Phytoremediation of heavy metals: the role of macrophytes in a stormwater basin

The aim of the study was to test the efficiency of aquatic vegetation to assimilate heavy metals and allow biological epuration in a stormwater basin. Through a periodical collection of water, sediments and macrophytes, adecrease of heavy metals concentrations was investigated from the inlet to the outlet of the basin. No evidence of metal reduction was noticed in the waters due to a general low level of heavy metals. However, accumulation of metals is greater in the sediments and decrease from the inlet to the outlet (47% reduction for Cd, 30% reduction for Pb, 75% reduction for Zn). Some specific organs of macrophytes accumulate heavy metals in various concentrations: Elodea canadensis (all organs merged) and crowns of Glyceria maxima, Sagittaria sagittifolia, Scirpus lacustris, Typha latifolia contain the highest concentrations in Cd, Pb and Zn.