Active carbon was prepared from Thevetia neriifolia nutshell by carbonization at 480°C in N2 and activation with CO2 at 840°C for 3 h. The values of 822.2 mg g-1, 0.113 cm3 g-1 and 551 m2 g-1 were obtained for iodine number, micropore volume and BET surface area, respectively. First, second and Pseudo-second orders kinetic models described kinetic data at various temperatures for adsorption of Pb(II) and Cd(II) ions from used oil onto the carbon. Pseudo-second order kinetic model fitted better and was controlled by film diffusion. Enthalpy and entropy were found to be negative for Pb(II) and positive for Cd(II). Adsorption process was non-spontaneous for Pb(II) and spontaneous for Cd(II) metal ions. However, low enthalpy value makes the adsorption process energetically stable. Thus, the active carbon could be adopted as a potential adsorbent for remediation of environment.
Friday O. Nwosu, Bamidele I. Olu-Owolabi and Kayode O. Adebowale, 2012. Kinetics and Thermodynamic Adsorption of Pb(II) and Cd(II) Ions from Used Oil onto Thevetia neriifolia Nutshell Active Carbon. Current Research in Chemistry, 4: 26-40.