Adsorption of Ni(II), Cu(II) and Fe(III) from Aqueous Solutions Using Activated Carbon

An activated carbon was tested for its ability to remove transition metal ions from aqueous solutions. Physical, chemical and liquid-phase adsorption characterizations of the carbon were done following standard procedures. Studies on the removal of Ni(II), Cu(II) and Fe(III) ions were attempted by varying adsorbate dose, pH of the metal ion solution and time in batch mode. The equilibrium adsorption data were fitted with Freundlich, Langmuir and Redlich-Peterson isotherms and the isotherm constants were evaluated. Time variation studies indicate that adsorptions follow pseudo-second order kinetics. pH was found to have a significant role to play in the adsorption. The processes were endothermic and the thermodynamic parameters were evaluated. Desorption studies indicate that ion-exchange mechanism is operating.