Determination of the Reaction Rate Constants and Decomposition Mechanisms of Ozone with Two Model Emerging Contaminants: DEET and Nortriptyline

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• 作者：F. Javier Benitez ; Juan L. Acero ; Juan F. Garcia-Reyes ; Francisco J. Real ; Gloria Roldan ; Elena Rodriguez ; Antonio Molina-D铆az
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：December 4, 2013
• 年：2013
• 卷：52
• 期：48
• 页码：17064-17073
• 全文大小：399K
• 年卷期：v.52,no.48(December 4, 2013)
• ISSN：1520-5045

文摘

Two representative substances of the so-called emerging compounds group (ECs), N,N-diethyl-m-toluamide (DEET) and nortriptyline hydrochloride, were selected to be subjected to ozonation processes, which constitute promising technologies for the removal of hazardous pollutants. The kinetic study provided ozonation rate constants, with an average value of 0.123 卤 0.003 L路mol^鈥?路s^鈥? for DEET, which remained almost unaffected with the pH; while values varying from 2.40 脳 10³ to 472 脳 10³ L路mol^鈥?路s^鈥? for nortriptyline were deduced in the pH range 2鈥?1. Because of the ionic nature of nortriptyline, the specific rate constants of the protonated and neutral species were determined, the values obtained being 2.1 脳 10³ and 4.3 脳 10⁵ L路mol^鈥?路s^鈥?, respectively. By means of liquid chromatography time-of-flight mass spectrometry analysis, the main byproducts formed in the ozonation reactions were identified (14 for DEET and 27 for nortriptyline), and the evolution of their concentrations with reaction time were established. According to these compounds and their concentration profiles, the reaction mechanisms for the ozonation of both emerging contaminants were proposed and discussed. A decrease in the toxicity was also observed during ozonation of nortriptyline.