scholarly journals The Influence of External Load on the Performance of Microbial Fuel Cells

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 612
Author(s):  
Szymon Potrykus ◽  
Luis Fernando León-Fernández ◽  
Janusz Nieznański ◽  
Dariusz Karkosiński ◽  
Francisco Jesus Fernandez-Morales
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
External Load ◽  
Population Distribution ◽  
Oxygen Demand ◽  
Internal Resistance ◽  
Pollutant Removal ◽  
External Resistance ◽  
Reverse Scan ◽  
Resistance Value

In this work, the effect of the external load on the current and power generation, as well as on the pollutant removal by microbial fuel cells (MFCs), has been studied by step-wise modifying the external load. The load changes included a direct scan, in which the external resistance was increased from 120 Ω to 3300 Ω, and a subsequent reverse scan, in which the external resistance was decreased back to 120 Ω. The reduction in the current, experienced when increasing the external resistance, was maintained even in the reverse scan when the external resistance was step-wise decreased. Regarding the power exerted, when the external resistance was increased below the value of the internal resistance, an enhancement in the power exerted was observed. However, when operating near the value of the internal resistance, a stable power exerted of about 1.6 µW was reached. These current and power responses can be explained by the change in population distribution, which shifts to a more fermentative than electrogenic culture, as was confirmed by the population analyses. Regarding the pollutant removal, the effluent chemical oxygen demand (COD) decreased when the external resistance increased up to the internal resistance value. However, the effluent COD increased when the external resistance was higher than the internal resistance. This behavior was maintained in the reverse scan, which confirmed the modification in the microbial population of the MFC.

The effect of external resistance on biofilm formation and internal resistance in Shewanella inoculated microbial fuel cells

RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 20317-20323 ◽  
Author(s):  
Ting Liu ◽  
Yang-yang Yu ◽  
Dongzhe Li ◽  
Hao Song ◽  
Xiaoli Yan ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Biofilm Formation ◽  
Shewanella Oneidensis ◽  
Internal Resistance ◽  
External Resistance

External resistance has a significant impact on the bioelectrochemical property and biofilm formation of Shewanella oneidensis MR-1 on MFC anodes.

scholarly journals Bioelectricity production from tofu wastewater using microbial fuel cells with microalgae Spirulina sp as catholyte

2020 ◽  
Vol 202 ◽  
pp. 08007
Author(s):  
Wahyu Zuli Pratiwi ◽  
Hadiyanto Hadiyanto ◽  
Purwanto Purwanto ◽  
Muthi’ah Nur Fadlilah
Keyword(s):  
Wastewater Treatment ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Organic Waste ◽  
Oxygen Demand ◽  
Salt Bridge ◽  
Cod Removal ◽  
Biofuel Production ◽  
Pre Treatment ◽  
Made In

Microalgae-Microbial Fuel Cells (MMFCs) are very popular to be used to treat organic waste. MMFCs can function as an energy-producing wastewater pre-treatment system. Wastewater can provide an adequate supply of nutrients, support the large capacity of biofuel production, and can be integrated with existing wastewater treatment infrastructure. The reduced content of Chemical Oxygen Demand (COD) is one way to measure the efficiency of wastewater treatment. MMFCs reactors are made in the form of two chambers (anode and cathode) both of which are connected by a salt bridge. Tofu wastewater as an anode and Spirulina sp as a cathode. To improve MFCs performance which is to obtain maximum COD removal and electricity generation, nutrient NaHCO3 as the nutrient carbon source for Spirulina sp was varied. The system running phase on 12 days. The results were Spirulina sp treated with MFCs technology has better growth than non-MFCs. The MMFC generated a maximum power density of 21.728 mW/cm2 and achieved 57.37% COD removal. These results showed that the combined process was effective in treating tofu wastewater.

scholarly journals Rumen Inoculum Enhances Cathode Performance in Single-Chamber Air-Cathode Microbial Fuel Cells

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 379
Author(s):  
Ignacio T. Vargas ◽  
Natalia Tapia ◽  
John M. Regan
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Rumen Fluid ◽  
Oxygen Demand ◽  
Air Cathode ◽  
Single Chamber ◽  
Higher Power ◽  
Mixed Microbial Community ◽  
Current Production ◽  
Soluble Chemical Oxygen Demand

During the last decade, bioprospecting for electrochemically active bacteria has included the search for new sources of inoculum for microbial fuel cells (MFCs). However, concerning power and current production, a Geobacter-dominated mixed microbial community derived from a wastewater inoculum remains the standard. On the other hand, cathode performance is still one of the main limitations for MFCs, and the enrichment of a beneficial cathodic biofilm emerges as an alternative to increase its performance. Glucose-fed air-cathode reactors inoculated with a rumen-fluid enrichment and wastewater showed higher power densities and soluble chemical oxygen demand (sCOD) removal (Pmax = 824.5 mWm−2; ΔsCOD = 96.1%) than reactors inoculated only with wastewater (Pmax = 634.1 mWm−2; ΔsCOD = 91.7%). Identical anode but different cathode potentials suggest that differences in performance were due to the cathode. Pyrosequencing analysis showed no significant differences between the anodic community structures derived from both inocula but increased relative abundances of Azoarcus and Victivallis species in the cathodic rumen enrichment. Results suggest that this rarely used inoculum for single-chamber MFCs contributed to cathodic biofilm improvements with no anodic biofilm effects.

scholarly journals Electricity generation and pollutants removal of landfill leachate by osmotic microbial fuel cells with different forward osmosis membranes

2021 ◽  
Author(s):  
Nan Jiang ◽  
Li Huang ◽  
Manhong Huang ◽  
Teng Cai ◽  
Jialing Song ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Active Layer ◽  
Landfill Leachate ◽  
Microbial Fuel Cells ◽  
Forward Osmosis ◽  
Feed Solution ◽  
Cellulose Triacetate ◽  
Ammonia Nitrogen ◽  
Pollutant Removal ◽  
Leachate Treatment

Abstract In this study, thin-film composite with embedded polyester screen, cellulose triacetate with a cast nonwoven and cellulose triacetate with embedded polyester screen (CTA-ES) were examined as the intermediate membranes in osmotic microbial fuel cells (OsMFCs). The reactors were fed with actual landfill leachate and the performance was studied in two operation modes: active layer facing draw solution and active layer facing feed solution (AL-FS). The OsMFC with CTA-ES exhibited the best energy generation (maximum power density: 0.44 W m-2) and pollutant removal efficiency (ammonia nitrogen: 70.12 ± 0.28%, total nitrogen: 74.04 ± 0.33%) in the AL-FS mode, which could be ascribed to the lowest internal resistance (236.75 ohm) and highest microbial richness. Pseudomonas was the highest proportion of microbial in OsMFCs. The results of this study has demonstrated the potential of OsMFCs for landfill leachate treatment.

scholarly journals Scaling up Microbial Fuel Cells for Treating Swine Wastewater

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1803 ◽  
Author(s):  
Yuko Goto ◽  
Naoko Yoshida
Keyword(s):  
Organic Matter ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Swine Wastewater ◽  
Flow Mode ◽  
Carbon Cloth ◽  
Simultaneous Generation

Conventional aerobic treatment of swine wastewater, which generally contains 4500–8200 mg L−1 of organic matter, is energy-consuming. The aim of this study was to assess the application of scaled-up microbial fuel cells (MFCs) with different capacities (i.e., 1.5 L, 12 L, and 100 L) for removing organic matter from swine wastewater. The MFCs were single-chambered, consisting of an anode of microbially reduced graphene oxide (rGO) and an air-cathode of platinum-coated carbon cloth. The MFCs were polarized via an external resistance of 3–10 Ω for 40 days for the 1.5 L-MFC and 120 days for the 12L- and 100 L-MFC. The MFCs were operated in continuous flow mode (hydraulic retention time: 3–5 days). The 100 L-MFC achieved an average chemical oxygen demand (COD) removal efficiency of 52%, which corresponded to a COD removal rate of 530 mg L−1 d−1. Moreover, the 100 L-MFC showed an average and maximum electricity generation of 0.6 and 2.2 Wh m−3, respectively. Our findings suggest that MFCs can effectively be used for swine wastewater treatment coupled with the simultaneous generation of electricity.

scholarly journals Microbial Structure and Energy Generation in Microbial Fuel Cells Powered with Waste Anaerobic Digestate

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4712
Author(s):  
Dawid Nosek ◽  
Agnieszka Cydzik-Kwiatkowska
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Volatile Fatty Acids ◽  
Current Knowledge ◽  
Oxygen Demand ◽  
Electricity Production ◽  
Stable Operation ◽  
Microbial Structure ◽  
Microbial Composition ◽  
Start Up

Development of economical and environment-friendly Microbial Fuel Cells (MFCs) technology should be associated with waste management. However, current knowledge regarding microbiological bases of electricity production from complex waste substrates is insufficient. In the following study, microbial composition and electricity generation were investigated in MFCs powered with waste volatile fatty acids (VFAs) from anaerobic digestion of primary sludge. Two anode sizes were tested, resulting in organic loading rates (OLRs) of 69.12 and 36.21 mg chemical oxygen demand (COD)/(g MLSS∙d) in MFC1 and MFC2, respectively. Time of MFC operation affected the microbial structure and the use of waste VFAs promoted microbial diversity. High abundance of Deftia sp. and Methanobacterium sp. characterized start-up period in MFCs. During stable operation, higher OLR in MFC1 favored growth of exoelectrogens from Rhodopseudomonas sp. (13.2%) resulting in a higher and more stable electricity production in comparison with MFC2. At a lower OLR in MFC2, the percentage of exoelectrogens in biomass decreased, while the abundance of genera Leucobacter, Frigoribacterium and Phenylobacterium increased. In turn, this efficiently decomposed complex organic substances, favoring high and stable COD removal (over 85%). Independent of the anode size, Clostridium sp. and exoelectrogens belonging to genera Desulfobulbus and Acinetobacter were abundant in MFCs powered with waste VFAs.

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