Oxidation of isoprothiolane by ozone and chlorine: Reaction kinetics and mechanism
Autor: | Xiaofeng Wang, Yuefeng F. Xie, Yin Li, Xiaomao Wang, Hongwei Yang |
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Rok vydání: | 2019 |
Předmět: |
Tartronic acid
Environmental Engineering Ozone Order of reaction Health Toxicology and Mutagenesis 0208 environmental biotechnology chemistry.chemical_element Hypochlorite Thiophenes 02 engineering and technology 010501 environmental sciences 01 natural sciences Medicinal chemistry Water Purification Reaction rate Chemical kinetics chemistry.chemical_compound Reaction rate constant Tandem Mass Spectrometry polycyclic compounds Chlorine Environmental Chemistry 0105 earth and related environmental sciences Public Health Environmental and Occupational Health General Medicine General Chemistry Pollution 020801 environmental engineering Kinetics chemistry Oxidation-Reduction Water Pollutants Chemical Chromatography Liquid |
Zdroj: | Chemosphere. 232:516-525 |
ISSN: | 0045-6535 |
Popis: | Isoprothiolane (IPT) was one of the most commonly used pesticides around the world. It was reported to be the highest concentration and frequency of detection of 13 most commonly used pesticides in Mekong Delta recently. The oxidation degradation kinetic of ozone and chlorine with IPT and the identification of the degradation products was investigated in this research. The results showed that both ozone and chlorine oxidized IPT rapidly under typical water treatment condition, and that both reactions followed second order reaction kinetics. The ozone reaction rates exhibited no pH dependence with the rate constant of 247.1 (±11.0) M−1s−1 at 25 °C, whereas chlorine reaction rates increased dramatically with decreasing pH. The rate constant for hypochloric acid was 73.3 (±3.1) M−1s−1 at 25 °C, while the reaction of hypochlorite was negligible. The degradation products by chlorine and ozone were identified by LC-MS/MS and the reaction pathways were proposed. The thioether and the carbon-carbon double bond in IPT were the reactive sites during chlorine and ozone oxidation. The thioether group was oxidized into sulfoxide and further sulfone group, and the carbon-carbon double bone were cleaved to form diisopropyl ester of malonic acid, diisopropyl ester of tartronic acid and diisopropyl ester of ketomalonic acid monohydrate. Compared to ozone reaction, it was more complicated for chlorine reaction, which yielded chlorine substituted, hydroxylated and dithiolane ring-opening products. |
Databáze: | OpenAIRE |
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