Study of the kinetics of sorption of praseodymium and neodymium ions using interpolymer systems based on KU-2-8 and AB-17-8 in salt forms

This paper presents a study of the kinetics of neodymium and praseodymium ions sorption using interpolymer systems based on KU-2-8 and AB-17-8 in salt forms. Sorption of target ions was carried out in a dynamic mode (with constant stirring) in interpolymer systems in molar ratios of 4:2 and 3:3 (cation exchanger to anion exchanger). Aliquots were collected during certain time intervals, then widely known kinetic models of sorption were used to construct linear graphs. According to the obtained results, the best model for describing sorption was pseudo-first order (the highest value for the 4:2 system = 0.97885 and 0.98112; for the 3:3 system = 0.9647 and 0.98779). Such results are important for understanding the mechanisms of the sorption process and establishing the limiting factor that can slow down this process. The kinetic model of pseudo-first order may indicate the need to improve the washing out of counterions from the polyelectrolyte matrix for their high ionization and accessibility of functional groups for metal ions. This assumption can be used in the future to optimize industrial schemes of ion-exchange sorption of REE.