摘要：Heavy metals cause some physiological and biochemical changes if they present with toxic concentrations in aquatic environments. The study was conducted in order to trace the potential of the aquatic plant Lemna minuta for the bioaccumulation of Zn, Mn, and Fe from contaminated water at low levels of these elements. The duckweed species was treated separately with ZnCl, MnCl_2x4H_2O, FeCl_3 (Valerus, Bulgaria) at 1 mg.l~(-1) concentrations for 96 hours period. In response to metal exposure, relative growth rate (RGR), bioconcentration factor (BCF), tolerant index (Ti) and photosynthetic pigments of L. minuta were studied. The highest relative growth rate reduction of this aquatic plant was found with Fe (1 mg.l~(-1)) treatment which is 50% lower compared to control. The BCF of the metals on the species were in decreasing order: Fe > Zn > Mn. The manganese content of 1 mg.l~(-1) led to an increase in photosynthetic pigments.
