Mechanistic Investigation of Enhanced Photoreactivity of Dissolved Organic Matter after Chlorination

• DOI: 10.1021/acs.est.1c02704
• Publication Date: 2021-06-24T13:32:48Z
• Authors: Dong Wan; Haiyue Wang; Virender K. Sharma; Steplinpaulselvin...; Hongliang Dai; Fan Luo; Chengjun Wang; Yong Chen
• Keywords: Hydroxyl radical

Chlorine is commonly used in disinfection processes wastewater treatment plants prior to discharge of the effluents into receiving waters. Effluent organic matter and humic substances constitute up 90% dissolved (DOM) water, which induces photogeneration reactive species (RS) such as excited triplet state DOM (3DOM*), singlet oxygen (1O2), hydroxyl radical (•OH). The RS plays an important role attenuation trace pollutants. However, effect chlorine on photoreactivity has remained unclear. Here, we investigated physicochemical properties subsequent variation after chlorination DOM. Solid-state 13C cross-polarization/magic angle-spinning NMR Fourier transform ion cyclotron resonance mass spectrometry verified that aromaticity, electron-donating capacity (EDC), average molecular weight decreased markedly chlorination. It was found for first time photoproduction 3DOM*, 1O2, •OH increased upon irradiation simulated sunlight. quantum yields were positively correlated with E2/E3 (ratio absorbance at 254 365 nm) while negatively EDC before These findings highlight synergetic photosensitization under sunlight, will promote removal pollutants surface