Optimal set anode potentials vary in bioelectrochemical systems

Rachel C. Wagner, Douglas F. Call, Bruce E. Logan

Research output: Contribution to journalReview article

123 Scopus citations

Abstract

In bioelectrochemical systems (BESs), the anode potential can be set to a fixed voltage using a potentiostat, but there is no accepted method for defining an optimal potential. Microbes can theoretically gain more energy by reducing a terminal electron acceptor with a more positive potential, for example oxygen compared to nitrate. Therefore, more positive anode potentials should allow microbes to gain more energy per electron transferred than a lower potential, but this can only occur if the microbe has metabolic pathways capable of capturing the available energy. Our review of the literature shows that there is a general trend of improved performance using more positive potentials, but there are several notable cases where biofilm growth and current generation improved or only occurred at more negative potentials. This suggests that even with diverse microbial communities, it is primarily the potential of the terminal respiratory proteins used by certain exoelectrogenic bacteria, and to a lesser extent the anode potential, that determines the optimal growth conditions in the reactor. Our analysis suggests that additional bioelectrochemical investigations of both pure and mixed cultures, over a wide range of potentials, are needed to better understand how to set and evaluate optimal anode potentials for improving BES performance.

Original languageEnglish (US)
Pages (from-to)6036-6041
Number of pages6
JournalEnvironmental Science and Technology
Volume44
Issue number16
DOIs
StatePublished - Aug 15 2010

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All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Environmental Chemistry

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