Characterization of activated carbons from waste materials by adsorption from aqueous solutions

Chars and activated carbons obtained from miscellaneous waste materials and by-products have been used to remove phenol and 2,3,4-trichlorophenol from one- and two-solute aqueous solutions. The effect of activation on the adsorption performance was studied. Activation not only improved the specific surface area and the adsorption capacity of chars but also affected the polarity of the surface. The best results were achieved with carbons from agricultural by-products. From two-component solutions the preferred adsorption of 2,3,4-trichlorophenol was experienced. The effectiveness of the removal of the non-preferentially adsorbing phenol is poor as long as the preferred trichlorophenol is present above a certain concentration. The greater the difference in the K values, the higher is this concentration. (C) 1997 Elsevier Science Ltd.