Maximum anode chamber volume and minimum anode area for supporting electrogenesis in microbial fuel cells treating wastewater

Microbial fuel cell (MFC) technology is a promising area in the field of renewable energy because of their capability to use the energy contained in wastewater, which has been previously an untapped source of power. Microscale MFCs are desirable for their small footprints, relatively high power density, fast start-up, and environmentally-friendly process. Microbial fuel cells employ microorganisms as the biocatalysts instead of metal catalysts, which are widely applied in conventional fuel cells. MFCs are capable of generating electricity as long as nutrition is provided. Miniature MFCs have faster power generation recovery than macroscale MFCs. Additionally, since power generation density is affected by the surface-to-volume ratio, miniature MFCs can facilitate higher power density. We have designed and fabricated a microscale microbial fuel cell with a volume of 4 μL in a polydimethylsiloxane (PDMS) chamber. The anode and cathode chambers were separated by a proton exchange membrane. Carbon cloth was used for both the anode and the cathode. Shewanella Oneidensis MR-1 was chosen to be the electrogenic bacteria and was inoculated into the anode chamber. We employed Ferricyanide as the catholyte and introduced it into the cathode chamber with a constant flow rate of approximately 50 μL/hr. We used trypticase soy broth as the bacterial nutrition and added it into the anode chamber approximately every 15 hours once current dropped to base current. Using our miniature MFC, we were able to generate a maximum current of 4.62 μA.

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The Electrical Properties and Changes on the Substrates of Microbial Fuel Cells Using Excess Sludge

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.535.141 ◽

2014 ◽

Vol 535 ◽

pp. 141-144

Author(s):

Xiao Qin Zhao ◽

Xiao Jie Sun

Keyword(s):

Fuel Cells ◽

Anaerobic Digestion ◽

Microbial Fuel Cells ◽

Control Device ◽

Anaerobic Sludge ◽

Excess Sludge ◽

Test Volume ◽

Significant Difference ◽

Nacl Concentration ◽

Anode Area

A single-chamber and membrane-less microbial fuel cells (MFC) was successfully started up using anaerobic sludge as inoculums without any nutrient elements for 20 d. Under 30 °C, excess sludge SS was about 21000 mg·L-1, anode area for 31.4 cm2and in 200 mM NaCl concentration agent conditions experiment MFC, while the control device (CD) directly with original sludge anaerobic digestion. The electricity generation of microbial fuel cell and the contrast of substrate changes were investigated. The results show that obtained maximum voltage is 597.3 mV, pH in MFC is slightly higher than in contrast test. Volume reduction in MFC is larger than the controls. Reducing sugar in MFC is lower than that in CDs. Proteins increase at first and then decrease, finally there is no significant difference in both of MFC and CD. Key words: Microbial Fuel Cells, Excess Sludge, Anaerobic Digestion, Reutilization

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Microbial diversity and population dynamics of activated sludge microbial communities participating in electricity generation in microbial fuel cells

Water Science & Technology ◽

10.2166/wst.2008.577 ◽

2008 ◽

Vol 58 (11) ◽

pp. 2195-2201 ◽

Cited By ~ 16

Author(s):

D. Ki ◽

J. Park ◽

J. Lee ◽

K. Yoo

Keyword(s):

Fuel Cells ◽

Activated Sludge ◽

Microbial Diversity ◽

Microbial Fuel Cells ◽

Electricity Generation ◽

Municipal Wastewater ◽

Treatment Plant ◽

Community Analysis ◽

Electricity Production ◽

Anode Chamber

In this study, we performed microbial community analysis to examine microbial diversity and community structure in microbial fuel cells (MFCs) seeded with activated sludge from a municipal wastewater treatment plant in South Korea. Because anode-attached biofilm populations are particularly important in electricity transfer, the ecological characteristics of anode-attached biofilm microbes were explored and compared with those of microbes grown in suspension in an anode chamber. 16S rDNA-based community analysis showed that the degree of diversity in anode-attached biofilms was greater than that of the originally seeded activated sludge as well as that of the suspension-grown microbes in the anode bottle. In addition, Bacteroidetes and Clostridia grew preferentially during MFC electricity generation. Further phylogenetic analysis revealed that the anode biofilm populations described in this work are phylogenetically distant from previously characterized MFC anode biofilm microbes. These findings suggest that a phylogenetically diverse set of microbes can be involved in the electricity generation of MFC anode compartments, and that increased microbial diversity in anode biofilms may help to stabilize electricity production in the MFC.

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The Effect of Increasing Surface Area of Graphite Electrode on the Performance of Dual Chamber Microbial Fuel Cells

Proceeding International Conference on Science and Engineering ◽

10.14421/icse.v1.284 ◽

2017 ◽

Vol 1 ◽

pp. 137-140

Author(s):

Pedy Artsanti ◽

Sudarlin Sudarlin ◽

Eka Fadzillah Kirana

Keyword(s):

Fuel Cells ◽

Surface Area ◽

Power Density ◽

Microbial Fuel Cells ◽

Textile Industry ◽

Graphite Electrode ◽

Salt Bridge ◽

Anode Chamber ◽

Dual Chamber ◽

Real Wastewater

The effect of increasing surface area of graphite electrode on the performance of dual chamber Microbial Fuel Cells (MFC) was observed. The surface area of graphite electrode (anode and cathode) that was using in this experiment was 29.5cm2 and 44.5cm2 for the A and B reactor, respectively. The anode chamber contained mixed microorganism culture from real wastewater of textile industry and the cathode chamber contained 0.1M potassium permanganate electrolyte solution. The salt bridge was required to stabilize the charge between the anode and cathode chambers, and the electrodes attached to the anode and cathode chambers as the electron catcher. Both, the A and B reactor were observed for 72 hours of running time. The voltage and power density were found to increase with the increase in surface area of the graphite electrode. The highest power density was 93.93mWm-2 and 197.23mWm-2 that obtained at 36 hours and 48 hours on the A and B reactor, respectively. At the end of experiment, these MFCs system could also reduce COD by 28.6% and 15.6% on A and B reactor, respectively.

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Laccase Immobilization Strategies for Application as a Cathode Catalyst in Microbial Fuel Cells for Azo Dye Decolourization

Frontiers in Microbiology ◽

10.3389/fmicb.2020.620075 ◽

2021 ◽

Vol 11 ◽

Author(s):

Priyadharshini Mani ◽

V. T. Fidal ◽

Taj Keshavarz ◽

T. S. Chandra ◽

Godfrey Kyazze

Keyword(s):

Enzyme Activity ◽

Fuel Cells ◽

Microbial Fuel Cells ◽

Shewanella Oneidensis ◽

Alginate Beads ◽

Reduction Reaction ◽

Anode Chamber ◽

Acid Orange 7 ◽

Dye Decolourization ◽

Freely Suspended

Enzymatic biocathodes have the potential to replace platinum as an expensive catalyst for the oxygen reduction reaction in microbial fuel cells (MFCs). However, enzymes are fragile and prone to loss of activity with time. This could be circumvented by using suitable immobilization techniques to maintain the activity and increase longevity of the enzyme. In the present study, laccase from Trametes versicolor was immobilized using three different approaches, i.e., crosslinking with electropolymerized polyaniline (PANI), entrapment in copper alginate beads (Cu-Alg), and encapsulation in Nafion micelles (Nafion), in the absence of redox mediators. These laccase systems were employed in cathode chambers of MFCs for decolourization of Acid orange 7 (AO7) dye. The biocatalyst in the anode chamber was Shewanella oneidensis MR-1 in each case. The enzyme in the immobilized states was compared with freely suspended enzyme with respect to dye decolourization at the cathode, enzyme activity retention, power production, and reusability. PANI laccase showed the highest stability and activity, producing a power density of 38 ± 1.7 mW m−2 compared to 25.6 ± 2.1 mW m−2 for Nafion laccase, 14.7 ± 1.04 mW m−2 for Cu-Alg laccase, and 28 ± 0.98 mW m−2 for the freely suspended enzyme. There was 81% enzyme activity retained after 1 cycle (5 days) for PANI laccase compared to 69% for Nafion and 61.5% activity for Cu-alginate laccase and 23.8% activity retention for the freely suspended laccase compared to initial activity. The dye decolourization was highest for freely suspended enzyme with over 85% decolourization whereas for PANI it was 75.6%, Nafion 73%, and 81% Cu-alginate systems, respectively. All the immobilized laccase systems were reusable for two more cycles. The current study explores the potential of laccase immobilized biocathode for dye decolourization in a microbial fuel cell.

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Influence of Humidity on Performance of Single Chamber Air-Cathode Microbial Fuel Cells with Different Separators

Processes ◽

10.3390/pr8070861 ◽

2020 ◽

Vol 8 (7) ◽

pp. 861

Author(s):

Mungyu Lee ◽

Sanath Kondaveeti ◽

Taeyeon Jeon ◽

Inhae Kim ◽

Booki Min

Keyword(s):

Fuel Cells ◽

Microbial Fuel Cells ◽

High Performance ◽

Cell Voltage ◽

Cyclic Voltammogram ◽

Anode Chamber ◽

Air Cathode ◽

Reduction Reactions ◽

Oxygen Reduction Reactions ◽

Anodic Reactions

The maximum performance of microbial fuel cells (MFCs) is significantly affected by the reduction reactions in the cathode, but their optimum condition is not fully understood yet. The air-cathode MFC operations with different separators (Nafion 117 and polypropylene (PP80) were evaluated at various relative humidity (RH) at the cathode chamber. Air cathode MFCs with a Nafion 117 separator at RH of 90 ± 2% produced the highest cell voltage of 0.35 V (600 Ω) and power density of 116 mW/m2. With a PP80 separator, the maximum power generation of 381 mW/m2 was obtained at a relatively lower RH of 30 ± 2%. The cyclic voltammogram and Tafel analysis indicated that the best performance of cathodic oxygen reduction reactions could be observed at 90% RH for Nafion and 50% RH for the PP80 separator. Additionally, the RH conditions also affected the anodic reactions and oxygen mass transfer rates to the anode chamber through the cathode and separators. This study suggests that the optimum RH condition at the cathode is important in order to obtain a high performance of MFC operations and needs to be controlled at different optimum levels depending on the characteristics of the separators.

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A microbial fuel cell equipped with a biocathode for organic removal and denitrification

Water Science & Technology ◽

10.2166/wst.2008.343 ◽

2008 ◽

Vol 58 (4) ◽

pp. 881-885 ◽

Cited By ~ 72

Author(s):

O. Lefebvre ◽

A. Al-Mamun ◽

H. Y. Ng

Keyword(s):

Fuel Cell ◽

Microbial Fuel Cells ◽

Suspended Solids ◽

Cathode Surface ◽

Domestic Wastewater ◽

Anode Surface ◽

Anode Chamber ◽

Chamber Volume ◽

Organic Removal ◽

Micro Organisms

Microbial fuel cells (MFCs) are a promising anaerobic technology but they are limited by the high cost of the catalyst used at the cathode (typically platinum). In this study, we designed a novel type of two-chambered MFC wherein an autoheterotrophic denitrifying biofilm replaced the costly catalyst on the cathode surface. Micro-organisms performed denitrification by using electrons supplied by bacteria oxidizing domestic wastewater and acetate as substrates in the anode chamber. This two-chambered MFC equipped with a biocathode generated during more than 1.5 month up to 9.4 mW m−2 of anode surface or 0.19 W m−3 of anode chamber volume, while removing over 65% of COD, 84% of total nitrogen and nearly 30% of suspended solids with domestic wastewater as a substrate, and nearly 95% of acetate in the subsequent experiments.

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Bioenergy Potential of Albumin, Acetic Acid, Sucrose, and Blood in Microbial Fuel Cells Treating Synthetic Wastewater

Processes ◽

10.3390/pr9081289 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1289

Author(s):

Madiha Tariq ◽

Jin Wang ◽

Zulfiqar Ahmad Bhatti ◽

Muhammad Bilal ◽

Adeel Jalal Malik ◽

...

Keyword(s):

Acetic Acid ◽

Fuel Cells ◽

Power Density ◽

Microbial Fuel Cells ◽

Industrial Wastewater ◽

Coulombic Efficiency ◽

Synthetic Wastewater ◽

Anode Chamber ◽

Batch Mode ◽

Voltage Generation

Microbial fuel cells (MFCs) are a recent biotechnology that can simultaneously produce electricity and treat wastewater. As the nature of industrial wastewater is very complex, and it may contain a variety of substrates—such as carbohydrates, proteins, lipids, etc.—previous investigations dealt with treatment of individual pollutants in MFCs; the potential of acetic acid, sucrose, albumin, blood, and their mixture has rarely been reported. Hence, the current investigation explored the contribution of each substrate, both separately and in mixture. The voltage generation potential, current, and power density of five different substrates—namely, acetic acid, sucrose, albumin, blood, and a mixture of all of the substrates—was tested in a dual-chambered, anaerobic MFC operated at 35 °C. The reaction time of the anaerobic batch mode MFC was 24 h, and each substrate was treated for 7 runs under the same conditions. The dual-chambered MFC consisted of anode and cathode chambers; the anode chamber contained the biocatalyst (sludge), while the cathode chamber contained the oxidizing material (KMnO4). The maximum voltage of 769 mV was generated by acetic acid, while its corresponding values of current and power density were 7.69 mA and 347.85 mW, respectively. Similarly, being a simple and readily oxidizable substrate, acetic acid exhibited the highest COD removal efficiency (85%) and highest Coulombic efficiency (72%) per run. The anode accepted the highest number of electrons (0.078 mmol/L) when acetic acid was used as a substrate. The voltage, current, and power density generated were found to be directly proportional to COD concentration. The least voltage (61 mV), current (0.61 mA), and power density (2.18 mW) were observed when blood was treated in the MFC. Further research should be focused on testing the interaction of two or more substrates simultaneously in the MFC.

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