scholarly journals Use of Biochar-Based Cathodes and Increase in the Electron Flow by Pseudomonas aeruginosa to Improve Waste Treatment in Microbial Fuel Cells

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1941
Author(s):  
Rosa Anna Nastro ◽  
Fabio Flagiello ◽  
Nicandro Silvestri ◽  
Edvige Gambino ◽  
Giacomo Falcucci ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Cathode Surface ◽  
Waste Treatment ◽  
Electron Flow ◽  
Phosphate Buffer Solution ◽  
Current Collector ◽  
Composite Cathode ◽  
Buffer Solution

In this paper, we tested the combined use of a biochar-based material at the cathode and of Pseudomonas aeruginosa strain in a single chamber, air cathode microbial fuel cells (MFCs) fed with a mix of shredded vegetable and phosphate buffer solution (PBS) in a 30% solid/liquid ratio. As a control system, we set up and tested MFCs provided with a composite cathode made up of a nickel mesh current collector, activated carbon and a single porous poly tetra fluoro ethylene (PTFE) diffusion layer. At the end of the experiments, we compared the performance of the two systems, in the presence and absence of P. aeruginosa, in terms of electric outputs. We also explored the potential reutilization of cathodes. Unlike composite material, biochar showed a life span of up to 3 cycles of 15 days each, with a pH of the feedstock kept in a range of neutrality. In order to relate the electric performance to the amount of solid substrates used as source of carbon and energy, besides of cathode surface, we referred power density (PD) and current density (CD) to kg of biomass used. The maximum outputs obtained when using the sole microflora were, on average, respectively 0.19 Wm−2kg−1 and 2.67 Wm−2kg−1, with peaks of 0.32 Wm−2kg−1 and 4.87 Wm−2kg−1 of cathode surface and mass of treated biomass in MFCs with biochar and PTFE cathodes respectively. As to current outputs, the maximum values were 7.5 Am−2 kg−1 and 35.6 Am−2kg−1 in MFCs with biochar-based material and a composite cathode. If compared to the utilization of the sole acidogenic/acetogenic microflora in vegetable residues, we observed an increment of the power outputs of about 16.5 folds in both systems when we added P. aeruginosa to the shredded vegetables. Even though the MFCs with PTFE-cathode achieved the highest performance in terms of PD and CD, they underwent a fouling episode after about 10 days of operation, with a dramatic decrease in pH and both PD and CD. Our results confirm the potentialities of the utilization of biochar-based materials in waste treatment and bioenergy production.

scholarly journals Performance Assessment of Multi-Electrodes Reactors for Scaling-up Microbial Fuel Cells

2020 ◽  
Vol 197 ◽  
pp. 08020
Author(s):  
Mariagiovanna Minutillo ◽  
Rosa Anna Nastro ◽  
Simona Di Micco ◽  
Elio Jannelli ◽  
Raffaele Cioffi ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Sodium Acetate ◽  
Phosphate Buffer Solution ◽  
Critical Factor ◽  
Scaling Up ◽  
Sole Source ◽  
Cylindrical Chamber ◽  
Air Cathode ◽  
Buffer Solution

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).

scholarly journals Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa

2016 ◽  
Vol 82 (16) ◽  
pp. 5026-5038 ◽  
Author(s):  
Erick M. Bosire ◽  
Lars M. Blank ◽  
Miriam A. Rosenbaum
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Electron Transfer ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Pure Culture ◽  
Bioelectrochemical Systems ◽  
Content Type ◽  
Mediated Electron Transfer ◽  
Phenazine Production ◽  
Model Strain

ABSTRACTPseudomonas aeruginosais an important, thriving member of microbial communities of microbial bioelectrochemical systems (BES) through the production of versatile phenazine redox mediators. Pure culture experiments with a model strain revealed synergistic interactions ofP. aeruginosawith fermenting microorganisms whereby the synergism was mediated through the shared fermentation product 2,3-butanediol. Our work here shows that the behavior and efficiency ofP. aeruginosain mediated current production is strongly dependent on the strain ofP. aeruginosa. We compared levels of phenazine production by the previously investigated model strainP. aeruginosaPA14, the alternative model strainP. aeruginosaPAO1, and the BES isolatePseudomonassp. strain KRP1 with glucose and the fermentation products 2,3-butanediol and ethanol as carbon substrates. We found significant differences in substrate-dependent phenazine production and resulting anodic current generation for the three strains, with the BES isolate KRP1 being overall the best current producer and showing the highest electrochemical activity with glucose as a substrate (19 μA cm−2with ∼150 μg ml−1phenazine carboxylic acid as a redox mediator). Surprisingly,P. aeruginosaPAO1 showed very low phenazine production and electrochemical activity under all tested conditions.IMPORTANCEMicrobial fuel cells and other microbial bioelectrochemical systems hold great promise for environmental technologies such as wastewater treatment and bioremediation. While there is much emphasis on the development of materials and devices to realize such systems, the investigation and a deeper understanding of the underlying microbiology and ecology are lagging behind. Physiological investigations focus on microorganisms exhibiting direct electron transfer in pure culture systems. Meanwhile, mediated electron transfer with natural redox compounds produced by, for example,Pseudomonas aeruginosamight enable an entire microbial community to access a solid electrode as an alternative electron acceptor. To better understand the ecological relationships between mediator producers and mediator utilizers, we here present a comparison of the phenazine-dependent electroactivities of threePseudomonasstrains. This work forms the foundation for more complex coculture investigations of mediated electron transfer in microbial fuel cells.

Variations of electron flux and microbial community in air-cathode microbial fuel cells fed with different substrates

2012 ◽  
Vol 66 (4) ◽  
pp. 748-753 ◽  
Author(s):  
Jaecheul Yu ◽  
Younghyun Park ◽  
Haein Cho ◽  
Jieun Chun ◽  
Jiyun Seon ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Microbial Communities ◽  
Microbial Fuel Cells ◽  
Electricity Generation ◽  
Electron Flow ◽  
Batch Mode ◽  
Electrochemically Active ◽  
Oxidation Of Organic Compounds ◽  
Current Production ◽  
Electron Sink

Microbial fuel cells (MFCs) can convert chemical energy to electricity using microbes as catalysts and a variety of organic wastewaters as substrates. However, electron loss occurs when fermentable substrates are used because fermentation bacteria and methanogens are involved in electron flow from the substrates to electricity. In this study, MFCs using glucose (G-MFC), propionate (P-MFC), butyrate (B-MFC), acetate (A-MFC), and a mix (M-MFC, glucose:propionate:butyrate:acetate = 1:1:1:1) were operated in batch mode. The metabolites and microbial communities were analyzed. The current was the largest electron sink in M-, G-, B-, and A-MFCs; the initial chemical oxygen demands (CODini) involved in current production were 60.1% for M-MFC, 52.7% for G-MFC, 56.1% for B-MFC, and 68.3% for A-MFC. Most of the glucose was converted to propionate (40.6% of CODini) and acetate (21.4% of CODini) through lactate (80.3% of CODini) and butyrate (6.1% of CODini). However, an unknown source (62.0% of CODini) and the current (34.5% of CODini) were the largest and second-largest electron sinks in P-MFC. Methane gas was only detected at levels of more than 10% in G- and M-MFCs, meaning that electrochemically active bacteria (EAB) could out-compete acetoclastic methanogens. The microbial communities were different for fermentable and non-fermentable substrate-fed MFCs. Probably, bacteria related to Lactococcus spp. found in G-MFCs with fermentable substrates would be involved in both fermentation and electricity generation. Acinetobacter-like species, and Rhodobacter-like species detected in all the MFCs would be involved in oxidation of organic compounds and electricity generation.

scholarly journals Investigation and Improvement of Scalable Oxygen Reducing Cathodes for Microbial Fuel Cells by Spray Coating

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 11 ◽  
Author(s):  
Thorben Muddemann ◽  
Dennis Haupt ◽  
Bolong Jiang ◽  
Michael Sievers ◽  
Ulrich Kunz
Keyword(s):  
Fuel Cells ◽  
Surface Area ◽  
Power Density ◽  
Microbial Fuel Cells ◽  
Cathode Surface ◽  
Weight Ratio ◽  
Strong Increase ◽  
Coating Quality ◽  
Catalyst Coating

This contribution describes the effect of the quality of the catalyst coating of cathodes for wastewater treatment by microbial fuel cells (MFC). The increase in coating quality led to a strong increase in MFC performance in terms of peak power density and long-term stability. This more uniform coating was realized by an airbrush coating method for applying a self-developed polymeric solution containing different catalysts (MnO2, MoS2, Co3O4). In addition to the possible automation of the presented coating, this method did not require a calcination step. A cathode coated with catalysts, for instance, MnO2/MoS2 (weight ratio 2:1), by airbrush method reached a peak and long-term power density of 320 and 200–240 mW/m2, respectively, in a two-chamber MFC. The long-term performance was approximately three times higher than a cathode with the same catalyst system but coated with the former paintbrush method on a smaller cathode surface area. This extraordinary increase in MFC performance confirmed the high impact of catalyst coating quality, which could be stronger than variations in catalyst concentration and composition, as well as in cathode surface area.

Biomimetically Generated Nanoparticles in Boosting the Performance of Microbial Fuel Cells

2021 ◽  
Vol 20 (5) ◽  
Author(s):  
S. A. Abbasi ◽  
Tabassum Abbasi ◽  
Pratiksha Patnaik
Keyword(s):  
Silver Nanoparticles ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Waste Treatment ◽  
Coulombic Efficiency ◽  
Precious Metals ◽  
Energy Yield ◽  
Gold And Silver Nanoparticles ◽  
Carbon Load ◽  
Physical And Chemical

Studies are presented in the context of the past attempts at finding nanocatalysts that can boost the performance of microbial fuel cells (MFCs) ? in terms of waste treatment and energy generation. Given the great potential of biomimetically synthesized nanoparticles (BMNPs) in providing less expensive and more environmentally friendly alternatives to NPs synthesized by physical and chemical methods, as well as a near-total lack of previous work in this area, the current research was undertaken. Effect of gold and silver nanoparticles (NPs), synthesized biomimetically using five freely available weeds, was assessed as catalysts in the MFCs. In all cases, the nanoparticles were seen to enhance the coulombic efficiency (reflective of the reduction in the waste’s organic carbon load), maximum attainable power density, and overall energy yield of the MFCs by >200% relative to the uncatalyzed MFCs. Gold nanoparticles were more effective than silver nanoparticles by ? 20%. The results reveal that biomimetically synthesized NPs can be highly effective in reducing the operational costs as well as ecological footprints of MFCs and further work should be focused on NPs of non-precious metals.

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