title: Electrochemical characterization of microbial bioanodes formed on a collector/electrode system in a highly saline electrolyte.
abstract: Bioanodes were formed with electrodes made of carbon felt and equipped with a titanium electrical collector, as commonly used in microbial fuel cells. Electrochemical impedance spectroscopy (EIS) performed on the abiotic electrode system evidenced two time constants, one corresponding to the "collector/carbon felt" contact, the other to the "carbon felt/solution" interface. Such a two time constant system was characteristics of the two-material electrode, independent of biofilm presence. EIS was then performed during the bioanode formation around the constant applied potential of 0.1 V/SCE. The equivalent electrical model was similar to that of the abiotic system. Due to the high salinity of the electrolyte (45 g·L(-1) NaCl) the electrolyte resistance was always very low. The bioanode development induced kinetic heterogeneities that were taken into account by replacing the pure capacitance of the abiotic system by a constant phase element for the "carbon felt/solution" interface. The current increase from 0 to 20.6 A·m(-2) was correlated to the considerable decrease of the charge transfer resistance of the "carbon felt/solution" interface from 2.4 10(4) to 92 Ω·cm(2). Finally, EIS implemented at 0.4 V/SCE showed that the limitation observed at high potential values was not related to mass transfer but to a biofilm-linked kinetics.
authors.affiliation: Laboratoire de Génie Chimique, CNRS-Université de Toulouse (INPT), 4 Allée Emile Monso, BP 84234, 31432 Toulouse, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Rousseau
authors.affiliation: Laboratoire de Génie Chimique, CNRS-Université de Toulouse (INPT), 4 Allée Emile Monso, BP 84234, 31432 Toulouse, France.
authors.forename: Mickaël
authors.initials: M
authors.lastname: Rimboud
authors.affiliation: Laboratoire de Génie Chimique, CNRS-Université de Toulouse (INPT), 4 Allée Emile Monso, BP 84234, 31432 Toulouse, France.
authors.forename: Marie-Line
authors.initials: ML
authors.lastname: Délia
authors.affiliation: Laboratoire de Génie Chimique, CNRS-Université de Toulouse (INPT), 4 Allée Emile Monso, BP 84234, 31432 Toulouse, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Bergel
authors.affiliation: Laboratoire de Génie Chimique, CNRS-Université de Toulouse (INPT), 4 Allée Emile Monso, BP 84234, 31432 Toulouse, France. Electronic address: regine.basseguy@ensiacet.fr.
authors.forename: Régine
authors.initials: R
authors.lastname: Basséguy
mesh_terms: D001674:Bioelectric Energy Sources / Q000382:microbiology; D018441:Biofilms; D004563:Electrochemistry; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry*; D004579:Electron Transport; D054712:Salinity
chemical_list: D004573:Electrolytes
keywords: Bioanode; Electrochemical impedance spectroscopy; Halotolerant; Limiting step; Microbial fuel cell