Adsorption of Pb(II) and Cd(II) from aqueous solutions using titanate nanotubes prepared via hydrothermal method

► The adsorption of Pb(II) and Cd(II) from aqueous solutions were mainly ascribed to the hydroxyl group in the titanate nanotubes. ► Both Pb(II) and Cd(II) adsorbed onto titanate nanotubes increased with the increase of pH value from 2.0 to 6.0. The optimum pH for Pb(II) and Cd(II) adsorption were found in the range of 5.0-6.0. ► The adsorption of Pb(II) and Cd(II) onto titanate nanotubes best fit the pseudo-second-order kinetic model. The Langmuir model was most appropriate to describe the equilibrium data. The monolayer maximum adsorption capacities of both metals were 520.83 and 238.61 mg g−1, respectively. ► The titanate nanotubes that adsorbed Pb(II) and Cd(II) could be readily regenerated using 0.1 M HCl. The desorption percentage could be up to 82.3% and 88.1% respectively for Pb(II) and Cd(II) by acid treatment for 3 h.