الفهرس 
Cover EnglishOnly 14 pages are availabe for public view
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Abstract
Removal of heavy metals (HMs) such as Pb from soil, wastewater, and air is essential for environment and human health. Phytoremediation is a well established. technology, known as ’green clean technology’ based on the use of certain green plants for contaminants removal from contaminated media. It is increasingly adopted as it is a cost effective and environmentally friendly alternative to traditional methods of treatment. Scented geranium, Pelargonium zonale, is a hyperaccumulator flowering plant recently used in HM removal from contaminated soil. In the present work plants were tested for natural lead extraction from artificially contaminated soil with different Pb concentrations (0, 2000, 5000, 7000 ppm) as lead acetate trihydrate (C2H3O2)2-Pb-3H2O. Utilization of EDTA(ethylenediaminetetraacetic acid) and the phytohormon IAA (Indole-3-acetic acid) as chelator, that would permit higher metal availability and uptake by the tested plants roots, was tested either separate or combined. For other concentrations, lead was artificially added to the planting media, petmos, at (0, 1500, 3500, 5500, 7500 ppm). EDTA and EDDS (S, S ethylenediaminedisuccinicacid) as chemical assistants providing higher Pb availability were used separate or combined to study lead extraction under their effects by plant roots. Laser Induced Breakdown Spectroscopy (LIBS) was used to follow up Pb relative concentrations in both planting media and plant parts at different sampling times during the experiment. This was achieved by focusing laser light pulses of a high energy Nd:YAG laser, emitting at 1064 nm, onto samples plant and soil samples previously dried, homogenized and pressed in tablets. The collected LIBS spectra were analyzed to retrieve relative concentrations of Pb. Laser Induced chlorophyll fluorescence (LICF), has been also used to evaluate chlorophyll formation and photosynthetic apparatus status in geranium plants. Such measurements were performed on plant fresh leaves grown under various Pb levels. Imaging implementation was tested to differentiate between healthy and stressed plants, using Laser Induced chlorophyll fluorescence Imaging (LICFI) to study Pb effects on chlorophyll fluorescence. However, EDTA was found to enhance Pb uptake from the soil which increased with time. EDTA and IAA combination enhanced Pb absorption of Pelargonium zonale plant roots.Pb had significant effects on various studied morphological parameters [shoot and root dry weight (g), leaves number, leaf area (cm2).] and on the pigment composition in the tested plant (chlorophyll a, chlorophyll b, total chlorophylls and total caroteniodes). Various histological deformation has been detected in some plant samples as a result of Pb exposure. Good correlation was found between LIBS and ICP-OES results of plant tissues spectrochemical analysis. Good correlation has been obtained between LICF, LICFI results and traditional method data of chlorophyll (a)determination indicating that LICF and LICFI techniques are rapid and reliable to be used in chlorophyll (a) determination for early prediction of abiotic stress in plants.