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The mobility of several radionuclides in a soil sample from a potential site in Egypt is examined. The retention of 152,154Eu (as homologs of 241Am), 60Co, 137Cs, and 99Mo in the presence of chelating ligands in the soil sample and without them is studied. Four chelating agents, namely, ethylenediaminetetraacetic acid (EDTA), citric and oxalic acids (as the major degradation products of EDTA), and humic acid are chosen for this purpose. The radionuclide retention on the soil without chelating ligands decreases in the order Co(II) > Eu(III) > Cs(I) > Mo(VI), with Kd equal to 11.38 mL/g for 99Mo and 1088 mL/g for 152,154Eu. The chelating ligands had little influence on the sorption of 60Co and 137Cs, but significantly decreased the retention of 152,154Eu owing to complexation. The soil sample on the potential nuclear site can act as a material for trapping the released radionuclides.

Common raw materials used in ceramic industry in Egypt have been collected from different ceramic factories. The samples were tested for their natural radioactivity contents by using HPGe high-resolution γ-ray spectrometer. Various radionuclides of the samples have been identified quantitatively based on their characteristic spectral peaks. The natural radioactivity due to the presence of 238U, 226Ra, 232Th, and 40K and the radiological parameters for 15 raw materials were measured. The three raw materials with the highest radioactivity were quantitatively analyzed using X-ray fluorescence (XRF). The most abundant oxides measured were generally SiO2, ZrO2, ZnO, Fe2O3, and CaO. The highest mean values of 238U, 226Ra, and 232Th activities were 394 ± 6, 428 ± 8, and 61.1 ± 1.5 Bq kg−1 (in zircon), and the highest 40K activity was 283 ± 4 Bq kg−1 (Aswan clay). The radium equivalent activities and some hazard indices were also calculated to assess the radiation hazards. The maximum mean value of the radium equivalent activity Raeq is 516 ± 10 Bq kg−1 (in zircon). The highest radioactivity level and dose rate in air were also obtained for zircon. The total absorbed dose rates in air, calculated from the concentrations of the three radionuclides, range from 4.29 ± 0.18 to 461 ± 9 nGy h−1; the external annual effective dose rates were determined to be between 0.03 ± 0.003 and 4.35 ± 0.23 mSv.

Zirconium antimonate (ZrSb) ion exchanger was prepared. Distribution coefficients of metal ions on ZrSb ion exchanger in solutions of various acids (hydrochloric, nitric, acetic, citric, ascorbic) and salts (sodium chloride and sodium nitrate) were determined to evaluate the ion exchange behavior and selectivity to specific ions. ZrSb, as compared to other inorganic ion exchangers, showed increased thermal and chemical stability. ZrSb is an efficient and promising ion exchanger for preparation of 137Cs/137mBa and 62Zn/62Cu radioisotope generators.

Preparation of uncontaminated phosphogypsum (PG) produced by wet-process phosphoric acid plant for its safe use in industry was investigated. PG is mainly composed of calcium sulfate and contains enhanced natural radioactivity. The activity of 238U, 226Ra, 210Pb, 232Th, and 40K in PG samples was measured by γ-ray spectrometry. The values of radiation hazard indices, calculated to evaluate the environmental impacts of PG samples, were higher than the permissible safe levels. Therefore, the PG should be treated before use in agriculture and/or building materials. This involves the leaching of PG with organic extractant such as TOPO in kerosene. Reduction in the radionuclide concentration was accompanied by a decrease in the concentration of total rare earth elements (ΣREE). Extraction treatment of PG waste under optimum conditions allows preparation of a decontaminated product that can be safely used in many branches of industry.

The sorption behavior of light rare-earth elements (La, Ce, Nd, Sm) on resorcinol-formaldehyde (RF) resin was studied. The effect of pH, shaking time, and temperature on the metal distribution coefficients was examined. The RF resin affinity for the examined lanthanides increases with a decrease in the ionic radius of the metal ion: Sm > Ce > Nd > La. The capacity of RF resins for the lanthanides shows the same trend. Because of the relatively high capacity of the resin, the presence of interfering ions affects the sorption percentage of the light REEs insignificantly. The thermodynamic functions of the sorption process were determined. They show that the adsorption of the light lanthanides on RF resin occurs spontaneously with the dehydrated metal ion.

This study concerns treatment of phosphogypsum (PG) waste from phosphoric acid production, containing 226Ra as major radioactive contaminant. Physical and chemical treatment was performed. The physical treatment was based on the particle size separation (dry and wet frationation), whereas the chemical treatment was carried out using leaching solutions (single and sequential leaching processes). The results showed that the particle size separation affected the distribution of radionuclides in PG waste. High enrichment fators (Q) of 226Ra and 210Pb were obtained in the wet fractionation. The Q value for 226Ra and 210Pb was 3.1 and 3.9 compared to the PG bulk. The chemical leaching conditions of PG waste were optimized. In the single chemical leaching, 40% of total radium-226 in PG was removed. In the sequential leaching, about 87% of 226Ra was removed when the PG waste was washed with alkali solutions and pretreated and leached with a nitric acid solution.

A novel polymeric impregnated material was prepared by loading 4,4′(5′)di-t-butylbenzo-18-crown-6 (DtBB18C6) onto poly(acrylamide-acrylic acid-acrylonitrile)-N,N′-methylenediacrylamide [P(AM-AA-AN)-DAM]. The sorption of 137Cs onto P(AM-AA-AN)-DAM/DtBB18C6 was studied using batch equilibrium technique with respect to the pH, contact time, and temperature. The applicability to treatment of low-level liquid radioactive waste was examined. The free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0) of the sorption were calculated. These parameters showed that the sorption of 137Cs onto P(AM-AA-AN)-DAM/DtBB18C6 was spontaneous and endothermic in nature. The Lagergren first-order, pseudo-second-order, and homogeneous particle diffusion models were tested kinetically to describe the reaction mechanism. The experimental data were fitted well by the pseudo-second-order kinetic model.