ACCUMULATION OF CHROMIUM AND NICKEL BY CANNA INDICA AND DECORATIVE MACROPHYTES GROWN IN FLOATING TREATMENT WETLAND

Water pollution is recognised as one of the major environmental problems. Floating treatment wetlands (FTW) have emerged as a powerful tool that can help in the revitalisation of polluted waters. This study is set out to assess the feasibility of selected plant species in FTW to accumulate Cr and Ni from water contaminated with low concentrations of both heavy metals. The results showed that all investigated species contained more Cr and Ni in the be-lowground biomass whereby the translocation of these metals into the aboveground parts was very low. Species Phragmites australis had great potential for accumulation of Cr and Ni with significantly higher Cr and Ni concentrations in roots compared to the other investigated species. Furthermore, the present study suggests that species Iris pseudacorus may also have a good potential for removal of both heavy metals, species Canna indica for the accumulation of Ni and species Alissmaplantago - aquatica, Menianthes trifoliata and Iris sibirica 'Perry's Blue' for the accumulation of Cr. Future studies should concentrate on the investigation and assessment of phytoremediation potential of the same species growing in water contaminated with higher levels of Cr and Ni.