[en] A combination of conventional ion exchange and electrochemical processes was conducted in production of electrically switched nickel hexacyanoferrate ion exchanger, specially used for ¹³⁴Cs recovery. The deposited films were physically characterized by energy dispersive x-ray spectroscopy and x-ray diffraction techniques. ¹³⁴Cs uptake was controlled by modulation of the ion exchanger potential in batch and flow systems. The deposited nickel hexacyanoferrate ion exchange film was found hydro-mechanically stable up to 130 bed volume/h. The ion uptake was about more than 90% achieved after 15 h of equilibrium . The reduced film state showed higher performance than the oxidized one in presence and absence of Na⁺ ions with different concentrations. The breakthrough of the electrically switched ion exchange (ESIX) process was also conducted in different stacking of electrodes cells. Three and six stacked electrodes assemblies showed longer breakthroughs than single electrode assembly at the same operating conditions. In vertical cell, representing larger scale tests, higher concentrations (60 ppm Cs⁺) could be successfully treated.

[en] Cylindrical powder compacts were prepared by uni-axial pressing of industrial T.V. waste glass. The anisotropic behavior was followed under isothermal conditions through the densification behavior of the products using a heating microscope. The samples became nearly fully dense at a temperature of about 650 degree in few minutes and showed an anisotropic shrinkage during densification. At the earlier stages of sintering the radial shrinkage was higher than the axial shrinkage, while this behavior was reversed at the later sintering stages. Explanation of this behavior was discussed on the basis of the phases formed for the samples during the sintering process. Experimental values for the shrinkage behavior in the radial direction were calculated and found to be in agreement with the theoretical values given in the literature. shielding bricks were prepared from TV glass waste in addition to another three different local industrial solid wastes, namely Jasin glass, arc furnace slag and fly ash, by mixing with cross linked poly bis phenol-epichlorohydrin resin. The products found applications as radioactive shielding bricks against 834.0 KeV for Mn-54, 1115.0 KeV for Zn-65, 301.7 KeV for Sn-113, 661.6 KeV for Cs-137 and 122.1 KeV for Co-57 sources

[en] The ion exchange behaviour of U(V I), Th(IV) and Ce(IV) on a system composed of AL₂ O₃-Si O₂-Ti O₂ mixed metal oxides was studied. The mixed metal oxide ternary system contains 5-50% Al₂ O₃, 0.85% Si O₂ and 7-80% Ti O₂, and it was prepared by hydrolysis, polymerization and poly condensation of the corresponding metal alkoxides in presence of alcohol and bidistilled water. The composition of the examined system was followed using X-ray fluorescence, while the DTA and TGA indicated both phase transfer and weight loss of the system during heat treatment. The uptake of U(V I), Th(IV) and Ce(IV) species on the different samples representing the ternary mixed metal oxide systems was carried out from different media. In the absence of complexing agents, the studies were carried out at low PH-values to avoid hydrolysis of Th(IV) and Ce(IV) species in aqueous solutions. The exchange behaviour of the mentioned elements species was also studied at higher PH-values in the presence of ammonium carbonate, as complexing agent. The effect of the organic acids oxalic and citric, as complexing agents, on the exchange behaviour also studied. From the different uptake studies of the U(V I), Th(V I), and Ce(IV) species from different media at different PH-values, some concentration and separation alternatives for these metal species were recommended

[en] A cerium tungestate was chemically synthesized and characterized using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), and thermal analysis. The sorptive removal of cobalt and europium ions from aqueous waste solution using synthetic cerium tungestate A was investigated. Experiments were carried out as a function of pH, solute concentration and temperature (298-333 K). Analysis of the respective rate data in accordance with three kinetic models revealed that the intraparticle diffusion was the rate limiting step for the sorption of both studied ions. Values of the pseudo firstorder and pseudo second- order rate constants and the particle diffusion coefficients were determined from the graphical representation of the proposed models. Activation energy and thermodynamic parameters of free energy (and 8710; G), enthalpy (and 8710; H) and entropy (and 8710; S) of activation for each sorption process were calculated from the linearized form of Arrhenius equation. The results indicated that cerium tungestate can be used as an efficient material for the removal of erupium and cobalt ions from waste solutions

[en] The kinetics and mechanism of exchange of Na⁺ ions on the thermally treated and untreated silicon antimonate exchangers have been studied as a function of particle sizes and reaction temperatures. The conditions of the experiments are set to favor the particle-diffusion mechanism and the physical thermodynamic parameters such as, effective diffusion coefficients, activation energies and entropies of activation have been evaluated. The diffusion of Na⁺ ion was found to be higher inside the untreated silicon antimonate than inside the thermally treated one. Surface area, pore sizes and porosities play a main role in the mobility of Na⁺ inside the matrix. The capacity for Na⁺ ions was found to have higher value in case of untreated sample than the treated one

[en] Syntheses of resin beads from unsaturated polyester and urea-formaldehyde were carried out by dispersion polymerization. The reaction was performed through gamma irradiation and chemical processing. Factors affecting the reaction and syntheses parameters that are the type and viscosity of dispersant, irradiation dose and agitation rate on the resin beads size were thoroughly investigated. The resulting resin beads were smooth on their spherical surface and the beads diameters were in the range 2-200μm. Some measurements such as beads diameter, surface hardness and scanning electron microscopy were studied. The bead diameter was generally decreased with increasing concentration and viscosity of the dispersant and agitation rate. A comparison study between irradiation and chemical processes for resin beads synthesis was discussed to identify the suitable process for preparing a resin beads in a pilot scale. The different methods of preparation were tried to be applied in the recovery of Li⁺, Na+, k⁺ and Cs⁺ ions from acidic media.

[en] The uptake of Eu(III) and Zr(IV) was studied on ceramic materials of Ti O₂, Si O₂ and Al₂ O₃, prepared by the hydrolysis process. The uptake behaviour of Eu(III) and Zr(IV) was investigated under different experimental conditions such as contact time, PH-value in the presence and in absence of complexing agent. X-ray fluorescence, powder morphology, specific surface area, X-ray diffraction analysis in addition to the DTA and TGA were applied on the tested ceramic samples. The present study showed that the ceramic materials, prepared by an advanced technique are not only efficient for uptake of Eu(III) and Zr(IV), but also permitted the separation of these radioisotopes. 8 figs., 1 tab

[en] The uptake of Eu(III) and Zr(IV) was studied on ceramic materials of TiO₂, SiO₂ and Al₂O₃, prepared by the hydrolysis process. The uptake behavior of Eu(III) and Zr(IV) was investigated under different experimental conditions such as contact time, pH-value in the presence and in absence of complexing agent. X-ray fluorescence, powder morphology, specific surface area, X-ray diffraction analysis in addition to the DTA and TG were applied on the tested ceramic samples. The present study showed that the ceramic materials, prepared by an advanced technique are not only efficient for uptake of Eu(III) and Zr(IV), but also permitted the separation of these radioisotopes. (author)

[en] Egyptian waste materials as air cooled blast furanace slag's were added in different quantities to mixtures of egyptian raw materials applying the single fast firing technique for producing wall tiles. The physico-chemical characteristics of the waste materials as well as the raw materials were studied before and after the thermal treatment. The reactions occurred during the firing procces and the formation of the end phases were followed using DTA-TG, X-ray diffractometry and heating microscopy. The effect of composition on bend strength, water absorption and firing shrinkage was studied. As a result, promising wall tiles with high bend strength, low water absorption and low firing shrinkage, containing high percentage of waste materials (50 wt% of the slag) and fired at 1100degree C for 30 minures were fabricated

[en] Low and Intermediate level radioactive wastes (LILW) and hazardous wastes, presents a waste disposal problem. In this respect, a process to immobilize different radioactive and hazardous wastes, including metals contaminated with radionuclides in a form that is non-dispersible and meet the Environmental Protection Agency (USA, EPA) leaching criteria is a must. In this stabilization and solidification process (S/S), simulated radioactive wastes of Cs, Sr, Ce, Cr, and Pb were immobilized in the stable form of sulfur polymer cement (SPC). In the present work, the mixture of the contaminant(s) and the sulfur mixture which is composed from 95% S and 5% aromatic/or aliphatic hydrocarbons used as polymerizing agents for sulfur (by weight), were added in a stainless steel vessel and primarily heated to 40 degree C for four hours, this time was sufficient for homogeneous mixing of the metals with sulfur and Na₂S (to convert the metals to their corresponding sulfides). Additional SPC was then added and the temperature of the mixture was raised to 135 ±1 degree C, resulting in a molten form that was poured into a stainless steel mold where it cooled and solidified. Durability of the fabricated SPC matrices was assessed in terms of water of immersion, porosity, and compressive strength. The water absorption and open porosity were very low and didn't exceed 2.5 % for all matrices, whereas the compressive strength ranged between 7 and 14 KN/m² depending on the matrix composition. The immobilized waste forms of SPC were characterized by X-ray diffraction (XRD) technique that showed that the different contaminants were stabilized during the solidification process to form stable sulfides. Leachability of the waste matrices was assessed by the Toxicity Characteristic Leaching Procedure (TCLP) of the EPA, optimized and compared with the new EPA Universal Treatment Standards.The TCLP results showed that the concentration of the most contaminants released were under detection limit of the test. Static leach tests were conducted using the IAEA standard method. The leach index of the prepared materials towards the