title: Analysis of the Importance of Oxides and Clays in Cd, Cr, Cu, Ni, Pb and Zn Adsorption and Retention with Regression Trees.
abstract: This study determines the influence of the different soil components and of the cation-exchange capacity on the adsorption and retention of different heavy metals: cadmium, chromium, copper, nickel, lead and zinc. In order to do so, regression models were created through decision trees and the importance of soil components was assessed. Used variables were: humified organic matter, specific cation-exchange capacity, percentages of sand and silt, proportions of Mn, Fe and Al oxides and hematite, and the proportion of quartz, plagioclase and mica, and the proportions of the different clays: kaolinite, vermiculite, gibbsite and chlorite. The most important components in the obtained models were vermiculite and gibbsite, especially for the adsorption of cadmium and zinc, while clays were less relevant. Oxides are less important than clays, especially for the adsorption of chromium and lead and the retention of chromium, copper and lead.
authors.affiliation: Department of Plant Biology and Soil Science, Universidad de Vigo. Vigo, Spain.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: González-Costa
authors.affiliation: Department of Plant Biology and Soil Science, Universidad de Vigo. Vigo, Spain.
authors.forename: Manuel Joaquín
authors.initials: MJ
authors.lastname: Reigosa
authors.affiliation: Department of Statistics and Operational Research, Universidad de Vigo. Vigo, Spain.
authors.forename: José María
authors.initials: JM
authors.lastname: Matías
authors.affiliation: Department of Plant Biology and Soil Science, Universidad de Vigo. Vigo, Spain.
authors.forename: Emma
authors.initials: E
authors.lastname: Fernández-Covelo
mesh_terms: D000327:Adsorption; D000465:Algorithms; D000538:Aluminum Silicates / Q000032:analysis / Q000737:chemistry*; D002104:Cadmium; D002857:Chromium; D000077215:Clay; D007854:Lead; D000069550:Machine Learning; D019216:Metals, Heavy / Q000737:chemistry*; D009532:Nickel; D010087:Oxides / Q000737:chemistry*; D012044:Regression Analysis; D015203:Reproducibility of Results; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D019216:Metals, Heavy; D010087:Oxides; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D002857:Chromium; D007854:Lead; D009532:Nickel; D000077215:Clay