Adsorption of phenol from aqueous solutions by Luffa cylindrica fibers: Kinetics, isotherm and thermodynamic studies

The present study is concerned with the removal of phenol from aqueous solution by adsorption onto low cost adsorbent. Luffa cylindrica fibers, LC, were investigated as an adsorbent for the removal of phenol. Batch adsorption experiments were performed as a function of pH, contact time, phenol concentration, adsorbent dose and temperature. The optimum conditions for maximum adsorption were attained at pH 7, LC dose of 3 g/L. Langmuir, Freundlich, Tempkin and Dubinin–Radushkevich isotherm models were selected to evaluate the adsorption of phenol on LC. It was found that the Langmuir isotherm model best fits the phenol adsorption onto LC. The pseudo-second-order rate equation as well as the micropore diffusion model described the kinetic data well. The adsorption process was found to be an exothermic process. Thermodynamic parameters of phenol adsorption were calculated. The FT-IR analysis confirms that the adsorption of phenol on LC has a good and favorable adsorptive capacity.