Synthesis and structural analysis of calcined poultry manure for hydroxyapatite development

This study investigates the viability of utilizing poultry manure, an abundant and low-cost waste material, for the synthesis of hydroxyapatite (HAp), a critical biomaterial for bone regeneration. Calcination of poultry manure was conducted at 750°C, 800°C, and 850°C for 5 h to produce HAp. The processed poultry manure was then characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS), X-ray fluorescence (XRF), and X-ray diffraction (XRD) analyses. The FTIR analysis confirmed the formation of HAp through characteristic phosphate absorption bands, with the highest purity observed at 850°C. SEM analysis revealed that increasing calcination temperature enhanced the crystallinity and particle uniformity of the samples. XRF analysis showed a significant increase in CaO (40.229–43.328 %) and P₂O₅ (17.905–19.239 %) content with rising temperatures, crucial for HAp synthesis. The Ca/P ratios were determined to be 1.28, 1.54, and 1.71, respectively, indicating variations in purity and phase composition. The 800°C provides a near-ideal Ca/P ratio while the 850°C achieves a ratio slightly above the ideal, indicating a high-purity HAp phase. XRD analysis corroborated these findings, identifying hydroxyapatite (Ca₁₀P₆O₂₆H₂), as the predominant phase with minimal secondary phases. These results suggest that calcination at 850°C is optimal for producing high-purity HAp from poultry manure, offering a sustainable and cost-effective alternative to synthetic HAp production for biomedical applications.