Removal of Cyanide in Ni(II)-Cyanide, Ni(II)-Cyanide-EDTA, and Electroplating Rinse Wastewater by Ferrate(VI) Academic Article uri icon


  • Cyanide is found as free cyanide and metal-cyanide complexes in metal finishing rinse wastewaters. Experiments were performed to seek removal of cyanide in Ni(II)-cyanide and Ni(II)-cyanide-ethylenediaminetetraacetate (EDTA) solutions by the environmentally friendly oxidant, ferrate(VI) (FeO 42-, Fe(VI)) as a function of pH (8.0-11.0). Incomplete removal of cyanide in Ni(II)-cyanide solutions (=60%) was observed at the studied pH range. However, cyanide removal efficiency approached to 100% in Ni(II)-cyanide-EDTA solutions. Formation of Ni(II)-cyanide and Ni(II)-EDTA complexes and relative rates of the reactions of Fe(VI) with various species (water, cyanide, Ni(II)-cyanide, and EDTA) present in solutions were responsible for the variation in removal efficiencies in mixtures at various pH. The oxidation of cyanide by Fe(VI) produced cyanate. Tests using electroplating rinse wastewaters demonstrated that Fe(VI) was highly effective in removing cyanide. 2010 Springer Science+Business Media B.V.

published proceedings


author list (cited authors)

  • Osathaphan, K., Tiyanont, P., Yngard, R. A., & Sharma, V. K.

citation count

  • 11

complete list of authors

  • Osathaphan, Khemarath||Tiyanont, Patarawan||Yngard, Ria A||Sharma, Virender K

publication date

  • July 2011