Variations in Uptake and Translocation of Copper, Chromium and Nickel Among Nineteen Wetland Plant Species

An experiment was carried out to investigate the variations in metal uptake and translocation among 19 wetland plant species in small-scale plots of constructed wetland using artificial wastewater containing 2.0 mg L(-1) copper (Cu), 1.0 mg L(-1) chromium (Cr), and 2.0 mg L(-1) nickel (Ni). More than 97% of Cu, Cr, and Ni were removed from the wastewater by the wetland plant species. There were more than 100-fold differences in the metal accumulation and more than ten-fold differences in the metal concentrations among the 19 plant species. These plants accumulated as high as 8.8% of Cu, 20.5% of Cr, and 14.4% of Ni when they were grown in the wetland soaked with the wastewater. Several plant species were found to be highly capable of accumulating one, two or all the three metals. The results indicated considerable variations in the metal removal abilities through phytoextraction among the 19 wetland plant species. It can be concluded that the selection of appropriate plant species in constructed wetland can be crucial for the improvement of metal removal efficiency of the wetland system.