Adsorption of zinc onto microwave assisted carbonized Acacia nilotica bark

Microwave assisted carbonized Acacia nilotica bark (MACANB) was investigated as a suitable low cost adsorbent for the removal of zinc (II) ions from aqueous solutions through batch adsorption. The ability of MACANB to remove zinc (II) ions from aqueous solutions by adsorption has been studied under several conditions such as pH, contact time, adsorbent dose, initial concentration of Zinc (II) ion and temperature. The models of Langmuir and Freundlich were applied to describe adsorption equilibrium. Kinetics data were fitted by pseudo-first-order and pseudo-second-order models. The results show that the equilibrium data follow Langmuir isotherm and the kinetic data follow pseudo-second-order model. Thermodynamic parameters (ΔG°, ΔS° and ΔH°) for adsorption system were determined at 30°C.