NATURAL HYDROXYAPATITE AS AN ADSORBENT FOR MICROORGANISMS (MOS) FROM AQUEOUS SYSTEM

Abstract

Natural hydroxyapatite (HAp) was isolated from calcination of waste caprine (goat) bone at 750 °C in muffle furnace. As produced material was characterized by using X-ray Diffraction (XRD) Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) analyses and ensured the synthesized material was nano rod hydroxyapatite. The pHPZC value of the HAp was 7.2 as determined by pH drift method. Adsorption of four different microorganisms (MOS) (E. coli, A. baumanii, S. aureus and C. albicans) onto natural HAp was investigated and found to adsorb onto HAp with the proportions greater than 25 % within the applied concentration ranges. Adsorption kinetics studies showed the adsorption process followed the pseudo-second order kinetics for all investigated MOS. Antimicrobial study revealed that three adsorbed species (E. coli, S. aureus and C. albicans) onto HAp remained viable form while HAp showed good antibacterial activity towards A. baumanii. Minimum inhibition concentration (MIC) and minimum biocidal concentration (MBC) values of HAp were found to be 12.5 and 100 mg·mL-1 respectively against A. baumanii. Thus, thermal treatment of waste bone powder is found to be cost-effective and environment-friendly method for the isolation of natural nano HAp and it can be applied as an adsorbent for different MOS from aqueous solution as well as a potential antibacterial agent.

Keywords

• adsorption kinetics
• antimicrobial study
• hydroxyapatite
• microorganisms
• waste bone