Synthesis, characterization, and performance evaluation of a new innovative hydroxyapatite-based biocomposite for wastewater treatment application

This study illustrates the synthesis and comprehensive characterization of a newly developed Hydroxyapatite-biomass-based biocomposite derived from synthesized hydroxyapatite and biomass, specifically Banana peel (BN). The biocomposite was prepared by integrating hydroxyapatite with Banana peel biomass, promoting the in-situ formation of a brushite calcium phosphate phase within the lignocellulosic matrix, leading to a reactive organo-mineral interface. Both the raw biomaterial and the resulting biocomposite were thoroughly characterized using surface and spectroscopic techniques. Such as Fourier transform infrared spectroscopy FTIR, X-ray diffraction XRD, scanning electron microscopy SEM, elemental analysis CHNS, energy dispersive spectroscopy EDX, thermogravimetric and differential analysis TG-DTA, and Nitrogen-desorption isotherms BET. Moreover, molecular interactions in the biocomposite system were studied using density functional theory DFT to identify the functional groups involved in the formation of the HAp-BN material. The synthesized HAp-BN biocomposite prepared was evaluated and compared with hydroxyapatite (HAp) and biomass (BN) for contaminant removal. Adsorption experiments demonstrate that the HAp-biomass biocomposite achieved significantly higher removal efficiency (96%) for Direct Yellow 177 GLE compared to hydroxyapatite (67%) and Banana peel biomass (36%) under the same operating conditions. The enhanced performance is attributed to the synergistic effect of the brushite phase and the oxygen-containing functional groups of the biomass, facilitating surface complexation, hydrogen bonding, and electrostatic interactions with the dye molecules.