Abstract

Environmental pollution with heavy and toxic metals, produced by mining, processes of metallurgy and other chemical industries is a worldwide problem to human health and environment because of their high concentrations in the biological food chains and long term presence in the ecosystems. The present study discusses the heavy-metal elimination by the bioremediation capability of Dunaliella algae’s. As the elimination of low metal-concentrations (lower than 50 mg/l) from water with usual chemical processes; such as precipitation with lime or ion exchange are not economical, this is supposed that such metals could be eliminated by this alga with high yields. Also in these methods with physicochemical basis the toxic remedies are remained but in bioremediation ones there is no need for such transportation or other additional removal processes. This paper studies the bioremediation of cadmium (Cd), plumb (Pb) and mercury (Hg) at different concentrations and under different conditions by Dunaliella alga. It was shown that the toxic effects of Hg are higher on this organism as compared to those of Cd and Pb. This is vivid that Dunaliella is highly tolerant to the ascending concentrations of heavy metals and their absorption in aquatic media. This approves the usage of Dunaliella as useful equipment for the elimination of heavy metals environment.

Key words: Dunaliella, bioremediation, heavy metals, mercury (Hg), cadmium (Cd), plumb (Pb).