Bioconcentration and translocation of heavy metals from landfill leachate by selected plants

It is reported in the literature that the most common pollutants in landfill leachate, apart from ammonium nitrogen, chlorides and sulfates, include heavy metals. Municipal waste landfills are considered a potential source of heavy metal contamination of groundwater, soil and plants. In high concentrations, they may pose a threat to human health and cause toxic effects in plants. Therefore, the aim of the study was to verify the content of heavy metals in leachate from four municipal waste landfills in Poland. The bioconcentration factor of heavy metals (BCF) from landfill leachate by emerged macrophytes (Phragmites australis) and submerged macrophytes (Ceratophyllum demersum) was assessed. Heavy metal translocation factor (TF) following exposure to landfill leachate were also analyzed. The obtained results showed that the content of selected heavy metals (Cu, Ni, Pb, Cr and Cd) in leachate remained at a low level (i.e. < 1 mg/l), which shows that heavy metals are not currently a serious problem in landfill leachate in Poland. The BCF values ​​were >1 only in a few cases (e.g. for Cr, where the BCF ranged from 1.02 to 4.62). For most variants, slightly higher metal contents were recorded in the roots than in the shoots. The TF of heavy metals in P.australis in almost all cases it was <1.0 except for Cd, where values ​​up to 784 were achieved in the control variant.