Phytoremediation study of water polluted with heavy metals using floating macrophytes: Lemna minor and Pistia stratiotes

摘要

This work aims to highlight the capacity of Lemna minor and Pistia stratiotes macrophytes todecontaminate waters polluted with heavy metals, through a process of phytoextraction andphytoaccumulation. The purpose of the study was to elaborate an in-situ bioremediation technology forthe waters of the decantation ponds originated from the mining industry. Experiments were conducted onwater samples collected from Aurul tailings management facility, in Baia Mare region, northern Romania.The materials deposited on this facility resulted from the re-processing of tailings containing residualgold. The capacity of phytoextraction and bioaccumulation of heavy metals in the plants tissues havebeen assessed. Three types of samples have been used in the laboratory experiment: a blank sampleconsisting of bottled drinking water, a water sample taken from the drainage ditch, and a sample takenfrom the tailings pond. The phytoextraction of heavy metals from the analyzed water samples (μg L-1)and the bioaccumulation of heavy metals in the tissues of the plants (mg kg-1 d.m.) were monitored. Theheavy metal concentrations have been measured before and after the phytoextraction process, and anaccumulation of heavy metals (Cd, Cu, Ni, Zn, Pb, Fe) in L. minor and P. stratiotes plant tissues has beennoticed.