Adsorption of Copper, Silver, and Zinc Cations on Polarized Activated Carbons

Abstract

The adsorption of silver, copper, and zinc cations from aqueous solutions on polarized activated carbons was studied along with the effect of the polarization methods. A significant difference between the adsorption activities of preliminary polarized activated carbon and activated carbon directly polarized by a potentiostat was not found. However, the adsorption of cations caused shifts in the potential of the preliminary polarized activated carbon to more positive values. The investigation of the adsorption kinetics and the isotherms of silver, copper, and zinc cations shows the dependence of the adsorption activity on the potential of carbon sorbents. The polarization of the activated carbon electrode leads to a change of the isotherm’s type from Langmuir to Henry through a row of transient and S-shaped isotherms. This observation can be explained by electroreduction or electro-oxidation of surface compounds of activated carbon. Adsorption rate constants for and ions at activated carbon were obtained.