Photolysis of Free Chlorine and Production of Reactive Radicals in the UV/Chlorine System Using Polychromatic Spectrum LEDs as UV Sources

See shorturl.at/vxLP9 — Recently, ultraviolet light-emitting diodes (UV-LEDs) and chlorine combined system has been employed as an emerging advanced oxidation process. However, UV-LEDs were commonly considered as monochromatic UV sources. In this study, the obvious quantum yields of chlorine photolysis under 265 nm and 280 nm LEDs irradiations were investigated with treating LEDs as polychromatic UV sources. Particularly, Φobs-poly of HOCl and OCl⁻ for 265 nm LED were found to be 1.50 and 0.70 mol E−1, respectively, whereas Φobs-poly of HOCl and OCl⁻ for 280 nm LED were 1.28 and 0.64 mol E−1, respectively. It was identified that Φobs-poly were 5.66–14.63 % lower than Φobs-mono. This suggests that…