الفهرس 
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Abstract
Summary and conclusions
The thesis aims to prepare some simple and mixed metal oxides using precipitation method. The prepared simple and mixed nanoparticles were investigated by using different instrumentals. The fabricated simple oxides and their nanocomposites were also used as adsorbents for the removal of organic dye from water.
This thesis consists of three main chapters:
Chapter 1: Introduction
This chapter includes a brief introduction about water pollution, sources of pollution and its harms on living things, as well as the different methods used to purify polluted water. It also includes the definition of nanomaterials and the different methods used in their preparation, as well as the different applications of nanomaterials. This chapter also contains literature survey on the previous work for the simple oxides and their nanocomposites. Also, it contains the applications of the metal oxide nanoparticles in various fields such as water treatment.
Chapter 2: Experimental part
This chapter contains the practical part of this thesis. It involves the description of the chemicals and reagents were used in the separation of silicon oxide and aluminum oxide from wastes using precipitation method. Silicon and aluminum oxide nanocomposites were synthesized by the mixing between them in bidistilled water. Using ultrasonication for 15 minutes. The obtained mixture dried and followed by the calcination at different temperatures. This chapter includes the description of the instrumental tools for the study of the synthesized simple and mixed oxides such as XRD, FTIR, HR-TEM, FE-SEM, UV-Visible spectra and TG- DTA. It also contains the explanation for the batch method which used for the removal of organic dye from water using the fabricated adsorbents. It also includes the explanation for various factors influencing the removal efficiency.
Chapter 3: Results and discussion
This chapter contains the discussion and results of the extracted data. It can be divided into two main parts.
Part 1: characterization part
The first part describes the characterization of the obtained simple oxides and their nanocomposites by different tools such as thermal analysis (TG-DTA), powder X-ray (XRD), infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and UV-Vis spectroscopy.
The extracted results showed that the extraction and preparation of aluminum oxide using precipitation method from the waste in the nanometer range. The X-ray diffraction showed the formation of γ-Al2O3 after the calcination at 500 °C for 3 h. The crystalline sizes of A1, A2, A3, A4 and A5 were found to be 3.4 nm, 4.4 nm, 3 nm, 5 nm and 6 nm. FTIR spectra showed the peaks at 840 cm-1, 780 cm-1 and 580 cm-1, reflected to the fabrication of γ-Al2O3. The Transmission electron microscopy showed that the regular and irregular needle shapes with hard agglomeration and the average particle sizes at 8.4 nm. SEM of the fabricated γ-Al2O3 displayed the presence of sheets, spherical and non-spherical shapes with agglomeration with grain size in the range 1 μm.
The extracted results displayed that the extraction silicon oxide from waste of rice husk using precipitation method in the nanometer range. The X-ray diffraction showed the formation of SiO2 in amorphous phase after calcination at 300 °C for 2 h. X-ray diffraction displays the crystalline phase of the synthesized silicon oxide after the calcination at 500 °C for 3 h. The average size of the fabricated silicon oxide determined and found to be 9 nm, 24 nm and 3 nm for (S2, S3 and S4). SEM images of the fabricated SiO2 displayed the presence of ultrafine and crystalline spherical and non-spherical shapes with agglomeration with grain size in the range 1 μm. FTIR spectra showed the peaks at 1050 cm-1 and 798 cm-1 correspond to the asymmetric and symmetric stretching vibrations of the Si–O–Si, respectively. The bands at 970 and 471 cm-1 were assigned to the bending vibrations of the Si–OH and Si–O–Si.
The extracted results indicated that SiO2/Al2O3 nanocomposites were synthesized after the mixing and calcination in the nanometer range. The X-ray diffraction confirmed that the presence of the obtained nanocomposites (Al2O3 and SiO2) after the calcination at 500 °C for 3 h without any impurities. The crystalline sizes of SA11, SA12 and SA21 were found to be 3 nm, 5 nm and 3 nm, respectively. The crystalline sizes of SA11, SA12 and SA21 after the calcination at 500 °C for 6 h were found to be 6.5 nm, 3 nm and 3 nm, respectively. After the calcination at 700 °C for 2 h, the new phase (Al2SiO5) appeared with Al2O3 and/or SiO2 depending on the ratio between Al2O3 and SiO2 in the preparation step. After the calcination at 700 °C for 2 h, the crystalline sizes of SA11, SA12 and SA21 were found to be 7 nm, 8 nm and 6 nm, respectively. The Transmission electron microscopy of the nanocomposite (SA11 sample) showed the regular and irregular spherical shapes. The average particle sizes determined from TEM images are found to be 17.9 nm. FE-SEM images of the fabricated SiO2/Al2O3 nanocomposite (SA11 sample) displayed the sheets, regular and irregular spherical shapes with agglomeration with grain size in the range 1 μm. FTIR spectra showed the peaks at 913 cm-1 and 752 cm-1 and these bands correspond to the Al-O-H formation vibration and Si-O-Al stretching vibration, respectively. The peaks at 450-469 cm-1, 752-800 cm-1 and 1100 cm-1, related to Si-O and Si-O-Si stretching vibration bands. The peaks at 600 cm-1, 752 cm-1 and 1100 cm-1 are related to Al-O stretching vibration bands.
Part2: Application part
The second part includes the adsorption data for the removal of sunset yellow dye using the fabricated Al2O3 and SiO2/Al2O3. This part includes the results and discussion of the factors affecting the removal of the dye under study from aqueous solutions such as pH, contact time, initial dye concentration, adsorbent dose, ionic strength and temperature. The optimum conditions for the adsorption process were extracted from the experimental data and the results were as the following:
i. The optimum pH for the adsorption of sunset yellow dye was found to be 2 for the prepared simple metal oxide and their nanocomposites.
ii. The contact times for the adsorption of sunset yellow dye using A2, SA11, SA12 and SA21 samples were found to be 150, 120, 120 and 120 min, respectively.
iii. The dye removal decreased with increasing the amount of KCl using the synthesized simple and mixed oxides.
iv. The dye removal increased with raising the temperature for all the synthesized materials.
v. The adsorption data followed well the Langmuir isotherm model for all the prepared simple and mixed nanomaterials. The adsorption of the sunset yellow dye fitted the pseudo second order model using A2, SA11, SA12 and SA21 samples.
vi. The adsorption of sunset yellow dye showed spontaneous, physisorption and endothermic process using the A2 and SA11 nanocomposite as adsorbents.
vii. The adsorption capacities of A2, SA11, SA12 and SA21 samples for removal sunset yellow dye were found to be 118, 64.3, 70.5 and 51.7 mg/g, respectively.