A Study of the Influence of Hydrophobicity of Activated Carbon on the Adsorption Equilibrium of Aromatics in Non-Aqueous Media

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Journal Title, Volume, Page: 
Adsorption December, Volume 9, Issue 4, pp 311-319
Year of Publication: 
2003
Authors: 
Hassan A. Arafat
Department of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH, USA
Current Affiliation: 
Department of Chemical Engineering, Faculty of Engineering and Information Technology, An-Najah National University, Nablus, Palestine
Neville G. Pinto
Department of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH, USA
Falk Ahnert
Freiberg University of Mining and Technology, Freiburg, Germany
Preferred Abstract (Original): 

The effect of hydrophobicity on the adsorption of aromatics on metal-free activated carbons was studied. Adsorption isotherms for phenol, aniline, benzene, and xylene were generated in cyclohexane and heptane media, using seven carbons with different surface heterogeneity. The hydrophobicity of these carbons was probed using flow microcalorimetry (FMC). Surface polarity and solvent and adsorbate hydrophobicity were found to influence the adsorption capacity. For adsorbates that do not form hydrogen bonds with oxygen on the carbon surface, higher surface acidity lowers adsorption capacity due to increased polarity. In contrast, for adsorbates that can form hydrogen bonds with surface oxygen, the capacity is enhanced at higher surface acidities. A higher solvent hydrophobicity was found to decrease capacity for all the aromatic adsorbates studied, except at high surface polarity, where the effect of the solvent was found to be minimal.