Effect of UV-LED Wavelength on Reactive Species Photogeneration from Dissolved Organic Matter
The photogeneration of reactive species from dissolved organic matter (DOM) plays a crucial role in the photochemical and photobiochemical processes in natural aquatic systems. However, the impact of the ultraviolet (UV) wavelength on the photogeneration of reactive species by different sources of D...
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MDPI AG
2024-02-01
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| Online Access: | https://www.mdpi.com/2073-4441/16/5/635 |
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| author | Ze-Chong Guo Lu Zhang Yong Chen Cheng Huang Zhi-Min Liao |
| author_facet | Ze-Chong Guo Lu Zhang Yong Chen Cheng Huang Zhi-Min Liao |
| author_sort | Ze-Chong Guo |
| collection | DOAJ |
| description | The photogeneration of reactive species from dissolved organic matter (DOM) plays a crucial role in the photochemical and photobiochemical processes in natural aquatic systems. However, the impact of the ultraviolet (UV) wavelength on the photogeneration of reactive species by different sources of DOM remains unclear. In this study, UV light at four wavelengths (365 nm, 310 nm, 280 nm, and 260 nm) provided by UV-LEDs were irradiated onto three types of DOM: humic acid (HA), fulvic acid (FA), and effluent organic matter (EfOM). Three reactive species produced by DOM, including excited triplet-state DOM (<sup>3</sup>DOM*), singlet oxygen (<sup>1</sup>O<sub>2</sub>), and hydroxyl radicals (•OH), were determined. UV<sub>365</sub> proved to be the most efficient wavelength for generating <sup>1</sup>O<sub>2</sub> and •OH, with formation rates of 3.47 × 10<sup>−6</sup> M s<sup>−1</sup> and 1.67 × 10<sup>−8</sup> M s<sup>−1</sup>, respectively, with the addition of FA and EfOM. The highest steady-state concentrations of all three reactive species were also generated under UV<sub>365</sub>, reaching 3.00 × 10<sup>−13</sup> M (<sup>3</sup>DOM*) and 1.64 × 10<sup>−11</sup> M (<sup>1</sup>O<sub>2</sub>) with the FA addition, and 1.44 × 10<sup>−10</sup> M (•OH) with the EfOM. Across the different DOM sources, UV<sub>365</sub> obtained the maximum quantum yields of reactive species, indicating the stronger effect of UV<sub>365</sub> on inducing the photosensitization of DOM compared to the other shorter wavelengths. This study expands our understanding of the photochemistry of DOM in aquatic environments. |
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| spelling | doaj.art-9ac0fcaf0caf44e8a7c3fbf8fc7272da2024-03-12T16:57:31ZengMDPI AGWater2073-44412024-02-0116563510.3390/w16050635Effect of UV-LED Wavelength on Reactive Species Photogeneration from Dissolved Organic MatterZe-Chong Guo0Lu Zhang1Yong Chen2Cheng Huang3Zhi-Min Liao4School of Environmental and Engineering, Huazhong University of Science and Technology, Wuhan 430074, ChinaSchool of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, ChinaSchool of Environmental and Engineering, Huazhong University of Science and Technology, Wuhan 430074, ChinaSchool of Environmental and Engineering, Huazhong University of Science and Technology, Wuhan 430074, ChinaJiangxi Jindalai Environmental Protection Co., Ltd., Nanchang 330100, ChinaThe photogeneration of reactive species from dissolved organic matter (DOM) plays a crucial role in the photochemical and photobiochemical processes in natural aquatic systems. However, the impact of the ultraviolet (UV) wavelength on the photogeneration of reactive species by different sources of DOM remains unclear. In this study, UV light at four wavelengths (365 nm, 310 nm, 280 nm, and 260 nm) provided by UV-LEDs were irradiated onto three types of DOM: humic acid (HA), fulvic acid (FA), and effluent organic matter (EfOM). Three reactive species produced by DOM, including excited triplet-state DOM (<sup>3</sup>DOM*), singlet oxygen (<sup>1</sup>O<sub>2</sub>), and hydroxyl radicals (•OH), were determined. UV<sub>365</sub> proved to be the most efficient wavelength for generating <sup>1</sup>O<sub>2</sub> and •OH, with formation rates of 3.47 × 10<sup>−6</sup> M s<sup>−1</sup> and 1.67 × 10<sup>−8</sup> M s<sup>−1</sup>, respectively, with the addition of FA and EfOM. The highest steady-state concentrations of all three reactive species were also generated under UV<sub>365</sub>, reaching 3.00 × 10<sup>−13</sup> M (<sup>3</sup>DOM*) and 1.64 × 10<sup>−11</sup> M (<sup>1</sup>O<sub>2</sub>) with the FA addition, and 1.44 × 10<sup>−10</sup> M (•OH) with the EfOM. Across the different DOM sources, UV<sub>365</sub> obtained the maximum quantum yields of reactive species, indicating the stronger effect of UV<sub>365</sub> on inducing the photosensitization of DOM compared to the other shorter wavelengths. This study expands our understanding of the photochemistry of DOM in aquatic environments.https://www.mdpi.com/2073-4441/16/5/635dissolved organic matterquantum yieldreactive speciessteady-state concentrationUV-LED irradiation |
| spellingShingle | Ze-Chong Guo Lu Zhang Yong Chen Cheng Huang Zhi-Min Liao Effect of UV-LED Wavelength on Reactive Species Photogeneration from Dissolved Organic Matter Water dissolved organic matter quantum yield reactive species steady-state concentration UV-LED irradiation |
| title | Effect of UV-LED Wavelength on Reactive Species Photogeneration from Dissolved Organic Matter |
| title_full | Effect of UV-LED Wavelength on Reactive Species Photogeneration from Dissolved Organic Matter |
| title_fullStr | Effect of UV-LED Wavelength on Reactive Species Photogeneration from Dissolved Organic Matter |
| title_full_unstemmed | Effect of UV-LED Wavelength on Reactive Species Photogeneration from Dissolved Organic Matter |
| title_short | Effect of UV-LED Wavelength on Reactive Species Photogeneration from Dissolved Organic Matter |
| title_sort | effect of uv led wavelength on reactive species photogeneration from dissolved organic matter |
| topic | dissolved organic matter quantum yield reactive species steady-state concentration UV-LED irradiation |
| url | https://www.mdpi.com/2073-4441/16/5/635 |
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