Removal of phenol from aqueous solution by adsorption

The paper presents the results of laboratory tests concerning the possibility of utilizing activated carbon produced in Poland and nonconventional adsorbents, such as modified Clarion clay and clinoptylolite, for removing organic phenol from water. The effect of contact time and pH of the model solution on the adsorption process was assessed during tests conducted under static conditions. A contact time of 30 min was considered as optimum, and the highest efficiency of the adsorption process was achieved using a pH of 7.0. Adsorbent doses affected the course and effectiveness of the adsorption process. The adsorption processes were best described by the Freundlich isotherm. On the basis of the isotherms, the adsorptive capacity of tested adsorbents was calculated. Activated carbon had an adsorptive capacity of 13.22 g/kg, modified Clarion clay 1.24 g/kg, and clinoptylolite 0.23 g/kg. The through-flow conditions were achieved by column filtration. On the basis of breakthrough curves, the adsorptive capacities were higher than those determined through static conditions, namely 61.23, 23.56, and 2.99 g/kg for activated carbon, modified Clarion clay, and clinoptylolite, respectively. Despite their inferior adsorptive characteristics, the modified Clarion clay and clinoptylolite may be applied in filtration systems prior to filters with activated carbon.