Sulfate reduction with electrons directly derived from electrodes in bioelectrochemical systems

In this paper, we reported microbially catalyzed sulfate reduction with polarized electrode (-400 mV vs. Ag/AgCl) as the sole electron donor. In potentiostatic batch assays, sulfate was reduced to sulfide, at rates falling in the range of 6.70-12.16 equiv./l d. Cyclic voltammetry tests revealed that the sulfate-reducing biofilms could accept electrons from electrodes directly without via electron shuttles or hydrogen production. Scanning electron microscope revealed that the electrode was colonized by several ellipse-shaped and short rod-shaped microorganisms, which closely related to Desulfobulbus propionicus and Geobacter species. (C) 2012 Elsevier B.V. All rights reserved.