Photocatalytic Degradation of Dicholoroacetic Acid. A Kinetic Study

C. ZALAZAR, C. A. MARTÍN Y A. E. CASSANO

Buenos Aires

Congreso; Monitoring Systems and Novel Technologies for Detection / Removal of Pollutants in / from Ecosystems; 2004

The photocatalytic oxidation of low concentration, aqueous solutions of dichloroacetic acid (DCA) - a typical by product of chlorine disinfection - was studied employing titanium dioxide and UV radiation. The study aims at the development of an intrinsic reaction kinetics to be apt for scaling-up purposes. Using the mass action law and the micro steady state approximation, a kinetic model was developed starting from a complete reaction sequence based on the direct hole attack of DCA. The obtained representation gives reaction rates for the DCA disappearance and the chloride ion formation that include the local rate of photon absorption and require only two kinetic parameters: