ЭЛЕКТРОХИМИЧЕСКОЕ ПОВЕДЕНИЕ СОЕДИНЕНИЙ ХРОМА (VI) В НИЗКОКОНЦЕНТРИРОВАННЫХ РАСТВОРАХ

Ольга КОВАЛЕВА Научно-исследовательский центр прикладной и экологической химии

Abstract

The peculiarities of chrome complexes in acid solutions are described. It is shown that due to these peculiarities, it would be possible to apply the electrochemical oxidation-reduction processes for the treatment of such solutions. These processes are influenced by the passivity of electrode surface, which can be removed either by the abrasive-mechanical cleaning, or application of pulse electrolysis with the periodic short-term alteration of current polarity. In the process of electrochemical treatment of zinc (II) and chromium(VI)-containing waters with the contents of ammonium ions, chromium (VI) ions will be reduced to chromium (III). It is shown that this reaction occurs not only and not mainly on cathode, but rather due to the interaction of chromate-ions with iron (II) ions or hydroxides, which are formed during the anodic dissolving of iron electrode. Therefore, using of electrochemical treatment with the dissolving iron electrodes, must significantly enhance the treatment degree of zinc-chromium-containing galvanic waste waters.