Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products

Nowadays photoactivation mechanism of titanium dioxide nanoparticles (TiO2 NPs) and reactive species involved in saline waters is not sufficiently established. In this study, TiO2 photocatalytic process under simulated solar irradiation was evaluated in synthetic seawater and compared with deionized...

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Autores: Porcar Santos, Oriol, Cruz Alcalde, Alberto, López Vinent, Núria, Zanganas, Dimitrios, Sans Mazón, Carme
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2020
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/164858
Acceso en línea:https://hdl.handle.net/2445/164858
Access Level:acceso abierto
Palabra clave:Fotocatàlisi
Aigua salada
Diòxid de titani
Nanopartícules
Photocatalysis
Saline waters
Titanium dioxide
Nanoparticles
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spelling Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-productsPorcar Santos, OriolCruz Alcalde, AlbertoLópez Vinent, NúriaZanganas, DimitriosSans Mazón, CarmeFotocatàlisiAigua saladaDiòxid de titaniNanopartículesPhotocatalysisSaline watersTitanium dioxideNanoparticlesNowadays photoactivation mechanism of titanium dioxide nanoparticles (TiO2 NPs) and reactive species involved in saline waters is not sufficiently established. In this study, TiO2 photocatalytic process under simulated solar irradiation was evaluated in synthetic seawater and compared with deionized water, using sulfamethoxazole (SMX) as model organic compound. For a TiO2 concentration of 100 mg L−1, SMX degradation resulted two times slower in seawater than in deionizedwater by the determination of their pseudo-first order rate constants of 0.020 min−1 and 0.041 min−1, respectively. Selected scavenging experiments revealed no significant contribution of hydroxyl radicals (¿OH) on the degradation process in seawater, while these radicals contributed to circa 60% on theSMX depletion in deionizedwater. Instead, the involvement of reactive halogen species (RHS) asmain contributors for the SMX degradation in seawater could be established. A mechanism for the RHS generationwas proposed, whose initiation reactions involve halides with the TiO2 photogenerated holes, yielding chlorine and bromine radicals (Cl¿ and Br¿) that may later generate other RHS. Production of RHS was further confirmed by the identification of SMX transformation products (TPs) and their evolution over time, carried out by liquid chromatography-mass spectrometry (LC-MS). SMX transformationwas conducted through halogenation, dimerization and oxidation pathways, involving mainly RHS. Most of the detected transformation products accumulated over time (up to 360 min of irradiation). These findings bring concerns about the viability of photocatalytic water treatments using TiO2 NPs in saline waters, as RHS could be yielded resulting in the generation and accumulation of halogenated organic byproducts.Elsevier B.V.2020info:eu-repo/semantics/articleinfo:eu-repo/semantics/acceptedVersionapplication/pdfhttps://hdl.handle.net/2445/164858Articles publicats en revistes (Enginyeria Química i Química Analítica)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésVersió postprint del document publicat a: https://doi.org/10.1016/j.scitotenv.2020.139605Science of the Total Environment, 2020, vol. 736, num. 139605https://doi.org/10.1016/j.scitotenv.2020.139605cc-by-nc-nd (c) Elsevier B.V., 2020http://creativecommons.org/licenses/by-nc-nd/3.0/esinfo:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/1648582026-05-27T06:46:51Z
dc.title.none.fl_str_mv Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
title Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
spellingShingle Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
Porcar Santos, Oriol
Fotocatàlisi
Aigua salada
Diòxid de titani
Nanopartícules
Photocatalysis
Saline waters
Titanium dioxide
Nanoparticles
title_short Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
title_full Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
title_fullStr Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
title_full_unstemmed Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
title_sort Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
dc.creator.none.fl_str_mv Porcar Santos, Oriol
Cruz Alcalde, Alberto
López Vinent, Núria
Zanganas, Dimitrios
Sans Mazón, Carme
author Porcar Santos, Oriol
author_facet Porcar Santos, Oriol
Cruz Alcalde, Alberto
López Vinent, Núria
Zanganas, Dimitrios
Sans Mazón, Carme
author_role author
author2 Cruz Alcalde, Alberto
López Vinent, Núria
Zanganas, Dimitrios
Sans Mazón, Carme
author2_role author
author
author
author
dc.subject.none.fl_str_mv Fotocatàlisi
Aigua salada
Diòxid de titani
Nanopartícules
Photocatalysis
Saline waters
Titanium dioxide
Nanoparticles
topic Fotocatàlisi
Aigua salada
Diòxid de titani
Nanopartícules
Photocatalysis
Saline waters
Titanium dioxide
Nanoparticles
description Nowadays photoactivation mechanism of titanium dioxide nanoparticles (TiO2 NPs) and reactive species involved in saline waters is not sufficiently established. In this study, TiO2 photocatalytic process under simulated solar irradiation was evaluated in synthetic seawater and compared with deionized water, using sulfamethoxazole (SMX) as model organic compound. For a TiO2 concentration of 100 mg L−1, SMX degradation resulted two times slower in seawater than in deionizedwater by the determination of their pseudo-first order rate constants of 0.020 min−1 and 0.041 min−1, respectively. Selected scavenging experiments revealed no significant contribution of hydroxyl radicals (¿OH) on the degradation process in seawater, while these radicals contributed to circa 60% on theSMX depletion in deionizedwater. Instead, the involvement of reactive halogen species (RHS) asmain contributors for the SMX degradation in seawater could be established. A mechanism for the RHS generationwas proposed, whose initiation reactions involve halides with the TiO2 photogenerated holes, yielding chlorine and bromine radicals (Cl¿ and Br¿) that may later generate other RHS. Production of RHS was further confirmed by the identification of SMX transformation products (TPs) and their evolution over time, carried out by liquid chromatography-mass spectrometry (LC-MS). SMX transformationwas conducted through halogenation, dimerization and oxidation pathways, involving mainly RHS. Most of the detected transformation products accumulated over time (up to 360 min of irradiation). These findings bring concerns about the viability of photocatalytic water treatments using TiO2 NPs in saline waters, as RHS could be yielded resulting in the generation and accumulation of halogenated organic byproducts.
publishDate 2020
dc.date.none.fl_str_mv 2020
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
format article
status_str acceptedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/164858
url https://hdl.handle.net/2445/164858
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Versió postprint del document publicat a: https://doi.org/10.1016/j.scitotenv.2020.139605
Science of the Total Environment, 2020, vol. 736, num. 139605
https://doi.org/10.1016/j.scitotenv.2020.139605
dc.rights.none.fl_str_mv cc-by-nc-nd (c) Elsevier B.V., 2020
http://creativecommons.org/licenses/by-nc-nd/3.0/es
info:eu-repo/semantics/openAccess
rights_invalid_str_mv cc-by-nc-nd (c) Elsevier B.V., 2020
http://creativecommons.org/licenses/by-nc-nd/3.0/es
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Elsevier B.V.
publisher.none.fl_str_mv Elsevier B.V.
dc.source.none.fl_str_mv Articles publicats en revistes (Enginyeria Química i Química Analítica)
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,300719

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