الفهرس 
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Abstract
Soil is the basic natural resource needed for more than 95٪ of the global food and fib er production; thus it represents a basic requisite for life on earth. So, soil pollution attracts the attention of the researchers to reduce soil pollution. As a result of the irrigation by wastewaters and the use of chemical fertilizers and pesticides, the amount of heavy metals in the soil exceeds the maximum permissible limits. Therefore, heavy metals can accumulate in the human body through plants grown in contaminated soil. Many remediation techniques were performed to decontaminate soils containing heavy metals, such as soil washing, phytoremediation and electrokinetic remediation. In the current investigation, the removal of heavy metals from soil layers (0-15 cm), (15-30 cm) and (30-45 cm) in soil columns, by iron nanoparticles (Fe NPs) and iron nanoparticles deposit on the surface of silica nanoparticles (SiOiFe NPs), has been studied. Fe NPs were prepared by borohydride reduction method. When Fe NPs irradiated with 308 nm excimer laser pulses; the maximum absorption increased as the number of pulses increased (50, 75 and 100 thousand pulses), due to the size reduction. The TEM photography gives good criteria about the size reduction process. Fe NPs and Si02IFe NPs proved to be a good technique for soil remediation in the case of Pb, Cd and Cu. Its effect was observed to much less efficient in the case of Co and Mn, and in the case of Ni found in the surface layer. Removal efficiency was found to vary for the three soil layers (0-15 cm), (15-30 cm) and (30-45 cm). The discussion of the obtained results based on the soil characterization was given here. Moreover, the mechanism of photofragmentation was described. To summarize, Fe NPs with different sizes as well as Si02IFe NPs proved to be an efficient technique for heavy metals removal.