Effects of pH and Inorganic Salts on the Adsorption of Phenol from Aqueous Systems on Activated Decolorizing Charcoal

An experimental investigation of the effects of pH and three inorganic salts (KCl, KI, and NaCl) on the adsorption isotherms of phenol (from a dilute aqueous solution) on activated charcoal was conducted. Each salt was studied at three different concentrations, i.e., 0.1, 0.001, and 0.005 M. The effect of pH (in the pH range 3 to 11) in the presence of KI, KCl, and NaCl was also investigated. The concentration of phenol in the aqueous systems studied ranged from 10 to 200 ppm. The temperature effect was also studied, and the resulting experimental equilibrium isotherms at 30, 40, and 55°C are well represented by Freundlich, Langmuir, and Redlich—Paterson isotherms. The relevant parameters for these isotherms are presented.