Efficiency and degradation products elucidation of the photodegradation of mefenpyrdiethyl in water interface using TiO_2 P-25 and Hombikat UV100

作     者：Amina Chnirheb Mourad Harir Basem Kanawati Mohammed El Azzouzi Istvan Gebefgi Philippe Schmitt-Kopplin 

作者机构：Department of BioGeoChemistry and AnalytikGerman Research Center for Environmental HealthHelmholtz Center MunichIngoldstdter Landstraβe 1D-85764 NeuherbergGermany University Mohammed V-AgdalFaculty of SciencesAvenue Ibn BatoutaBP 1014 RabatMorocco. Lehrstuhl fr Chemische-Technische Analyse und Chemische LebensmitteltechnologieTechnische Universitt MuenchenWeihenstephaner Steig 2385354 Freising-WeihenstephanGermany 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2012年第24卷第9期

页      面：1686-1693页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 

基　　金：supported by the German Academic Exchange Service (DAAD) within the Morrocan/German exchange program 

主　　题：photodegradation mefenpyrdiethyl P-25/Hombikat UV100 kinetic degradation products 

摘      要：The photodegradation of mefenpyrdiethyl （MFD）, an herbicide safener, was investigated in aqueous suspensions by using Degussa P-25 and Hombikat UV100 titanium oxide under simulated sunlight irradiation. The effects of initial concentration of the herbicide, pH, catalysts and hydrogen peroxide doses as well as their combinations were studied and optimized. Accordingly, the kinetic parameters were determined and the effectiveness of the processes was assessed by calculating the rate constants. A pseudo first-order kinetics was observed. Under experimental conditions, the degradation rate constants were strongly influenced using P-25 and no noticeable effect was observed for Hombikat UV100. DFT calculations with B3LYP/6-311＋G（2d,p）//B3LYP/6-31＋G（d,p） level of theory were performed to check whether significant conformational changes occur when the charge state of the MFD substrate changes and whether these changes could play a role in the dependency of photodegradation rate constant on the studied pH. High resolution mass spectrometry （FT-ICR/MS） was implemented to identify the main degradation products.