Surface modification of ball clay minerals with gamma irradiation polymerization for removal of cerium and gadolinium ions from aqueous phase

Abstract

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.