Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/326184
Type: Artigo
Title: Kinetic Studies Of The Reaction Between Pesticides And Hydroxyl Radical Generated By Laser Flash Photolysis
Author: Gozzi
Fabio; Oliveira
Silvio C.; Dantas
Renato F.; Silva
Volnir O.; Quina
Frank H.; Machulek
Amilcar
Jr.
Abstract: Due to contamination of the environment by pesticides and their mishandling, there is the need for treatment of contaminated sites and correct disposal of materials containing them. Thus, studies with advanced oxidation processes are expanding and can determine the rate constant of the hydroxyl radical with organic compounds of great importance in environmental contamination. In this context, the use of laser flash photolysis has been shown to be viable for the determination of these constants. RESULTS: The reaction rate constants of different pesticides with HO center dot in degassed acetonitrile have been determined. They were 1.6 x 10(9) M-1 s(-1), 0.6 x 10(9) M-1 s(-1), 1.2 x 10(9) M-1 s(-1), 2.4 x 10(9) M-1 s(-1) and 2.2 x 10(9) M-1 s(-1) for the pesticides carbaryl, propoxur, fenoxycarb, ethoxysulfuron and chlorimuron-ethyl, respectively. These values are about an order of magnitude smaller than the diffusion controlled rate and correlate with the relative rates of disappearance of the pesticides in the photo-Fenton reaction in water. CONCLUSION: The correlation of the relative rate constants determined by laser flash photolysis with the relative rates of photo-Fenton degradation of the pesticides is compelling evidence for the participation of the hydroxyl radical in the degradation of these pesticides in the latter system. (C) 2015 Society of Chemical Industry
Subject: Advanced Oxidation Processes
Hydroxyl Radical
Laser Flash Photolysis
Pesticides
Kinetics
Photo-fenton
Editor: Wiley-Blackwell
Hoboken
Rights: fechado
Identifier DOI: 10.1002/jsfa.7258
Address: http://onlinelibrary-wiley-com.ez88.periodicos.capes.gov.br/doi/10.1002/jsfa.7258/full
Date Issue: 2016
Appears in Collections:Unicamp - Artigos e Outros Documentos

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