POTENTIALITY OF USING A. PINNATA TO BIOREMEDIATE DIFFERENT HEAVY METALS FROM POLLUTED DRAINING WATER

摘要

Azolla pinnata is a small aquatic fern which considered as a multipurpose organism. It isused in bioremediation to remove heavy metals from polluted draining waters. In view of its potentiality, Azolla pinnata were tested for their growth on different media (Yoshida, peat moss, and Soil media) to select the best medium for the growth of Azolla. Then the best medium was examined for the potentiality of Azolla to withstand a different concentration of different heavy metals. Yoshida medium was the most suitable medium, as it recorded the highest significant records in fresh and dry weight, being 25.38 and 1.69 g/ pot respectively, the doubling time was 5.43 days, NPK being 3.87, 0.85 and 1.95 respectively and nitrogenase activity being 14.32 μmol C2H4/ g dry weight. / hr). The fresh and dry weight of Azolla exposed to Pb+2,Co+2 or Cu+2, was found to be increased by increasing the concentration of the metals from 5 to 35 ppm/liter, then they decreased when the fern exposed to 45 ppm/liter for all of them. While, doubling time decreased gradually by increasing the concentration of Pb+2 , Co+2 orCu+2 from 5 to 35 ppm/liter and started to increase by increasing the concentration of Pb+2 to 45 ppm/liter in the medium.