A novel starch-based adsorbent for removing toxic Hg(II) and Pb(II) ions from aqueous solution

► A novel starch-based adsorbent is synthesized by a facile approach. ► It is an effective adsorbent for removal of toxic Hg(II) and Pb(II) ions from water. ► The adsorption ability can be tailored by changing the feeding ratio of reagents. ► It is applied to remove the metal ions from the decoctions of four medicinal herbals efficiently.