Adsorption of 2-Chlorophenol on Kaolin

Abstract

2-chlorophenol was removed by adsorption on kaolin from a local deposit. The raw kaolin itself could remove a substantial amount of 2-chlorophenol. The thermally treated pure kaolin was found to be the best adsorbent for 2-chlorophenol. The treatment of pure kaolin with NaOH improved the adsorption. 2-chlorophenol was adsorbed over a wide pH range. The adsorption data fitted both Freundlich and Langmuir adsorption isotherms and the values of the constants obtained from the isotherms indicated favourable adsorption. The adsorption process was found to be exothermic and was accompanied by a decrease of entropy and Gibbs energy.

Keywords: 2-Chlorophenol, Freundlich isotherm, kaolin, Langmuir isotherm, thermodynamic parameters, adsorption kinetics