ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Simultaneous selective separation of silver (I) and lead (II) ions from a single dilute source solution through two supported liquid membranes composed of selective crown ethers in supra molecular solvent

Foujan Falaki, Mojtaba Shamsipur, and Farzaneh Shemirani

Department of Chemistry, Shahr-E-Qods Branch, Islamic Azad University, Tehran, Iran

E-mail: foujanfalaki@gmail.com

Received: 13 September 2020  Accepted: 18 December 2020

Abstract:

In this study, an alternative application of supported liquid membranes (SLMs) containing specific ion carriers dissolved in supra molecular solvent (SUPRA) to the selective and simultaneous separation of Ag⁺ and Pb²⁺ ions from a dilute source solution is introduced. A two-membrane three-compartment cell was used. Two micro-porous polypropylene supported membranes loaded with dibenzyl-diaza-18-crown-6 (DBzDA18C6) and dicyclohexyl-18-crown-6 (DC18C6) dissolved in supra molecular solvent (SUPRA) were used for selective transport of silver (I) and lead (II) ions, respectively. At first, vesicles of decanoic acid (SUPRA), as green solvent, were synthesized. Then, each of two mentioned crown ethers was easily dissolved into the SUPRA phase and used as the selective membrane phase for facile and simultaneous transport of lead and silver ions through the designed cell. The DBzDA18C6-loaded membrane was placed between the first and the second compartments (MP₁), whereas the DC18C6-loaded membrane was placed between the second and the third ones (MP₂) of the transport cell. Using this cell assembly, simultaneous separation and transport of Ag⁺ and Pb²⁺ ions are possible from a 1.854 × 10^–4 M picric acid source solution containing these two species and several other interfering ions into the two corresponding receiving compartments of the transport cell. The silver (I) and lead (II) ions quantitatively transport during 75 and 15 min of time into two individual receiving solutions, respectively. Sodium thiosulfate (0.6 M at pH 6.4) and sodium pyrophosphate (0.25 M at pH 7) were used as selective stripping agents for Ag⁺ and Pb²⁺ ions (RP₁ and RP₂), respectively.

Keywords: Simultaneous silver and lead transport; Supported liquid membranes; Selective crown ethers; Supra molecular solvent (SUPRA)

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01734-4

Chemical Papers 75 (10) 5489–5502 (2021)