Theoretical and experimental insights about the adsorption of uranyl ion on a new designed Vermiculite-Polymer composite

Abstract

A new Polyacrylamide (PAA)-Vermiculite (V) composite was synthesized and characterized with the help of FTIR, SEM, and PZC analyses. The effects of ion concentration, pH and ionic strength parameters to adsorption process were investigated in detail. The obtained data were analyzed and discussed in the light of the Langmuir, Freundlich and Dubinin-Radushkevich (DR) models. It was shown that the adsorption of UO22+ increased with the increasing of the pH while the increasing or decreasing of the ionic strength did not lead to significant changes in adsorption process. The adsorption of uranyl ion on new designed material followed an endothermic and spontaneous process with increased disorderliness at adsorbate/adsorbent interface. It was noticed that the adsorption process exhibits a pseudo-second-order kinetics. The interaction mechanism regarding to the interaction between uranyl ion and new designed Polyacrylamide (PAA)-Vermiculite (V) composite was highlighted in the light of Density Functional Theory (DFT) calculations. Both theoretical and experimental analyses made proved that the designed new material with a adsorption capacity of 0.375 mol kg−1 is a potential adsorbent for effective removal of uranyl ions from solutions.