Preparation of a novel chelating resin containing amidoxime–guanidine group and its recovery properties for silver ions in aqueous solution

A novel chelating resin containing amidoxime–guanidine functional group, PSGA resin, has been first synthesized from the functionalization of chloromethylated poly (styrene–divinylbenzene) (CMPS) bead with dicyandiamide (DCDA); the nitrile group in MPS/DCDA bead was changed into amidoxime group by treatment with hydroxylamine under alkaline condition, successively. The resulting PSGA resin was characterized with the Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM), elemental analysis and Brunauer–Emmett–Teller (BET). Meanwhile, the adsorption behavior of the PSGA resin for Ag(I) in aqueous solution was investigated by batch method. It is noteworthy that, the adsorption of the resulting PSGA resin for Ag(I) could reach almost 100% in a wide range of pH when an initial concentration of Ag(I) was below 400 mg L−1. Furthermore, the PSGA resin can selectively separate Ag(I) in the case of coexisting Zn(II), Cd(II), Mg(II) and Ni(II), and Ag(I) adsorbed by PSGA resin could be easily desorbed.

► The resin containing amidoxime–guanidine functional group was firstly synthesized.
► All synthesized processes were done at moderate conditions.
► The resulting adsorbent has excellent adsorption for Ag(I) in aqueous solution.
► Removel percentage for Ag(I) could reach almost 100% at low concentration.
► The resin shows excellent selectively separate for Ag(I) and can be easily desorbed.