The adsorption of caffeine was studied by using three phenolic resin adsorbents

JDW-1

JDW-2 and JDW-3

prepared in the laboratory and a commercial product Duolite S-761 under static and dynamic conditions. The experimental results show that JDW’s are superior to Duolite S-761 in adsorption of caffeine．A semi-empirical rate equation adequately fits the sorption rate data of caffeine in the initial period till about 32％～51％ of the equilibrium sorption．The results confirm the particle-diffusion control mechanism of the sorption process．The equilibrium sorption date for phenolic resin adsorbents／caffeine systems can be described by the Langmuir isotherm equation with a correlation coefficient larger than 0.99．It implies the monomolecular sorption in these systems.