Separation characteristics of two systems of binary mixtures, namely, (i) copper and calcium; (ii) copper and beta naphthol were studied using micellar-enhanced ultrafiltration (MEUF). Sodium dodecyl sulfate (SDS) was taken as the anionic surfactant. An organic polyamide membrane of molecular weight cut-off 5 kDa was used in cross flow MEUF experiments. Suitable feed surfactant concentration was found to be about 25 kg/m(3). The effects of the feed composition, the transmembrane pressure drop, and the cross flow rate on the permeate flux and observed retention of each solute were studied. For single solute systems, the observed retention of both copper and calcium were about 99% for a solute concentration up to 1.0 kg/m(3) but the retention reduced to 90% to 92% when solute concentration was increased to about 3 to 4 kg/m(3). Retention of copper and calcium was in the range of 88 to 97% for various compositions in their binary mixture. Retention of beta naphthol was in between 82 to 84% in its mixture with copper, whereas, about 92% separation of beta naphthol was achieved in the single solute system. Binding isotherms of both calcium and copper and beta naphthol and copper were evaluated in their binary mixture using extended Langmuir isotherm. A two-step chemical treatment was adopted to recover the surfactant.