A hydrothermal synthesis of eggshell and fruit waste extract to produce nanosized hydroxyapatite

Eggshells are typically considered to be garbage because they have no value as food but they favor microbial growth. Vast quantities of eggshell waste are available from food processing, baking, and hatching industries. The present study provides a simple hydrothermal method to obtain high-purity hydroxyapatite (HA) nanoparticles from eggshells and three kinds of fruit waste extracts: grape, sweet potato, and pomelo peels. These synthesized nanoparticles have been characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy studies. The results showed that hydrothermal reaction times and biomolecule amounts influenced product shape, product size, and synthetic HA crystal morphology. The HA taken from pomelo peelings exhibited good aspect ratios with physical shapes similar to those of the crystalline HA structures of natural human bone. HA synthesized from eggshell powders contains several important trace elements, such as Na, Mg, and Sr.