TREATMENT OF WASTE WATER CONTAINING HEXAVALENT CHROMIUM AND COMPLEX IRON CYANIDES

摘要

1389378 Purification of waste water AMCHEM PRODUCTS Inc 30 April 1973 [31 Aug 1972] 20353/73 Heading C1C Waste water, from the surface treatment of aluminium, containing hexavalent Cr and complex iron cyanides is purified by removing these materials by a process which comprises adding to the water an ionic compound AX the anion X of which is capable of reducing the hexavalent Cr to trivalent Cr and the cation A forms a water-insoluble precipitate with the complex iron cyanide. The trivalent Cr is removed by treating the water with alkali to precipitate (Cr(OH) 3 . The preferred salt AX is zinc dithionite.