Open AccessAnalysis of the Importance of Oxides and Clays in Cd, Cr, Cu, Ni, Pb and Zn Adsorption and Retention with Regression Trees
Author(s) -
Juan José González-Costa,
Manuel J. Reigosa,
J. M. Matías,
Emma Fernández-Covelo
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0168523
Subject(s) - gibbsite , kaolinite , vermiculite , cadmium , cation exchange capacity , chromium , adsorption , chemistry , zinc , copper , ion exchange , hematite , environmental chemistry , clay minerals , inorganic chemistry , mineralogy , soil water , materials science , geology , soil science , ion , organic chemistry , composite material
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.