ABSTRACT:The adsorption of Pb 2+ and Ni 2+ ions from aqueous solution onto montmorillonite (MMT) has been investigated at 293 K, 303 K, 313 K and 323 K using batch equilibrium experiments. In order to optimize the adsorption conditions, the effects of contact time, solution pH and initial metal ion concentrations were tested thoroughly. The adsorption isotherms were best described by the Langmuir model at lower temperatures, while the Freundlich model gave a better fit at higher temperatures.