Photocatalytic Degradation of Ni(II)-Cyano and Co(III)-Cyano Complexes Academic Article uri icon


  • Cyanide and metal-cyanide complexes are common constituents of effluents of mining, petroleum refining, and coal gasification. This paper presents the photocatalytic degradation of free cyanide, Ni(II)-cyanide (Ni(CN)42-), and Co(III)-cyanide (Co(CN)63-) complexes in aqueous TiO2 suspensions. The effect of pH (9.5-12.0), TiO 2 loading (0.1-2.0 g/l), and the airflow rate (0.5-2.0 l/min) in a photoreactor on the degradation of the cyanide complexes was investigated. Free cyanide fully converted to cyanate (NCO-) under alkaline conditions. The maximum removal of the Ni(CN)42- ion in 180 min was found to be 90 %; forming CN- and NCO- ions as the major and minor products, respectively. Comparatively, the Co(CN)63- ion could be degraded only up to 30 % in 180 min. The schemes of the photocatalytic oxidation of cyanides are briefly described. The possible causes for differences in degradation of Ni(CN)42- and Co(CN)63- are also discussed. Optimum conditions for efficient removal of Ni(CN)42- and Co(CN)63- ions separately and in mixtures are given. 2013 Springer Science+Business Media Dordrecht.

published proceedings


author list (cited authors)

  • Osathaphan, K., Ruengruehan, K., Yngard, R. A., & Sharma, V. K.

citation count

  • 13

complete list of authors

  • Osathaphan, Khemarath||Ruengruehan, Kaiwit||Yngard, Ria A||Sharma, Virender K

publication date

  • August 2013