Photobleaching-induced changes in photosensitizing properties of dissolved organic matter

Handle URI:
http://hdl.handle.net/10754/563885
Title:
Photobleaching-induced changes in photosensitizing properties of dissolved organic matter
Authors:
Niu, Xi-Zhi; Liu, Chao; Gutiérrez, Leonardo A.; Croue, Jean-Philippe
Abstract:
Photosensitizing properties of different dissolved organic matter (DOM) were investigated according to their performance in singlet oxygen (1O2), triplet state of DOM (3DOM*), and hydroxyl radical (·OH) productions. The photobleaching of DOM solutions after irradiation was characterized by fluorescence excitation-emission matrix and UV-Vis spectroscopy. The photosensitizing properties of pre-irradiated DOM solutions were changed in a sunlight simulator. The performance of DOMs in photosensitized degradation of several contaminants was investigated. For a 20h exposure, the observed degradation rate constant (kobs) of some contaminants decreased as a function of exposure time, and highly depended on the properties of both DOM and contaminant. Degradation of contaminants with lower kobs was more susceptible to DOM photobleaching-induced decrease in kobs. Under the current experimental conditions, the photobleaching-induced decrease of DOM photo-reactivity in contaminant degradation was mainly attributed to indirect phototransformation of DOM caused by the interactions between photo-inductive DOM moieties and photochemically-produced reactive species. Reactive contaminants can inhibit DOM indirect photobleaching by scavenging reactive species, photosensitized degradation of these contaminants exhibited a stable kobs as a result. This is the first study to report DOM photobleaching-induced changes in the simultaneous DOM photosensitized degradation of contaminants and the inhibitory effect of reactive contaminants on DOM photobleaching.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division; Environmental Science and Engineering Program; Water Desalination and Reuse Research Center (WDRC)
Publisher:
Elsevier BV
Journal:
Water Research
Issue Date:
Dec-2014
DOI:
10.1016/j.watres.2014.08.017
Type:
Article
ISSN:
00431354
Appears in Collections:
Articles; Environmental Science and Engineering Program; Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorNiu, Xi-Zhien
dc.contributor.authorLiu, Chaoen
dc.contributor.authorGutiérrez, Leonardo A.en
dc.contributor.authorCroue, Jean-Philippeen
dc.date.accessioned2015-08-03T12:18:19Zen
dc.date.available2015-08-03T12:18:19Zen
dc.date.issued2014-12en
dc.identifier.issn00431354en
dc.identifier.doi10.1016/j.watres.2014.08.017en
dc.identifier.urihttp://hdl.handle.net/10754/563885en
dc.description.abstractPhotosensitizing properties of different dissolved organic matter (DOM) were investigated according to their performance in singlet oxygen (1O2), triplet state of DOM (3DOM*), and hydroxyl radical (·OH) productions. The photobleaching of DOM solutions after irradiation was characterized by fluorescence excitation-emission matrix and UV-Vis spectroscopy. The photosensitizing properties of pre-irradiated DOM solutions were changed in a sunlight simulator. The performance of DOMs in photosensitized degradation of several contaminants was investigated. For a 20h exposure, the observed degradation rate constant (kobs) of some contaminants decreased as a function of exposure time, and highly depended on the properties of both DOM and contaminant. Degradation of contaminants with lower kobs was more susceptible to DOM photobleaching-induced decrease in kobs. Under the current experimental conditions, the photobleaching-induced decrease of DOM photo-reactivity in contaminant degradation was mainly attributed to indirect phototransformation of DOM caused by the interactions between photo-inductive DOM moieties and photochemically-produced reactive species. Reactive contaminants can inhibit DOM indirect photobleaching by scavenging reactive species, photosensitized degradation of these contaminants exhibited a stable kobs as a result. This is the first study to report DOM photobleaching-induced changes in the simultaneous DOM photosensitized degradation of contaminants and the inhibitory effect of reactive contaminants on DOM photobleaching.en
dc.publisherElsevier BVen
dc.subjectContaminant degradationen
dc.subjectDissolved organic matteren
dc.subjectDOM characterizationen
dc.subjectPhotobleachingen
dc.subjectPhotosensitizationen
dc.titlePhotobleaching-induced changes in photosensitizing properties of dissolved organic matteren
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.contributor.departmentEnvironmental Science and Engineering Programen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.identifier.journalWater Researchen
dc.contributor.institutionFacultad del Mar y Medio Ambiente, Universidad del PacificoGuayaquil, Ecuadoren
kaust.authorNiu, Xi-Zhien
kaust.authorLiu, Chaoen
kaust.authorCroue, Jean-Philippeen
kaust.authorGutiérrez, Leonardo A.en
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