title: Lowering the applied potential during successive scratching/re-inoculation improves the performance of microbial anodes for microbial fuel cells.
abstract: Microbial anodes were formed under polarisation at -0.2V/SCE on smooth graphite plate electrodes with paper mill effluents. Primary, secondary and tertiary biofilms were formed by a successive scratching and re-inoculation procedure. The secondary and tertiary biofilms formed while decreasing the polarisation potential allowed the anodes to provide current density of 6A/m(2) at -0.4V/SCE. In contrast, applying -0.4V/SCE initially to form the primary biofilms did not lead to the production of current. Consequently, the scratching/re-inoculation procedure combined with progressive lowering of the applied potential revealed an efficient new procedure that gave efficient microbial anodes able to work at low potential. The observed progressive pH drift to alkaline values above 9 explained the open circuit potentials as low as -0.6 V/SCE. The remarkable performance of the electrode at alkaline pH was attributed to the presence of Desulfuromonas acetexigens as the single dominant species in the tertiary microbial anodes.
authors.affiliation: Centre Technique du Papier, 341 Rue de la Papeterie, 38400 Saint Martin d'Hères, France. francoise.ketep@ensiacet.fr
authors.forename: Stephanie F
authors.initials: SF
authors.lastname: Ketep
authors.forename: Alain
authors.initials: A
authors.lastname: Bergel
authors.forename: Marie
authors.initials: M
authors.lastname: Bertrand
authors.forename: Wafa
authors.initials: W
authors.lastname: Achouak
authors.forename: Eric
authors.initials: E
authors.lastname: Fourest
mesh_terms: D001674:Bioelectric Energy Sources; D018441:Biofilms; D057919:Biological Oxygen Demand Analysis; D017931:DNA Primers / Q000235:genetics; D020564:Deltaproteobacteria / Q000235:genetics / Q000378:metabolism*; D058645:Denaturing Gradient Gel Electrophoresis; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006108:Graphite; D006863:Hydrogen-Ion Concentration; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D006108:Graphite