@article {LIANG2023120775,
	title = {The synergistic effect of radical and non-radical processes on the dephosphorization of dimethoate by vacuum ultraviolet: The overlooked roles of singlet oxygen atom and high-energy excited state},
	journal = {Water Research},
	volume = {247},
	year = {2023},
	pages = {120775},
	abstract = {Organophosphorus pesticides are extensively utilized worldwide, but their incomplete dephosphorization poses significant environmental risks. This study investigates the dephosphorization of dimethoate (DMT), a representative organophosphorus pesticide, using a vacuum ultraviolet system. Surprisingly, in addition to hydroxyl radicals ({\textbullet}OH), non-radical processes such as photoexcitation and singlet oxygen atoms (O(1D)) exert more significant effects on DMT dephosphorization. The degradation kinetics of DMT demonstrate a perfect linear correlation with the radical yield in both UV-based and VUV-based advanced oxidation processes (AOPs), with greater efficacy of radical attack observed in the VUV system. This heightened efficiency is attributed to the excitation of DMT to a high-energy excited state induced by UV185 radiation. Additionally, {\textbullet}OH alone is inadequate for achieving complete dephosphorization of DMT. The Fukui index and singly occupied orbital (SOMO) analysis reveal that the O(1D) generated by UV185-induced photolysis of O2 exhibits exceptional selectivity towards P=S bonds, thereby playing an indispensable role in the dephosphorization process of DMT. This study highlights the significant contribution of non-radical pathways in DMT dephosphorization by VUV, which holds great implications for the advancement of photochemical-based AOPs.},
	keywords = {Excited state, Non-radical processes, Singlet oxygen atom, Spin density, Transition state},
	issn = {0043-1354},
	doi = {https://doi.org/10.1016/j.watres.2023.120775},
	url = {https://www.sciencedirect.com/science/article/pii/S0043135423012150},
	author = {Jialiang Liang and Jingke Wu and Pengfei Gan and Yudan Liu and Zhen, Peng and Yunyi Li and Zhiwei Zhao and Liu, Wen and Meiping Tong}
}
