Abstract
In this study, the extraction efficiency of rhenium ions in the form of perrhenate (ReO4?) from model aqueous solutions was investigated using a binary ion-exchange system based on KU-2-8 (strongly acidic cation-exchange resin) and AV-17-8 (strongly basic anion-exchange resin). The ion exchangers were separately weighed and combined in varying molar ratios (6:0, 5:1, 4:2, 3:3, 2:4, 1:5, and 0:6), and were immobilized within a chemically resistant polypropylene mesh bag to maintain phase separation while allowing solution contact. Sorption experiments were conducted at room temperature with initial Re concentrations of 100 mg/L, across different pH values (native pH � 6.2 and adjusted pH = 4.0) to evaluate the pH effect on ion-exchange performance. The optimal performance was observed at a KU-2-8:AV-17-8 molar ratio of 2:4 and pH = 4.0, where rhenium ion removal was significantly higher than at the natural pH of ammonium perrhenate solution. Moreover, the combined system outperformed individual resins used alone (6:0 or 0:6). This enhancement is attributed to synergistic effects between cationic and anionic components, as well as improved local ion exchange conditions within the mesh environment. These results demonstrate the potential of dual-ion-exchanger systems in controlled microenvironments for efficient and selective recovery of rhenium from aqueous media.