The, Mineralization of natural hydroxyapatite for high efficiency of Pb2+ ion removal in aqueous solution

Abstract

Mineralized hydroxyapatite (m-HA) was prepared by soaking natural hydroxyapatite (n-HA) extracted from pig bone in the simulated body fluid (SBF) for 3 days. XRD and FE-SEM characterizations confirmed the formation of new HA crystal layer in the structure of m-HA. Experiments of lead ion adsorption were performed for both n-HA and m-HA by immersing 50 mg of each different powder samples in 100 mL of lead ion solution at a concentration of 100 ppm. Results analyzed by ICP-MS showed that m-HA has an excellent ability to remove lead ions compared to n-HA. After 4 hours of adsorption experiments, m-HA material eliminated almost 100% of lead ions while n-HA only removes 65.4%. The mechanism of lead ion removal for m-HA was determined, including the ion-exchange and physical adsorption.