Effective removal of Cu2+ from aqueous solution by synthetic abalone shell hydroxyapatite microspheres adsorbent

Abstract Hydroxyapatite (HA) is regarded as an excellent adsorbent because of its efficient adsorption capacity and ion exchange property. It is expected to be applied to the adsorption of heavy metals in wastewater. In this paper, HA microspheres were synthesized using waste abalone shells by simple hydrothermal self-assembly method to remove Cu 2 + in wastewater. Also, several main factors which may influence the removal efficiency such as solution pH, initial Cu 2 + concentration, contact time and temperature were investigated. The results showed that the adsorption capacity of abalone shell HA microspheres for Cu 2 + could reach 517.1377 mg/g. Thermodynamic analysis indicated the removal of Cu 2 + by HA microspheres was a spontaneous and exothermic process because of the negative values of △ H0 and △ G0. HA microspheres prepared from waste shells are economical and pose excellent adsorption capacities. This technology is promising for environmental protection.