Selective Sorption of Gold and Iron Ions in the PMAA-P4VP Intergel System

This study presents a method for the efficient separation of gold and iron ions using cross-linked polyelectrolyte interpolymer systems. The research aims to investigate the sorption behavior resulting from the remote interaction of intergel systems based on polymethacrylic acid (gPMAA) and poly-4-vinylpyridine (gP4VP) hydrogels. According to the atomic emission spectroscopy results, the individual gPMAA (6:0) hydrogel exhibits negligible activity toward gold ions, with a sorption degree of only 5.97%, while maintaining a high sorption efficiency for iron ions at approximately 90.27%. The interpolymer interaction effect is most pronounced in the equimolar (3:3) intergel system, where the sorption efficiency for gold ions significantly increases, reaching a peak of 63.97% after 24 h of contact. In contrast, the sorption efficiency for iron ions remains consistently high across all molar ratios, fluctuating between 88.27% and 91.33%. The polymer chain binding degree (θ) further confirms these trends, reaching maximum values of 1.09% for gold and 7.18% for iron ions. These findings demonstrate that the gPMAA-gP4VP system possesses a high selective affinity for iron over gold under the studied conditions, providing a viable approach for the selective separation and recovery of metals from multicomponent industrial solutions.