Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers
Autor(a) principal: | |
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Data de Publicação: | 2007 |
Outros Autores: | , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10316/7779 https://doi.org/10.1007/s10311-006-0072-z |
Resumo: | Abstract The photodegradation of the herbicides atrazine and ametryn with visible light in aerated neutral aqueous solutions and 5, 10, 15, 20-tetrakis (2,6-dichloro-3-sulfophenyl) porphyrin or 5, 10, 15, 20-tetrakis (4-sulfophenyl) porphyrin as sensitizers are reported for the first time. Our findings show that the degradation percentage reached 30% for atrazine and 63% for ametryn. The final photoproducts were characterized as dealkylated s-triazines. Photolysis of the pesticides in the presence of a singlet oxygen quencher showed only a minor contribution of this type of mechanism, while a bimolecular quenching reaction between the triplet state of the sensitizer and the pesticides is excluded by flash photolysis studies. It is proposed that the mechanism may involve the formation of a superoxide radical anion from the triplet state of the sensitizer and molecular oxygen, followed by a radical decomposition pathway. |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizersAbstract The photodegradation of the herbicides atrazine and ametryn with visible light in aerated neutral aqueous solutions and 5, 10, 15, 20-tetrakis (2,6-dichloro-3-sulfophenyl) porphyrin or 5, 10, 15, 20-tetrakis (4-sulfophenyl) porphyrin as sensitizers are reported for the first time. Our findings show that the degradation percentage reached 30% for atrazine and 63% for ametryn. The final photoproducts were characterized as dealkylated s-triazines. Photolysis of the pesticides in the presence of a singlet oxygen quencher showed only a minor contribution of this type of mechanism, while a bimolecular quenching reaction between the triplet state of the sensitizer and the pesticides is excluded by flash photolysis studies. It is proposed that the mechanism may involve the formation of a superoxide radical anion from the triplet state of the sensitizer and molecular oxygen, followed by a radical decomposition pathway.2007info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/7779http://hdl.handle.net/10316/7779https://doi.org/10.1007/s10311-006-0072-zengEnvironmental Chemistry Letters. 5:1 (2007) 29-33Rebelo, SusanaMelo, A.Coimbra, R.Azenha, M.Pereira, MarietteBurrows, HughSarakha, Mohamedinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2020-05-29T10:04:32Zoai:estudogeral.uc.pt:10316/7779Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T21:01:27.604906Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers |
title |
Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers |
spellingShingle |
Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers Rebelo, Susana |
title_short |
Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers |
title_full |
Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers |
title_fullStr |
Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers |
title_full_unstemmed |
Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers |
title_sort |
Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers |
author |
Rebelo, Susana |
author_facet |
Rebelo, Susana Melo, A. Coimbra, R. Azenha, M. Pereira, Mariette Burrows, Hugh Sarakha, Mohamed |
author_role |
author |
author2 |
Melo, A. Coimbra, R. Azenha, M. Pereira, Mariette Burrows, Hugh Sarakha, Mohamed |
author2_role |
author author author author author author |
dc.contributor.author.fl_str_mv |
Rebelo, Susana Melo, A. Coimbra, R. Azenha, M. Pereira, Mariette Burrows, Hugh Sarakha, Mohamed |
description |
Abstract The photodegradation of the herbicides atrazine and ametryn with visible light in aerated neutral aqueous solutions and 5, 10, 15, 20-tetrakis (2,6-dichloro-3-sulfophenyl) porphyrin or 5, 10, 15, 20-tetrakis (4-sulfophenyl) porphyrin as sensitizers are reported for the first time. Our findings show that the degradation percentage reached 30% for atrazine and 63% for ametryn. The final photoproducts were characterized as dealkylated s-triazines. Photolysis of the pesticides in the presence of a singlet oxygen quencher showed only a minor contribution of this type of mechanism, while a bimolecular quenching reaction between the triplet state of the sensitizer and the pesticides is excluded by flash photolysis studies. It is proposed that the mechanism may involve the formation of a superoxide radical anion from the triplet state of the sensitizer and molecular oxygen, followed by a radical decomposition pathway. |
publishDate |
2007 |
dc.date.none.fl_str_mv |
2007 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10316/7779 http://hdl.handle.net/10316/7779 https://doi.org/10.1007/s10311-006-0072-z |
url |
http://hdl.handle.net/10316/7779 https://doi.org/10.1007/s10311-006-0072-z |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Environmental Chemistry Letters. 5:1 (2007) 29-33 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799133905841815552 |