Adsorption of fifteen kinds of volatile organics on activated carbon from aqueous solution was carried out in a batch system. It was assumed that the rate of adsorption was controlled by intraparticle surface diffusion, and the effective surface diffusion coefficient for each organic was determined by applying the concentration-time diagrams appropriated for Freundlich isotherms. The effective surface diffusion coefficients, D_ε, thus obtained, are successfully correlated to the ratio of the boiling point of adsorbate to adsorption temperature as
D_ε=1.1×10^-4exp(-5.32T_b/T) [cm²/sec]