Salt Bridge Microbial Fuel Cell Research Articles

Performance of salt‐bridge microbial fuel cell (SB‐MFC) with various microorganism cultures on the generation of electricity from tofu wastewater

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

Investigation of polypyrrole/TiO2 and poypyrrole/WO3 nanocomposites as anode modifier in salt bridge microbial fuel cell using municipal wastewater

Developing nanocomposite materials based on conducting polymers (CPs) and metal-oxide nanoparticles, which combine redox electrochemistry of CPs with intrinsic properties of nano-scale semiconducting materials, may offer improved microbial fuel cells (MFCs) performances. Polypyrrole (PPY) based nanocomposites were synthesized by chemical oxidative polymerization method and were further used as an anode modifier in salt bridge MFCs. The PPY-based nanocomposites were characterized by X-ray diffraction, Fourier-Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM). The maximum power density of 16.7 mW/m2, 20.1 mW/m2, and 22.5 mW/m2 were obtained for MFC2-PPY, MFC3-PPY/TiO2 and MFC4-PPY/WO3 respectively, suggesting that modification of the anode with PPY- based nanocomposites is beneficial in the electricity generation of the MFC, and have superior performance as compared to the controller MFC1-CC (11.6 mW/m2).

Investigation and Taguchi Optimization of Microbial Fuel Cell Salt Bridge Dimensional Parameters

One major problem of two chamber salt bridge microbial fuel cells (MFCs) is the high resistance offered by the salt bridge to anion flow. Many researchers who have studied and optimized various parameters related to salt bridge MFC, have not shed much light on the effect of salt bridge dimensional parameters on the MFC performance. Therefore, the main objective of this research is to investigate the effect of length and cross sectional area of salt bridge and the effect of solar radiation and atmospheric temperature on MFC current output. An experiment has been designed using Taguchi L9 orthogonal array, taking length and cross sectional area of salt bridge as factors having three levels. Nine MFCs were fabricated as per the nine trial conditions. Trials were conducted for 3 days and output current of each of the MFCs along with solar insolation and atmospheric temperature were recorded. Analysis of variance shows that salt bridge length has significant effect both on mean (with 53.90% contribution at 95% CL) and variance (with 56.46% contribution at 87% CL), whereas the effect of cross sectional area of the salt bridge and the interaction of these two factors is significant on mean only (with 95% CL). Optimum combination was found at 260 mm salt bridge length and 506.7 mm2 cross sectional area with 4.75 mA of mean output current. The temperature and solar insolation data when correlated with each of the MFCs average output current, revealed that both external factors have significant impact on MFC current output but the correlation coefficient varies from MFC to MFC depending on salt bridge dimensional parameters.

Potential of lignin as a mediator in combined systems for biomethane and electricity production from ethanol stillage wastewater

This study investigated the feasibility of using lignin waste from pulp and paper industry as a mediator for treating ethanol stillage wastewater in microbial fuel cells (MFCs). Two configurations of MFCs used a salt-bridge and proton exchange membrane (PEM), and the influence of lignin and KMnO4 as mediators in PEM MFCs was evaluated. For salt-bridge MFC, graphite plates were used as cathode and anode while carbon cloth and graphite rods were substituted for cathode and anode in PEM MFC. The external resistance for both configurations was 550 ± 50Ω. Results showed that PEM MFC generated higher electric power with satisfactory treatment of wastewater. When lignin was added as a mediator in PEM MFC, the maximum power density increased to 93 W/m2 with COD removal efficiency of about 81% after 6-day operation. This study showed the potential for the treatment of lignin-rich wastewater and ethanol stillage wastewater simultaneously with possibility of electric power generation.

Impact of Salt on Bioelectricity Generation in a Dual-Chambered Microbial Fuel Cell Using Sago-Processing Wastewater

Effect of NaCl on electricity generation, COD removal, reduction in carbohydrate and starch content in dual chambered, salt bridge Microbial Fuel Cells (MFCs) employing raw sago-processing wastewater with an organic load of 14,400 mg COD/l as substrate was evaluated. Four dual chambered MFCs were constructed and the study aimed to find out the impact of addition of NaCl which is carried out for effective MFC performance. Isolation and identification of microbes from initial influent and final effluent was performed using serial dilution, spread plate and selective agar techniques. Interestingly, it was found that the MFC in which NaCl was added to its cathode chamber was best in performance compared to other three MFCs, with a maximum voltage of 603mV and current of 6.03mA. It also documented that the maximum COD removal efficiency of 83% with a total reduction of carbohydrate and starch content from the wastewater was obtained. Utilizing sago wastewater for the production of bioelectricity from MFC technique is considered as a feasible and sustainable process.

Mineralization of Chinese Medicine Wastewater and Power Generation Using an Improved Salt Bridge Microbial Fuel Cell

Mineralization of Chinese Medicine Wastewater and Power Generation Using an Improved Salt Bridge Microbial Fuel Cell

The Harnessing Of Bioenergy From A Dual Chambered Microbial Fuel Cell (Mfc) Employing Sago-Processing Wastewater As Catholyte

The application of microbial fuel cell (MFC) for wastewater treatment is an emerging strategy for the simultaneous treatment of pollutants and generation of electricity. The feasibility of utilizing sago-processing wastewater as a catholyte and comparing it with synthetic catholyte was investigated using dual-chambered salt bridge MFCs. The wastewater catholyte was again varied as with and without sago sludge inoculation, and the effect of sludge addition on MFC performance was determined. Three dual-chambered salt bridge MFCs namely synthetic catholyte (MFC-SC), wastewater catholyte (MFC-WC), and Sludge inoculated wastewater catholyte (MFC-WS) were designed and their performance was compared. Synthetic catholyte was the best in power generation than the other two MFCs and it documented maximum open circuit voltage of 0.35 V and closed circuit voltage of 0.31 V. Sludge inoculated wastewater catholyte (MFC-WS) was better compared to wastewater catholyte (MFC-WC) in power generation with a maximum degradation in chemical oxygen demand of 80.4% and total removal of carbohydrates and starch. The attachment of bacteria on graphite electrode was observed using Scanning Electron Microscope (SEM). The results evidently demonstrated that wastewater catholyte can be a promising alternative to synthetic and chemical catholyte.

Simultaneous Chromium Removal and Power Generation Using Algal Biomass in a Dual Chambered Salt Bridge Microbial Fuel Cell

Microbial Fuel Cell (MFC) is a bio-electrochemical device used essentially for power generation and is now emerging as a sustainable waste treatment system. In this paper, we report detoxification of chromium VI contaminated water using algae biomass in a dual chamber salt bridge MFC. The device showed high chromium removal efficiency with 98% removal achieved in 96 h at pH 2. Initial pH of the cathode solution had a significant effect on device performance with acidic pH values favouring high chromium removal, Open Circuit Potential (OCV), power density and anodic COD removal. The power density value of 207 mW/m 2 and open circuit potential of 760 mV was attained at pH 2. Algae biomass driven MFC thus, proved to be an efficient bioremediation device with good power production.

Application of Assumed IVIVC in Product Life Cycle Management: A Case Study of Trimetazidine Dihydrochloride Extended Release Tablet

Microbial Fuel Cell (MFC) is a bio-electrochemical device used essentially for power generation and is now emerging as a sustainable waste treatment system. In this paper, we report detoxification of chromium VI contaminated water using algae biomass in a dual chamber salt bridge MFC. The device showed high chromium removal efficiency with 98% removal achieved in 96 h at pH 2. Initial pH of the cathode solution had a significant effect on device performance with acidic pH values favouring high chromium removal, Open Circuit Potential (OCV), power density and anodic COD removal. The power density value of 207 mW/m 2 and open circuit potential of 760 mV was attained at pH 2. Algae biomass driven MFC thus, proved to be an efficient bioremediation device with good power production.

Electrochemical analysis of Clostridium propionicum and its acrylic acid production in microbial fuel cells

AbstractCurrently, acrylic acid is produced at a low yield by the resting cells of Clostridium propionicum with the supplement of extra electron acceptors. As an alternative way, acrylic acid production coupled with electricity generation was achieved by C. propionicum‐based microbial fuel cells (MFCs). Electricity was generated in the salt‐bridge MFCs with cysteine and resazurin in the anode chamber as mediators, and K3Fe(CN)6 as the cathode electron acceptor. Power generation was 21.78 mW/m2 with an internal resistance of 9809 Ω. Cyclic voltammograms indicated the main mechanism of power production was the electron transfer facilitated by mediators in the system. In the salt‐bridge MFC system, 0.694 mM acrylic acid was produced together with electricity generation.

Effect of ionic strength, cation exchanger and inoculum age on the performance of Microbial Fuel Cells

Abstract Power generation in Microbial fuel cells (MFCs) is a function of various physico-chemical as well as biological parameters. In this study, we have examined the effect of ionic strength, cation exchanger and inoculum age on power generation in a mediator MFC with methylene blue as electron mediator using Enterobacter cloacae IIT-BT08. The effect of ionic strength was studied using NaCl in the anode chamber of a two chambered salt-bridge MFC at concentrations of 5 mM, 10 mM and 15 mM. Maximum power density of 12.8 mW/m2 was observed when 10 mM NaCl was used. Corresponding current density was noted to be 35.5 mA/m2. Effect of cation exchanger was observed by replacing salt-bridge with a proton exchange membrane of equal surface area. When the salt-bridge was replaced by a proton exchange membrane, a 3-fold increase in the power density was observed. Power density and current density of 37.8 mW/m2 and 110.3 mA/m2 respectively were detected. The influence of the pre-inoculum on the MFC was studied using E. cloacae IIT-BT08 grown for 12, 14, 16 and 18 h. It was observed that 16 h grown culture when inoculated in the anode chamber gave the maximum power output. Power density and current density of 68 mW/m2 and 168 mA/m2 respectively were obtained. We demonstrate from these results that both physico-chemical as well as biological parameters need to be optimized for improving the power generation in MFCs.

Electricity generation using microbial fuel cells

Conversion of biomass into electricity is possible using microbial fuel cells (MFCs). The present paper deals with the studies of a two-chambered salt bridge MFC using Enterobacter cloacae IIT-BT 08 in MYG medium. The effect of different electron mediators, concentration of the mediator, ionic strength (salt concentration) of the medium and the surface area of the salt-bridge in contact with the anode and cathode chambers on the power generation in MFCs are reported. In the case of methyl viologen (MV) (0.1 mM) as the electron mediator, the voltage generation was 0.4 V but no current was detected. Different concentrations of methylene blue (MB) were also studied as the mediator. A maximum voltage of 0.37 V was seen at 0.05 mM MB, whereas a maximum current and power of 56.7 μ A and 19.2 μ W , respectively, were observed in the case of 0.03 mM MB with a voltage of 0.34 V. The corresponding power density and current density of 9.3 mW / m 2 and 27.6 mA / m 2 , respectively, were obtained. When the surface area of the salt bridge in contact with the anode and cathode chambers was increased, a proportionate improvement in the power output from 19.2 to 708 μ W was detected. The maximum power density and current density of 236 mW / m 2 and 666.7 mA / m 2 , respectively, which are found to be very promising for a salt bridge MFC were observed.

Electricity generation using membrane and salt bridge microbial fuel cells

Microbial fuel cells (MFCs) can be used to directly generate electricity from the oxidation of dissolved organic matter, but optimization of MFCs will require that we know more about the factors that can increase power output such as the type of proton exchange system which can affect the system internal resistance. Power output in a MFC containing a proton exchange membrane was compared using a pure culture ( Geobacter metallireducens) or a mixed culture (wastewater inoculum). Power output with either inoculum was essentially the same, with 40±1 mW/m 2 for G. metallireducens and 38±1 mW/m 2 for the wastewater inoculum. We also examined power output in a MFC with a salt bridge instead of a membrane system. Power output by the salt bridge MFC (inoculated with G. metallireducens) was 2.2 mW/m 2. The low power output was directly attributed to the higher internal resistance of the salt bridge system ( 19920 ± 50 Ω ) compared to that of the membrane system ( 1286 ± 1 Ω ) based on measurements using impedance spectroscopy. In both systems, it was observed that oxygen diffusion from the cathode chamber into the anode chamber was a factor in power generation. Nitrogen gas sparging, L-cysteine (a chemical oxygen scavenger), or suspended cells (biological oxygen scavenger) were used to limit the effects of gas diffusion into the anode chamber. Nitrogen gas sparging, for example, increased overall Coulombic efficiency (47% or 55%) compared to that obtained without gas sparging (19%). These results show that increasing power densities in MFCs will require reducing the internal resistance of the system, and that methods are needed to control the dissolved oxygen flux into the anode chamber in order to increase overall Coulombic efficiency.