A parametric study on the retention of radioactive ions in a flow-through reactor from its synthetic solution on reactive cloth filter (RCF) was achieved. The study takes into consideration the physical and chemical parameters which control the process. In this respect a mathematical model is proposed for explaining the kinetic behavior of the radioactive ions retention along the reactor. It is based on the effect of external and internal diffusion of the solute as well as the chemical reaction on the sorption process. The accumulated amount of sorped species is calculated and compared with the obtained experimental values. The comparison shows a satisfactory agreement. (C) 2011 Elsevier B.V. All rights reserved.