Effect of Contact Area and Shape of Anode Current Collectors on Bacterial Community Structure in Microbial Fuel Cells

Low electrical conductivity of carbon materials is a source of potential loss for large carbonaceous electrode surfaces of MFCs due to the long distance traveled by electrons to the collector. In this paper, different configurations of titanium current collectors were used to connect large surfaces of carbon cloth anodes. The current collectors had different distances and contact areas to the anode. For the same anode surface (490 cm(2)), increasing the contact area from 28 cm² to 70 cm² enhanced power output from 58 mW.m-2 to 107 mW.m-2. For the same contact area (28 cm-2), decreasing the maximal distance of current collectors to anodes from 16.5 cm to 7.75 cm slightly increased power output from 50 mW.m-2 to 58 mW.m-2. Molecular biology characterization (qPCR and 16S rRNA gene sequencing) of anodic bacterial communities indicated that the Geobacter number was not correlated with power. Moreover, Geobacter and Desulfuromonas abundance increased with the drop in potential on the anode and with the presence of fermentative microorganisms. Electrochemical impedance spectroscopy (EIS) showed that biofilm resistance decreased with the abundance of electroactive bacteria. All these results showed that the electrical gradient arising from collectors shapes microbial communities. Consequently, current collectors influence the performance of carbon-based anodes for full-scale MFC applications.

Références

Titre
Effect of Contact Area and Shape of Anode Current Collectors on Bacterial Community Structure in Microbial Fuel Cells
Type de publication
Article de revue
Année de publication
2022
Revue
Molecules
Volume
27
Ticket
7
Start Page
2245
ISSN
1420-3049
Soumis le 21 juillet 2022