Novel concepts of liquid-phase adsorption at the oil/water interface of a bicontinuous microemulsive phase are presented. These ideas are assessed using a tetradecanel didodecyldimethylammonium bromide/water bicontinuous microemulsion (BME) to adsorb chromate anions from aqueous solution. The adsorption isotherms are investigated as a function of solution ionic strength. Our results show that the BME is an effective adsorbent for removing CrO42- from solutions with good selectivity over Br- and high enrichment ratio, arising from the large internal surface area of the oil/water interface. An approximate model adsorption isotherm is derived from basic thermodynamic considerations. The proposed model is validated against our experimental data with satisfactory agreement for low chromium content in the BME. Implications of these concepts and results for adsorptive separation of generic contaminant from a liquid phase are discussed in comparison with conventional adsorption processes using solid adsorbents and also with micellar-enhanced ultrafiltration process. (c) 2006 American Institute of Chemical Engineers AIChE J, 52: 2767-2773, 2006.