Adsorption from aqueous solutions of chlorinated organic compounds onto activated carbons

The adsorption capacities of five chlorinated organic compounds, chloroform (CHCl3), 1,1,2,2-tetrachloroethane (S-TET), 1,1,2,2-tetrachloroethylene (PER), 1,2-dichloropropane (DCP), and bis(1-chloroisopropyl) ether (BCIPE) for DTO, WD-EXTRA, and AG-5 activated carbons were investigated. Moreover, the effective molecular diameters of investigated chlorocompounds were calculated. The Freundlich and Langmuir equations of adsorption isotherms describe the experimental data with good correlation for each studied system. The equilibrium data were also analyzed using the equations of Dubinin and Radushkevich and of Dubinin and Astakhov. The degree of filling of the micropores and the average free energy for adsorption in the investigated systems were determined based on these models. It was found that the highest adsorption capacity in relation to all investigated compounds is exhibited by DTO activated carbon. For DTO activated carbon the adsorption affinity of the compounds decreases in the order BCIPE > PER approximate to S-TET > DCP > CHCl3, whereas for WD-EXTRA S-TET > BCIPE > PER > DCP > CHCl3 and for AG-5 S-TET > PER > BCIPE > DCP > CHCl3. The obtained adsorption isotherms are generally L-type according to the Giles classification. (C) 2003 Elsevier Inc. All rights reserved.