Nano round polycrystalline adsorbent of chicken bones origin for Congo red dye adsorption

Nano round polycrystalline adsorbent (NRPA) of chicken bones origin was utilize as effective adsorbent in Congo red dye removal via aqueous media. The NRPA adsorbent was prepared via thermal decomposition and its structure was investigated with the aids of Transmission Electron Microscopy, Fourier Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy, Energy Dispersive X-ray Analysis (EDX), and X-ray Diffractometer (XRD). A monophasic apatite phase was confirmed from XRD investigation, while functional groups analysis showed that NRPA possessed CO₃^2-_, PO₄^3- and OH^- absorption bands. The maximum adsorption capacities derived from Langmuir isotherm is 98.216 mg g^-1. From the combined values of n from Freundlich and separation factor (R_L) of Langmuir models, the adsorption of CR by NRPA is favourable. Thermodynamic values of 5.280 kJ mol^-1 and 16.403 kJ mol^-1 K^-1 were found for ΔH° and ΔS° respectively. The entire values of ΔG° which ranges from - 35.248 to - 459.68 kJ mol^-1 were all negative at different temperatures. Thus, nano polycrystalline adsorbent of chicken bone origin can serve as excellent adsorbent in Congo red dye removal from waste water.