Synthesis and adsorption properties of macroporous cross-linked polystyrene that contains an immobilizing 2,5-dimercapto-1,3,4-thiodiazole with tetraethylene glycol spacers

A novel chelating resin macroporous cross-linked polystyrene immobilizing 2,5-dimercapto-1,3,4-thiodiazole via a hydrophilic tetraethylene glycol spacer (PS-TEGBMT) is synthesized and the structure is characterized by means of Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray microanalysis (EDX), and elementary analysis. Its adsorption capacity for several metal ions such as Hg2+, Ag+, Ni2+, Pb2+, Cd2+, Fe3+, Bi3+, Zn2+, and Cu2+, are investigated. The initial experimental result shows that this resin has higher adsorption selectivity for Hg2+ and Ni2+ than for the other metal ions and the introduction of hydrophilic TEG spacer is beneficial to increase adsorption capacities. The result also shows that the Langmuir model is better than the Freundlich model to describe the isothermal process of PS-TEG-BME resin for Hg2+. Five adsorption-desorption cycles demonstrate that this resin are suitable for reuse without considerable change in adsorption capacity.