Characterization of hydroxyapatite synthesized from paper mill sludge.

Hydroxyapatite, Ca10(PO4)6(OH2) is major mineral constituent of vertebrate bones and teeth. It is extensively used in biomedical field due to its biocompatible, bioactive and osteoconductive properties. Hydroxyapatite (HAp) has recently gained attention as efficient adsorbents, owing to its physical and chemical nature as it can substitute both cationic and anionic complexes present in an aqueous solution in its atomic arrangement. The Hydroxyapatite has been reported to be an efficient adsorbent in removing divalent heavy metal ions. In this work, an attempt has been made to synthesis hydroxyapatite by wet chemical precipitation method by extracting the calcium source from paper sludge ash. Experimental works were carried out under controlled condition by maintaining pH, temperature, stirring speed and aging period. The obtained powder is optimized at 600⁰C based on the TG-DTA results. The presence of hydroxyl ion in the apatite lattice was confirmed by absorption bands at 3410.15 cm⁻¹ through FT-IR studies. The mean pore diameter and pore volume of the HAp was deducted through BET analysis as 45.22 nm and 1.7100 cm³g⁻¹. [ABSTRACT FROM AUTHOR]