FIELD: environmental protection.
SUBSTANCE: invention relates to waste and recycled water containing thiocyanates (SCN-), and can be used at non-ferrous metallurgy, chemical and mining enterprises. Thiocyanate-containing waste water is treated with persulphate in presence of iron(III) ions in molar ratio [S2O8 2-]:[Fe+3], equal to 1:0.2. During oxidative decomposition of thiocyanates, hydrocyanic acid is formed, which is subjected to stripping with subsequent absorption in an alkaline solution.
EFFECT: invention provides high degree of purification of waste water in a wide range of concentrations thiocyanates without any supply of medium pH regulators into reaction zone, improves sanitary conditions due to low-toxic, easy-to-use and transportation of reagent; also, disclosed method reduces operating costs and reduces cost of cleaning due to recovery of expensive cyanide for reuse in technological process.
1 cl, 3 ex
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