Transport mechanism of thorium(IV) through a polymer inclusion membrane containing di-2-ethylhexyl phosphoric as carrier

Document Type : Research Article

Authors

1 Material and nuclear fuel cycle research school, Nuclear science and technology research institute, Atomic energy organization of Iran, Tehran-Iran

2 Chemical engineering department, Tehran university, P.O. Box: 11365-4563, Tehran- Iran

Abstract

The paper, presents an analysis of the mechanism of thorium ions (IV) transfer in a polymer inclusion membrane (PIM). A PIM membrane containing polyvinyl chloride (PVC) as the base polymer‌, and Di-(2-ethylhexyl) phosphoric acid (D2EHPA) as extracting agent (carrier) was used for the recovery of Th(IV) ions in nitric acid medium. First of all, the influence of the carrier concentration as an important parameter in the transport efficiency was investigated. Also, the aqueous phase parameters including the initial concentration of thorium (IV) and pH of the feed phase, the strippiing phase acid concentration were evaluated. Regardless of the initial concentration of thorium (IV), for experimental conditions, 45% Wt of D2EHPA, was found as the optimal value of carrier concentration, for which the process was the most effective. Studies on the transport kinetics and transport mechanism of Th(IV) ions carried out and the results showed that the transport of Th(IV) across PIM was consistent with the first order kinetics equation and the “jumping” mechanism for the experimental conditions was concluded as the dominant transport mechanism.

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