Sulfonamide based polymeric sorbents for selective mercury extraction

New polymeric resin with sulfonamide pendant functions have been prepared for the selective extraction of mercuric ions. This polystyrene sulfonamide resin with a 3.5 mmol/g total nitrogen content is able to selectively sorb mercury from aqueous solutions. The mercury sorption capacity of the resins are around 1.71 mmol/g for acetyl sulfonamide resin and 2.9 mmol/g for methanesulfonyl sulfonamide resin under non-buffered conditions. The experiments performed under identical conditions with some metal ions reveal that Cd(II), Pb(II), Zn(II) and Fe(III) ions are also extractable in low quantity (0.05-0.1 mmol/g). The mercury-loaded polymers (acetyl sulfonamide and methanesulfonyl sulfonamide) may be quantitatively regenerated with hot acetic acid and 4 M HNO₃.