الفهرس 
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Abstract
Name: Shimaa Mohamed Abdel Moniem Mohamed
Title: Removal of Metal ions from Industrial Wastewater by photocatalysis
Degree: Doctor of Philosophy (Ph.D.)
Removal of metal ions from industrial wastewater by photocatalysis using simulated sun light as a source of green energy are the main aim of research study. It involves detoxification of metal ions in order to reduce their contamination into the environment and recovery of precious metal from industrial wastewater. Commercially available TiO2 was used in comparing with new prepared nano-structured photocatalysts such as simonkolleite-TiO2 photocatalyst with different Zn contents and metal-free graphitic carbon nitride (g-C3N4) photocatalyst. The used photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR, Raman and UV–Visible diffuse reflectance spectroscopy (DRS). The DRS confirmed that both the new prepared photocatalysts have narrower bandgap energy comparing with that of TiO2. Formic acid was used as a holes scavenger in order to improve the photocatalytic reduction mechanism. Under simulated sunlight, the best efficiency of Cr(VI) photoreduction has been achieved using 1000 ppm simonkolleite-TiO2 photocatalyst of 5% Zn/TiO2 weight ratio, 100 ppm g-C3N4 photocatalyst, when pH of the medium was set at 2-2.5 comparing with only 47.3% reduction efficiency at 1500 ppm TiO2. Furthermore, the best efficiency of Ag+ photoreduction has been achieved using 200 ppm simonkolleite-TiO2 photocatalyst of 5% Zn/TiO2 weight ratio, 100 ppm g-C3N4 photocatalyst, at pH 4, comparing with only 38.3% reduction of silver ions using TiO2 photocatalyst. Integrated management of wastewater generated from a hard chrome metal plating workshop were applied through waste minimization, maintenance of the industrial facilities led to reducing the consumption of hazardous chemicals during two shift (16h) by 83.3%., and achieving a rinse-water reduction of 99.8%. (about 41.56 m3 of water was reduced). Furthermore, implementation of solar photocatalytic reduction process for the discharged wastewater at the optimum operating reaction conditions was very effective in complete detoxification of Cr(VI) ions into Cr(III).