Microwave-assisted hydrothermal synthesis of carbonated apatite with calcium and phosphate resources derived from green mussel shell and bovine bone wastes

• The microwave-assisted method retrieved calcium and phosphate supplies from natural resources for the synthesis of carbonate-rich apatite. • The microwave-assisted approach yielded hydroxyapatite rich in carbonates. • Microwave-assisted methods confirmed brushite, hydroxyapatite, calcite, and gypsum phase transitions. • The thermal behavior of carbonate-rich hydroxyapatite was investigated in order to improve osteoconduction. Resources recovery of calcium and phosphates from respective green mussel shells and bovine bones by calcination and chemically extracting are viable precursors for carbonate-rich apatite biomedical material applications. Because of their high osteoconductivity, carbonate-rich apatite bioceramics are being studied intensively for synthetic bone transplants. In the study, powder processing routes of calcination and following chemical dissolution in MgCl 2 and H 2 SO 4 were each for recovering calcium of mussel shells and phosphate of bovine bones yielding a crystal-forming solution feedstock for use in microwave-irradiated synthesis. FTIR spectra and XRD patterns validated the crystallinity and phase identification for as-synthesized powders. As a result, the presence of CO 3 , PO 4 3- , and OH- bands in carbonate-calcium phosphate complexes were present in FTIR spectra. According to the XRD Rietveld method, the as-synthesized powder product contained brushite, carbonated hydroxyapatite (CHA), calcite, and gypsum. The recoverable CHA crystallites' size was 40 nm. This present study demonstrated that microwave irradiation synthesis of CHA powder with calcium and phosphates derived from mussel shells and bovine bones is the potential to yield a large amount of CHA for bioceramics and would aid in the design of a powder processing step for preparing the CHA powder precursor in biomedical applications.