화학공학소재연구정보센터
Journal of Chemical Technology and Biotechnology, Vol.67, No.2, 183-189, 1996
Chemical and Thermal Regeneration of an Activated Carbon Saturated with Chlorophenols
An activated carbon obtained by activation of olive stones in carbon dioxide at 1113 K has been used in this study. This was saturated with o-chlorophenol and m-chlorophenol from their corresponding aqueous solutions. The spent activated carbon samples were regenerated by means of organic solvent treatments and subsequent heat treatments. The organic solvents used were : acetone, methanol, ethanol and benzene. The extent of the chemical regeneration in these systems is a function of the strength of the adsorbent-adsorbate interactions. When the systems are treated with organic solvents the adsorbate extracted mainly comes from the physisorbed fraction. When the samples extracted with organic solvents are thermally regenerated by heating at 1073 K in an inert flow, in most of the cases, the amount of adsorbate removed increased in comparison to treatments without solvents. A part of the physisorbed fraction remaining in these samples after the solvent treatments is released at lower temperatures than the chemisorbed fraction. During the heat treatment, part of the physisorbed fraction is transformed to a chemisorbed one which has a greater desorption energy than the former.