Rhizofiltration of Heavy Metals from Eutrophic Water Using Pistia Stratiotes in a Controlled Environment

Abstract

The remediation of waters polluted with heavy metals using Pistia stratiotes was studied with the aim of assessing the potential of P.stratiotes as a rhizofiltration agent. Wild plants of P. stratiotes were grown in various high concentration solutions of Chromium(Cr), Lead(Pb) and Nickel(Ni). The plants were allowed to grow for twenty one days before harvesting. Metal concentrations were then determined using Atomic Absorption Spectrophotometry. The data generated from the analysis was subjected to analysis of variance (ANOVA) to determine if there is any significant difference between the treatments and the rate of multiplication of the plants. Different concentrations of the metals that were over 300 times what is obtainable in normal plants were observed. The uptake of Ni by P. stratiotes is higher than the uptake of other metals in this study. The uptake of metals was greater in the 2000 ppm treatment than in the other treatments. The plant is able to tolerate the high concentration of heavy metals without showing any visible symptoms. It is also capable of growing past and reproducing within the shortest possible time. P. stratiotes is an excellent candidate for rhizofiltration of heavy metal from polluted waters.