Synthesis and characterization of nano-hydroxyapatite from carbide lime waste through a green conversion approach

Annually, a substantial quantity of industrial waste is generated globally, and the build-up of this waste poses a serious risk to society. The generation of carbide lime waste as a byproduct during acetylene gas production in industries has resulted in many environmental issues. This study attempts to convert carbide lime waste into nanohydroxyapatite (nHAp) that can be used to treat patients suffering from orthopaedic injuries. The synthesis of nHAp from carbide lime was carried out by chemical precipitation method using 85 % orthophosphoric acid. The resulting nHAp was physicochemically characterized by different instruments. Fourier Transform Infrared Spectroscopy (FTIR) was used to analyze the functional groups to confirm the conversion of carbide lime. The structural analysis of the synthesized nHAp was done by X-Ray Diffractometer (XRD). Field Emission Scanning Electron Microscopy (FESEM) was used to find the morphology of nHAp particles. The elemental composition of nHAp was studied by Energy Dispersive X-ray Spectroscopy (EDX). The hydrodynamic size of nHAp was calculated by the nano-zeta sizer instrument. Thermo Gravimetric Analyzer (TGA) studied the thermal behaviour of nHAp and carbide lime. Further, mechanical testing was carried out for nHAp using the Vickers microhardness test. In vitro tests, such as biodegradation and cell viability, were also conducted. As a result, the nHAp was found to be biocompatible and biodegradable. In the future, this nHAp biomaterial can be modified for different biomedical applications.