الفهرس | Only 14 pages are availabe for public view |
Abstract This work was conducted to study the efficiency of various agents to stabilize Cu, Zn and Pb in contaminated agricultural soils and to determine the ability of both canola and flax as phytoremediater plants for soil polluted with Cu, Zn and Pb. The study also aims to investigate the effect of DTPA in enhancing the availability of Cu, Zn and Pb and their accumulation in plant tissues. Three surface soil samples (0-30cm) were collected to represent different sources of contamination, Elgabal Elasfar farm, mostorod and Helwan. Incubation experiment was conducted to evaluate the tested agents to stabilize Cu, Zn, and Pb in the studied soils. Each soil was cured with each of the five immobilizing agents (hydrogel, polymer, zeolite, Mud and goethite) with two rates (0.5 and 1.0% and three replicates. Green house pot experiments were conducted using canola and flax plants, DTPA was added to the pots as a chelator at rates of 0.2 and 0.4%. Sequential chemical extraction procedure was used to heavy metals fractionation. The results indicated that the tested agents at application rate of 0.5% could be arranged according to their efficiency in immobilizing Cu as the following, zeolite > polymer = goethite >mud > hydrogel. In case of Zn, the reduction follows the order, hydrogel > mud = goethite > polymer > zeolite. While for Pb the order was, hydrogel > mud > zeolite > goethite > polymer. The distribution of heavy metals among different fractions revealed that, the addition of the tested stabilizing agents (except for zeolite) reduced the more available Cu fraction, i.e. exchangeable form. The reduction was 38.5 - 43.6, 51.8 - 55.6 and 52 - 56% for soils of Helwan, Mostorod and Algabal Alasfar, respectively |