Equilibrium, kinetic and thermodynamic studies on the removal of Aluminum by modified Eucalyptus camaldulensis barks

In this study, a low-cost eco-friendly adsorbent was prepared from Eucalyptus camaldulensis barks through chemical activation. The effect of operating variables namely initial pH, sorbent dose, initial metal concentration, shaking speed and temperature on the aluminum removal percentage and uptake capacity has been studied. The optimal pH was found as 5.0 and the sorbent dosage 5.0 g/L. Temperature effect proved the process to be endothermic. The experimental observations were fitted to Langmuir and Freundlich isotherms where Langmuir proved to be a better fit. Pseudo-second order and intraparticle diffusion kinetic models were employed to the experimental data to verify the mechanism of sorption. The constants of isotherms and kinetic models were evaluated at different operating conditions. From the thermodynamic studies, the activation energy was evaluated as 43.23 kJ mol−1.