Cost effective process for detoxification of cyanide-containing effluents
AssigneeDegussa AG
InventorsM. Q. Ahsan, Stephen Gos, Helmut Knorre, Roy Norcross, Friedrich W. Merz
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Abstract
This invention pertains to a method of treating cyanide contained in wastewater with particularly high levels of solids in the stream. The process involves either simultaneous or step-wise dosage of hydrogen peroxide in the form of an aqueous solution of a concentration between 35% to 90% by weight, preferably at least 50% by weight, and SO.sub.2 either in the form of gaseous SO.sub.2 or solution of sodium and/or potassium sulfite or metabisulfite resulting in the conversion of cyanide ions to non-toxic cyanate ions.
Claims21
A process for detoxifying cyanide-containing effluents comprising adjusting the the pH of said effluent to a pH of 7.0 to 12.0, reacting said effluent with a sufficient amount of H.sub.2 O.sub.2 and either SO.sub.2 or an alkali/alkaline earth metal sulfite in order to convert said cyanide-containing effluents to effluents containing environmentally less toxic materials, wherein said H.sub.2 O.sub.2 is present in a stoichiometric ratio of 1:1 to 3:1 of H.sub.2 O.sub.2 :
- cyanide, and said SO.sub.2 or sulfite is present in a stoichiometric ratio of 1:1 to 3:1 of SO.sub.2 or sulfite:
- cyanide.
A process for detoxifying cyanide-containing effluents consisting essentially of adjusting the pH of said effluent to a pH of 7.0 to 12.0, reacting said effluent with a sufficient amount of H.sub.2 O.sub.2 and either SO.sub.2 or an alkali/alkaline earth metal sulfite in order to convert said cyanide-containing effluents to effluents containing environmentally less toxic materials, wherein said H.sub.2 O.sub.2 is present in a stoichiometric ratio of 1:1 to 3:1 of H.sub.2 O.sub.2 :
- cyanide, and said SO.sub.2 or sulfite is present in a stoichiometric ratio of 1:1 to 3:1 of SO.sub.2 or sulfite:
- cyanide.
Dependencies are inferred from the claim text.