Selective separation of mercury (II) using a synthetic resin containing amine and mercaptan as chelating groups

A chelating resin with amine-mercaptan groups has been prepared. The resin obtained showed high durability towards mineral acids and alkalis. The recovery of Hg(II) was investigated by both batch and column methods. The uptake capacity reached 3.10 mmol/g, i.e. 621.8 mg/g. The nature of interaction between the metal ion and the resin was found to be dependent upon the acidity of the medium as well as the type of the conjugate anion. This interaction was explained to proceed via complex formation or ion exchange mechanism. Hg(II) could be selectively separated from Ca(II), Mg(II), Pb(II), Cd(II), Cu(II) and Zn(II) at pH 2.7. The elution process of Hg(II) was tested using HCl, HNO3 and H2SO4 with different concentrations. HNO3 and H2SO4 gave a high elution ratio (>90%), whereas HCl showed a low elution ratio (≈32%).