title: Relative contribution of set cathode potential and external mass transport on TCE dechlorination in a continuous-flow bioelectrochemical reactor.
abstract: Microbial bioelectrochemical systems, which use solid-state cathodes to drive the reductive degradation of contaminants such as the chlorinated hydrocarbons, are recently attracting considerable attention for bioremediation applications. So far, most of the published research has focused on analyzing the influence of key (bio)electrochemical factors influencing contaminant degradation, such as the cathode potential, whereas only few studies have examined the potential impact of mass transport phenomena on process performance. Here we analyzed the performance of a flow-through bioelectrochemical reactor, continuously fed with a synthetic groundwater containing trichloroethene at three different linear fluid velocities (from 0.3 m d(-1) to 1.7 m d(-1)) and three different set cathode potentials (from -250 mV to -450 mV vs. the standard hydrogen electrode). The obtained results demonstrated that, in the range of fluid velocities which are characteristics for natural groundwater systems, mass transport phenomena may strongly influence the rate and extent of reductive dechlorination. Nonetheless, the relative importance of mass transport largely depends on the applied cathode potential which, in turn, controls the intrinsic kinetics of biological reactions and the underlying electron transfer mechanisms.
authors.affiliation: Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy. Electronic address: roberta.verdini@uniroma1.it.
authors.forename: Roberta
authors.initials: R
authors.lastname: Verdini
authors.affiliation: Water Research Institute (IRSA), National Research Council (CNR), via Salaria km 29.300, 00015 Monterotondo (RM), Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Aulenta
authors.affiliation: Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: de Tora
authors.affiliation: Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy.
authors.forename: Agnese
authors.initials: A
authors.lastname: Lai
authors.affiliation: Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Majone
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors; D004566:Electrodes; D004579:Electron Transport; D060587:Groundwater; D054879:Halogenation; D014241:Trichloroethylene / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D014241:Trichloroethylene
keywords: Bioelectrochemical system; Bioremediation; Chlorinated solvent; Mass transport phenomena; Reductive dechlorination; Trichloroethene