Efficient removal of Hg2+ in aqueous solution with fishbone charcoal as adsorbent.

The Hg2+ removal performance of fishbone charcoal prepared from discarded fishbone has been investigated in this work. The XRD, FTIR, and BET results demonstrated that the main composition of fishbone charcoal was hydroxyapatite and the specific surface area was 117 m2/g. The adsorption experiments indicated that fishbone charcoal had an extremely high adsorption capacity for Hg2+ (243.77 mg/g). The excellent Hg2+ adsorption capacity might be ascribed to the ion exchange of Hg2+ to the Ca2+ in the structure of fishbone charcoal, complexation of Hg2+ with ≡Ca(OH)2+ on the surface of fishbone charcoal, as well as electrostatic interaction between electronegative fishbone charcoal surface and cation Hg2+. This work transformed kitchen garbage (i.e., fishbone) into an effective mercury adsorbent with considerable capacity, giving a perspective sight for the utilization of solid waste.