title: Anaerobic arsenite oxidation with an electrode serving as the sole electron acceptor: a novel approach to the bioremediation of arsenic-polluted groundwater.
abstract: Arsenic contamination of soil and groundwater is a serious problem worldwide. Here we show that anaerobic oxidation of As(III) to As(V), a form which is more extensively and stably adsorbed onto metal-oxides, can be achieved by using a polarized (+497 mV vs. SHE) graphite anode serving as terminal electron acceptor in the microbial metabolism. The characterization of the microbial populations at the electrode, by using in situ detection methods, revealed the predominance of gammaproteobacteria. In principle, the proposed bioelectrochemical oxidation process would make it possible to provide As(III)-oxidizing microorganisms with a virtually unlimited, low-cost and low-maintenance electron acceptor as well as with a physical support for microbial attachment.
authors.affiliation: Laboratory of Chemical and Environmental Engineering (LEQUiA), Institute of the Environment, University of Girona, C/Maria Aurèlia Capmany, 69 E-17071 Girona, Spain.
authors.forename: Narcis
authors.initials: N
authors.lastname: Pous
authors.affiliation: Water Research Institute (IRSA-CNR), National Research Council, Via Salaria Km 29.300, 00015 Monterotondo, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Casentini
authors.affiliation: Water Research Institute (IRSA-CNR), National Research Council, Via Salaria Km 29.300, 00015 Monterotondo, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Rossetti
authors.affiliation: Water Research Institute (IRSA-CNR), National Research Council, Via Salaria Km 29.300, 00015 Monterotondo, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Fazi
authors.affiliation: Laboratory of Chemical and Environmental Engineering (LEQUiA), Institute of the Environment, University of Girona, C/Maria Aurèlia Capmany, 69 E-17071 Girona, Spain.
authors.forename: Sebastià
authors.initials: S
authors.lastname: Puig
authors.affiliation: Water Research Institute (IRSA-CNR), National Research Council, Via Salaria Km 29.300, 00015 Monterotondo, Italy. Electronic address: aulenta@irsa.cnr.it.
authors.forename: Federico
authors.initials: F
authors.lastname: Aulenta
mesh_terms: D000332:Aerobiosis; D001151:Arsenic / Q000737:chemistry*; D018053:Arsenites / Q000737:chemistry*; D001673:Biodegradation, Environmental; D004566:Electrodes; D020563:Gammaproteobacteria / Q000378:metabolism*; D006108:Graphite; D060587:Groundwater / Q000737:chemistry*; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D018053:Arsenites; D014874:Water Pollutants, Chemical; D006108:Graphite; C015001:arsenite; D001151:Arsenic
keywords: Arsenic bioremediation; Arsenite oxidation; Bioelectrochemical systems