title: Plants increase arsenic in solution but decrease the non-specifically bound fraction in the rhizosphere of an alkaline, naturally rich soil.
abstract: We aimed at determining the major physical-chemical processes that drive arsenic (As) dynamic in the rhizosphere of four species (Holcus lanatus, Dittrichia viscosa, Lotus corniculatus, Plantago lanceolata) tested for phytostabilization. Experiments were performed with an alkaline soil naturally rich in As. Composition of the soil solution of planted and unplanted pots was monitored every 15 days for 90 days, with a focus on the evolution of As concentrations in solution and in the non-specifically bound (i.e. easily exchangeable) fraction. The four species similarly increased As concentration in solution, but decreased As concentration in the non-specifically bound fraction. The major part (60%) of As desorbed from the non-specifically bound fraction in planted pots was likely redistributed on the less available fractions of As on the solid phase. A second part (35%) of desorbed As was taken up by plants. The minor part (5%) of desorbed As supplied As increase in solution. To conclude, plants induced a substantial redistribution of As on the less available fractions in the rhizosphere, as expected in phytostabilization strategies. Plants however concomitantly increased As concentration in the rhizosphere solution which may contribute to As transfer through plant uptake and leaching.
authors.affiliation: Ecole Nationale Supérieure des Mines de Saint-Etienne, Département SPIN, Laboratoire GéoSciences & Environnement, 158 cours Fauriel, F-42023 Saint Etienne Cedex 2, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Obeidy
authors.affiliation: CIRAD, UPR Recyclage et risque, F-97743 Saint-Denis, La Réunion, France. Electronic address: matthieu.bravin@cirad.fr.
authors.forename: Matthieu N
authors.initials: MN
authors.lastname: Bravin
authors.affiliation: Ecole Nationale Supérieure des Mines de Saint-Etienne, Département SPIN, Laboratoire GéoSciences & Environnement, 158 cours Fauriel, F-42023 Saint Etienne Cedex 2, France; CNRS, UMR-5600 EVS, F-69362 Lyon Cedex, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Bouchardon
authors.affiliation: Ecole Nationale Supérieure des Mines de Saint-Etienne, Département SPIN, Laboratoire GéoSciences & Environnement, 158 cours Fauriel, F-42023 Saint Etienne Cedex 2, France; CNRS, UMR-5600 EVS, F-69362 Lyon Cedex, France.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Conord
authors.affiliation: Ecole Nationale Supérieure des Mines de Saint-Etienne, Département SPIN, Laboratoire GéoSciences & Environnement, 158 cours Fauriel, F-42023 Saint Etienne Cedex 2, France; CNRS, UMR-5600 EVS, F-69362 Lyon Cedex, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Moutte
authors.affiliation: Ecole Nationale Supérieure des Mines de Saint-Etienne, Département SPIN, Laboratoire GéoSciences & Environnement, 158 cours Fauriel, F-42023 Saint Etienne Cedex 2, France; CNRS, UMR-5600 EVS, F-69362 Lyon Cedex, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Guy
authors.affiliation: Ecole Nationale Supérieure des Mines de Saint-Etienne, Département SPIN, Laboratoire GéoSciences & Environnement, 158 cours Fauriel, F-42023 Saint Etienne Cedex 2, France; CNRS, UMR-5600 EVS, F-69362 Lyon Cedex, France; Université de Lyon, F-69362 Lyon Cedex, France; Université Jean Monnet, F-42023 Saint-Etienne Cedex 2, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Faure
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000493:pharmacokinetics; D019659:Asteraceae / Q000378:metabolism; D031752:Holcus / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D000070116:Lotus / Q000378:metabolism; D010943:Plantago / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000493:pharmacokinetics; D012996:Solutions / Q000378:metabolism
chemical_list: D012987:Soil; D012989:Soil Pollutants; D012996:Solutions; D001151:Arsenic
keywords: Arsenate; Bioavailability; Contamination; Metalloid; Phytostabilization; Soil-root interface