title: Bacterial immobilization and oxidation of arsenic in acid mine drainage (Carnoulès creek, France).
abstract: The acid waters (pH=2.73-3.37) originating from the Carnoulès mine tailings contain high dissolved concentrations of arsenic (1-3.5 mmol l(-1)) and iron (20-40 mmol l(-1)). At the outlet, arsenite predominates. During the first 30 m of downflow, 20-60% is removed by coprecipitation with Fe(III). This process results from bacterially mediated As- and Fe-oxidation. The precipitation rates in the creek depend on the oxygen concentration in spring water and are lower during the dry summer period when the anoxic character of the spring water inhibits the activity of oxidizing bacteria. Ex situ experiments show that the presence of bacteria-rich precipitates increases the As- and Fe-removal rates. Three strains of bacteria promoting the oxidation of As have been isolated, and two of them have the characteristics of Thiomonas ynys1. The third strain, which is not identified yet, also catalyzes the oxidation of Fe.
authors.affiliation: Laboratoire Hydrosciences Montpellier, UMR 5569, Université Montpellier 2, Place E Bataillon, 34095 Montpellier cedex 05, France. casiot@msem.univ-montp2.fr
authors.forename: Corinne
authors.initials: C
authors.lastname: Casiot
authors.forename: Guillaume
authors.initials: G
authors.lastname: Morin
authors.forename: Farid
authors.initials: F
authors.lastname: Juillot
authors.forename: Odile
authors.initials: O
authors.lastname: Bruneel
authors.forename: Jean Christian
authors.initials: JC
authors.lastname: Personné
authors.forename: Marc
authors.initials: M
authors.lastname: Leblanc
authors.forename: Katia
authors.initials: K
authors.lastname: Duquesne
authors.forename: Violaine
authors.initials: V
authors.lastname: Bonnefoy
authors.forename: Françoise
authors.initials: F
authors.lastname: Elbaz-Poulichet
mesh_terms: D001151:Arsenic / Q000737:chemistry / Q000378:metabolism*; D001419:Bacteria; D011232:Chemical Precipitation; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D008906:Mining; D010084:Oxidation-Reduction; D010100:Oxygen; D014873:Water Pollutants / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
chemical_list: D014873:Water Pollutants; D007501:Iron; D001151:Arsenic; D010100:Oxygen