Adsorption of Copper(II) Ions by Soil as Influenced by Organic Components of Soil Solutions

Copper(II) is adsorbed by soils according to the ion-exchange mechanism, with both Ca2+ and H+ replaced in the solution. This process is proved to be reversible and can be described quantitatively by the equa-tions of Freundlich and Vanslow–Nikol’skii. Tartaric and fulvic acids reduce the copper adsorption at a concen-tration of Cu2+ lower than 0.5 mM, while they facilitate adsorption at higher concentrations, because of the precipitation of weakly soluble copper tartrate and fulvate.