Sorption selectivity of a number of REE ions (Pr3+, Nd3+, Sm3+, Yb3+) was studied with the help of the KB-2E macroreticular carboxylic cation exchanger with a different content of a crosslinking agent. Selectivity was weakly dependent on the degree of crosslinking of the cation exchanger and concentration of the sorbed metal ion, which could be explained by the macroreticular structure of the cation exchanger. An increase in sorption selectivity of heavier REEs (Yb3+) correlated with a decrease in their crystallographic radius. It was concluded that a coordinate link of REE ions and oxygen donor atoms - a part of the cation exchanger - had been formed.
Acid-base properties and selectivity of absorption such ions as REE (Eu3+, Gd3+, Nd3+, Yb3+) from solutions with various ionic force by the fibrous ampholytes PAN-FOSPAN and PAN-IDUC are investigated. PAN-FOSPAN shows the greatest selectivity to ions of REE. This fact can be used for division and the subsequent definition of ions. PAN-IDUC as a high selective fibrous sorbent after alkaline treatment is perspective one for absorption of the REE sum.
The equilibrium and dynamics of sorption of Co2+ and Cu2+ ions have been investigated on highly cross-linked carboxyl cation exchangers of gel (KB-125P) and macroreticular (KB-2E-10) structure from solutions with an ionic strength of 0.1 and 1. It has been established that there is a weak effect of salt background concentration on selectivity of ion sorption in static conditions. In dynamic conditions with increased levels of background electrolytes, there is a decrease in the degree of ion exchanger layer KB-2E-10, which indicates a decrease in the selectivity of sorption. For the cation exchanger KB-125P, on the contrary, there is an increase in the degree of the layer use. It has been concluded that the gel structure of the sorbent KB-125P provides selective sorption of Co2+ and Cu2+ ions from solutions with high salt background. Coloring of cation exchangers layer KB-125P and KB-2E-10 in the absorption of Cu2+ and Co2+ makes it possible to create effective indicator tubes on their basis.
The combihed mathematical model of ion exchange sorption, wkiich includes equations of saturation, formalistic kinetics aqd one of the.diffusion equations of h'eterophase, processes was suggested. On the basis of this model the tree-module program complex has been,devcloped. The first program module includes the equation of accumulation of sorbate subject to two kinds of sorption centers: intemal and extemal: Ones of them (extemal) are located on a surface and the others (intemal) are located inside of ionite granule pores. This equation allows to calculate some thermodynamic data. The second program module connects with searching kinetic equation based on the specific physical model of interaction a sorbate-ion with a ionite granule and allows to determine the diffusion model of sorption. nird~module determines the number of bonds of an absorbent-ion with a sorbent matrix. This approach was applied for the determination of regularities of sorption of rare-earth metal (REM) ions on ionites Kl3-2E and KBS. The basis of handling was experimental kinetics data of sorption of ions Nd'+ and Yb3+ by cations with different granulation and cross-linking. The form of the diffusion kinetic model (the second program module) demonstrated that the anti-Jander mechanism is realized for the most cases. The relation between antiJander constants and the nature of absorbent ions can be used for separation of the absorbent ions. The calculation of the reaction orders (n) demonstrated that values n did not depend.on the nature of an absorbent ion and the solution temperature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.