Preference of heavy metals accumulation, tolerance limit and biochemical responses of eichhornia crassipes (mart.) exposed to industrial waste water

Discharge of industrial waste water often poses serious threat to our environment. In the present study, heavy metals content in industrial waste water from common industrial effluent treatment plant in Unnao district (U.P.), India were quantified. The nickel (1.2 mg l-1) and chromium (1.8 mg l-1) content was high in industrial waste water and concentration was found in order Cr>Ni>Zn>Cu. Eichhornia crassipes Mart. plants were exposed to various concentrations of above evaluated industrial waste water (0, 25, 50, 75 and 100%) for 10 days and observed for their visible effects, tissue accumulation level and biochemical constituents (pigments, total protein, sugar and relative water contents and amylase activity) including antioxidants (catalase activity, peroxidase activity and Proline content) in E. crassipes leaves and roots. The accumulation of heavy metals was observed more in root than the leaves (Cr>Ni>Zn>Cu). Also inhibited biochemical constituents (pigments, protein and sugar contents and amylase activity) including antioxidants (catalase, peroxidase activity and proline content) in E. crassipes. Study concluded that, E. crassipes indicated accumulation of high content of Cr (Cr>Ni>Zn>Cu), exhibited visible symptoms of toxicity and altered biochemical constituents with exposure of industrial waste water. These findings may be helpful in phytoremedial approaches to minimize heavy metals content in surface water.