Adsorption of Hg(II) from aqueous solutions by thiol-functionalized polymer-coated magnetic particles

A selective adsorbent for Hg(II) was prepared by coating CoFe2O4 particles with polystyrene and further modified with 2-(3-(2-aminoethylthio)propylthio)ethanamine. The coating method did not alter the saturation magnetization value of the adsorbents and it improved particle acid resistance and adsorption efficiency. The adsorbent could adsorb Hg(II) in a wide pH range with optimum pH of 7–8. The adsorption of Hg(II) followed Langmuir isotherm and pseudo-second order kinetics with the maximum adsorption capacity of 0.42 mmol Hg g−1. Showing a selectivity in Hg(II) adsorption over co-existing ions, these adsorbents could be reused without significant efficiency loss over at least ten consecutive trials.