Arsenic sorption properties in a chronosequence of soils derived from clay parent material. One century of the discovery of arsenicosis in Latin America (1914 – 2014).
Résumé
he aim of this study was to characterize arsenic mobility in soils developed from clayey bedrocks. A soil chronosequence was determined that represents all possible pedogenesis in French northeast climate conditions (from young Technosol to stagnic Luvisol and albic Planosol). Each soil represents a pedogenetic step derived from young Technosol (Callovo-Oxfordian clay). Soil horizons were characterized for their physicochemical properties. Batch experiments were conducted to adsorb arsenic on soil samples and to determine the distribution coefficient-Kd in linearity conditions. Adsorption isotherms were obtained for three surface horizons and seemed to follow Langmuir model. Kd of the horizons were obtained in the linear part of the isotherm: young Technosol Kd: 843.04 L kg-1 (R2 = 0.9907), albic Planosol Kd: 649.24 L kg-1 (R2 = 0.9998) and vertic Cambisol Kd: 194.63 L kg-1 (R2 = 0.997). By Principal Component Analysis (PCA), it was determined that Kd seems to be much higher in younger than in developed soils. © 2014 Taylor & Francis Group.