AQUATIC PLANTS AS BIOINDICATORS FOR HEAVY METAL CONTENT IN SURFACE WATER ECOSYSTEMS - LEMNACEAE SPECIES.

Two aquatic floating plants of Lemnaceae species were selected, viz., Lemna gibba and Lemna minor to examine their potential to bioremediate toxic metals from polluted water of studied lake. Toxic metals chosen were cadmium, cobalt, copper, nickel, lead and zinc monitored in water, sediment and roots and leaves of the abovesaid plants. The quantity of toxic metals in water, sediment and the tissues of plants were exploited to evaluate the bioconcentration factor, transfer factor value and enrichment coefficient value. The strength and dangerous condition noted in the examined aquatic plants, the six toxic metals were arranged in the order of Zn > Pb > Cd > Cu > Ni > Co. Bioconcentration factor value lies 1.47 to 8.97 for Lemna gibba and 1.38 to 8.67 for Lemna minor. Thus, both these plants showed their broad range of tolerance to all the evaluated metals, which recommends the application of these plants for industrial scale of heavy metal removal. [ABSTRACT FROM AUTHOR]