Removal of Heavy Metals Using Myriophyllum verticillatum (Whorl-Leaf Watermilfoil) in a Hydroponic System

Abstract

The heavy metal accumulation capacity of M. verticillatum in a hydroponic system was investigated in this study. M. verticillatum was grown in a model aquatic setup consisting of aeration, lighting, and hydroponic systems for 21 days in different kinds and concentrations of heavy metal solutions prepared in a Hoagland E- Medium. Any visual changes observed in individual M. verticillatum plants at the onset and end of the study were noted daily. At the end of the experiments, the heavy metal concentrations in the plant biomass were determined. M. verticillatum tolerated the heavy metal ions very well and was also able to grow within the studied concentration range. The heavy metal accumulation followed the order of Pb+2> Cu+2 > Cd+2 > Zn+2 in all mixed and individual aqueous solutions. However, M. verticillatum accumulated a large amount of Pb+2 ions, but new shoots also continued to grow. This may be an indicator that M. verticillatum may be a hyperaccumulator for Pb+2 ions. M. verticillatum also exhibited proton secretion during the metal accumulation period because of its ion exchange capacity.