Conversion of lime mud waste to hydroxyapatite biomaterials

• DOI: 10.1016/j.matchemphys.2021.124544
• Publication Date: 2021-03-26T04:51:32Z
• Authors: Chokchai Yatongchai; Boonlom Thavornyu...
• Keywords: Ammonium phosphate

Abstract An economical method to convert a lime mud (LM) waste from the pulp and paper manufacturing process to hydroxyapatite nanoparticles (nHA) was first introduced. In this work, LM was used as a calcium precursor source to synthesize single phase nHA through the chemical precipitation method with ammonium phosphate dibasic as the phosphate precursor. Transmission electron microscopy (TEM) observation confirmed that the produced nHA had rod-like nanocrystals with an average crystal size of 30 nm. X-ray diffraction (XRD) analysis revealed the pure phase of nHA. The synthesized nHA was identified as AB-type carbonate substitution using Fourier Transform infrared spectroscopy (FTIR). The concentration of toxic elements contained in the synthesized HA was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). The result showed that HA nanocrystals prepared in this work contained lower concentration of toxic heavy metals than the concentration limits suggested by ASTM.