This work presents a fundamental study for prediction of breakthroughs in a continuous flow membrane system containing powdered activated carbon (PAC) for phenol removal. The adsorption isotherm of phenol on PAC typically followed the Freundlich equation. A surface diffusion model was employed to simulate the adsorption of phenol in the systems. The model agrees well with the experimental breakthrough data, and it could be effectively applied to predict the breakthrough curve for design of adsorption-membrane filtration system. Intraparticle transport appears to be the rate-limiting step in this system. Surface diffusivity (D-s,) obtained by fitting the model breakthrough curve to that of the experiment was 3.3 x 10(-8) cm(2).s(-1).