Adsorption removal of uranium from aqueous solution by hydroxyapatite: Recent advances and prospects

Abstract

Uranium separation from radioactive wastes or uranium extraction from sea water are closely related to nuclear energy. Hydroxyapatite (HAP) has special structure, excellent performance, low cost, wide sources and good biocompatibility, which has received more and more attention in uranium separation. In this paper, the application of HAP and its composites in uranium adsorption was reviewed, including the structure, properties and synthesis of HAP, the modification and functionalization of HAP composites, uranium adsorption properties and mechanism by HAP composites. In general, HAP composites can be prepared by various methods, and the properties of adsorbents depended on the preparation methods. In order to further improve adsorption and application performance, HAP composites need to be modified or functionalized. The uranium adsorption property of HAP composites is affected by pH, adsorbent dosage, uranium concentration, reaction temperature, reaction time, coexisting ions, etc. Physicochemical characterization and theoretical simulation can be used to further analyze the adsorption mechanism. According to literature analysis, common adsorption mechanism of uranium adsorption by HAP composites may include electrostatic interaction, complexation reaction, ion exchange, dissolution precipitation, etc. In conclusion, HAP composites can adsorb uranium quickly and effectively, which may be a very good choice for treating uranium-containing wastewater.