الفهرس 
Water pollution
Nanostructured materialsOnly 14 pages are availabe for public view
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Abstract
Humankind faces a serious problem with water pollution therefor water treatment becomes one of the most important issues nowadays as it contains many toxic pollutants, such as heavy metal ions and organic dyes which could damage the environment. . The disposal of heavy metal ions from urban areas to the environment is a great problem because the metal ions are vulnerable to leaching into groundwater. Textile industry wastewaters are widespread; some are polluted with biological agents and can be remediated by simple wastewater treatment. The major problem associated with the discharge of large quantities of these organic compounds and heavy metals in wastewater is their chemical stability and low biodegradability in water due to their complex aromatic structure and synthetic origin, which is potentially harmful to the environment, also many of them are known to be toxic or carcinogenic. New environmental laws require wastewater treatment of these materials. Nanostructured materials are powerful molecular tools for the analysis of many metal ions and anions and photocatalytic degradation of organic dyes. It has been noticed that these materials were of wide attention, due to their high stability. These are efficiently in terms of sensitivity and selectivity with real-time monitoring, including non-destructive, nonexpensive, low detection limit and fast response time. Among these nanomaterials, mesoporous silica, which has achieved significant advances for use in detection systems. It exhibited high uniform channels, large surface area, narrow pore-size distribution, tunable pore sizes over a wide range. These excellent properties have significant influence to improve the electrochemical signal and enhance the charge transport to understand the metal coordination with specific color optimization. In addition, mesoporous materials can be used broadly in different nanotechnological applications such as catalysis, adsorption, separation, sensing, medicine, lasers, drug, gene delivery and intrapore inclusion chemistry. The thesis comprises three main chapters; introduction, experimental and results and discussion. Chapter 1: [Introduction] Chapter (1) includes main points as water pollution, sources of water pollution, water treatment, and synthesis of mesoporous materials, their applications and titanium dioxide photocatalysts. Chapter 2: [Experimental] This chapter describes the synthesis procedure of azo dye 4-(4-Nitrophenylazo)- naphthalen-1-ol (NPAN). Additionally, the syntheses of mesoporous silicates, SBA-15, SBA-16 and MCM-41, via surfactant template method were reported as well as the chloro- functionalization of these nanostructured materials. Anchoring of NPAN into the functionalized mesoporous materials in order to design the optical nanosensors and the synthesis of mesoporous molecular sieves embedded titanium by incorporation of titanium dioxide into mesoporous silicates were explained. Chapter 3: [Results and discussion] This chapter includes the results and discussion and consists of two parts. Part 1: (Development of nanomaterial chemosensors for toxic metal ions sensing) This part focus on the investigation of mesoporous materials, SBA- 15, SBA-16, MCM-41, their chloro-functionalized ones and their loaded forms using different spectroscopic techniques such as X‐ray diffraction (XRD), friourtrasfere infra-red (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and Nitrogen Adsorption-Desorption isotherm (BET), The UV/Vis spectral measurements (UV-Vis absorption) and emission techniques measurements. These techniques are used to confirm the basic unit structure, morphology, pore size, surface area, uniform distribution, highly parallel channel and high thermal stability of the synthesized mesoporous silicates. The characteristics FT-IR spectra of azo dye (NPAN) were also assigned. Three optical nanosensors have been designed by anchoring azo dye namely; 4-(4-Nitro-phenylazo)-naphthalen-1-ol (NPAN) into chlorofunctionalized mesoporous materials, the sensing response of the designed optical nanosensors NPAN/SBA-15, NPAN/SBA-16 and NPAN/MCM-41 to different metal ions such as Cd (II), Hg (II), Mn (II), Zn (II), Fe (II), and Pb (II) in various pHs 1.1, 4.9,7 and 12 were tested using steady-state absorption and emission techniques. The recognition reversibility on adding EDTA or citric acid has been investigated. Also, the binding constants of the formed complexes have been calculated. Finally, the effect of ionic radius of metal ions on the binding ability has been evaluated; additionaly the reusability of these nanosensors has been investigated. The high values of the binding constants for the designed nanosensors have been observed at pHs 7 and 12, confirming the strong chelation of different metals to the nanosensor at these pHs. Also, the high binding constants and sensitivity have been observed for NPAN-MCM-41 as a nanosensor to detect the different metal ions. from the obtained results, we have succeeded to transform the harmful azo dye to environment-friendly via designing of the optical nanosensors used to detect toxic metal ions in wastewater with high sensitivity. Part 2: (Fabrication of Molecular Sieves Embedded Titanium for textile dye Removal from Effluents: Photocatalytic Activities, Luminescence, Reusability, and Active Species Detection). This part focus on the investigation of, mesoporous materials, SBA- 15, SBA-16, MCM-41, and their titanium loaded forms using sets of spectroscopic techniques such as X‐ray diffraction (XRD), friourtrasfere infra-red (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and Nitrogen Adsorption-Desorption isotherm (BET), The UV/Vis spectral measurements (UV-Vis absorption) and emission techniques measurements. These techniques are used to confirm the basic unit structure, morphology, pore size, surface area, uniform distribution, highly parallel channel and high thermal stability of the synthesized mesoporous silicates. The current study reports on the synthesis of mesoporous molecular sieves embedded titanium dioxide and characterizes the photocatalysts using a number of spectroscopic techniques. The efficiency of photocatalysts has been evaluated by following the kinetics and mechanism of the removal of a textile dye, methylene blue, under UV light irradiation using steady-state absorption and emission techniques. The effects of contact time ,adsorbent doses, pH of the solution, and the initial dye concentration, on the photocatalytic removal efficiency of the methylene blue dye were investigated. Also, a comparative study of the dye removal efficiency has been made between the investigated photocatalysts, Ti-SBA-15, Ti-SBA- 16, and Ti-MCM-41. Finally, the main active species in the photoremoval of MB have been explored by performing the radical trapping experiments using the photocatalysts, in which the presence of different scavengers such as EDTA, 1,4-benzoquinone, BQ and isopropyl alcohol, ISA were used to capture holes (h+), superoxide radical (·O2 -) and hydroxyl radical (·OH). The optimization of the variable conditions was performed with the main objective of obtaining maximum percentage Removal toward MB dye as organic compounds. Design expert as a multiple response method were applied to the optimization of any combination of four factors, namely the effects of adsorbent dose, contact time, pH of the solution and the initial dye concentration. The effect of the adsorbent dose on the photocatalytic removal of MB at a fixed concentration of the dye (Co= 8.95mgL−1) and a variable dose of Ti-SBA-15, Ti-SBA-16, and MCM-41-Ti in the range of 0.015–0.04g under UV light irradiation was examined using steady state absorption technique the absorption spectra of MB decrease in the presence of different amounts of the adsorbent dose, Ti-SBA-15, Ti-SBA-16, and MCM-41-Ti under UV irradiation and at the indicated time intervals, where by studying these factors : 1-The effect of adsorbent dose the efficiency increases slightly with increasing the amount of the photocatalyst from 0.015–0.04g. The slight increase in the efficiency may be due to a decrease in the light penetration caused by the additional catalyst particles that compensated the expected increase in the catalytic activity. 2- the photocatalytic removal of MB by the photocatalyst using steadystate fluorescence technique It can be seen that the fluorescence spectra of MB via the removal process in the presence of 0.015g of the adsorbent dose and MB initial concentration of 8.95 mg L−1 at room temperature under light irradaiation. As can be seen, the fluorescence intensity decreased sharply in the presence of the photocatalysts at the indicated time intervals. 3- The effect of apH The second set of experiments was carried out at a fixed amount of the photocatalyst, by varying the pH of the solution. As known, the pH is one of the most factors that influence both the adsorbent surface and the adsorbate in solution, where the absorption spectra of MB in the absence and presence of 0.015g of the investigated adsorbent dose at different pHs, 4.9, 7 and 12 and MB initial concentration of 8.95 mg L−1 at room temperature under light irradaiation, as the removal increase by increasing pH till we reach pH =7 then it decrese at pH =12. . 4-The effect of initial dye concentration The effect of MB concentration was investigated at varying concentrations in the range of 6, 8.95 and 11.2 mg L−1, where the optimum equilibrium achieved dose was 0.015 g. So the maximum percentage removal of dye was obtained at initial dye concentration 8.95 mg L−1 for Ti-SBA-15. Adsorption kinetics assists in evaluating the rate and mechanism of mass transfer of adsorbate from liquid phase to solid adsorbent surface. Several kinetic models are needed to examine the mechanism of the solute sorption onto a Sorbent. As can be seen, the pseudo-second-order rate equation model shows the best fitting, in which the plots of t/qt versus t show linearity, with high correlation coefficients, R2 that are close to unity and are in a good agreement with the experimental values. As well as the reusability of these photocatalysts were checked. And also the thesis comprises of 38 Figures, 5 Tables, 13 Schemes.