Phytoaccumulation of heavy metals in native plants growing on soils in the Spreča river valley, Bosnia and Herzegovina

This study evaluated the phytoremediation potential of eight native plant species on heavy metal polluted soils along the Spreča river valley (the northeast region of Bosnia and Herzegovina). Plants selected for screening were: ryegrass (Lolium perenne L.), common nettle (Urtica dioica L.), mugwort (Artemisia vulgaris L.), wild mint (Mentha arvensis L.), white clover (Trifolium repens L.), alfalfa (Medicago sativa L.), dwarf nettle (Urtica urens L.) and yarrow (Achillea millefolium L.). All aboveground parts of selected native plants and their associated soil samples were collected and analysed for total concentration of Ni, Cr, Cd, Pb, Zn and Cu. The bioaccumulation factor for each element was also calculated. The levels of Cr (90.9-171.1 mg/kg) and Ni (80.1-390.5 mg/kg) in the studied soil plots were generally higher than limits prescribed by European standards, indicating that the soils in the Spreča river valley are polluted by Cr and Ni. Among the eight screened plant species, no hyperaccumulators for toxic heavy metals Ni, Cr, Cd and Pb were identified. However, the concentrations of toxic heavy metals in the above-ground parts of Artemisia vulgaris L. and Trifolium repens L. were significantly higher than in the other studied plants, indicating that both plant species are useful for heavy metal removal.