Photocatalytic oxidation of monuron in the suspension of WO3 under the irradiation of UV-visible light

► We investigated the photodegradation of monuron in UV-Vis/WO3 system. ► Hydroxyl radicals are believed to play a major role in this system. ► The generation of hydroxyl radicals mainly proceeds through the oxidation path. ► The influence of inorganic oxidants on the performance of this system was studied. ► Comparison between monuron decay pathways by UV-Vis/WO3 and UV/TiO2 was also conducted.