Photo-oxidation of dissolved cyanide using TiO2 catalyst

Catalytic oxidation of free cyanide using TiO2 and UV radiation was investigated. The cyanide photo-oxidation rate was determined for different initial cyanide concentrations, pH, catalyst form, sparged gas, and temperature; and followed pseudo-first-order kinetics with respect to cyanide concentration. The TiO2 catalyzed UV-O-2 reaction resulted in twice the oxidation rate of free cyanide, however, the rate appeared to be independent of oxygen partial pressure (0.2-1.0 atm) at the gas flow rates studied. An increase in temperature from 20 to 35 degreesC did not influence the rate of cyanide oxidation. (C) 2002 Elsevier Science B.V. All rights reserved.