| abstract |
A cyanide-containing aqueous stream is treated to reduce the cyanide concentration by oxidation of cyanide using oxygen as the oxidizing agent under mild reaction conditions in the presence of a metal chelate catalyst. Especially effective chelates are metal phthalocyanines, particularly where the metal is vanadium or a member of the iron group metals. The oxidation can be effected homogeneously using water soluble metal chelates, or can be performed heterogeneously, especially in a continuous fashion using a packed bed reactor, by using suitable water-insoluble metal chelates, especially when supported on appropriate carriers. |