الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The nuclear industry produces large volumes of radioactive waste solution that require treatment before final disposal or storage. The major contaminants of these wastes are the fission products. REEs are also important in the context of the nuclear fuel cycle because they are produced during the fission of uranium and are hence present in radioactive wastes. REEs can be used as non-active mimics to determine the expected behavior of the long-lived, radiotoxic minor actinides (MA) in used nuclear fuel due to their chemical similarity. REEs demand throughout the world is projected to increase. The main components of thesis are introduction, materials and methods, results and discussion. Introduction This chapter can be concluded to historical back ground about ion exchange, classification of ion exchangers, ion exchange theory, concepts of ion exchange and applications of ion exchangers. A literature survey concerned with different composite ion exchangers was reported. Paterials and Methods This chapter presents all chemicals used in this work, their purity methods used for preparation of different reagents and methods of preparation of different materials used in this study. Also, this chapter presents the different batch experiments used in this work, column technique used for separation of lanthanide ions from their mixture, conductivity experiment, ion memory and anti- bacterial behavior of POTZr(IV)WP.
3. Results and Discussion
All results and their discussions are presented in this chapter as following:
3.1. Preparation and characterization of POTZr(IV)WP
Different materials as POT, Zr(IV)W, Zr(IV)WP and POTZr(IV)WP were prepared. POTZr(IV)WP was prepared with different molar ratios and with different mixing methods.
Mixture of 0.1 M sodium tungstate, 0.1 M K2S2O8 and 4 M H3PO4 were added DROP wisely to mixture solution of 0.05 M o-toluidine , 0.1 M zirconium oxychloride and 0.1 g CTAB.
Different techniques were used for characterization of the prepared materials such as IR spectra, X-Ray diffraction patterns, SEM, differential thermal analysis (DTA and TGA), TEM, XRF, CHNSO elemental analysis, chemical stability and pH titration curve.
IR spectra of POTZr(IV)WP showed number of characteristic peaks which reveal the binding of Zr(IV)WP with POT to form POTZr(IV)WP.
The pattern obtained from the X-ray powdered diffraction pattern showed that POTZr(IV)WP was semi-crystalline in nature.
The SEM pictures showed that POTZr(IV)WP was successfully prepared and the surface morphology of composite material differs from their individual inorganic and organic components. TEM pattern confirmed that particle size of POTZr(IV)WP was in the range of nano size.
DTA/TGA analysis of POTZr(IV)WP showed that the material has good thermal stability.
The solubility experiments concluded that POTZr(IV)WP has good thermal stability in acids and alkali solvents. from XRF and CHNSO elemental analysis it can be diduce the chemical formula of POTZr(IV)WP as:
[(ZrO2)(WO2)(H2PO4)(-C7H7NH-)].1.78H2O
The pH-titration curve of POTZr(IV)WP indicated two inflexion point which indicated that the material behaves as bi-functional and may be acts a strong cation-exchanger.
3.2. Electrical conductivity
POTZr(IV)WP showed electrical conductivity at different drying temperatures. POTZr(IV)WP showed conductivity values higher than Zr(IV)WP.
3.2.Distribution Studies
Distribution experiment was performed to know the selectivity behavior of POTZr(IV)WP for La, Ce, Nd and Sm ions at different pH values and at different reaction temperatures. Distribution coefficient was calculated to know the selectivity of this composite material.
3.3.Kinetic Studies
In this section different kinetic models were used to analyze the experimental data at different temperature. The kinetic models which concern with the rate of reaction were studied. The pseudo first order model, pseudo second order model and elovich kinetic model were applied. The studied system was obeyed to pseudo second order model. Kinetic models which describe the diffusion mechanism such as film diffusion model, intra-particle diffusion model and particle diffusion model were also studied. It was concluded that particle diffusion model controlled the sorption process. The thermodynamic parameters were calculated and the spontaneous nature of the sorption process confirmed from the negative values of ∆Go. Also, The reaction was endothermic in nature due to ∆Ho have positive values. The positive values of ∆So indicated that randomness process with structural process when La, Ce, Nd and Sm ions sorbed onto POTZr(IV)WP. The calculated values of Di were found in the range of 10-12 m2/s which indicate chemisorption process.
3.4.Equilibrium isotherm studies
In order to know the sorption isotherm model which control the sorption process, Langmuir, Freundlich, D-R and Temkin isotherm models were applied to analyze the experimental data. It was observed that Langmuir model controlled the sorption process. from model parameters surface properties and affinity of sorbent were known. It was found that The sorption capacity increased with temperature which indicate endothermic process. Also, The D-R model revealed that the sorption process waschemisorption.
3.5.Column operations The breakthrough curves (C/Co vs. volume) were obtained for La3+, Ce3+, Nd3+ and Sm3+ onto POTZr(IV)WP in the H+ form, at bed depth 1.5 cm, flow rate 0.5 mL/min and at 20 mg/L of concentration of each studied ions. An efficient elution of adsorbed ions from POTZr(IV)WP in column was essential to obtain ions which used in different applications. The elution behavior of La3+, Ce3+, Nd3+ and Sm3+ was achieved using different eluting agents.
3.6.Anti-bacterial behavior of POTZr(IV)WP The experimental results showed that POTZr(IV)WP has anti- bacterial behavior. When the sample introduced to E.coli the count decreased from 5900 to 1100 cfu/ml. In addition the count decreased from 7000 to 1200 cfu/ml when the material introduced to yeast andmould.
3.7.Ion printed memory of POTZr(IV) With help of thermal treatment POTZr(IV)WP has been carried out for enhancement the material to be selective for Ce3+.
3.8. group separation of La3+, Ce3+, Nd3+ and Sm3+ from monazite solutionIt was found that the uptake of total REEs at pH = 4 was about 33 % from the initial lanthanide ions contained in the solution of initial 165 mg/L of lanthanides.