Preparation of a novel chloromethylated polystyrene-2-mercapto-1,3,4-thiadiazole chelating resin and its adsorption properties and mechanism for separation and recovery of Hg(II) from aqueous solutions.

ABSTRACT

With an efficient methodology, a novel chloromethylated polystyrene-g-2-mercapto-1,3,4-thiadiazole chelating resin (MTR resin) was prepared via a one-step reaction. The structure of MTR resin was characterized by elements analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Meanwhile, the adsorption properties of the resin for Hg(II) were investigated by batch and column experiments. The results showed that the resin possessed much better adsorption capability for Hg(II) than for other metal ions. The statically and the dynamic saturated adsorption capacities were 343.8 mg/g and 475.1 mg/g. The adsorption kinetic and equilibrium data were well fitted to the second-order model and the Langmuir isotherm model, respectively. Desorption of mercury from the resin can be achieved using 30 mL of 2 mol/L HCl-5% thiourea solution with a desorption ratio of 92.3%. Compared with other absorbents, MTR resin was greatly conserve natural resources and reduce the cost.