The extraction and the removal of Cd(II) using polymer inclusion membrane containing symmetric room temperature ionic liquid as ion carrier

Abstract

Since cadmium is a hazardous material for environment, various techniques have been developed for safe removal of cadmium. Among these techniques, ionic polymer inclusion membranes (IPIMs) have a higher membrane structural stability that can be used to separate and recover cadmium ions with a higher selectivity. Also, the ion transport capacity of IPIMs can be further increased by selecting suitable ion carriers and plasticizers. In this study, preparation of IPIMs was accomplished by selecting newly synthesized symmetric and having different alkyl chain room temperature ionic liquids as ion carriers for selective the separation of cadmium from iodide-containing acidic solutions. The highest mass transport was determined as 0.958 μmol s−1 cm−2 from 25 mg L−1 and 2.02 μmol s−1 m−2 from 75 mg L−1 Cd(II) solution, respectively, when using the optimized IPIM containing 24.97% (w/w) 2-nitrophenyl octyl ether as plasticizer and 35.12% (w/w) 1,3-decyl-1 H-imidazol-3-ium bromide as carrier. The mass transport of cadmium was determined as 0.567 μmol s−1 m−2 in the presence of Cr3+, Fe2+, Co2+, Ni2+ and Zn2+. Surface analyses were explored by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), while the structural analysis was carried on by Fourier infrared spectroscopy (FTIR) before/after Cd transport experiments.