Selective adsorption of Hg(II) by γ-radiation synthesized silica-graft-vinyl imidazole adsorbent

► Silica-based adsorbent was prepared by γ-radiation induced grafting. ► Vinyl imidazole was successfully grafted onto the silica. ► SS-g-VIM adsorbent had an excellent selectivity for Hg(II) adsorption. ► The Hg(II) adsorption capacity of SS-g-VIM was high. ► The adsorption behaviors were investigated comprehensively.