Removal of Cd(II) ion from wastewater by adsorption onto treated old newspaper: kinetic modeling and isotherm studies

Background: This paper studied the ability of using treated old newspaper (TNP) as synthetic adsorbent for the removal of Cd(II) from aqueous solutions by batch operation. Various operating parameters such as pH, initial metal ion concentration, adsorbent dosage, and equilibrium contact time have been studied. Results: The results indicated that the adsorption of Cd(II) increased with the increasing pH, and the optimum solution pH for the adsorption of Cd(II) was found to be 6.4. Adsorption was rapid and occurred within 15 min for Cd(II) concentration range from 5 to 30 mg/L. Conclusions: The kinetic process of Cd(II) adsorption onto TNP was found to fit the pseudo-second-order model. The equilibrium adsorption data for Cd(II) were better fitted to the Langmuir adsorption isotherm model.