Zinc Uptake Potential in Water Lettuce (Pistia Stratiotes, Linn)

The macrophyte Pistia stratiotes Linn. was exposed to the of Zinc (Zn) viz.1 ppm, 2 ppm, 3 ppm, 4 ppm and 5 ppm and studied its potential of Zn absorption at different time periods with the interval of 5 days for continuous thirty days, arranging simultaneously a set of control without Zn for the comparison in same environment with similar all other operating conditions. It is observed that Zn absorption was higher at initial period of exposure and gradually reached to the saturation in all the exposed Zn concentrations. The absorption of Zn was higher at 3 ppm and all above exposure concentrations. The absorption potential was higher in roots than the absorption potential of shoots at all concentrations of Zn. The Transfer Factor (TF) was highest (0.270) in Set 4 having 3.0 ppm Zn concentration after 10 days. The study concluded that, Pistia stratiotes L. is capable to absorb Zn at higher concentrations and is hyper accumulator of Zn. Therefore, it may be used in Natural Treatment Systems of Phytoremediation for Pollution remediation using innovative constructed wetlands like floating wetland reactor systems.