Effect of Chemical Activation on the Surface Properties of Apricot Stones Based Activated Carbons and Its Adsorptive Properties Toward Aniline

The present study reports the preparation of activated carbons from apricot stones (an agricultural waste) by chemical activation with phosphoric acid (H₃PO₄) and Zinc Chloride (ZnCl₂) in N₂ atmosphere. The potential use of the prepared activated carbons as adsorbents and the effects of chemical activation on the surface properties and adsorptive mechanism of Aniline were investigated. The physico-chemical properties of the obtained materials were characterized by Nitrogen adsorption–desorption isotherms, Scanning Electron Microscope coupled to energy dispersive X-ray (SEM-EDX), Fourier Transform Infrared Spectroscope (FTIR), Boehm titration and pH of point of zero charge (pH_pzc). The results show that the prepared samples present high apparent surface areas and pore volume with surface functional groups. Adsorption studies were carried out under varying conditions of contact time, initial concentration and temperature. Pseudo-first order and pseudo-second order kinetic models were applied, finding that the pseudo-second order model was the most suitable for the fitting of the experimental kinetic data. The equilibrium adsorption data were analyzed using Langmuir and Freundlich isotherm models. The equilibrium data were well fitted to the Freundlich isotherm. Based on the results, it is, therefore, suggested that the adsorption is mainly brought about by dispersive interactions between Aniline and activated carbon surface. The prepared activated carbons could be used as a low-cost alternative to commercial activated carbon for the removal of aniline from wastewater.