Practical Application of Peroxygen Compounds for the Treatment of Cyanide Laden Wastewater in the Presence of Sulfur Containing Species

Wastewater containing cyanide in both simple and complexed forms is generated by a variety of industries including, for example, petrochemical refining and goldmining. These wastewaters often contain additional contaminating species such as sulfide or thiocyanate ions which render the effluents rather more complex. The potential application of chemical oxidation technology via treatment with peroxygen reagents such as hydrogen peroxide or Caro’s acid (H 2 SO 5 ) can be markedly affected by these additional contaminants. This paper describes the real effects observed and the resultant practical implications for treatment of two different types of cyanide laden industrial wastewater with peroxygen based systems when either sulfide or thiocyanate ions were additionally present.