Influence of the Ionic Strength of Solution on the Adsorptionof Metal Ions from Aquatic Environment on ActivatedCarbons

摘要

Adsorption of Cr3+, [Cr(C2O4)3]3-, Ni2+ and [Ni(CN)4]2- ions has been carried out on different activated carbons at pH 6 or 7rnand as a function of ionic strength. This has allowed to know the effect of this parameter on the electrostatic interactions,rneither attractive or repulsive, between the carbon surface and the metal ion species. It also enabled us to evaluate the relativernimportance of electrostatic and dispersive interactions. Results indicate that there was a screening effect of the electrolyternwhich brought about a decrease in the importance of electrostatic interactions. This in turn produced an increase or decreasernin the adsorption extent with increasing ionic strength.