Assessment of wild plants for phytoremediation of heavy metals in soils surrounding the thermal power station
The present investigation was carried out to evaluate the phytoextraction potential of three main wild plant species: annual nettle (Urtica urens L.), daisy fleabane (Stenactis annua (L.) Ness.) and yarrow (Achillea millefolium L.) that grow spontaneously in heavy metal contaminated areas near the thermal power station in Kakanj, Bosnia and Herzegovina. Analyses of the heavy metal content (Ni, Fe, Cr, Cu, Zn, Cd, Pb, Mn) in soil and plant samples taken from the examined area were performed using atomic absorption spectrophotometry. The results obtained revealed that the examined soils are polluted by Ni and Pb and contain relatively high value of Cr and Fe. Annual nettle, daisy fleabane and yarrow have not shown high efficiency in the absorption and accumulation of heavy metals from polluted soils, and therefore these plants are not be considered as potential phytoremediators of soils on the examined area. Furthermore, the results of the study undoubtedly confirm the fact that the total content of heavy metals in soils is not a sufficient parameter for estimating the toxicity of heavy metals in soils and consequently for their transfer and accumulation in plants.