Experimental studies on adsorption equilibrium adsorption rate and fixed-bed adsorption were performed to investigate the adsorption behavior of an activated carbon and the capacity of fixed-bed adsorber for the removal of phenol from aqueous solution. The composed prediction model equations for adsorption behavior were solved by finite element method(FEM). Adsorption behavior of adsorbent was analyzed by the surface and pore diffusion models. Both of the models can be applied to predict the performance of the adsorbent. However, the pore diffusion model was slightly better than the surface diffusion model in representing the experimental data. Therefore, the pore diffusion model was applied to predict the adsorber performance by changing operational variables associated with adsorption process of phenol on the granular activated carbon for the design purpose for fixed-bed adsorber.