Lead Adsorption by Nano-Hydroxyapatite Granules in a Fixed-Bed Column
The sorption of Pb2+ ions was conducted in a fixed-bed column by using nano-hydroxyapatite granules. The breakthrough and exhaustion time decreased with increasing flow rate, decreasing bed depth and increasing influent lead concentration. The proposed mechanism is a partial dissolution of calcium followed by the precipitation of an apatite by the ion-exchange mechanism with the formula Ca10−xPbx(PO4)6(OH)2 and Pb10(PO4)6(OH)2.