Adsorption processes of Cd(II) and Pb(II) from aqueous solutions onto pumice stone powder (PSP) were investigated in batch mode. The influences of solution pH, contact time, adsorbent dosage, initial metal (M) concentration, and temperature on adsorption process were investigated. The kinetic and isotherm data were analysed using different model equations. The adsorption process was consistent with the Langmuir model for both metal ions with high R2 and low χ2 values for both Pb(II) and Cd(II). The maximum monolayer adsorption capacities were and mg g−1 for Pb(II) and for Cd(II), respectively. |