Photo induced dissociation of ferri and ferro cyanide in hydroponic solutions|
Yu, X.Z.; Peng, X.Y. & Wang, G.L.
The potential for photo-induced dissociation of ferri- and ferro-cyanide was investigated. The overall
reactions followed first order kinetics, judged by the free cyanide analyzed in aqueous solution. The dissociation rates
for ferri- and ferro-cyanide were mathematically described by the equations: C(CN,t)= C(CN,0)e1.3t and C(CN,t)= C(CN,0)e0.39t, respectively. In addition, photo-induced dissociation of both iron cyanides was enhanced under an alkaline environment
than a neutral condition. Results from the temperature-dependent tests indicated that the dissociation rate of ferricyanide
was significantly higher than that of ferro-cyanide at all treatment temperatures. The kinetic parameter,
activation energy (Ea) was also experimentally determined to be 12.02 and 12.32 kJ/mol for ferri- and ferro-cyanide,
respectively. The results obtained suggest that both iron cyanides are susceptible to photo-dissociation and the rates are
positively correlated to the change of temperatures. The information collectively also has important implications for
waste management of iron cyanides as well as for risk assessment in a field trial.
Cyanide; Dissociation; Ferri-cyanide; Ferro-cyanide; Temperature