Moh. Abduh Wafi, Mutiara Garnet Ahmad, Misto Misto et al.

Jurnal ILMU DASAR • 2024

The application of ceramic-based Microbial Fuel Cells (MFCs) for the treatment of tofu liquid waste presents a promising and environmentally sustainable approach. The purpose of this study was to determine the effect of adding variations in substrate concentration and to determine the effect of variations in the surface area of the electrode (anode and cathode), resulting in a maximum power density value for a period of 13 days of measurement. The initial step is measuring the voltage and current with the substrate concentration without a dilution process, then the concentration variations are carried out by dilution 10 times, 8 times, 5 times, 4 times, and 2 times on ceramics with a diameter of 8 cm. The second step is measuring the voltage and current by varying the surface area of the electrodes (cathode and anode). The results of the measurements obtained that the maximum power density value obtained was 188.23 mW/m2 without a dilution process, namely with a concentration of 3640 ppm for the third day. Meanwhile, the results of the measurement of the variation of the electrode surface area obtained a maximum power density value of 205.88 mW/m2 on the electrode surface area of 3.57 m2 for the third day. The more surface area of the electrode given at the time of measurement, the more bacteria contact the electrode, causing the resulting power density value to be even greater.

Mariagiovanna Minutillo, Rosa Anna Nastro, Simona Di Micco et al.

E3S Web of Conferences • 2019

The microbial fuel cells (MFCs) represent an emerging technology for converting directly organic waste into electricity. In recent years, the application of MFCs to the energy recovery from wastes has been widely explored. The main aspect that limits the development and implementation of this technology on a larger-scale is the possibility of realizing its scaling-up. In order to overcome this critical factor, it is useful to analyze novel MFCs configurations based on compact reactors with multiple electrodes.In this paper, single chamber MFCs provided with multiple fiber brush anodes and a single air-cathode were designed and realized by using a 3D printer. The reactors had a cubic shape, with a cylindrical chamber of 350 mL in volume. The mineral medium added with sodium acetate (0.25 M), as sole source of carbon and energy to sustain exoelectrogenic bacteria metabolism, were used. Anodes biofilms were prepared from a mix of compost and sodium acetate dissolved in phosphate buffer solution (0.2M), in a 1:3 ratio. The performances of two MFCs provided with two and three anodes were assessed in terms of voltage, current density and power density. These performances were compared to those of a smaller cubic MFC (30mL).

Umi Nihayah, M. Ramdlan Kirom

The International Journal of Pegon : Islam Nusantara civilization • 2022

dengan bantuan mikroorganisme. Pada penelitian ini menggunakan desain dual chamber MFC 10x10x5 cm untuk mengetahui keluaran arus dan tegangan yang dihasilkan menggunakan membran berongga semen ukuran diameter 3 cm dan tebal 0,5 cm dengan campuran Natrium Clorida (NaCl). Kompartemen anoda menggunakan plat seng (Zn) dan katoda menggunakan plat tembaga (Cu) dengan ukuran sama 5x3 cm. Penelitian menggunakan perbandingan 1:1 untuk variasi limbah organik substrat limbah cair tahu dan limbah kulit pisang dengan dicampur lumpur sawah. Dari hasil pengukuran, produksi listrik maksimal selama 14 hari pada substrat limbah cair tahu yaitu dengan inkubasi 6 hari dan pada substrat limbah kulit pisang padat dan cair yaitu dengan inkubasi 3 hari. Hasil pengukuran dapat diperoleh tegangan 252,010 mV, arus 2,52 mA, dan daya 390,648 mW pada substrat limbah cair tahu, tegangan 82,609 mV, arus 0,828 mA, dan daya 68,543 mW pada substrat limbah kulit pisang padat, dan tegangan 66 mV, arus 0,66 mA, dan daya 43,6 mW pada substrat limbah kulit pisang cair. 
 
 Currently, Indonesia has a big challenge to increase quality energy in order to support sustainable development. So far, the energy used to produce electricity is oriented towards fossil energy which causes negative impacts, while the utilization of non-fossil energy is still low. The solution provided is the use of new and renewable energy that can be used for electricity production needs such as the use of Microbial Fuel Cell (MFC) technology. MFC is a bioelectristry-based device that converts chemical energy into electricity by utilizing organic compounds as well as utilizing enzymatic catalysts with the help of microorganisms. In this study, it used a dual chamber MFC 10x10x5 cm design to determine the output of current and voltage generated using a cement hollow membrane measuring 3 cm in diameter and 0.5 cm thick with a mixture of Sodium Clorida (NaCl). The anode compartment uses zinc plate (Zn) and the cathode uses copper plate (Cu) with the same size of 5x3 cm. The study used a ratio of 1: 1 for the variation of organic waste substrates of tofu liquid waste and banana peel waste mixed with rice field sludge. From the measurement results, electricity production is a maximum of 14 days on the tofu liquid waste substrate, namely with 6 days incubation and on the solid and liquid banana peel waste substrate, namely with 3 days incubation. The measurement results can be obtained a voltage of 252,010 mV, a current of 2.52 mA, and a power of 390.648 mW on the tofu liquid waste substrate, a voltage of 82.609 mV, a current of 0.828 mA, and a power of 68.543 mW on the solid banana peel waste substrate, and a voltage of 66 mV, a current of 0.66 mA, and a power of 43.6 mW on the liquid banana peel waste substrate.

Xiaoyuan Zhang, Deepak Pant, Fang Zhang et al.

ChemElectroChem • 2014

Abstract Activated carbon (AC) is a low‐cost and effective catalyst for oxygen reduction in air cathodes of microbial fuel cells (MFCs), but its performance must be maintained over time. AC was modified by three methods: 1) pyrolysis with iron ethylenediaminetetraacetic acid (AC‐Fe), 2) heat treatment (AC‐heat), and 3) mixing with carbon black (AC‐CB). The maximum power densities after one month with these AC cathodes were 35 % higher with AC‐Fe (1410±50 mW m −2 ) and AC‐heat (1400±20 mW m −2 ), and 16 % higher with AC‐CB (1210±30 mW m −2 ) than for plain AC (1040±20 mW m −2 ), versus 1270±50 mW m −2 for a Pt control. After 16 months, the Pt cathodes produced only 250±10 mW m −2 . However, the AC‐heat and AC‐CB cathodes still produced 960–970 mW m −2 , whereas plain AC produced 860±60 mW m −2 . The performance of the AC cathodes was restored to >85 % of the initial maximum power densities by cleaning with a weak acid solution. Based on cost considerations among the AC materials, AC‐CB appears to be the best choice for long‐term performance.

Gerard M. Delaney, H. Peter Bennetto, Jeremy R. Mason et al.

Journal of Chemical Technology and Biotechnology. Biotechnology • 1984

Abstract Various phenoxazine, phenothiazine, phenazine, indophenol and bipyridilium derivatives were tested for their effectiveness as redox mediators in microbial fuel cells containing Alcaligenes eutrophus, Bacillus subtilis, Escherichia coli , or Proteus vulgaris as the active biological agent, and glucose or succinate as the oxidisable substrate. A ferricyanide‐Pt cathode was used. The open‐circuit cell e.m.f.′s increased in the order of increasing negative formal redox potentials at pH 7(E 7 m ) of the redox compounds. Several of the redox agents worked well as mediators, maintaining steady currents over several hours, and thionine was found to be particularly effective in maintaining relatively high cell voltages when current was drawn from the cell. A number of the compounds tested did not function well, either because they were incompletely or slowly reduced by the microorganisms or because of their instability. P. vulgaris , with thionine as mediator and glucose as substrate, showed the best performance in a fuel cell. This system was examined in some detail under various conditions of external load to establish the effects of organism concentration, mediator concentration, and substrate addition. Coulombic outputs from these cells were calculated by integration of the current‐time plots. Coulombic yields of 30–60% were obtained, on the basis of (theoretical) complete oxidation of added substrate to CO 2 and water.

Adriano S. Gomes, Camilo E. La Rotta, Marcia Nitschke et al.

ECS Transactions • 2011

Microbial fuel cells (MFCs) are devices that use microorganisms to produce electricity. Pseudomonas aeruginosa is a rod-shaped bacterium and the only bacterial species that produces pyocyanin (PYO). In MFCs, the pyocyanin can play an important role as an electron shuttle. PYO production can be improved in glycerol enriched culture media. Glycerol has become a huge market problem because it is de main biodiesel byproduct. Its use as fuel in MFC is being promising. In the present study we evaluated in a MFC the current output achieved by pure cultures of P. aeruginosa cultivated in King broth medium using Nafion® 117 as proton exchange membrane. Results have shown that a maximum current output of 15.3 μAcm-2 can be achieved when using the chosen culture medium. In parallel, experiments involving the oxygen reduction reaction showed that Nafion® membranes can lose the activity due to the medium composition.

André Luiz Candido da Silva, Antonio Teixeira e Silva

Brazilian Journal of Radiation Sciences • 2021

The aim of this work is to present a comparative analysis in terms of the irradiation performance of cylindrical uranium dioxide fuel rods and monolithic uranium molybdenum fuel plates in pressurized light water reactors.To analyze the irradiation performance of monolithic uranium molybdenum fuel plates when subjected to steady state operating conditions in light water pressurized reactors, the computer program PADPLAC-UMo was used, which performs thermal and mechanical analysis of the fuel taking into account the physical , chemicals and irradiation effects to which this fuel is subjected. For the analysis of the uranium dioxide fuel rods, the code FRAPCON was used, which is an analytical tool that verifies the irradiation performance of fuel rods of pressurized light water reactor, when the power variations and the boundary conditions are slow enough for the term permanent regime to be applied. The analysis for a small nuclear power reactor, despite the higher power density applied to the fuel plate in relation to the fuel rod, showed that the fuel plates have lower temperatures and lower fission gas releases throughout the analyzed power history, allowing the use of a more compact reactor core without exceeding the design limits imposed on nuclear fuel.

M. Guo, X. R. Zai, T. Li et al.

Fuel Cells • 2018

Abstract As exogenous substances, L‐methionine, L‐threonine and L‐lysine were added into the marine sediment to construct marine sediments microbial fuel cells (MSMFCs) and the effects on the anodic electrochemical activity were following investigated. The results show that the addition of the amino acid increases anodic electrochemical activity, and the anode in L‐methionine modified sediment presents better performance than others. The specific capacitance of anode in L‐methionine modified sediment (192.00 F cm −2 ) is 4.0 times bigger than that of anode in unmodified sediment, generating a maximum current density of 2.560 × 10 −4 A cm −2 . In their Tafel curves, the anodic exchange current density in the L‐methionine modified sediment (2.14 × 10 −6 A cm −2 ) is 93.04 times higher than that of unmodified anode, which suggests that the electrochemical activity of redox, anti‐polarization ability and electron transfer kinetic activity are improved significantly. The MSMFC with L‐methionine modified sediment generates the higher power densities than the blank (143.2 mW m −2 versus 59.2 mW m −2 ), and its current also increases by 2.8 times. This demonstrates that L‐methionine provides a practical advantage on the anodic electrochemical and battery performance. Therefore, amino acids are good tools to evaluate its power generation of the MSMFCs.

Yongfeng Liu, Jianhua Gao, Na Wang et al.

Applied Sciences • 2018

A three-dimensional and isothermal anode relative humidity (ARH) model is presented and used to study the anode inlet humidity effects on the fastest power attenuation single cell in a vehicle fuel cell stack. The ARH model is based on the phenomenon that the anode is more sensitive than the cathode to water flooding. The pressure drop is considered in the ARH model, and saturation pressure is established by a pressure drop. Based on the pressure drop and relative humidity, simulations and tests are completed. First, the geometric model and computational grids are established, based on real structure of the proton exchange membrane fuel cell (PEMFC). Second, single cell distribution in the stack, test schematic and experimental conditions are demonstrated. Finally, polarization curves with 10 cells are displayed and discussed under these conditions that working temperature 70 °C, and diverse relative humidity (40%, 55%, 70%, 85%, and 100%). The test results of 34 cm2 fuel cell stack are compared against simulation results. The results show that C10 (the single cell with the farthest distance from the gas inlet) power attenuation is the fastest and that its performance is the poorest under the experimental conditions. The polarization curves predicted by the ARH model indicate fairly good coherence with the experimental results, compared against the Fluent original model. The ARH model calculation deviation is 28% less than the Fluent model at 360 mA·cm−2 for a relative humidity of 85%. The current density distribution is almost uniform, and membrane water content is negatively affected by high humidity.

Chun-Hsien Kuo

ECS Meeting Abstracts • 2020

When the volume of a product decreases and the need of power supply remains, the problem of lacking of space for power equipment appears. In this condition, flat planar fuel cells could be one of the solutions for this challenge; additionally, flat planar flexible fuel cells with non-latch locks can be applied to products with curvy surface in order to fit with their aesthetic design. This research analyzes the parameters of fuel cell bending deformation to find the best combination. The Taguchi method is applied to optimize the following parameters: bending direction, width of pressing bead, pressing force, curvature depth, bending times, opening rate of cathode air-intake holes, as well as elongation. The test results indicate the highest contribution rate with the bending depth, followed by the bead area, and the third one is the circular cathode air-intake holes. All of the above parameters have contribution rates over 10%. Moreover, the 15% elongation of cathode, arranged with larger curvature depth and smaller width of pressing bead, concentrates the force within specific portion and makes the internal resistance smaller. The overall performance of the fuel cell is thus improved. Fuel cell components in this research are laminated with glue, instead of screw locking, in order to better prevent gas leakage and to have better anti-vibration ability. The fuel cell can even be formed into U-shape to fit the curvy surface of different products. The fuel cell’s power density acquired from the optimized parameters by the Taguchi method is 82.5mW/cm^2. This is also the optimized power density for the fuel cell.

Idoia San Martín, Alfredo Ursúa, Pablo Sanchis

Energies • 2014

This paper reports on the modelling of a commercial 1.2 kW proton exchange membrane fuel cell (PEMFC), based on interrelated electrical and thermal models. The electrical model proposed is based on the integration of the thermodynamic and electrochemical phenomena taking place in the FC whilst the thermal model is established from the FC thermal energy balance. The combination of both models makes it possible to predict the FC voltage, based on the current demanded and the ambient temperature. Furthermore, an experimental characterization is conducted and the parameters for the models associated with the FC electrical and thermal performance are obtained. The models are implemented in Matlab Simulink and validated in a number of operating environments, for steady-state and dynamic modes alike. In turn, the FC models are validated in an actual microgrid operating environment, through the series connection of 4 PEMFC. The simulations of the models precisely and accurately reproduce the FC electrical and thermal performance.

Samar Amari, Mohammad Boshrouyeh Ghandashtani

Water and Environment Journal • 2019

Abstract The two‐chambered microbial fuel cell (MFC) was designed and used for studying the efficiency of the real wastewater treatment from a non‐steroidal anti‐inflammatory pharmaceutical plant as well as from synthetic wastewater containing diclofenac sodium (DS). The removal of the contaminants was expressed regarding chemical oxygen demand (COD) removal, as measured by spectrophotometry experiments. Moreover, the effect of two different types of the cathode on current characteristics and COD removal was investigated. This research showed that the Pt‐coated Ti cathode could lead to higher efficiency of both power density and COD removal. In this case, the results indicated that the maximum power density ( P max ) was 20.5 and 6.5 W/m 3 and the maximum COD removal was 93 and 78% for MFCs using real and synthetic wastewater, respectively.

Mojeed Opeyemi Oyedeji, Abdullah Alharbi, Mujahed Aldhaifallah et al.

Energies • 2023

Microbial fuel cells (MFCs) are biocells that use microorganisms as biocatalysts to break down organic matter and convert chemical energy into electrical energy. Presently, the application of MFCs as alternative energy sources is limited by their low power attribute. Optimization of MFCs is very important to harness optimum energy. In this study, we develop optimal data-driven models for a typical MFC synthesized from polymethylmethacrylate and two graphite plates using machine learning algorithms including support vector regression (SVR), artificial neural networks (ANNs), Gaussian process regression (GPR), and ensemble learners. Power density and output voltage were modeled from two different datasets; the first dataset has current density and anolyte concentration as features, while the second dataset considers current density and chemical oxygen demand as features. Hyperparameter optimization was carried out on each of the considered machine learning-based models using Bayesian optimization, grid search, and random search to arrive at the best possible models for the MFC. A model was derived for power density and output voltage having 99% accuracy on testing set evaluations.

Thabed Tholib Baladraf

ECS Meeting Abstracts • 2021

The increase in world population is in line with the increase in the amount of energy demand, especially electricity. However, the energy used today is still using fossil energy, which one day will run out. Dependence on non-renewable energy causes weak energy resistance, resulting in electricity scarcity. Microbial fuel cells (MFC) can be a new alternative energy source because they can generate electrical energy by utilizing the interactions of bacteria found in nature. To fulfill electricity needs, researchers created a tool that can generate electrical energy by utilizing food waste and human waste as a substrate which is converted into electrical energy through the bioelectrochemical activity of electrons and protons by bacteria. The tool is integrated with the internet of things as an effort to use technology so that it can control temperature and voltage automatically. This research was aimed to determine the design of a tool to convert food waste and human waste into clean renewable electrical energy, determine the working principle of the tool, determine the efficiency of the tool in producing electrical energy, and determine the potential of the tool to meet electricity needs. The research was carried out using 3 variations, namely variation 1 (zinc and cathode), variation 2 (food waste, human waste, and water), variation 3 (carbon, cathode, nutrient broth, electrolyte solution, food waste, and human waste). The tool created is portable with a DC voltage of 12 V to AC 220 V 500 W and the best results are obtained from variation 3 with 26.6 volts from 1.8 liters of food waste and human waste to obtain a voltage efficiency of up to 95%. This tool has the potential to overcome the electrical energy crisis and fulfill people's electricity needs by utilizing food waste and human waste.

Alfredo Costilla Reyes, Celal Erbay, Salvador Carreon-Bautista et al.

Applied Sciences • 2018

Microbial Fuel Cell (MFC) technology is a novel Energy Harvesting (EH) source that can transform organic substrates in wastewater into electricity through a bioelectrochemical process. However, its limited output power available per liter is in the range of a few milliwatts, which results very limited to be used by an Internet of Things (IoT) smart node that could require power in the order of hundreds of milliwatts when in full operation. One way to reach a usable power output is to connect several MFCs in series or parallel; nevertheless, the high output characteristic resistance of MFCs and differences in output voltage from multiple MFCs, dramatically worsens its power efficiency for both series and parallel arrangements. In this paper, a Power Management System (PMS) is proposed to allow maximum power harvesting from multiple MFCs while providing a regulated output voltage. To enable a more efficient and reliable power-harvesting process from multiple MFCs that considers the biochemical limitations of the bacteria to extend its lifetime, a power ranking and MFC health-protection algorithm using an interleaved EH operation was implemented in a PIC24F16KA102 microcontroller. A power extraction sub-block of the system includes an ultra-low-power BQ25505 step-up DC-DC converter, which integrates Maximum Power Point Tracking (MPPT) capabilities. The maximum efficiency measured of the PMS was ~50.7%. The energy harvesting technique presented in this work was tested to power an internet-enabled temperature-sensing smart node.

Emut Sukma Sejati, Sudarlin

Journal of Physics: Conference Series • 2021

Abstract Ceramic is low-cost separator membrane has widely applied in dual-chambered Microbial Fuel Cell (MFC). Its big pores and other chemical and physical advantages make it suitable to substitute expensive exchange separator membranes. The purpose of this study is to enhance electricity of ceramic-based microbial fuel cell by using various number of carbon electrode pairs. This study uses tempe waste as anolyte and KMnO4 as its catholyte to gain electricity. Three variety of electrode pairs data of electricity result is processed statistically to examine significant difference of voltage, current, and power density as parameters. The result of this study shows that electricity of three-electrode pairs has a higher average of power density with the number 1447,91 mW/m 2 , the difference between three and two electrode pairs is around 588 mW/m 2 and between three and one electrode pairs is 910 mW/m 2 . It has significant difference between one, two, and three-electrode pairs in the parameters.

Yang-Guo Zhao, Yanhui Zhao, Yi Zhang et al.

Water Science and Technology • 2018

Abstract Thermophile pretreatment of activated sludge greatly improves the biodegradability of sludge, but whether the pretreated products are suitable for the electricity generation of microbial fuel cells (MFCs) is still little known. In this study, municipal activated sludge pretreated by a thermophilic bacterium and heating, respectively, was separately fed into the MFCs. The performance of MFCs was examined and changes of anodic microbial communities were investigated with scanning electron microscopy and 16S rRNA gene high-throughput sequencing on the Illumina Miseq platform. The results showed that MFCs fed with heating-pretreated sludge performed preferably and the power density reached 0.91–2.86 W/m3. MFC anodes were covered with considerable Geobacter spp. However, the bioaugmentation of sludge with the thermophile was not able to support a high potential output although the pretreatment significantly increased the soluble chemical oxygen demand. The maximum power density approached 0.20 W/m3 even when the anolyte was regularly changed. It was observed that amending pH did not improve the performance of MFC. Investigation on this anodic microbial community found that the relative abundance of Lactobacillus spp. exceeded 91%. Consequently, the thermophile-pretreated products stimulated the growth of non-exoelectrogens and finally the niches of anodic biofilm were completely occupied by Lactobacillus spp.

Pranabendu Mitra, Gordon A. Hill

The Canadian Journal of Chemical Engineering • 2011

Abstract A complete microbial fuel cell (MFC) operating under continuous flow conditions and using Chlorella vulgaris at the cathode and Saccharomyces cerevisiae at the anode was investigated for the production of electricity. The MFC was loaded with different resistances to characterise its power capabilities and voltage dynamics. A cell recycle system was also introduced to the cathode to observe the effect of microalgae cell density on steady‐state power production and dynamic voltage profiles. At the maximum microalgae cell density of 2140 mg/L, a maximum power level of 0.6 mW/m 2 of electrode surface area was achieved. The voltage difference between the cathode and anode decreased as the resistance decreased within the closed circuit, with a maximum open circuit voltage (infinite resistance) of 220 mV. The highest current flow of 1.0 mA/m 2 of electrode surface area was achieved at an applied resistance of 250 Ω.

Bustami Ibrahim, Uju Uju, Alvindo Chrisna Mukti

Jurnal Pengolahan Hasil Perikanan Indonesia • 2019

Microbial fuel cell (MFC) is a bioreactor utilizing bacteria as electrocatalysts to convert bioenergy from biomass into electrical energy. The aim of this research were to determine the effects of the electrode distance on the bacterial density and the electrical value generated by the MFC as well as to evaluate the ability of MFC in reducing the pollutant. Single chamber MFC system with various electrode distances including 2 cm, 4 cm, and 6 cm were assembled. The wastewater of fish pindang processing was used as the medium<br />for the MFC. The results showed that the distance had no effect on the biofilm density of the electrode and the reduction of the wastewater pollutant load. However, the distance affected the electrical value of the<br />MFC. Biofilm density on the MFC electrode after 120 hours was 0.65-6.46 CFU/ cm2. The highest voltage was obtained from the 6 cm electrode distance with the voltage 0.38±0.01 V. Positive correlation (R2 = 0.99)<br />between microbial density and electricity produced at the cathode was observed, but weak at the anoda (R2 = 0.47). The MFC system could decrease the BOD value up to 50.78% and COD up to 33.29%, however the TAN value was increased to 6 mg/L.

Xiaoye Xing, Zhongliang Liu, Wenwen Chen et al.

Catalysts • 2020

Dandelion seeds (DSs) have the advantages of high nitrogen content, low cost and easy availability and thus are ideal carbon precursors for fabricating carbon nanomaterials. Herein, this paper prepared a carbon nanosheet material by one-step carbonizing DSs with KOH activation (self-doped-nitrogen porous carbon nanosheets (N-CNS)) and without KOH activation (unactivated self-doped-nitrogen porous carbon nanosheets (N-UA-CNS)), which could dope nitrogen atoms directly into carbon materials without additional processes. Scanning electron microscopy(SEM) images and X-ray diffraction(XRD) patterns both showed that N-CNS was of macro-porous structure, and beneficial for microorganisms’ growth. The Brunauer Emmett Teller(BET) surface area of N-CNS was 2107.5 m2 g−1, which was much higher than that of N-UA-CNS. After carbon clothes were modified by the obtained materials, the internal resistance of both N-CNS-modified carbon cloth (N-CNS-CC) and N-UA-CNS-modified carbon cloth (N-UA-CNS-CC) was greatly reduced and was found to be only 2.7 Ω and 4.0 Ω, respectively which are all significantly smaller than that of blank carbon cloth (65.1 Ω). These electrodes were assembled in microbial fuel cells (MFCs) as anode, and the operation experiments showed that the N-CNS modification shortened start-up time, improved output stability and increased maximum output voltage significantly. The maximum power density of N-CNS-CC MFC was 1122.41 mW m−2 which was 1.3 times of that of N-UA-CNS-CC MFC and 1.6 times of that of CC MFC. The results demonstrated that N-CNS was an ideal modification material for fabricating MFC anodes with simple preparation process and low cost.

Junxian Shi, Anhuai Lu, Haibin Chu et al.

Applied Sciences • 2018

Developing simple and cheap electrocatalysts or photocatalysts for cathodes to increase the oxygen reduction process is a key factor for better utilization of microbial fuel cells (MFCs). Here, we report the investigation of natural wolframite employed as a low-cost cathode photocatalyst to improve the performance of MFCs. The semiconducting wolframite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The band gap and photo respond activities were determined by UV-vis spectroscopy and linear sweep voltammetry (LSV), respectively. Compared with the normal graphite cathode, when MFCs were equipped with a wolframite-coated cathode, the maximum power density was increased from 41.47 mW·m−2 to 95.51 mW·m−2. Notably, the maximum power density further improved to 135.57 mW·m−2 under light irradiation, which was 2.4 times higher than with a graphite cathode. Our research demonstrated that natural wolframite, a low-cost and abundant natural semiconducting mineral, showed promise as an effective photocathode catalyst which has great potential applications related to utilizing natural minerals in MFCs and for environmental remediation by MFCs in the future.

Silvia Wessel, Shanna Knights, Mike Lauritzen et al.

ECS Meeting Abstracts • 2014

Over the past 30 years Ballard’s PEM fuel technology evolved from proof-of-concept single cells via sub-scale and full-scale prototype systems to products in the areas of motive power (buses and materials handling), back-up power, co-generation, and distributed power generation which have been deployed extensively in demonstration programs and field trails. Today, Ballard is a leader in fuel cell stack design and manufacturing with products being commercially deployed in the materials handing and back-up power markets which both benefit from attractive financial value propositions. Furthermore, extensive research and development is also focused on bus stack and large scale distributed generation technology. In early technology demonstrations and field trials specifically in the transportation sector fuel cell performance was the key attribute under consideration; however, today the emphasis is on durability and cost which are the two major challenges that still hinder large-scale commercialization of fuel cell technology across all markets. Since 1991 Ballard’s fuel cell bus technology has been deployed in a variety of demonstration projects and today 49 fuel cell buses are in operation worldwide. The largest bus fleet deployed in 2009 in Whistler, B.C. has accumulated more than 150,000 hours of operational hours and a total driving distance of >3 million kilometers. The figure on the right shows the average cell performance of the buses which exceeds the warranted operational life of 8000 hours of the HD6 stack. As opportunities in the fuel cell bus market have accelerated over the last decade and with the development of over six generations of fuel cell modules, Ballard has overcome technical barriers related to power density and reliability. To date, the bus transportation platform developed by Ballard has been proven to meet the demands of range and duty cycle expectations, but the key barriers pertaining to cost and durability under the wide range of operating conditions necessary for transportation fuel cell stacks still remain. Ballard’s overall activities on reducing product cost have been driven by several approaches; (1) product design improvements that include reduced platinum loadings, lower part counts, and enhanced durability, (2) reduced sourcing costs through lower materials costs and increased volumes, (3) increased manufacturing efficiencies including use of continuous, automated assembly, (4) production scale up through increased market penetration. Since 2003 Ballard has achieved substantial cost reductions while increasing stack operational life 4-fold. Ballard’s large numbers of demonstration programs and field trials have been instrumental in providing insight into stack and MEA failure modes and this understandingtogether with modeling and fundamental research has been a driver in durability improvement through MEA design opportunities and operational mitigation strategies. The work that will be presented will provide an overview of Ballard’s Fuel Cell bus program, discuss the different aspects of stack durability that has been achieved over the last 10 years, and provide an insight into current research and development that is needed to narrow the durability and cost gap for large-scale commercialization.

Gaixiu Yang, Dong Chen, Pengmei Lv et al.

Scientific Reports • 2016

Abstract Bimetallic nanoparticles with core-shell structures usually display enhanced catalytic properties due to the lattice strain created between the core and shell regions. In this study, we demonstrate the application of bimetallic Au-Pd nanoparticles with an Au core and a thin Pd shell as cathode catalysts in microbial fuel cells, which represent a promising technology for wastewater treatment, while directly generating electrical energy. In specific, in comparison with the hollow structured Pt nanoparticles, a benchmark for the electrocatalysis, the bimetallic core-shell Au-Pd nanoparticles are found to have superior activity and stability for oxygen reduction reaction in a neutral condition due to the strong electronic interaction and lattice strain effect between the Au core and the Pd shell domains. The maximum power density generated in a membraneless single-chamber microbial fuel cell running on wastewater with core-shell Au-Pd as cathode catalysts is ca. 16.0 W m −3 and remains stable over 150 days, clearly illustrating the potential of core-shell nanostructures in the applications of microbial fuel cells.

Kumar Pijush Kataky, Amaresh Dalal, Gautam Biswas et al.

IOP Conference Series: Earth and Environmental Science • 2020

Abstract Microbial Fuel Cell (MFC) has various application potential as in generation of bioelectricity, bio-hydrogen production, waste water treatment and it is also used as biosensors. It would not be possible to headway without mentioning that MFCs have quite a many similarities with Chemical Fuel Cells (CFC). It is seen that a lot of research is carried out for CFCs as compared to MFCs. Most of the research works on MFCs include experimental approach while very few computational studies have been carried out for MFCs. So an endeavour is made to create a model which mimics the working by simulating the key physical and biochemical processes occurring. Results imply that variation of current density occurs with change in Reynolds number (Re) and kinetic rate of reaction (k) which lead to the study of effects of variation of flow rates, turbulence and the action of different bacteria in the efficiency of MFCs. The current density achieved computationally is around 512 mA/m 2 for Re=5 and k=10 −3 which is in good agreement with the experimental data. Regions of higher current density are found which can be used to improvise the MFCs. Present mathematical model provides a new perspective in understanding the biomass concentration across the MFC and gives better knowledge of the mechanisms taking place. This simple computational framework provides insight into the fluid dynamics involved during continuous feeding, by overcoming the limitations and technical barriers in monitoring and examining through experiments. By implementing the findings from this model optimization of designs can be achieved leading to higher current generation, increase in efficacy and cost effective production techniques which paves the way for future work.

Uttam Ghosh, Rahul Gautam, Jagdeep Nayak

Global NEST International Conference on Environmental Science & Technology • 2022

Microbial Fuel Cell (MFC) technology is based on bioelectrochemical system, extract power from organic load of the wastes to produce bio-electricity. The present study have evaluated the effect of the different electrode materials in two sets of mediator-less H- type double chambered MFC operated at 30 ± 2 °C in a batch mode. In MFCGG, graphite rods (G) and in MFCCBG carbon brush (CB) and graphite rod (G) were used as anode and cathode electrode respectively. The both MFC were fed with distillery spent wash as a substrate with HRT of 21 days. The maximum COD removal of 61.07 % and 67.17 %; open circuit voltage (OCV) of 565 and 735 mV were achieved in MFCGG and MFCCBG respectively. The peak power densities of 3.19 W/m2 and 5.4 W/m2 were recorded in MFCGG and MFCCBG. These results suggest the efficacy of carbon brush anode in MFCCBG compared to graphite rod as an anode material in MFC for bioelectricity production.

Prapti Ira Kumalasari, Junety Monde, Zefanya Bernadi Yusuf et al.

CHEESA: Chemical Engineering Research Articles • 2019

<p class="PageNumber1">Kalimantan merupakan pulau yang terkenal akan sektor pertambangan salah satunya di daerah delta Mahakam, yang dalam proses eksploitasinya berpotensi menghasilkan limbah logam berat, seperti logam berat Cr<sup>6+</sup>. Pencemaran logam Cr<sup>6+</sup> cukup sulit untuk terurai dilingkungan dan bersifat karsinogenik, karena dengan konsentrasi kecil saja dapat menimbulkan tingkat keracunan yang sangat tinggi pada makhluk hidup, sehingga pengolahan terhadap limbah tersebut sangat penting. <em>Microbial Fuel Cell</em> merupakan suatu metode yang dapat membantu proses pengolahan limbah dengan cara mereduksi Cr<sup>6+</sup> menjadi Cr<sup>3+</sup> dengan katalisis mikrobiologis. Penelitian ini menggunakan metode reaktor <em>double-chamber</em> yaitu terdapat ruang anoda yang berisi bakteri anaerob dan <em>basic anolyte</em>, sedangkan pada ruang katoda terdapat kalium dikromat dengan konsentrasi 18 mg/L dan variasi pH 3, 4 dan 5 yang dilakukan selama 10 hari. Kondisi pH optimum pada proses reduksi terjadi pada pH 4 dengan besar persen penurunan sekitar 98%. Dan produksi listrik tertinggi pada hari ke-2 pada variasi pH 3 dengan nilai power density sebesar sebesar 11, 06 mW/m<sup>2</sup>.</p>

Shalini Prajapati, Pydi Setty Yelamarthi

Asia-Pacific Journal of Chemical Engineering • 2020

Abstract Microbial fuel cell (MFC) is a promising technology for wastewater treatment coupled with electricity generation. Biowaste‐derived electrodes are used to improve the surface area, roughness, and hydrophilicity, which play pivotal role in the enhanced biofilm formation. In the present study, Ficus religiosa leaves (FRL) biowaste was used to develop the bioelectrode. In this study, Congo red (CR) dye decolorization was performed using MFC, wherein the effect of dye decolorization with respect to dye concentration, glucose concentration, and hydraulic retention time (HRT) was studied. The surface roughness and distribution of carbon powder on carbon cloth were confirmed using scanning electron microscope (SEM) analysis. Also, Bacillus subtilis adhesion and chain‐like structure formation on the electrode confirmed the biofilm formation on the electrode. The polarization curve was performed to assess the MFC performance. The maximum power density of 70.50 mW/m 2 and current density of 251.79 mA/m 2 at 2,224 Ω was achieved. The maximum decolorization of 80.95 ± 2.08% and COD reduction of 73.96 ± 1.76% were obtained, respectively, after complete treatment of MFC for 54 h. UV‐visible spectrometry analysis of dye contained samples during MFC treatment at various time intervals was confirmed the cleavage of azo bond (NN), and the corresponding peak intensity variation was noticed at 490 nm.

Wenguo Wu, Huiya Hong, Jia Lin et al.

Biosensors • 2024

Simultaneous monitoring of antimicrobial responses to bacterial metabolic activity and biofilm formation is critical for efficient screening of new anti-biofilm drugs. A microbial fuel cell-based biosensor using Pseudomonas aeruginosa as an electricigen was constructed. The effects of silver nanoparticles (AgNPs) on the cellular metabolic activity and biofilm formation of P. aeruginosa in the biosensors were investigated and compared with the traditional biofilm detection method. The crystal violet staining results showed that the concentration of AgNPs being increased to 20 and 40 μg/mL had a slight and obvious inhibitory effect on biofilm formation, respectively. In comparison, the detection sensitivity of the biosensor was much higher. When the concentration of AgNPs was 5 μg/mL, the output voltage of the biosensor was suppressed, and the inhibition gradually increased with the AgNPs dose. AgNPs inhibited the activity of planktonic cells in the anolyte and the formation of biofilm on the anode surface, and it had a dose-dependent effect on the secretion of phenazine in the anolyte. The biosensor could monitor the impacts of AgNPs not only on biofilm formation but also on cell activity and metabolic activity. It provides a new and sensitive method for the screening of anti-biofilm drugs.

Bustami Ibrahim, Pipih Suptijah, Bagus Sukma Agung

Jurnal Pengolahan Hasil Perikanan Indonesia • 2017

Microbial fuel cell (MFC) is a technology that can produce electricity with helping exoelectrogenic<br />bacteria. The technology can also utilize fishery processing wastewater as a media for bacteria to live, so<br />it can reduce organic pollution load in the wastewater. Purpose of this research was to identify the effect<br />of electrodes distance to electricity and water quality parameters of fisheries processing wastewater using<br />MFC technology.. The MFC system used was single chamber system. The distance between electrodes used<br />were 2 cm, 4 cm and 6 cm and the electrodes were made of stainless wire mesh coated with chitosan and<br />active carbon. The results showed that electrodes distance affected to MFC electricity within salted boiled<br />fish wastewater media. The average value of electric current during 48 hours observation on the distance<br />of 2 cm, 4 cm and 6 cm were 0.17±0.06 mA, 0.46±0.17 mA and 0.44±0.16 mA, respectively. Average values<br />of electric voltage on the distance of 2 cm, 4 cm and 6 cm were 0.12±0.03 V, 0.34±0.07 V and 0.37±0.08 V,<br />respectively. The research also showed that MFC system can decrease average value of BOD 20.5%, COD<br />30.41%, and TAN 21.2 % of salted boiled fish wastewater media.<br /><br />

Jon Chouler, Mirella Di Lorenzo

Water Science and Technology • 2019

Abstract Microbial fuel cell (MFC) technology holds enormous potential for inexpensive real-time and onsite testing of water sources. With the intent of defining optimal operational conditions, we investigated the effect of environmental factors (changes in temperature, pH and ionic strength), on the performance of a single chamber miniature MFC sensor. The pH of the influent had the greatest effect on the MFC performance, with a 0.531 ± 0.064 μA cm−2 current variation per unit change of pH. Within the range tested, temperature and ionic strength had only a minor impact (0.010 ± 0.001 μA °C−1 cm−2 and of 0.027 ± 0.003 μA mS−1 cm cm−2 respectively). Under controlled operational conditions, for the first time, we demonstrated the ability of this biosensor to detect one of the most commonly applied pesticides worldwide, atrazine. The sensitivity to atrazine was 1.39 ± 0.26 ppm−1 cm−2, with a detection range of 0.05–0.3 ppm. Guidelines for systematic studies of MFC biosensors for practical applications through a factorial design approach are also provided. Consequently, our work not only enforces the promise of miniature MFC biosensors for organic pollutants detection in waters, but it also provides important directions towards future investigations for infield applications.

Tensay Kifle, Esayas Alemayehu, Chali Dereje Kitila

Environmental Health Engineering and Management • 2023

Background: The energy crisis is a growing problem around the world, requiring the creation of alternative energy sources that can generate less carbon dioxide and benefit the ecosystem. Reutilization of wastewater is becoming the emerging energy solution. Wastewater contains a large amount of organic matter that can be oxidized in microbial fuel cells (MFCs) to produce electricity. MFCs use biodegradable materials to create energy in the presence of microorganisms. Methods: Purposive sampling technique was employed to collect samples from critical polluting sources. The samples were certainly maintained in a refrigerator at 4°C. Several mixes for sample were prepared and tested analytically- for physio-chemical and bacteriological characterizations of each substrate status at pre- and post-treatment stages. Electricity generating capacity of MFCs that employing different substrates was investigated experimentally using batch reactors. The cross-sectional methodology was employed to study possible power generation. Results: The maximum voltage output of 118.93, 144.84, and 89.76 mV were produced keeping the resistance unlimited for MFC1 (urine substrate), MFC2 (blackwater substrate), and MFC3 (graywater substrate), respectively. MFC that utilized graywater as a substrate brought the tiniest quantity of electricity; however, it stood the most stable. The highest COD reduction (65.83%) in the process was reported in urine substrate and the highest BOD5 removal (69.18%) was reported in black water substrate. Conclusion: The experimental results provided a promising indication of MFCs viability, providing hope for future power generation and alternative wastewater treatment option in developing countries.

Diana Marcela Vanegas-Hernández, Mónica Liliana Cardona-Aristizabal, Zulamita Zapata-Benabithe

Revista Facultad de Ingeniería • 2020

In this work, three types of activated carbons were evaluated as electrodes in the anode chamber of a two-chamber microbial fuel cell (MFC). The evaluation was applied using a pure Shewanella Putrefaciens culture due to its gram-negative characteristics. In the cathode chamber, a platinum electrode was used, and a Nafion® 117 proton exchange membrane was selected as a separator of both chambers. The activated carbons were obtained from different precursors (coffee husk, commercial coal, and mineral coal), with different microporous and surface properties. From the voltage and current measurements, it was found that the cell power values varied between 0.008 mW and 0.045 mW. The electrode obtained from chemical activation of coffee husk with H3PO4 at 450 °C (Q) showed the best electrochemical behaviour and highest power values. This result may be mainly related to the macroscopic morphology and mesopores that improve the wettability of the surface by the medium thought carbonaceous material. SEM images showed a better biofilm formation, larger filaments of the bacteria, and micro-beds formation over the surface of bio-anode Q, which improved the interaction with the microorganism, its metabolism, and electrons extracellular transfer. Therefore, activated carbon from coffee husk could be considered as a promising material for electrodes of microbial fuel cells.

Seonyeob Kim, Agha Raza Abid, Jae Jun Jang et al.

Journal of Fuel Cell Science and Technology • 2013

A new hybrid system of molten carbonate fuel cell (MCFC) and homogenous charge compression ignition (HCCI) engine is suggested to improve the overall system efficiency and performance. In the proposed system, the catalytic burner in a standalone MCFC system is replaced with the HCCI engine. The HCCI engine is chosen over conventional spark-ignition or compression-ignition engines since it has been demonstrated to operate with highly diluted reactant mixture, which is suitable to run directly with the MCFC anode off-gas. A nonisothermal numerical model that incorporates major fuel cell losses is developed to predict the fuel cell performance. The fuel cell model assumes parallel anode and cathode flow configuration with LiNaCO3 as an electrolyte. It is integrated with an in-house HCCI engine model to investigate the hybrid system performance. At the selected design point operation around 300 kW power output, the maximum hybrid system efficiency is 21.2% (relative) higher than that of a standalone fuel cell system and, thus, achieving around 60% overall, which demonstrates the potential of the suggested hybrid system as a highly-efficient distributed power generation source in the near future.

P. Gazdzicki, J. Mitzel, A. M. Dreizler et al.

Fuel Cells • 2017

Abstract The paper focuses on the investigation of durability and performance of a low temperature polymer electrolyte membrane fuel cell (PEMFC) stack as a function of Pt loading in automotive test conditions. Major motivations are problems related to the need to reduce the amount of Pt in membrane electrode assemblies (MEAs) in order to make PEMFC more competitive. The particular challenge is to maintain sufficiently high performance and long‐term durability. The study shows that for cathode Pt loadings below 0.2 mg cm −2 and for current densities exceeding 1 A cm −2 a sudden drop of performance is observed. The same threshold value is found for the increase of irreversible voltage losses which lead to an intense reduction of PEMFC durability for cathodic loadings below 0.2 mg cm −2 . Another durability issue at cathodic Pt loadings < 0.4 mg cm −2 is the acceleration of reversible degradation, which leads to a strong voltage drop during continues fuel cell operation (i.e., without a recovery interruption).

Antonia Jimenez Rodrí­guez, Antonio Serrano, Teresa Benjumea et al.

Emerging Science Journal • 2019

The bioelectrochemical systems are a sustainable technology that can be used to obtain electricity and/or reduced compounds. However, this novel technology presents several challenges prior to its implementation at full-scale. The aim of the present study was to evaluate different nanomaterials of electrode and mediators to increase the performance of BioElectrochemical Systems production. In order to achieve this objective, it was compared the use of Multiwall Carbon Nanotubes and Multiwall Carbon Nanotubes plus electron exogenous mediator (Meldola's Blue) against plain graphite anode in order to evaluate the overall start-up time and other electro-chemical features. The use of multi-walled carbon nanotubes reduces substantially (by 75%) the start-up time required in a microbial fuel cell to produce stable voltage both, with and without the use of mediator compare to the plain anode. This reduction of the required time can be a consequence of the formation of anodic binders between this compound and the bacteria. With the independence of the start-up time, the current production was similar in the three studied cases, about 650 mV. Use of nanotubes modified anode surfaces might be especially interesting in cases of recovery after unstable operation of a microbial fuel cell, and/or reducing the start-up time for the generation of energy from new systems.

I. S. Michie, J. R. Kim, R. M. Dinsdale et al.

Water Science and Technology • 2013

For the successful scale-up of microbial fuel cell (MFC) systems, enrichment strategies are required that not only maximise reactor performance but also allow anodic biofilms to be robust to environmental change. Cluster analysis of Denaturing Gradient Gel Electrophoresis community fingerprints showed that anodic biofilms were enriched according to substrate type and temperature. Acetate produced the highest power density of 7.2 W m−3 and butyrate the lowest at 0.29 W m−3, but it was also found that the trophic conditions used to acclimate the electrogenic biofilms also determined the MFC response to different substrate types, with both acetate and butyrate substrates recording power densities of 1.07 and 1.0 W m−3 respectively in a sucrose enriched reactor. When temperature perturbations were introduced to investigate the stability of the different substrate acclimated electrogenic biofilms, the 20 °C acclimated acetate reactor was unaffected by 10 °C operation but all reactors acclimated at 35 °C were adversely affected. When the operating temperature was raised back to 35 °C both the acetate and butyrate reactors recovered electrogenic activity but the sucrose reactor did not. It is thought that this was due to the more complex syntropic interactions that are required to occur when metabolising more complex substrate types.

Khair Un Nisa, Williane da Silva Freitas, Alessandra D’Epifanio et al.

Catalysts • 2024

Microbial fuel cells (MFCs) are sustainable energy recovery systems because they use organic waste as biofuel. Using critical raw materials (CRMs), like platinum-group metals, at the cathode side threatens MFC technology’s sustainability and raises costs. By developing an efficient electrode design for MFC performance enhancement, CRM-based cathodic catalysts should be replaced with CRM-free materials. This work proposes developing and optimizing iron-based air cathodes for enhancing oxygen reduction in MFCs. By subjecting iron phthalocyanine and carbon black pearls to controlled thermal treatments, we obtained Fe-based electrocatalysts combining high surface area (628 m2 g−1) and catalytic activity for O2 reduction at near-neutral pH. The electrocatalysts were integrated on carbon cloth and carbon paper to obtain gas diffusion electrodes whose architecture was optimized to maximize MFC performance. Excellent cell performance was achieved with the carbon-paper-based cathode modified with the Fe-based electrocatalysts (maximum power density-PDmax = 1028 mWm−2) compared to a traditional electrode design based on carbon cloth (619 mWm−2), indicating the optimized cathodes as promising electrodes for energy recovery in an MFC application.

Ivar Kruusenberg, Kush Chadha, Taarini Atal

ECS Meeting Abstracts • 2022

It is of utmost importance to develop light weight fuel cell stacks and find the ways to integrate these to light weight and low temperature fuel cell systems. In order to meet the future energy demands non-polluting, compact, transportation and portable applications are required. Current energy systems have lower power density (kW/kg) resulting in optimized power only at higher overall weight. Systems with higher power density demands higher initial setup costs. Low temperature PEMFC, on other hand offers various advantages but fails to provide the required output without exceeding the weight of the fuel cell stack and thereby fuel cell systems. A fuel cell system consists of a fuel cell stack, compressed gas in cylinder, pressure relief valves, regulators, water pump, sensors and cvm. A fuel cell stack is the main component consisting of one of the devices with maximum weight and cost contribution. In such case, developing a system with stack having higher power density reduces overall weight and increases power density (kW/kg). PowerUP Energy Technologies has developed light weight fuel cell stack to achieve higher power density. Experiments considering flow field designs, recirculation strategy, different anode configuration has been a subject of study. Dead-end anode, closed cathode configuration of fuel cell stack further improves fuel utilization. Recirculation line of hydrogen if further added can improve in overall fuel utilization. Counter flow arrangement for reactant distribution further removes the necessity of humidifying the gases. This result in removal of humidifiers and thereby reducing the weight of the fuel cell system in total. Portable fuel cell systems have flexibility for ease in transportation and stationery solutions. Furthermore, lighter fuel cell stacks add advantage for higher output power at lower overall weights. This stack developed is further optimized with improved flow field designs and design of manifold. These fuel cell stacks are used in PowerUP’s portable fuel cell electric generators that are more efficient and sustainable than the currently used fossil fuel based solutions.

Dinh Thi Thu Ha, Pham Ngoc Phat

Vietnam Journal of Science and Technology • 2024

The two main pollution parameters, BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand), are crucial factors in assessing water quality and pollution levels. Currently, COD can be measured using sensor devices, while BOD relies on the activity of microorganisms. Traditionally, the quantification of biologically oxidizable organic carbon involves measuring oxygen consumption over a five-day period, commonly known as the BOD5 test. However, the BOD5 test has several disadvantages, such as its time-consuming nature, unsuitability for process control, and the requirement for highly skilled samplers. It was hypothesized that the output of a single-chamber microbial fuel cell (SCMFC) with an air cathode could serve as an alternative method for measuring BOD. To validate this hypothesis, this study conducted some experiments using the model of SCMFC. When artificial wastewater, utilizing sodium acetate as fuel, was employed, a strong linear correlation (R2 > 0.99) between the total charge transferred and BOD5 concentration was confirmed. Additionally, the linear relationship was also investigated for real domestic wastewater. This relationship was also examined for real domestic wastewater, resulting in a combined correlation with an R2 value exceeding 0.98. Until now, research on biosensors (particularly SCMFC-based biosensors) in Vietnam has been relatively new and not extensively conducted. The results of this study could provide a solid foundation for the development of continuous and onsite BOD sensors to monitor BOD concentrations in wastewater streams.

Sho Tamura, Motoaki Morita, Shinichi Motoda et al.

ECS Transactions • 2014

It has been reported that the potential of stainless steel (S.S.) ennobles to 400 mV by the formation of biofilm in seawater. This phenomenon can lead to the development of a battery by coupling an active counter electrode. On the other hand, TiO 2 is well known as an n-type semiconductor which exhibits the photo-catalytic effect under the UV irradiation. When a TiO 2 coated metal is irradiated by the UV light, excited electrons are transferred to the base metal, this phenomenon leads to the active shift of electrode potential. This effect can be applied to microbial fuel cell as a non-sacrifice electrode. We have investigated the electrochemical characteristics of the marine microbial fuel cell (MMFC) composed of biofilm covered stainless steel cathode and TiO 2 anode in seawater. However, it is needed to improve the photo-potential characteristics of electrodes for the practical application.The present work attempted to improve the battery performance by assembling the double layered TiO 2 anode electrode.Results from experimental, by using the double layered anode for MFC, cell voltage increases 120 mV and maximum power density enhances 1.4 times compared with the value of single layered one coated by squeegee printing method. The double layered electrode has anatase / rutile hetero-junction, therefore it promotes the electron transfer between base metal and TiO 2 coating interface. In addition, the double layered electrode has a high durability against the cyclic irradiation because TiO 2 intermediate layer behaves as a corrosion protective barrier which suppresses the direct contact between electrolyte and base metal.