Cathodic biofilm activates electrode surface and achieves efficient autotrophic sulfate reduction
Guillermo Pozo, Ludovic Jourdin, Yang Lu, Jurg Keller, Pablo Ledezma, Stefano Freguia
ELECTROCHIMICA ACTA | PERGAMON-ELSEVIER SCIENCE LTD | Published : 2016
Recent evidence suggests that autotrophic sulfate reduction could be driven by direct and indirect electron transfer mechanisms in bioelectrochemical systems. However, much uncertainty still exists about the electron fluxes from the electrode to the final electron acceptor sulfate during autotrophic sulfate reduction. In this study, linear sweep voltammetry and chronamperometry coupled to off-gas measurement demonstrates that autotrophic sulfate reduction (0.9 ± 0.1 mol SO42−-S m2 d−1) is driven by electron fluxes from the cathode to sulfate via hydrogen as intermediate, with 95 ± 0.04% Coulombic efficiency towards sulfide production. Moreover, the biofilm-forming sulfate-reducing bacteria (..View full abstract
Awarded by Australian Research Council
The authors thank the Australian Research Council for funding support through Discovery Project DP120104415 and the AWMC Analytical Services Laboratory (ASL) for the IC, TIC and VFA analyses. The authors furthermore acknowledge the facilities, and the scientific and technical assistance, of the Australian Microscopy & Microanalysis Research Facility at the Centre for Microscopy and Microanalysis, The University of Queensland. We would also like to thank Dr. B. C. Donose for fruitful discussions and SEM imaging of the electrode samples. Guillermo Pozo acknowledges a Chilean Scholarship (Becas Chile) from the National Commission for Science Research and Technology (CONICYT, Chile).