[Photochemical reaction types of the azole fungicide fluconazole under UV-vis irradiation].

This study selected the azole fungicide fluconazole as a model compound, and investigated its photodegradation kinetics and photoreaction types in pure water. It was found that under UV-vis irradiation (lambda > 200 nm), the fluconazole photodegraded fast and followed the pseudo-first-order kinetics, whereas under simulated sunlight (lambda > 290 nm), photodegradation did not occur. The ROS scavenging experiments and competition kinetic examination indicated that the compound underwent both direct photolysis and self-sensitized photooxidation via *OH other than 1O2. The bimolecular rate constant for the reaction between fluconazole and *OH was (5.95 +/- 0.58) x 10(9) L x (mol x s)(-1), and the corresponding environmental half-life was calculated to be (32.41 +/- 3.16) h in surface waters. Furthermore, it was deduced from the photodegradation product identification that the UV-vis degradation pathways involved photoinduced defluorination, hydrolysis and photooxidation.