Pentachlorophenol (PCP) adsorption from aqueous solution by activated carbons prepared from corn wastes

Abstract

Corn wastes generated from starch and glucose production industry were used for the preparation of activated carbons. The prepared activated carbons and a commercial activated carbon were evaluated for their capability of adsorbing pentachlorophenol (PCP) from aqueous solution. Batch adsorption experiments were performed under different operating conditions including pH (2–8), adsorbent dosage (0.5–4.0 g/l), initial PCP concentration (10–100 mg/l), contact time (30–300 min), and temperature (25–45 °C). The kinetics and equilibrium models describing the adsorption of PCP by the prepared adsorbents were obtained. The adsorption of PCP by corn waste-based adsorbents was found to follow the second-order kinetics and the Freundlich equilibrium models. The intraparticle diffusion mechanism was successfully fitted to the obtained experimental data. Thermodynamic studies indicated that the adsorption process was exothermic. The adsorbents surface characterization revealed the presence of many functional groups capable of binding the adsorbate molecules. The study results suggest the possible use of corn wastes as a starting material for the production of activated carbon, thus lowering the costs of wastewater treatment processes.