Evaluation of the Potential Ecological Risk of Heavy Metal Pollution in Soil and Bioaccumulation Characteristics of Dominant Plants in Siding Pb-Zn Mine

Abstract

Soils and dominant plants were surveyed and studied in the Siding mine area. Based on the determination of heavy metal concentration of soil from 8 sections and 14 dominant plant species in different parts, the potential ecological hazard was assessed using the Hakanson Index Method. The results indicated that the soil of Siding mine area was seriously contaminated by Pb and Zn.The Eir values of Pb and Zn were higher than 320, and the degree of ecological hazard was extremely high, while the Eir values of Cu and Cr were lower than 40, the degree of ecological hazard was low. Statistical analyses showed that mining and smelt activities had a great influence on the content and distribution of heavy metals. Pb-Zn and Pb-Cu were likely from a same source, while Cr had a different cumulating character. Furthermore, had Pb, Zn, Fe, Mn, Cu and Cr in 14 dominant plant species at defferent levels, but they had not reached the level for hyperaccumulators. Among all the dominant plants, Phragmites australis(Cav.)Trin. ex Steud., Imperata cylindrica(Linn.)Beauv., Herba Taraxaci and Pteris vittata L. appeared to have good accumulation of Pb and Zn, and would be very useful in the restoration of Pb and Zn polluted areas.