Speciation Distributions and Availability of Zn, Pb, Cu and Ni in a Mine Drainage Contaminated Paddy Soils
Various depths paddy soils, which collected from nearby one of the abandoned Pb-Zn mines in Lanping County of China, were analyzed, determining the total metal concentration by acid digestion and the chemical speciation of Zn, Pb, Cu and Ni by a somewhat modified Tessier’s sequential extraction method. High concentrations of Zn and Pb were found in surface soils indicating that the paddy soils seriously suffered from Zn and Pb contamination. The extraction percentage of Zn, Pb, Cu and Ni with modified Tessier’s sequential extraction procedures were at the ranges of 93.15-96.41%, 93.26-96.25%, 91.51-94.75% and 91.28-94.25%, respectively. Extraction efficiencies demonstrated that this sequential extraction approach is suitable to evaluate these metals potential risk among this contaminated site. Extraction results showed that the residual fraction was the predominant fraction for Zn, Pb, Cu and Ni among all tested soils. However, the exchangeable fraction was the lowest among all fractions. Meanwhile, the metals mobility and bioavailability in tested soils were compared and predicted using mobility coefficients and bioavailability coefficients. The mobility coefficients of metals decreased in the order of Cu> Ni> Zn> Pb, and the bioavailability coefficients of metals decreased in the order of Pb>Cu>Zn/Ni.
Weiguo Pan, Jianxing Ren and Yongguang Li
D. R. Miao and W. Q. Yang, "Speciation Distributions and Availability of Zn, Pb, Cu and Ni in a Mine Drainage Contaminated Paddy Soils", Advanced Materials Research, Vols. 347-353, pp. 826-831, 2012