title: Sorption of Cu, Pb and Cr on Na-montmorillonite: competition and effect of major elements.
abstract: The competitive sorption among Cu, Pb and Cr in ternary system on Na-montmorillonite at pH 3.5, 4.5 and 5.5 and at different heavy metal concentrations, and the effect of varying concentrations of Al, Fe, Ca and Mg on the sorption of heavy metals were studied. Competitive sorption of Cu, Pb and Cr in ternary system on montmorillonite followed the sequence of Cr≫Cu>Pb. Moreover, the competition was weakened by the increase of pH while was intensified by the increase of heavy metal concentration. The sorption of heavy metal on montmorillonite was inhibited by the presence of Ca and Mg, while Al and Fe showed different patterns in affecting heavy metal sorption. Aluminum and Fe generally inhibited the sorption of heavy metal when the pH and/or concentration of major elements were relatively low. However, promoting effects on heavy metal sorption by Al and Fe were found at relatively high pH and/or great concentration of major elements. The inhibition of major elements on heavy metal sorption generally followed the order of Al>Fe>Ca⩾Mg, while Fe was more efficient than Al in promoting the sorption of heavy metals. These findings are of fundamental significance for evaluating the mobility of heavy metals in polluted environments.
authors.affiliation: Department of Soil, Plant, Environment and Animal Production Science, Faculty of Agriculture, University of Naples "Federico II", Via University 100, 80055 Portici (Naples), Italy. junzh1002@sina.com
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: Vincenza
authors.initials: V
authors.lastname: Cozzolino
authors.forename: Massimo
authors.initials: M
authors.lastname: Pigna
authors.forename: Qiaoyun
authors.initials: Q
authors.lastname: Huang
authors.forename: Antonio Giandonato
authors.initials: AG
authors.lastname: Caporale
authors.forename: Antonio
authors.initials: A
authors.lastname: Violante
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002857:Chromium; D001546:Bentonite; D007854:Lead; D003300:Copper; D012964:Sodium