The ionic exchange (IE) model has been used to predict the influence of positive metal ion complexation upon micellar-enhanced ultrafiltration (MEUF) results, The three different systems studied were sodium dodecyl sulfate-ethylene diamine tetra-acetic acid (EDTA)-Cu(II); SDS-Tartrate ion-Cu(II), and the hydrolysis of the uranyl ion-SDS, In the appropriate experimental conditions, 98% of Cu(II) is recovered in the filtrate with the use of EDTA, The IE model allows for the accurate prediction of Cu(II) release by the addition of tartrate ion as a function of pH. In the case of uranyl ion hydrolysis, the IE model showed that the UO2(OH)(2) species is not predominant under the experimental conditions.