Artificial wetlands and their importance for water quality

The efficiency of a constructed wetland to remove Cd, Ni and Pb was studied over a six-month period. The distribution of these metals in the sediments was examined using a sequential extraction method. Results showed that high levels of Cd and Pb were present and that each metal has a characteristic distribution in the sediment. There was a significant difference in the removal efficiency of metals during dry weather and during storm events. Although, the removal of Ni and its distribution did not show any consistent trend, it was evident that a significant amount of Ni was removed during the storm event