TREATMENT OF FERRICYANIDE WASTEWATER WITH CHLORINE DIOXIDE AND SODIUM TRIPOLYPHOSPHATE

Chlorine dioxide was used to treat water treated with potassium ferricyanide to simulate ferricyanide wastewater. The ferricyanide was strongly oxidized by chlorine dioxide in the presence of sodium tripolyphosphate, with a final total cyanogen content of less than 0.011 mmol/L after the treatment. The treatment could be carried out successfully at ambient temperatures, and we established the following optimum conditions: a molar ratio of sodium tripolyphosphate to ferricyanide of 1.17, a treatment time of 60 min, and a molar ratio of chlorine dioxide to ferricyanide of 7.