This study deals with the evaluation of the single and binary removal of Pb2+ and Cd2+ from aqueous solutions using HNO3 modified olive pomace (N-OP). For the specific binary adsorption behavior, a renovative isotherm model was developed based on the additivity of the single adsorption contributions of Pb2+ and Cd2+ calculated from the binary data. The effect of the initial metal ion concentration, pH, ionic strength, and temperature on the adsorption of the single Pb2+ and Cd2+, and their binary adsorption were investigated using batch experiments at the optimum conditions. The N-OP displayed maximum adsorption capacities of 64 mg g(-1) for Pb2+ and 20.5 mg g(-1) for Cd2+ from the single metal ion solutions using 1.0 g L-1 N-OP. The results were best fitted with the Langmuir model for Pb2+ and the Radke-Prausnitz model for Cd2+ adsorption at 25 degrees C. The reusability of the N-OP was confirmed with desorption studies. The thermodynamic study revealed that the adsorption of Pb2+ was exothermic and that of Cd2+ was an endothermic process. The existence of Cd2+ in a binary solution increased the Pb2+ removal while that of Pb2+ reduced the Cd2+ removal with N-OP. This behavior may contribute to a selective removal of the heavy metal ions from their mixture.