Phytoremediation of Low Levels of Heavy Metals Using Duckweed (Lemna minor)

Abstract

The treatment of waste waters by bioremediation is nowadays an interesting approach due to low cost, simplicity, and the quality of being more environ- ment friendly as compared to other remediation techniques. Certain plants as Lemna minor are able to remove heavy metals from contaminated waters. The removal effi ciency of this plant was evaluated with different experiments for the contaminants arsenic, mercury, lead, chromium, copper, and zinc. The elements were monitored in water as function of time during a period of 15–25 days, for the experiments using plants, in contaminated waters and controls, with and without plants. The foliar tissues were also analyzed to determine the mass of contaminant accumu- lated by the specie. The removal effi ciency varied from 3 to 30% depend- ing on the element. The contaminants did not affect signifi cantly the agronomical behavior of the Lemna minor at the levels used in the experi- ments (low levels). The plant is well-suited for the phytoremediation in particular mercury phytoremediation.