COMPARISON OF ACTIVATED CARBONS PREPARED FROM AGRICULTURAL RAW-MATERIALS AND SPANISH LIGNITES WHEN REMOVING CHLOROPHENOLS FROM AQUEOUS-SOLUTIONS

Activated carbons obtained from agricultural by-products and Spanish lignites, as well as a commercial one, have been used to study the removal of ortho- and metachlorophenol from aqueous solutions, both under static and dynamic conditions. Results obtained show that although both isomers are adsorbed to the same extension, the interaction of metachlorophenol with the surface of the carbon is stronger than in the case of the other isomer. Characteristics of the carbon beds have been related with the textural characteristics of the adsorbents. Thus, it has been found that the pore volume accessible to water is an important parameter determining the yield of the removal process. The bed characteristics have been studied as a function of type of activated carbon, particle size, concentration, and pH of the solutions. The efficiency of these activated carbons to remove orthochlorophenol is higher under static conditions than under dynamic ones.