Phytoremediation Ability of the New Heavy Metal Accumulator Plants

Environmental pollution with heavy metals is a global disaster. This study investigated metal-accumulating ability of plants growing in a lead and zinc mine area located in Hamedan, Iran. Three dominant plants, including Conium maculatum, Stachys inflata, and Reseda lutea, were collected, and the concentrations of Cd, Cu, Pb, Ni, and Zn in the aerial parts of the plants and in the soils, collected from the mine area and out of the mine, were measured via atomic absorption spectrometry. The concentrations of all the metals in the soil of the mine were greater than the control area (1 km out of mine area); Pb, Zn, Cu, Ni, and Cd were 120, 17, 17, 2.6, and 40 times higher than in the control area, respectively. In the studied plants, Pb and Zn were the highest in C. maculatum (1,200 and 820 mg kg−1, respectively). The highest concentrations of Cu, Ni, and Cd were in S. inflata (140, 96, and 20 mg kg−1, respectively). Phytoremediation tests were done using experimental pots, and results indicate that the plant species are effective accumulator plants for the phytoremediation of heavy metal–polluted soils. Specifically, C. maculatum was effective in removing Pb and Zn, S. inflata was effective in reducing Ni, and R. lutea was effective in reducing Cu.