1. Generation mechanism of singlet oxygen from the interaction of peroxymonosulfate and chloride in aqueous systems.
- Author
-
Wang A, Zhu BZ, Huang CH, Zhang WX, Wang M, Li X, Ling L, Ma J, and Fang J
- Subjects
- Humans, Singlet Oxygen, Chlorides chemistry, Chlorine, Peroxides chemistry, Oxidation-Reduction, Water, Hydrogen Peroxide, Water Pollutants, Chemical chemistry
- Abstract
Peroxymonosulfate (PMS, HSO
5 - ) is a widely-used disinfectant and oxidant in environmental remediation. It was deemed that PMS reacted with chloride (Cl- ) to form free chlorine during water purification. Here, we demonstrated that singlet oxygen (1 O2 ) was efficiently generated from PMS and Cl- interaction. Mechanism of1 O2 formation was uniquely verified by the reaction of HSO5 - and chlorine molecule (Cl2 ) and the oxygen atoms in1 O2 deriving from the peroxide group of HSO5 - were revealed. Density functional theory calculations determined that the reaction of HSO5 - and Cl2 was thermodynamically favorable and exergonic at 37.8 kcal/mol. Quite intriguingly,1 O2 was generated at a higher yield (1.5 × 105 M- 1 s- 1 ) than in the well-known reaction of H2 O2 with Cl2 (35 M- 1 s- 1 ). Besides chlorine,1 O2 formed in PMS-Cl- interaction dominated the degradation of micropollutants, also it substantially enhanced the damage of deoxynucleoside in DNA, which were beneficial to micropollutant oxidation and pathogen disinfection. The contribution of1 O2 for carbamazepine degradation was enhanced at higher Cl- level and lower pH, and reached 96.3% at pH 4.1 and 5 min. Natural organic matter (NOM) was a sink for chlorine, thereby impeding1 O2 formation to retard carbamazepine degradation.1 O2 also played important roles (48.3 - 63.5%) on the abatement of deoxyguanosine and deoxythymidine at pH 4.1 and 10 min in PMS/Cl- . On the other hand, this discovery also alerted the harm of1 O2 for human health as it can be formed during the interaction of residual PMS in drinking water/swimming pools and the high-level Cl- in human bodies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)- Published
- 2023
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