Application of 2-(octylsulphanyl)benzoic acid as Pb2+ selective ionophore in hybrid membrane system

Abstract

AbstractA solution of 2-(octylsulphanyl)benzoic acid in 1,2-dichloroethane was used as a liquid membrane for selective pertraction of Pb2+ cations. Transport processes were carried out in a multi-membrane hybrid system (MHS) consisting of two cation-exchange membranes (CEM) and a flowing liquid membrane (FLM) in the following order: CEM | FLM | CEM. The liquid membrane phase was dehydrated continuously using a pervaporation method (PV). The system was capable of transporting Pb2+ ions selectively from a multi-cation aqueous solution composed of Na+, K+, Ca2+, Mg2+, and Pb2+ nitrates. A comparative study of the carrier efficiency under various feed pH conditions was performed. It was found that the carrier exhibited sufficient selectivity and transport efficiency under a broad range of operational conditions, with a maximum transport rate of Pb2+ ions attaining the value of (1.09 ± 0.03) × 10−10 mol cm−2 s−1 and the selectivity coefficient of up to 40.