STUDY OF THE COPPER-ION SPECIATION IN AQUATIC SYSTEMS - APPLICATION OF FOAM FRACTIONATION TO CU(II)-FULVIC ACIDS EQUILIBRIUM

By means of foam fractionation, the species formed by the association of Cu(II) and fulvic acids (AF) are selectively separated in neutral m edium with an ionic strength of 7 mM (NaCl), for different relationshi ps AF/Cu (0.50; 1.00 and 2.00). The surfactants CTABr (cationic), NaDB S (anionic) and Tergitol NPX (non ionic) were used for that purpose. I t was obtained a linear correlation between the higher proportion AF:C u and the increase of formed anionic species. These results show the s tability of the complexes formed by AF and Cu(II), therefore it is pos sible their extrapolation in the local nature aquatic system.