Uptake of radionuclide thorium by twelve native plants grown in uranium mill tailings soils from south part of China

摘要

The concentrations of thorium (Th-232) in soil from a uranium mill tailings repository in South China were analyzed. The results showed that all the soil samples were acidic and the concentrations of Th-232 in all the soil samples were more than the natural radionuclide content in soil of China. Through the field investigation, twelve kinds of dominant plants were discovered. The total quantity of Th-232 in the whole plant is highest in rice flat sedge. We also found that Miscanthus floridulus has the greatest transfer factor (TF) for Th-232, rice flat sedge has the greatest bioconcentration factor (BF) for Th-232. At the mean time, M. floridulus has the greatest phytoremediation factor (PF) for Th-232. On the basis of the above conclusions and the definition for hyperaccumulator, rice flat sedge and M. floridulus could be the candidates of phytoremediation for radionuclide Th-232 in the soil. (C) 2016 Elsevier B.V. All rights reserved.