In this study, a simple and effective technique for determining overall mass transfer coefficients in fixed bed sorption columns with recycling is presented. The overall mass transfer coefficient (K-c) of patulin for adsorption out activated carbon packed columns were determined at different flow rates. The K-c values increased from 4.74x10(-2) to 12.96x10(-2)cms(-1) when the flow rate increased from 5 to 100 ml min(-1) which is a very clear indication of turbulence created through the column to eliminate the film resistances on the activated carbon surface. (C) 1998 Elsevier Science Limited. All rights reserved.