comparable freshwater MFC employing platinum catalyst, which proves that mMFC & mpMFC worked better. Dapis pleousa & Synechococcus moorigangaii were identified as dominant marine cyanobacteria. It was demonstrated that mpMFC, operated using seawater, employing a cyanobacteria biocathode, is suitable for circularized renewable energy production. The outcomes of this study implies that, mpMFCs are good candidates for circular renewable energy production.

Tesfalem Atnafu, Seyoum Leta

Research Square (Research Square) • 2021

Abstract BackgroundMicrobial fuel cells (MFCs) drawbacks are anode (cathode) limitation and electrochemical loss. Engineering the biofilm for enhanced attachment to the electrode is the prospect of MFC. Recent studies, recommend the formation of thick anode biofilm that could result in a synergetic effect between microbial communities. To address these issues, a microbial electrode jacket dish (MEJ-dish) was invented that supports microbial growth over the anode electrode surface. The MFC reactor with MEJ-dish was hypothesized to develop a fragment of biofilm (thick and thin) across the electrode. This reactor is called a fragmented electroactive biofilm-microbial fuel cell reactor (FAB-MFC).ResultsThe maximum voltage generated (0.87 V) was recorded in FAB-MFC. In addition, during the first 3-10 days, the FAB system enables to significantly (p<0.05) maximize the voltage generation at pH variation from 6.5 to 7.5. However, at alkaline pH 8.5, the FAB system generates a lower voltage relative to non-FAB. On the contrary, in FAB reactors the COD removal was improved regardless of pH variation (6.5-8.5). This shows, unlike voltage generation, the biofilms (either electroactive or not) formation were vital for COD removal even without voltage generation. At acidic and neutral pH (7.5), the fragmented (hybrid) biofilm formation across the bioelectrode (anode) could not only important for voltage generation but also contributes to the effective functioning of electroactive biofilm (EABs) growth and development by reducing the effect of pH variation. To address this contradictory effect of increasing COD removal associated with the lower voltage at higher pH, might be to use both FAB and non-FAB in a single MFC reactor. There might be a mutualistic effect across the bioelectrode biofilms.ConclusionsThis study showed that the voltage generated was significantly higher in FAB-MFC as compared with non-FAB-MFC setup within limited pH (6.5-7.5); relatively, COD removal was enhanced within wider pH 6.5-8.5. This supports the conclusion that biofilm formed across the FAB was vital for COD removal, even though not participated in voltage generation. However, this might be affected by the degradable organic content and the nature of the microbial community in the inoculum and domestic wastewater, which requires further studies.

Praveena Gangadharan, Indumathi M Nambi

Research Square • 2020

Abstract The study investigates the performance of Cu 2+ as dissolved cathodic electron-shuttle mediator (dcESM) for simultaneous Cr 6+ reduction and electricity generation in a microbial fuel cell (MFC) at pH 2 and 4 conditions. The dcESM behavior of Cu 2+ on carbon cloth (CC) catalyzes the reduction of Cr 6+ into Cr 3+ at pH 2 by undergoing redox reactions. However, at pH 4, a simultaneous reduction of Cu 2+ and Cr 6+ was observed. Cyclic voltammetry (CV) studies were performed at pH 2 and 4 to probe the dcESM behavior of Cu 2+ for Cr 6+ reduction on CC electrode. Also, at pH 2, increasing the concentration of Cu 2+ from 50 mg L -1 to 500 mg L -1 favors the Cr 6+ reduction by reducing the reaction time from 108 h to 48 h and improving the current production from 3.94 mA m -2 to 6.24 mA m -2 , respectively. Nevertheless, at pH 4, the efficacy of Cr 6+ reduction and electricity generation from MFC is decreased from 62.91% to 18.21% and 4.42 mA m -2 to 1.10 mA m -2 , respectively, by increasing the Cu 2+ concentration from 50 mg L -1 to 500 mg L -1 . Furthermore, the performance of dcESM behavior of Cu 2+ was explored on carbon felt (CF) and platinum (Pt) electrodes, and compare the results with CC. In MFC, at pH 2, with an initial concentration of 100 mg L -1 , the reduction of Cr 6+ in 60 h is 9.63 mg L -1 for CC, 0.17 mg L -1 for CF, and 51.32 mg L -1 for Pt cathodes. The reduction of Cr 6+ (initial concentration of 100 mg L -1 ) at pH 4 in 120 h is 44.72 mg L -1 for CC, 32.13 mg L -1 for CF, and 70.85 mg L -1 for Pt cathodes. Maximum power densities of 1659 mW m -2 , 1509 mW/m -2 , and 1284 mW/m -2 were achieved when CF, CC, and Pt, respectively were employed as cathodes in the MFC.

Xinhong Peng, Xizhang Chu, Shenghui Wang et al.

RSC Advances • 2016

Ni–ferrite-decorated anode enhanced the MPD by 26% to 806.4 mW m −2 .

Paulo Henrique da Silva, Ilka Djanira Ferreira do Nascimento, Galba Maria de Campos-Takaki

Research, Society and Development • 2022

For decades, non-renewable energy resources have been used indiscriminately, but their slow depletion and extremely harmful impacts on the environment have shifted the focus to sustainable and renewable energy sources. Among the renewable energy sources, biofuel cells are defined as devices that convert chemical energy present in chemical bonds into electrical energy. Biocells are classified into two broad categories of enzymatic fuel cells, which employ enzymes as biocatalysts, and microbial fuel cells, which use microorganisms as biocatalysts. An important requirement in the functioning of a biofuel cell is the transfer of electrons from inside an active site of an enzyme to the outside, as the electrodes being solid cannot penetrate the enzymes. A wide range of molecules can be used as electrochemical mediators, some with high toxicity and many non-toxic fungal substances having an enormous potential to be used as electrochemical mediators. In this work, the fungal pigment bikaverin was compared to the synthetic dye Congo red, in order to obtain the best energy-optimizing molecule in an enzymatic fuel cell. Congo red presented a higher current density of 273 mA.cm-2 compared to bikaverin, 230 mA.cm-2, but because it presents a more stable chronoamperometric graph and does not have high toxicity, the fungal biopigment proved to be the best option for optimization. on the potential of energy generated in an enzymatic fuel cell.

Hussein H. Abd-almohi, Ziad T. Alismaeel, Mohanad J. M-Ridha

Al-Khwarizmi Engineering Journal • 2022

Microbial Desalination Cell (MDC) is capable of desalinating seawater, producing electrical power and treating wastewater. Previously, chemical cathodes were used, which were application restrictions due to operational expenses are quite high, low levels of long-term viability and high toxicity. A pure oxygen cathode was using, external resistance 50 and 150 k Ω were studied with two concentrations of NaCl in the desalination chamber 15-25 g/L which represents the concentration of brackish water and sea water. The highest energy productivity was obtained, which amounted to 44 and 46 mW/m3, and the maximum limit for desalination of saline water was (31% and 26%) for each of 25 g / L and 15 g / L, respectively, when using an external resistance of 150 KΩ. At 50 KΩ, 13 and 12 mW/m3 were obtained, and the maximum desalination limit were 20% and 2% when using 25 g / L and 15 g / L, respectively. The concept of the mixing process was introduced in the desalination chamber to improve the performance of the system, where the highest energy productivity was obtained, which amounted 45 and 47 mW/m3, and the percentage of salt removal in the desalination chamber were 40% and 55% when using 15 g/L and 25 g/L and 150 KΩ, respectively. This study demonstrated a promising approach to using the mixing process in the desalination room in order to increase the desalination and electrical productivity.

Yucui Shi, Yongwei Li, Qing Liu et al.

Environment Protection Engineering • 2023

A new type of bioelectrochemical system features a constructed wetland (CW) coupled with a microbial fuel cell (MFC) to treat Cr(VI) wastewater while generating electricity. The optimal operating parameters for treating wastewater containing Cr(VI) are discussed. The results show that the CW-MFC system is more effective in the treatment of Cr(VI)-containing wastewater and generating electricity. A COD concentration of 300 mg/dm 3 corresponded to the greatest COD and Cr(VI) removal rates with a maximum power density of 505.62 mW/m 3 , whereas a Cr(VI) concentration of 80 mg/dm 3 yielded the greatest COD removal rate, with a maximum power density of 484.43 mW/m 3 . A hydraulic retention time (HRT) of 3 days yielded the largest pollutant removal rates with a maximum power density of 479.21 mW/m 3 . Considering that the comprehensive operating conditions of CW-MFC are based on planting plants, the COD concentration is 300 mg/dm 3 , the Cr(VI) concentration is 80 mg/dm 3 , and the HRT is 3 days. The abundance of electrogenic bacteria Geobacter and metal dissimilatory reducing bacteria Acinetobacter in CW-MFC is higher than that in the control group. The results of this study provide theoretical guidance for determining the optimal operating conditions and energy recovery of the CW-MFC system for treating chromium wastewater.

Lisa Deleebeeck, Kent Kammer Hansen

Journal of Fuel Cell Science and Technology • 2015

The influence of the current collector on the performance of a hybrid direct carbon fuel cell (HDCFC), consisting of solid oxide fuel cell (SOFC) with a molten carbonate–carbon slurry in contact with the anode, has been investigated using current–voltage curves. Four different anode current collectors were studied: Au, Ni, Ag, and Pt. It was shown that the performance of the direct carbon fuel cell (DCFC) is dependent on the current collector materials, Ni and Pt giving the best performance, due to their catalytic activity. Gold is suggested to be the best material as an inert current collector, due to its low catalytic activity.

Subhashis Das, Rajnish Kaur Calay

Energies • 2022

Microbial fuel cells (MFCs) are a kind of bioreactor for generating electricity, facilitated by exoelectrogens while treating wastewater. The present article focuses on the performance of an air cathode plexiglass MFC in terms of chemical oxygen demand (COD) removal efficiency and power output by performing two sets of experiments. The proton exchange membrane and electrode materials were Nafion 117 and carbon felts, whereas, for stable biofilm formation on the anode surface, a pure culture of Shewanella baltica 20 was used. Firstly, sterile Luria-Bertani (LB) media containing lactate, ranging from 20 to 100 mM, was continuously fed to an MFC, and a maximum power density of 55 mW/m2 was observed. Similarly, artificial wastewater with COD ranging from 3250 mg/L to 10,272 mg/L was supplied to the MFC in the second set of experiments. In this case, the maximum power density and COD removal efficiency were 12 mW/m2 and 57%, respectively. In both cases, the hydraulic retention time (HRT) was 1.5 h. It was found that electricity generation depends on the characteristics of the wastewater. These initial findings confirm that the design aspects of an MFC, i.e., surface area to volume ratio, and external resistance with respect to the quality of influent need to be optimised to improve the MFC’s performance.

D. Vidhyeswari, A. Surendhar, S. Bhuvaneshwari

Water Science and Technology • 2021

Abstract The aim of this study is to synthesise SPEEK composite proton exchange membrane with the addition of TiO2 nanofillers for microbial fuel cell application. SPEEK composite membrane with varying weight percentage of TiO2 (2.5, 5, 7.5 and 10%) was prepared to study the effect of TiO2 concentration on membrane performance. Synthesized composite membranes were subjected to various characterization studies such as FT-IR, XRD, Raman spectroscopy, TGA, UTM and SEM. Physico-chemical properties of membrane such as water uptake capacity, ion exchange capacity and thickness were also analyzed. 5% TiO2 – SPEEK composite membrane exhibited the higher water uptake capacity value and Ion exchange capacity value of 31% and 1.71 meq/g respectively. Performance of the MFC system with TiO2 – SPEEK membranes were evaluated and compared with the pristine SPEEK and Nafion membrane. 5% TiO2 – SPEEK membrane produced the higher power density (1.22 W/m2) and voltage (0.635 V) than the other membranes investigated. Efficacy of MFC in wastewater treatment was evaluated based on the chemical oxygen demand (COD), total organic carbon content and turbidity. Biofilm growth over the surface of the electrodes was also analyzed using scanning electron microscopy.

Iwona Gajda, Buddhi Arjuna Mendis, John Greenman et al.

• 2020

<p>A microbial fuel cell (MFC) is a renewable energy converter, which transforms organic biomass directly into electricity, using biofilm-electrode metabolic interaction within a bioelectrochemical cell. Efficiency of this transformation can be enhanced through miniaturisation. Miniaturisation of MFCs offers higher surface-area-to-volume ratio and improved mass transfer.</p> <p>The development of mL-scale; power dense and low cost MFCs, are of great interest in diverse areas of research, ranging from modern bio-robotics, internet-of-things devices, electrical energy generation, remote sensing to wastewater treatment and mineral recovery. The biofilms increased ability in converting organic pollutants into electric power more efficiently, makes mL-sized MFCs attractive for the development of multi-modular stacks and usable off-grid power sources with an ability of enhanced wastewater treatment. This work focuses on small scale MFCs; i) minimising the distance between feeding stream and the biofilm, ii) construction and analysis of a  millilitre scale prototype, using a low cost ceramic separator for higher energy recovery efficiency and sensitivity enhancement to substrates and pollutants. The study aims to test efficient cathode modifications, using graphene ink and magnetite (Fe<sub>3</sub>O<sub>4</sub>); in order to improve the oxygen reduction reaction (ORR). This in turn is envisioned in an increase of the output, reaching comparable power levels to the larger MFC prototypes tested so far. The additives are chosen such that,  both graphene and iron–based oxides are known from the literature to be catalysts for electrochemical processes, this work focusses on their incorporation into the open-to air cathode in novel, low cost MFC bioreactors.</p> <p>The miniaturised MFC construction constituted of an in-house fabricated small scale ceramic cylinder of internal volume of 3.88 mL. An anode, made of carbon veil fibre with a coating of activated carbon powder, was placed inside the ceramic cylinder, while the cathode was attached to the outer surface of the structure. Three types of cathodes were tested: i) activated carbon as the control (AC), ii) AC with a graphene ink coating (AC+G) and iii) AC with graphene ink and magnetite powder blend (AC+G+M). Experiments were conducted in triplicate using activated sludge and urine inoculum and thereafter continuously supplemented with 100% real human urine. The results show that the control produced up to 0.85 mW (219 W/m<sup>3</sup>), while AC+G produced 1.22 mW (312 W/m<sup>3</sup>), and AC+G+M 1.12 (288 W/m<sup>3</sup>) which is a 44 % and a 32 % increase respectively in comparison to the control. Comparison of linear sweep voltammetry (LSV) showed superior performance of both modified electrodes against the unmodified AC cathode; further resulting in an enhancement of ORR reaction rate. Power outputs from this work show over 14 times improvement in power density levels in comparison to larger reactors of 20 times the volume, as well as comparable raw (actual) power levels. This makes these novel small-scale bioreactors particularly attractive for use in numerous practical applications such as energy autonomous robots (e.g. EcoBots) and multi-modular stacks for off-grid energy sources.</p> <p> </p>

Ankisha Vijay, Prakash C. Ghosh, Suparna Mukherji

Energies • 2023

Saline wastewater pollution is a critical issue that needs to be addressed. The present study focused on the development of a dual-chambered microbial fuel cell (MFC) treating saline wastewater at the anode. Halophilic exo-electrogenic bacteria enriched from seawater (Arabian Sea, Mumbai, India) were used in the anodic chamber of the MFC. Denitrification using denitrifying bacteria was employed in the cathodic chamber. The maximum power density was significantly increased from 96.77 mW/m2 to 162.09 mW/m2 with a rise in NaCl concentration from 20 to 40 g/L. Nitrate removal in the cathode chamber increased from 80 ± 3% to 89 ± 3.2% with increase in salt concentration from 20 g/L to 40 g/L and concomitantly COD removal in the anode chamber increased from 76 ± 3.8% to 83 ± 4%. Cyclic voltammetry (CV) analysis revealed higher electrochemical activity at 40 g/L salt concentration. Electrochemical impedance spectroscopy (EIS) analysis exhibited that charge transfer and solution resistances were lower when the salinity was increased. Microbial community analysis revealed the presence of Clostridium, Shewanella, and Bacillus as the most abundant genera in the anodic chamber. This study demonstrated the dual applicability of the system targeted for removal of organics from saline wastewater and nitrate removal from contaminated wastewater accompanied by power generation from the MFC.

Shunliang Liu, Yali Feng, Haoran Li

bioRxiv (Cold Spring Harbor Laboratory) • 2021

Abstract The inhibitory effect of electron mediator 2,6-anthraquinone disulphonate (AQDS) on Geobacter metallireducens nanowire in the microbial fuel cell (MFC) was studied. In the culture process of G.metallireducens with Fe(OH) 3 as an electron acceptor, the concentration of reduction product Fe (II) in solution without AQDS was higher than that with AQDS after 10 days, due to the formation of microbial nanowires. The effects of nanowire on electron transfer efficiency and electrical current characteristic were studied using a double chamber MFC reactor. The transfer efficiency between biofilm and electrodes was increased by nanowire, which increased the maximum output voltage of MFC was 442 mV. The nanowire biofilm electrode had a bigger cyclic voltammetry curve peak, smaller activation resistance, and a stronger current response signal through electrochemical measurement, which indicates that the nanowire enhanced the electrochemical activity of the electrode.

Yan-Ming Chen, Chin-Tsan Wang, Yung-Chin Yang

Energies • 2018

Hydrodynamic boundary layer is a significant phenomenon occurring in a flow through a bluff body, and this includes the flow motion and mass transfer. Thus, it could affect the biofilm formation and the mass transfer of substrates in microbial fuel cells (MFCs). Therefore, understanding the role of hydrodynamic boundary layer thicknesses in MFCs is truly important. In this study, three hydrodynamic boundary layers of thickness 1.6, 4.1, and 5 cm were applied to the recirculation mode membrane-less MFC to investigate the electricity production performance. The results showed that the thin hydrodynamic boundary could enhance the voltage output of MFC due to the strong shear rate effect. Thus, a maximum voltage of 22 mV was obtained in the MFC with a hydrodynamic boundary layer thickness of 1.6 cm, and this voltage output obtained was 11 times higher than that of MFC with 5 cm hydrodynamic boundary layer thickness. Moreover, the charge transfer resistance of anode decreased with decreasing hydrodynamic boundary layer thickness. The charge transfer resistance of MFC with hydrodynamic boundary layer of thickness 1.6 cm was 39 Ω, which was 0.79 times lesser than that of MFC with 5 cm thickness. These observations would be useful for enhancing the performance of recirculation mode MFCs.

Linlin Liu, Haleh Baghernavehsi, Jesse Greener

Preprints.org • 2024

High-power output and high conversion efficiency are crucial in the study of microfluidic microbial fuel cells (MFCs). In our previous work, we attempted various methods to increase the power density of the MFCs, but nutrient consumption was limited to the bottom (electrode) layer of the microfluidic channel due to the diffusion limitations. In this work, long-term experiments were conducted on a new 4-electrode microfluidic MFC design, which grew Geobacter sulfurreducens biofilms on upward- and downward-facing electrodes in the microchannel. It was discovered that inoculation and growth of the electroactive biofilm did not proceed as fast as the downward facing anode, which we hypothesize is due to gravity effects that negatively impacted bacterial settling on that surface. Rotating the device during the growth phase resulted in uniform and strong outputs from both sides, yielding individual power densities of 4.03 and 4.13 W m-2, which was increased to nearly double when the top- and bottom-side electrodes were operated in parallel as a single 4-electrode MFC. Similarly, acetate consumption could be doubled with the 4-electrodes operated in parallel.

, Sarunyou Kasemanand

• 2015

In this research, a biogas sorption enhanced chemical looping reforming (SECLR) process integrated with high temperature proton exchange membrane fuel cell (HT-PEMFC)is analyzed. The thermodynamic concept and electrochemical model are used to identify the suitable operating conditions of the proposed process. Exergy and energy analyses are used to describe the effect of various parameters, such as reforming temperature, steam-to-biogas molar ratio, CaO-to-biogas molar ratio and NiO-to-biogas molar ratio, on the process performance. The exergy destruction of each unit is employed to identify the quality of energy that is used in each unit. The data obtained can be used to improve the energy and exergy efficiencies of the process. The simulation results show that the exergy efficiency of the process is improved from 16.60% to 26.72% when a process heat integration is applied.

, Juan Carlos Trujillo Caballero

• 2012

PEMFCs are the most popular type of Fuel Cells (FCs) and traditionally use hydrogen as the fuel. One FC problem is its relative slow dynamics caused by the time constant of the hydrogen and oxygen supply systems that can be in the range of several seconds. In this sense, supercapacitors (SCs) respond faster than FC to a fast increase or decrease in power demand. Thus, using SCs together with FCs improves FC life and performance by absorbing faster load changes and preventing fuel starvation of the FC. Therefore, it becomes necessary to study structures of power conditioners with their respective control systems that can mitigate the disadvantages mentioned of the FC itself. Several researches have studied the different topologies with their respective control proposals to operate FC and SC. This thesis proposes a digital control scheme to operate a PEMFC module of 1.2 kW and a SC through a DC/DC hybrid converter. A FC has been proposed as a primary source of energy and a SC has been proposed as an auxiliary source of energy. An experimental validation of the system implemented in the laboratory is provided. Several tests have been performed to verify that the system achieves an excellent output voltage (V0) regulation and SC Voltage (VSC) control, under disturbances from FC power (PFC) and output power (P0) as well as other perturbations described in analysis results.

, Ana Sotres Fernández

• 2015

A microbial fuel cell (MFC) is a bioelectrochemical system (BES) capable of converting the chemical energy contained in the chemical bonds of a substrate into electrical energy by means of electrochemical reactions catalyzed by microorganisms. The amount of energy to be gained by bacteria capable of transferring electrons to an anode is significantly higher compared to other alternative electron acceptors. Exoelectrogenic microbial populations tend to be selectively enriched on the anode electrode, being essential for the performance improvement of the MFC in terms of electricity production from organic matter oxidation. MFC technology arises as an attractive alternative for the treatment of high strength animal wastewater, such as pig slurries, to potentially improve energetic valorisation of organic wastes, concomitantly to carbon and nitrogen content reduction or recovery. The first part of the thesis (Chapters 4, 5 and 6) focuses on the study of microbial populations harboured on the anode electrode of MFCs. The effect of different ion exchange membrane materials and different inoculum sources over the microbial population was studied in discontinuously fed MFCs. A detailed study of the microbial community dynamics and composition onto the anode biofilms, under different feeding conditions (synthetic wastewater and the liquid fraction of pig slurry), was then studied in continuously fed MFC. A highly diverse microbial community is shown to be present under these different scenarios and, its final composition is being dependent on the factors studied. The second part of the thesis is focused on understanding the nitrogen dynamics in a two-chambered MFC, and the possible strategies available to remove or recover it. First of all, the diffusion/migration of ammonia nitrogen through the cation exchange membrane was studied in batch essays under different operational conditions (Chapter 7). The results obtained showed that the diffusion/migration of ammonia nitrogen is dependent on the voltage applied and, when using pig slurry, ammonia migration reaches values close to 50%. These results suggested that the use of MFC technology could be a good strategy to deal with the nitrogen excess in this kind of substrates. Two different processes for MFC nitrogen recovery and removal were developed. First, a physicochemical-based process for nitrogen recovery was developed coupling a stripping-absorption unit to the cathode chamber (Chapter 7). Results showed the stripping/absorption-BES system is a feasible technology to recover ammonia from pig slurries. Second, a nitrogen removal strategy by means of biological processes was studied using synthetic high strength wastewater as feed (Chapter 8). In this case, the ammonia nitrogen migrating from the anode to the cathode, was removed applying intermittent aeration cycles in the cathode chamber of the MFC where a concomitant nitrifying-denitrifying microbial community being established. The feasibility to recover/remove nitrogen from high strength animal wastewater, such as pig slurries, using different MFC strategies has been demonstrated at lab scale. Hence, it can be considered as a potential technology for scaling up the treatment of high strength (organic and nitrogen) wastewaters, so as to accomplish the requirements needed for agricultural uses. Likewise, the knowledge acquired about the biofilm developed on the anode reveals itself as a key point for the resilience of BES at different environmental conditions and for further developments. Una celda de combustible microbiana (MFC), es un tipo de sistema bioelectroquímico (BES) capaz de convertir la energía contenida en los compuestos químicos en energía eléctrica mediante reacciones electroquímicas catalizadas por microorganismos. Las poblaciones de microorganismos exoelectrogénicos tienden a enriquecerse selectivamente en los electrodos del compartimento ánodico, siendo esenciales para la mejora del rendimiento de las MFCs en términos de producción de electricidad a partir de la oxidación de la materia orgánica. La tecnología de las MFCs se plantea como una alternativa para el tratamiento de aguas residuales de alta carga de origen animal, como por ejemplo los purines, para mejorar potencialmente su valorización energética, vinculada a la reducción o recuperación del contenido de carbono y nitrógeno. La primera parte de esta tesis (Capítulos 4, 5 y 6) está centrada en el estudio de las poblaciones microbianas hospedadas en los electrodos de las MFCs. Se estudió el efecto de diferentes tipos de materiales de membranas de intercambio iónico, así como inóculos de diferente naturaleza, sobre las poblaciones de microorganismos en MFCs operando en discontinuo. Posteriormente, se realizó un estudio más detallado de la dinámica y la composición microbiana establecida sobre el biofilm del ánodo, bajo diferentes condiciones de alimentación (agua residual sintética y la fracción líquida de purín porcino), en MFCs operadas en modo continuo. Bajo estas condiciones de estudio, se mostró una elevada diversidad de la comunidad microbiana, siendo la composición final dependiente de los factores estudiados. La segunda parte de la tesis está centrada en el estudio de la dinámica del nitrógeno en MFCs de doble compartimento, y el desarrollo de posibles estrategias para eliminarlo o recuperarlo. Primero, se estudió la difusión/migración del amonio a través de una membrana de intercambio catiónico, en experimentos en discontinuo bajo diferentes condiciones de operación (Capítulo 7). Los resultados obtenidos mostraron que la difusión/migración del amonio es función del voltaje aplicado, y cuando se usan purines, la migración de amonio llega a valores cercanos al 50%. Estos resultados sugirieron que el uso de la tecnología de las MFCs podría ser una buena estrategia para tratar el exceso de nitrógeno de esta clase de residuos orgánicos. Se desarrollaron dos procesos diferentes de recuperación y eliminación de nitrógeno. Primero, se desarrolló un proceso fisicoquímico para la recuperación de nitrógeno acoplando una unidad de stripping/absorción al compartimento catódico (Capítulo 7). Los resultados mostraron que este sistema de BES-stripping/absorción se puede considerar como una tecnología factible para llevar a cabo la recuperación del nitrógeno de los purines. En segundo lugar, se estudió una estrategia de eliminación de nitrógeno mediante procesos biológicos, utilizado en este caso agua residual sintética de alta carga (Capítulo 8). En este caso, el amonio que migró desde el ánodo al cátodo, fue eliminado aplicando ciclos intermitentes de aireación en el compartimento catódico de la MFC, lo que provoca el establecimiento de una población nitrificante-desnitrificante. La viabilidad para recuperar/eliminar nitrógeno de aguas residuales de alta carga de origen animal, como purines, mediante MFCs ha sido demostrada a escala de laboratorio utilizando diferentes estrategias. Por lo tanto, se puede considerar, que es una tecnología potencialmente aplicable en el tratamiento de aguas residuales de alta carga (carbono y nitrógeno), así como para lograr los requerimientos necesarios para uso agrícola. Igualmente, el conocimiento adquirido sobre el desarrollo del biofilm en el ánodo, revela que es un factor clave para la adaptabilidad de BES en diferentes condiciones medioambientales y para futuros desarrollos.