CHARACTERIZATION OF THE INFLUENCE OF SURFACTANT ADSORPTION LAYERS ON THE EXTRACTION BEHAVIOR OF HEAVY-METALS

The surfactants sodium dodecyl sulphonate, cetylpyridinium chloride an d i-octylphenylethoxylate have great influence on the H2O/toluene inte rface state. They change the zetapotential, the structure and the surf ace tension depending on the type of their head group, the concentrati on and the kind of the counter-ions. A comparison of the extraction gr ade and the results of the interface measurements show that the follow ing parameters improve the mass transfer to metal ions: a) the interfa ce activity of the complex-forming agent or ion exchanger, b) a negati ve zetapotential, c) a monomolecular adsorption layer of the anionic s urfactant.