title: The study of electrochemically active microbial biofilms on different carbon-based anode materials in microbial fuel cells.
abstract: In this communication we show that the achievable maximum current density for mature wastewater-based microbial biofilms is strongly dependent on the electrode material and the operation temperature. On graphite and polycrystalline carbon rods, the catalytic current of about 500 microA cm(-2) (projected surface area) at 30 degrees C was achieved. Carbon fiber veil or carbon-paper based materials, having a large microbially-accessible surface gave a projected current density approximately 40% higher than on graphite rod. In contrast, the biofilm cannot form well on graphite foil. Elevating the temperature from 30 to 40 degrees C increased current density by 80% on graphite rod anodes. Interestingly, the formal potential of the active site (-0.12 V (vs. standard hydrogen electrode (SHE))) is similar to all electrocatalytically active microbial biofilms and to that found for Geobacter sulfurreducens in previous studies. In addition, the real surface area values measured by BET surface area technique cannot provide a reasonable explanation for suitability of an electrode material for the formation of electrochemically active biofilm.
authors.affiliation: Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Strasse 4, 17487 Greifswald, Germany. lydiayliu@yahoo.com
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Falk
authors.initials: F
authors.lastname: Harnisch
authors.forename: Katja
authors.initials: K
authors.lastname: Fricke
authors.forename: Uwe
authors.initials: U
authors.lastname: Schröder
authors.forename: Victor
authors.initials: V
authors.lastname: Climent
authors.forename: Juan Miguel
authors.initials: JM
authors.lastname: Feliu
mesh_terms: D001674:Bioelectric Energy Sources; D018441:Biofilms / Q000254:growth & development; D002244:Carbon; D055664:Electrochemical Techniques; D004566:Electrodes; D008855:Microscopy, Electron, Scanning; D018505:Waste Management / Q000379:methods
chemical_list: D002244:Carbon