الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 163 |  |  |
| | | from | 163 | | |
Abstract
English SummaryThis thesis consists of three main chapters Chapter 1: Introduction The first chapter comprises the introduction in which an outline on the water pollution, the definition of nanoparticles, their synthesis methods and their applications in different fields is presented. This chapter also includes a literature survey on the previous work of the oxides of interest.Chapter 2: The experimental This chapter includes complete description of the materials, reagents, equipment, and the methods used for the preparation of different oxides like, zinc ferrite, nickel ferrite, cobalt ferrite, zinc ferrite doped by nickel, and zinc ferrite doped by cobalt, by using different fuels via combustion method. ZnFe2O4 nanoparticles were prepared by using a mixture of ferric and zinc and glycine, tartaric acid or a mixture of glycine and tartaric acid as fuels, the rough an autocombustion method. After that the ignited products were calcined at 400 ◦C for 1h. Similarity NiFe2O4 and CoFe2O4 nanopaticles were prepared via an autocombustion method using the same fuels and nickel and iron nitrates or cobalt and iron nitrates, respectively. The products werw also calcined at 400 ◦C for 1h. Nickel doped ZnFe2O4, and cobalt doped ZnFe2O4 nanoparticles were also prepared by an autocombustion method using nickel nitrate and cobalt nitrate for the doping, respectively. The produced samples were calcined at 400 ◦C for 1h.This chapter also includes description of congo red dye on the prepared nanomaterials and the factors effecting the adsorption process.Chapter 3: Results and discussion This chapter contains the results obtained and the discussion of the results. And this chapter can be divided into three parts:Part one It contains the characterization of the prepared nanomaterials such as ZnFe2O4, NiFe2O4 and CoFe2O4 using different techniques such as XRD, HR-TEM, FE-SEM, and FT-IR The XRD pattern revealed that crystallite size of the ZnFe2O4, NiFe2O4 and CoFe2O4 were 47, 32, and 23, respectively, and the products were pure phases. The FE-SEM images exhibited that the products were cotton like morphology with agglomerates of spherical particles. The HR-TEM image of the products: ZnFe2O4, NiFe2O4 and CoFe2O4 showed that the products are composed of spherical and irregular particles with an average size of 30, 25, and 15.5 nm, respectively.Part two: It includes characterization of the prepared nickel doped ZnFe2O4, (NixZn1-xFe2O4), and cobalt doped ZnFe2O4 (CoxZn1-xFe2O4) nanoparticles using XRD, FE-SEM, EDS and HR-TEM. The XRD patterns showed that the products were single phases. There was a small shift of (311) peak, for x= 0.025-0.2, and it was due to the change of lattice parameters changed correspondingly due to the difference between ionic ridii of Ni (0.78 ◦A), Zn (0.82 ◦A), and co (0.72 ◦A). The small broadening in the peaks width of the doped nanomaterials indicated decreasing in crystal sizes. The crystallite sizes for NixZn1-xFe2O4 were found to be 11.04, 16, 13.1, and 11.8 nm for x= 0.025, 0.05, 0.1 and 0.2, respectively. The average crystallite sizes for CoxZn1-xFe2O4 were estimated to be 7.9, 12.6, 15.5 and 14.4 nm for x= 0.025, 0.05, 0.1, and 0.2, respectively. The FE-SEM images of the doped nanomaterials revealed that the products consists of aggregates of spherical particles with porous structure. The EDS analysis showed that % Ni was ca. 0.6% for Ni0.025Zn0.975Fe2O4 and % Co was 1.14% for Co0.025Zn0.975Fe2O4 products.
The HR-TEM images of doped nanomaterials showed that the products are composed of spherical and irregular particles with average sizes consistent with the XRD results.Part three This part includes the results and discussion of the factors affecting on the removal of the congo red dye from aqueous solutions on nanosized ZnFe2O4, NiFe2O4, CoFe2O4, Ni doped ZnFe2O4, and Co doped ZnFe2O4. And the following remarks were obtained:- The optimum pH at which the maximum adsorption occurred was found to be 6.- The equilibrium time for CR adsorption was about 80 min, in case of ZnFe2O4, NiFe2O4, CoFe2O4, Co doped ZnFe2O4, and 100 min, in case of Ni doped ZnFe2O4.- The adsorption increased with increasing the solution temperature in case of CoFe2O4 and ZnFe2O4 but decreased with the increase of the solution temperature in case of NiFe2O4. The adsorption capacity of CR dye increased with increasing the amount of KCl for ZnFe2O4, NiFe2O4, CoFe2O4 nano-oxides. For ZnFe2O4, NiFe2O4, CoFe2O4 nano-oxides, the adsorption capacity decreased with increasing the initial dye concentration. For ZnFe2O4, NiFe2O4, CoFe2O4 nano-oxides, the removal percentage enhanced with increasing the adsorbent dose. The CR dye removal fitted to Langmuir isotherm model for ZnFe2O4 and CoFe2O4 nano-oxides, but it fitted to Freundlish isotherm model for NiFe2O4 nano-oxide. The CR dye removal fitted to pseudo-second-order model for ZnFe2O4, NiFe2O4, CoFe2O4 nano-oxides. The adsorption of CR dye on ZnFe2O4 and CoFe2O4 nano-oxides, was endothermic and spontaneous process, and on NiFe2O4 was exothermic and spontaneous process.The thesis includes 103 references.