Kamaraj Sathish kumar - Electrochemical and chemical enrichment methods of a sodicesaline inoculum for microbial fuel cells

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      Publication Details (including relevant citation   information):

        International Journal of Hydrogen Energy

      Abstract:

      ABSTRACT a b s t r a c t In microbial fuel cells   (MFCs) efficient extracellular electron transfer microbes, also   known as anode-respiring bacteria, play an important role on cell   performance. This type of microbes can be developed by   application of enrichment procedures. The objective of this study   was to compare a chemical (only C, final terminal electron   acceptor Fe(III)), an electrochemical (only E), and a hybrid   method (H, i.e., E followed by 3 serial transfers in iron (III)   citrate medium) enrichment methods departing from a salineesodic   soil inoculum. In the electrochemical enrichment procedure in an   electrolysis cell, the inoculum was sub-jected to a continuous   electrical stress continually by posing the cell at À150 mV/SCE   (þ94 mV/SHE). The only C enrichment method delivered powers   superior to the only E one (higher values of P An,max ¼ 49 mW m   À2 and P V,max ¼ 558 mW m À3 of C compared to 33 and 379 of only   E). Interestingly, overall resistance as determined by EIS was   lower for only E (1240 U) than for only C (1632 U). Yet, the   hybrid H method, showed electrochemical characteristics   consistently superior to both only C and only E methods (higher P   An,max and P V,max , lower internal resistance). Further detailed   electrochemical studies of only E-method showed that the anodic   resistance decreased with the time of operation of the   electrolysis cell that would be consistent with the   adaptability/enrichment purpose of the method. Also, Cyclic   voltammetry peaks with values close to those reported for   bacterial cytochromes appeared with time of cell operation. To   the best of our knowledge, this is the first time that it is   reported that serial transfers with Fe(III) as electron acceptor   to an inoculum previously enriched in an electrolysis cell, leads   to improved characteristics of MFC and increased Fe(III)-reducing   capability of the inoculum.

      Address (URL): http://www.sciencedirect.com/science/article/pii/S0360319912026365