Decontamination of substance contg. cyanide, esp. waste water - by treatment with acid, and stripping and destruction of hydrogen cyanide formed

摘要

In decontamination of substances or solns. contg. cyanide, esp. waste water, the substance or soln. is treated with acid in a desorption container, and the HCN formed is stripped and destroyed. Pref. stripping is with an air stream, which is esp. circulated between absorption and desorption containers. The HCN is passed to an absorption container and absorbed in a soln., esp. an alkaline soln. e.g. NaOH. The soln. in the absorber may be circulated. The soln. contg. cyanide is withdrawn from the absorber and treated batchwise, continuously or in a circulation process. Destruction of the cyanide is by anodic electrolytic oxidn., or treatment with a hypochlorite soln., O3, or a peroxy cpd. (H2O2, Na2S2O8 or caroate). ADVANTAGE - The cyanide is sepd. from other components e.g. organic matter, and the decontamination is then in a soln. freed from interfering material.