| abstract |
Contaminating ions are removed from an aqueous medium, e.g., hexavalent chromium ions from cooling tower waters, by an electrochemical method which includes formation of an insoluble iron compound or complex of the contaminant ion, utilizing an anode of iron, iron alloy or insoluble iron compound. The hexavalent chromium contaminant, as chromate or dichromate, is changed to trivalent chromium, a less toxic form. The method is applicable to the removal of other contaminant ions, e.g., cyanide, which also converts to less toxic form. Also described are electrolytic cells and apparatuses useful in effecting the method. |