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 secondorder 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.

The adsorption of aluminium(III) and iron(III) ions from their single and binary systems, by RHAC was investigated in a batch system. The activated carbon prepared from rice hulls was characterized by scanning electron microscopy and Fourier transformation infrared techniques. Batch adsorption experiments were performed under different operating conditions including pH (2 -5), adsorbent dosage (0.5 -2.0 g/l), initial ion concentration (5 -100 mg/l), and contact time (30 -240 min). The equilibrium time for maximum ions removal was found to be 180 min in single and binary ions systems. The kinetics of adsorption was evaluated using the pseudo-first order, pseudosecond order and Elovich kinetic models. The Langmuir, Freundlich and Temkin equilibrium models were applied to the adsorption experimental data. Real wastewater samples were collected from different locations to investigate the efficiency of rice hull activated carbon in treating real samples. The real wastewater samples were treated with the activated carbon prepared from rice hulls and a commercial activated carbon. The results showed that the activated carbon prepared in the present work was more efficient in the removal of aluminium and iron from real wastewater as compared to the commercial activated carbon which is more advantageous considering both economics and environmental parameters.