Dialysis and photo-electrodialysis processes using new synthesized polymeric membranes for the selective removal of bivalent cations

Polymer inclusion membranes (PIM) have emerged as a new technique for the ions selective separation. In this work, a novel class of membrane for the separation of M2+ ions (=Ni2+, Cu2+ and Zn2+) coupled with photo-electrodialysis was developed. The membrane was polymerized from cellulose triacetate (CTA) and other polymers (PVP, PEI or PEG), tri-ethyl hexyl phosphate (TEHP) was incorporated in the membrane as a plasticizer. The cellulose plasticized membranes were characterized by FTIR spectroscopy, scanning electron microscopy (SEM) and thermal analysis (TGA). Photoelectro-dialysis was performed under visible light. The M2+ transport across combined PIM with photo-electrode FeAl2O4 showed acceptable ions transport efficiency (33% after 3 h). The spinel oxide semi-conductor p-FeAl2O4 prepared from nitrates decomposition was synthesized by chemical route and characterized by X-ray diffraction (XRD). It absorbed over the whole solar spectrum, it is low cost, non-toxic and exhibited a chemical stability over a wide pH range.