The oxide/water interface of metal oxides has been identified as the most important inorganic mineral phase in water body and soil in controlling trace metal ion concentrations due to their relatively high surface area, abundance, and coating of clay minerals. In this paper, the effects of external and internal mass transport limitations on cadmium adsorption onto porous amorphous aluminum oxide/solution interfaces were studied. A modified two‐stage rate model was developed and used to interpret the time dependent experimental results. The effects of pH, aluminum oxide concentration, metal concentration and background electrolyte were performed and discussed.