Investigation of Complexation Mechanisms in Some Cation Solutions

Metal cations represent a considerable part among surface water and land pollutants. Industrial and agronomic effluents, containing in the most cases mercury, cadmium, lead and other cations, until now have been treated by mechanical, physicochemical and biological methods. Biological treatments are the most effective and economically suitable method. Anyway, even biological treatment could not remove all organic and anorganic pollutants. Latest researches deal with removing pollutants from land using bioextraction, based on biosynthetic processes in plants, including toxic metals (phytoremedation). Bioextraction processes where metal cations are transported from land in plant, especially cations of heavy metals, are dependent on balances that are establishing in aqueous solutions, depending on pH and present coexisting components. Present investigations of bioextraction treatment included monitoring of efficiency in removing heavy metals with addition of various organic components. This paper deals with investigation of Cd(II), Pb(II) and Fe(III) interactions in aqueous solutions with addition of crown ethers, cationic and anionic tenzides. Specially there is considered impact of tenzides, as surface active components, present in waste waters. Mechanism of complexation and balance state restoration are investigated depending on solution pH and metal cationic and organic additive concentration.Used methods were extraction, tenziometry, spectrometry and polarography.