Control of reaction conditions:

Cyanide breaking by primary oxidation: pH 10-11; theoretical dosage: simple cyanide CN-: Cl2 = 1:2.73; complex cyanide CN-: Cl2 = 1:3.42. The reaction end point was 300-350 MV and the reaction time was 10-15 minutes.

Secondary oxidation cyanide breaking: pH 7-8 (with H2SO4 callback); theoretical dosage: simple cyanide CN-: Cl2 = 1:4.09, complex cyanide CN-: Cl2 = 1:4.09. The end point of the reaction was 600-700 MV controlled by ORP, and the reaction time was 10-30 minutes. The residual chlorine concentration in the effluent was controlled at 3-5 mg/1.

The treated cyanide-containing wastewater was mixed into electroplating wastewater for treatment.