Evaluation of Poly (Vinyl Chloride)/2-Nitrophenyl Octyl Ether/Di(2-Ethylhexyl) Phosphoric Acid Polymer Inclusion Membrane Performance for Zinc Recovery and Separation

Membrane technology, based on a different kind of polymeric membranes, is among the most recognized and crucial technologies for the treatment of wastewater. Polymer Inclusion Membranes (PIMs) were used in selective and facilitated transport of different heavy metals from acidic media. The motivation of this study is to synthesize novel PVC-based polymer inclusion membranes (PIMs) with specific percentages of plasticizer and carrier to transport and separate Zn(II) ions under particular conditions. In the synthesis of these membranes, the efforts are directed towards minimizing the quantities of organic solvents employed as plasticizing and carrier agents. This reduction not only contributes to environmental sustainability but also enhances health and economic aspects. These findings align with the ongoing commitment to advancing environmentally conscious practices in membrane synthesis. Polymer inclusion membranes consisting of poly (vinyl chloride) (PVC) as base polymer, 2-nitrophenyl octyl ether (NPOE) as a plasticizer (10 wt. %), and D2EHPA as a carrier (30 wt. %) were prepared. The membranes were characterized by attenuated total reflectance-fourier transformed infrared (ATR-FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to collect information on their morphology and composition. Mechanical properties and hydrophobicity of the PIMs were determined by the tensile strength and the contact angle measurements. To further verify the feasibility of the new composition of the membranes, the PVC/NPOE/D2EHPA PIM was used to evaluate the effect of the pH of the feed phase on zinc transport ([Zn 2+ ] = 30 mg.L −1 , pH range varied from 2 to 5). At optimal pH equal to 5, zinc ions were completely transported through the selected PIM after only 4 h by using 1 M of sulfuric acid as a receiving phase. The stability of the studied PIM was also examined. We note that Zn(II) flux through this membrane decreases slightly after six extraction cycles. Moreover, the selectivity coefficient revealed that the PIM is more selective towards Zn(II) than Ni(II) cations. The performances of the PIM system for zinc, nickel and copper separation were evaluated.