Adli A Hanna, Marwa A Sherief, Reham MM. Aboelenin and Sahar MA Mousa

Keywords: Barium hydroxyapatite, preparation, charsacterization, removal, metals.

Abstract: The aim of this study was preparation and characterization of barium hydroxyapatite, Ba10 (PO4)6(OH)2, BHP, to be used as ion exchanger for removal of some toxic cations from their aqueous solutions. The starting materials were barium hydroxide and phosphoric acid. The effects of the ratio between phosphoric acid and barium hydroxide on the produced hydroxyapatite were studied. X-ray diffraction, IR spectra, Transition electron microscope, and surface area were used for characterization of the produced barium hydroxyapatite. The x-ray patterns indicated the formation of the crystalline barium hydroxyapatite by using 0.02M H3PO4, while the other normality gives more than one phase. The IR spectrum exhibits specific absorption peaks at 558.2, 693.28, 1008.11, 1428.99, 1751.53, 1941.97, 3440.87, which characterizes the barium hydroxyapatite. It is observed that the intensity of the specific peaks on the x-ray charts increases with increasing of the acid normality, this indicate that the crystallinity improves by the increase of the acid normality. The TEM showed that: (1) the particle size of the barium hydroxyapatite lies in the scale of nanoparticles (40- 180 nm). (2) the size of the barium hydroxyapatite increases with increasing the ratio of phosphoric acid. (3) the particles have irregular shape and not depend on the ratio of phosphoric acid. (4) The sample produced by using phosphoric acid = 0 .04 M showed a bone structure. The measurements of the surface area indicated that it depends on the morphology of the produced samples which by turn depends on the normality of phosphoric acid. The more suitable sample was used to remove Cu, Cd, Ni, and Zn from their aqueous solutions.

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