الفهرس 
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Abstract
Nanotechnology for drinking water treatment is gaining momentum through a global perspective. The unique properties of nanomaterials and their emergence with current water treatment technologies present great opportunities to revolutionize water treatment. Although many nanotechnology strategies highlighted in this review are still in the laboratory stage, some have made their way to pilot testing or even large-scale commercialization. Herein, this research will be focused on the as-synthesized of strontium-silicate chitosan nanocomposites using different preparation methods and its applications in drinking water treatment from some pollutants.
This thesis consists of four main chapters:
1- Chapter (I): Introduction
The first chapter contains a general introduction includes a brief overview of water treatment from pollutants, with mentioning of different types of pollutants such as heavy elements, including the toxic element cadmium. Some of the traditional methods used in treating heavy elements, such as ion exchange, chemical precipitation, reverse osmosis, filtration, as well as flocculation and flocculation, have also been listed. What is adsorption and its types as well as its advantages are explained. Also, general methods of preparing nanometric materials have been clarified.
2- Chapter (II): The review of literature
This chapter contains a general survey of previous research on nanostructures and combinations, their different types, their various applications, and also a general survey of previous research on silicon dioxide, strontium oxide, strontium silicate nanoparticles and chitosan is presented. As well as its applications, especially in the field of water treatment.
3- Chapter (III) ): The experimental section
This chapter contains the practical part of this thesis. This part included a listing of the chemicals and devices used in this study and used in conducting the characterization of oxides and nanometer combinations under study, especially X-ray diffraction technology, scanning electron microscope and transmission and infrared spectroscopy. The methods used to prepare silicon oxide, strontium oxide, strontium silicate ultrafine and their nanometric combinations with chitosan are also listed. The use of prepared oxides and nanometric combinations as adsorbents have also been studied. The different factors affecting the adsorption process were studied, such as pH value, initial concentrations of the toxic cadmium element, contact time, amount of adsorbent and the effect of temperature. In addition, they discussed the practical application of the prepared materials and the percentage of removing the cadmium element from real water samples.
4- Chapter (IV): Results and discussion
This chapter includes an account of all the results obtained and a discussion. It consists of two main parts:
Part 1: It describes the characterization of the as-prepared SiO2, SrO, Sr2SiO4, chitosan/ SiO2, chitosan/ SrO, chitosan/ Sr2SiO4 nanocomposites were accurately described using different instruments such as XRD, FT-IR, SEM and TEM.
Part 2: This part deals with Cd(II) ions removal using SiO2, SrO, Sr2SiO4, chitosan/ SiO2, chitosan/ SrO, chitosan/ Sr2SiO4 nanocomposites. The results of the factors affecting the adsorption process for removing the cadmium element from aqueous solutions were interpreted, such as pH, initial concentrations of the toxic cadmium element, contact time, amount of adsorbent, and effect of the temperature, also the optimum conditions for the removal process were reached. A kinetic study was done, as well as a study of isothermal adsorption and their types, with an account of the product and its discussion. It was found that the order of removal of cadmium follows the second order, and the removal process follows the Langmuir system. The thermodynamics of the adsorption of the cadmium element on the prepared oxides and their nanometric combinations were studied.
• The optimum pH given highest Cd(II) ions removal were at pH= 7.0 for (S1-800), (R1000), (RS1-800), (CS1-800), (CR1000) and (CRS1-800) nanocomposites, respectively.
• The optimum contact time for (S1-800), (R1000), (RS1-800), (CS1-800), (CR1000) and (CRS1-800) nanocomposites for the adsorption of different concentration Cd(II) ions were at 120 , 180, 150, 180 , 120 and 180 min, respectively.
• The removal percent of Cd(II) ions is concentration dependent using of (S1-800), (R1000), (RS1-800), (CS1-800), (CR1000) and (CRS1-800) nanocomposites.
• The experimental results showed that the adsorption capacity decreased very slowly with increasing the solution temperature. This indicates that the adsorption of Cd(II) ions on the as-prepared adsorbents is an endothermic process.
• These results suggested that pseudo second-order adsorption mechanism is predominate and that the overall rate of the adsorption process.