COMPETITIVE ADSORPTION OF PHENOLS ON GAC .2. ADSORPTION DYNAMICS UNDER ANOXIC CONDITIONS

The impact of the presence of molecular oxygen in the test environment is further evaluated for adsorption behavior of a mixture of phenolic compounds on fixed-bed GAC adsorbers. Adsorption breakthrough curves are obtained for the single-solute system phenol, o-cresol, and 3-ethy lphenol; the binary solute system of phenol and o-cresol; and the tern ary solute system of phenol, o-cresol, and 3-ethylphenol. The plug-flo w homogeneous surface diffusion model is evaluated as a predictor of a dsorber performance for these systems. The binary and ternary solute c alculations of the model are performed using kinetic parameters determ ined for the single-solute system. The ideal adsorbed solution theory is used to describe the equilibrium on the surface of the adsorbent pa rticle. The model predictions for the single-solute system agree very well with the experimental breakthrough curves conducted under anoxic conditions, with exceptions to the later portion of the o-cresol break through, where tailing of the experimental breakthrough has been notic ed due to the presence of limited concentrations of dissolved oxygen i n the feed. The model predictions for the binary and ternary solute sy stems agree well with the experimental data collected under anoxic con ditions.