title: Validation of TOF-SIMS and FE-SEM/EDS Techniques Combined with Sorption and Desorption Experiments to Check Competitive and Individual Pb2+ and Cd2+ Association with Components of B Soil Horizons.
abstract: Sorption and desorption experiments were performed by the batch method on the B horizons of five natural soils: Umbric Cambisol, Endoleptic Luvisol, Mollic Umbrisol, Dystric Umbrisol, and Dystric Fluvisol. Individual and competitive sorption and desorption capacity and hysteresis were determined. The results showed that Pb2+ was sorbed and retained in a greater quantity than Cd2+ and that the hysteresis of the first was greater than that of the second. The most influential characteristics of the sorption and retention of Pb2+ were pH, ECEC, Fe and Mn oxides and clay contents. For Cd2+ they were mainly pH and, to a lesser extent, Mn oxides and clay content. The combined use of TOF-SIMS, FE-SEM/EDS and sorption and desorption analyses was suitable for achieving a better understanding of the interaction between soil components and the two heavy metals. They show the preferential association of Pb2+ with vermiculite, chlorite, Fe and Mn oxides, and of Cd2+ with the same components, although to a much lesser extent and intensity. This was due to the latter's higher mobility as it competed unfavourably with the Pb2+ sorption sites. TOF-SIMS and FE-SEM/EDS techniques confirmed the results of the sorption experiments, and also provided valuable information on whether the soil components (individually or in association) retain Cd2+ and/or Pb2+; this could help to propose effective measures for the remediation of contaminated soils.
authors.affiliation: Department of Plant Biology and Soil Science, Faculty of Biology, University of Vigo, Lagoas, Marcosende, Vigo, Pontevedra, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Cerqueira
authors.affiliation: Department of Plant Biology and Soil Science, Faculty of Biology, University of Vigo, Lagoas, Marcosende, Vigo, Pontevedra, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Arenas-Lago
authors.affiliation: Department of Plant Biology and Soil Science, Faculty of Biology, University of Vigo, Lagoas, Marcosende, Vigo, Pontevedra, Spain.
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Andrade
authors.affiliation: Department of Plant Biology and Soil Science, Faculty of Biology, University of Vigo, Lagoas, Marcosende, Vigo, Pontevedra, Spain.
authors.forename: Flora A
authors.initials: FA
authors.lastname: Vega
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D015203:Reproducibility of Results; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D013696:Temperature
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead