GREEN CHEMISTRY APPROACHES TO EXTRACTING CALCIUM PHOSPHATE FROM FISH BONE WASTES

This study explores the extraction of calcium phosphate (CaP) bioceramics from fish bone waste using green chemistry approaches, specifically the alkali treatment method. Fish bones from trout (TF), mackerel (MF), and grey mullet (GMF) were processed to obtain CaP powders, which were characterised using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS). The XRD analysis confirmed the presence of hydroxyapatite (HA) in all the samples, with the TF exhibiting the highest crystallinity. The FTIR spectra revealed characteristic phosphate and hydroxyl groups, indicating the presence of HA. The TEM images showed distinct particle morphologies, with the TF particles aggregated and irregular, the MF particles fibrous, and the GMF particles spherical and uniform. The XPS analysis indicated that the highest elemental compositions with oxygen, calcium, and phosphorus contents were in the TF (47.233 %, 16.187 %, and 9.288 %, respectively). The degradation and ion release studies in phosphate-buffered saline (PBS) showed significant magnesium release, particularly from the TF (32.550 ppm on day 1) and calcium release primarily from the TF (524.89 ppm on day 1). The study demonstrates the potential of fish bone-derived CaP for biomedical applications, such as bone grafts and dental implants, highlighting the environmental and economic benefits of utilising fish bone waste.