Adsorption of Cadmium, Copper and Chromium by an Agricultural Soil Impacted by Mining Activities

被引：7

作者：

Mosai, Alseno K. ^{[1
]}

Bakatula, Elisee N. ^{[2
]}

Tutu, Hlanganani ^{[1
]}

机构：

[1] Univ Witwatersrand, WITS, Sch Chem, Mol Sci Inst, Private Bag X3, ZA-2050 Johannesburg, South Africa

[2] Univ Montreal, Ecole Polytech Montreal, Civil Geol & Min Engn Dept, Montreal, PQ, Canada

来源：

WATER AIR AND SOIL POLLUTION | 2017年 / 228卷 / 08期

基金：

新加坡国家研究基金会;

关键词：

Agricultural soil; Adsorption capacity; Cadmium; Copper; Chromium; HEAVY-METAL IONS; AQUEOUS-SOLUTIONS; SPECIATION; SORPTION; EAST; ZINC;

D O I：

10.1007/s11270-017-3487-1

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Batch adsorption studies for cadmium (Cd), copper (Cu) and chromium (Cr) onto an agricultural soil impacted by mining activities were conducted in single-and multi-component systems. The effect of initial concentration, pH and competing ions (Fe3+, Ca2+, Co2+, Mg2+, K+, Ni2+ and Zn2+) on adsorption was studied. The soil exhibited high adsorption capacities for the elements at all initial concentrations with the adsorption process better described by the Freundlich isotherm. Adsorption was found to proceed via an ion exchange mechanism. The pseudo second-order kinetic model described the adsorption of the elements (R-2 > 0.999), indicating a chemisorption process. The adsorption of Cd increased with pH in both systems while that for Cu decreased. The adsorption of Cr decreased with pH in the single-component system, but increased in the multicomponent system. The adsorption of Cd was affected more by competing ions while Cu and Cr were not significantly affected (p > 0.05). Elemental speciation under varying conditions was studied using the PHREEQC geochemical modelling code. The observed high capacity of the soil for the elements pointed to the soil's potential as a repository, a feature that would change depending on the speciation of the elements and soil conditions.

引用

页数：12