A comparative study of kinetic models for ligand exchange of I- --> Cl- and Br- --> Cl- as ligands as a function of pH and concentration using diaminoethyl-sporopollenin (DAE-sporopollenin) resin were investigated during the ligand-exchange reaction of the liquid phase. A batch technique was employed for the study of the kinetics of I and Br/Cl exchange as ligands. Five kinetic models were applied to the experimental data. The rate of ligand exchange was increased with decreasing of the hydrated ionic radius and pH. The curve fitting of the mathematical models and the behavior of the kinetic curves are discussed for direct ligand exchange under the conditions employed.