Heavy Metal Concentrations and Accumulation Characteristics of Dominant Woody Plants in Iron and Lead−Zinc Tailing Areas in Jiangxi, Southeast China

Abstract

Phytoremediation using woody plants can effectively reduce heavy metal (HM) concentrations in soils. However, the remediation capacity of woody plants depends greatly on plant species and soil environmental conditions. In order to evaluate the HM remediation potential of woody plants from different tailing areas, the HM accumulation characteristics of roots, shoots, and leaves of 12 dominant native woody plants growing in iron and lead-zinc tailing areas were analyzed. The results showed that the concentrations of Cd, As, Ni, Mn, and Cr in most plants in the two tailing areas exceeded the level of normal plants. The distribution of different elements in plants was generally as follows: root > leaf > shoot for Pb and As; root > shoot > leaf for Cr; and leaf > shoot > root for Zn, Ni, and Mn. The distribution of Cu and Cd in plants varied with the type of HM pollution in the two tailing areas. There were significant (p < 0.05) negative correlations between available phosphorus in the soil and Pb, Cd, and Zn in the plant roots when the soil was heavily polluted with Pb, Cd, and As; similarly, there were significant (p < 0.01) negative correlations between readily available potassium in the soil and Pb, Zn, and Ni in plant roots. Based on the higher than average concentration of HMs in plants, and higher bioconcentration factors and translocation factors, some plants were considered woody plant species with phytoremediation. Slash pine (Pinus elliottii) and indian azalea (Rhododendron simsii) had strong enrichment and translocation abilities for Cd, oriental white oak (Quercus glauca) and beautiful sweetgum (Liquidambar formosana) for Mn and paulownia (Paulownia fortunei) for Zn. The plants listed above can be used as potential species for phytoremediation in iron and lead-zinc tailing areas.