Walaa R. Mohamed’s research while affiliated with Egyptian Atomic Energy Authority and other places

Surface modification of ball clay was produced by gamma irradiation of a mixture containing ball clay (BC), acrylic acid (AA), phosphoric acid (PA), and N,N`-methylenebisacrylamide (DAM) solution to produce a composite sorbent (BC-AA-PA). Both BC and BC-AA-PA composite were characterized using SEM, FT-IR, XRD, and XRF. Comparative evaluation of both materials for the sorption of gadolinium and cerium ions was explored. The outcomes exposed that the removal percentage enhanced from 38.2% to 91% and from 24.9% to 88% for gadolinium and cerium ions by BC and BC-AA-PA, respectively. The proposed sorption mechanism illustrated that the sorption occurs by an ion exchange process. Sorption kinetics, equilibrium isotherm, and desorption studies were conducted. The sorption obeyed the pseudo-second-order model and Langmuir isotherm model. The comparison of sorption capacity of BC-AA-PA with other sorbents in the literature indicated that BC-AA-PA has a much higher sorption capacity than many sorbents (1.085 and 0.907 mmol/g for Gd³⁺ and Ce³⁺, respectively). Desorption of gadolinium and cerium ions from BC-AA-PA was investigated; the results certified that 0.1 M HNO3 is the best eluent with a percentage of 99.99 and 92% for Ce³⁺ and Gd³⁺, respectively, and the BC-AA-PA can be applied for further sorption processes. Hence, BC-AA-PA composite sorbent is recommended for the sorption of lanthanides from the liquid phase.

Application of fixed bed column for separation of gadolinium and neodymium ions from their aqueous solutions using cyphos IL-104 impregnated silica was investigated. The performance of separation of the two lanthanide elements was evaluated by determining the column capacity, the total quantity sorbed of metal ions, and the removal percentage. These indicative column performance parameters were evaluated in altered conditions including fixed bed height of 2.0 and 3.0 cm, flow rate of 1.0 and 2.0 mL/min, and solution feed concentration of 50 and 100 ppm. Breakthrough modeling of the sorption process across the column was performed by employing Thomas and Adams–Bohart models. It was found that it took less time to reach the breakthrough when the flow rate and initial concentration increased, while the height of the bed decreased. Also, the column capacity increased by increasing the bed depth, decreasing the flow rate, and increasing the initial metal ion concentrations. 0.1 M nitric acid was found to be the best media for the separation of Nd3+ and Gd3+ ions.

Impregnation of trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate, as an ionic liquid, into silica was carried out for removal of neodymium and gadolinium ions from aqueous solution. Silica and the impregnated silica (Cyphos@silica) were characterized using FT-IR, SEM, XRD and TGA. Comparative sorption behavior of silica and Cyphos@silica for sorption of neodymium and gadolinium ions was investigated. The experimental outcome revealed that the impregnation process enhanced the sorption behavior of silica, from 18 to 67% for neodymium ion and from 20 to 89.45% for gadolinium ion. From the kinetic studies, the sorption could be described well by pseudo-second-order model. Langmuir and Freundlich isotherms were performed to determine the best fit equation for the sorption process; the results indicated that the latter surpasses the former. Comparison of the sorption capacity of Cyphos@silica with other materials reported in the literature shows that the former has a comparatively high sorption capacity. Desorption percent of gadolinium and neodymium ions from Cyphos@silica using 1.0 mol/L of HNO3 was found to be 97.74 and 86.33%, respectively. The desorption studies revealed the reusability of Cyphos@silica for further sorption.