| abstract |
Multivalent heavy metal ions are removed from metal plating waste streams by passing them through an unexpanded vermiculite cation exchange column. The column is effective to remove copper, zinc, and nickel ions and mixtures thereof. Where cyanide and cyanide-metal complexes are also present in the plating waste stream, the stream is pretreated to destroy the cyanide and cyanide complexes prior to passage through the ion exchange column. |