Photomineralization of aqueous salicylic acids. Photoproducts characterization and formation of light induced secondary OH precursors (LIS-OH)
| Autor: | Abdelaziz Boulkamh, Claire Richard, Mohamad Sleiman, R. Tafer |
|---|---|
| Přispěvatelé: | Institut de Chimie de Clermont-Ferrand (ICCF), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-SIGMA Clermont (SIGMA Clermont)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université frères Mentouri Constantine I (UMC), Université des Frères Mentouri, Laboratoire des Techniques Innovantes de Préservation de l’Environnement |
| Rok vydání: | 2016 |
| Předmět: |
BSTFA
Environmental Engineering Light Radical Carboxylic acid 02 engineering and technology 010501 environmental sciences Photochemistry 01 natural sciences Absorbance Derivatization agents T-Box chemistry.chemical_compound OH radical [CHIM]Chemical Sciences Phenols Photodegradation Waste Management and Disposal 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering chemistry.chemical_classification Aqueous solution Photolysis Hydroxyl Radical Ecological Modeling Photodissociation Water 021001 nanoscience & nanotechnology Substituted phenols Pollution Photobleaching Salicylates Hydroperoxides chemistry DNPH 0210 nano-technology |
| Zdroj: | Water Research Water Research, 2016, 106, pp.496-506. ⟨10.1016/j.watres.2016.10.038⟩ Water Research, IWA Publishing, 2016, 106, pp.496-506. ⟨10.1016/j.watres.2016.10.038⟩ |
| ISSN: | 1879-2448 0043-1354 |
| DOI: | 10.1016/j.watres.2016.10.038⟩ |
| Popis: | International audience; The photolysis of aqueous 5-chlorosalicylic acid (ClSA) and dihydroxybenzoic acid (DHBA), its main photoproduct, was studied to determine the extent of degradation caused by simulated solar light. Photoproducts identification was achieved using high resolution LC-MS and GC-MS. About 40 photoproducts from C19 to C1 were characterized, including a dihydroxycyclopentadienic acid, a ring contraction photoproduct, and numerous carbonyls and carboxylic acid derivatives that were detected thanks to derivatization. UV–visible spectral monitoring of the reactions revealed that ClSA and DHBA underwent photobleaching after developing a temporarily featureless absorbance between 300 and 500 nm. Measurement of OH radicals using terephtalic acid as a probe showed that OH radicals were generated with an average rate of 7 × 10−9 M s−1 and a total cumulated concentration of 10−3 M, corresponding to ∼ 5-fold the initial concentration of DHBA. Furthermore, TOC analysis indicated that significant mineralization (51–90%) occurred. These findings are consistent with the formation of light induced secondary OH (LIS-OH) precursors such as featureless long wavelength absorbing compounds as well as non-absorbing hydroperoxides. The formation of LIS-OH illustrated here may also take place in the aqueous photodegradation of other substituted phenols likely present in dissolved organic matter and humic substructures, it deserves to be studied in more details. |
| Databáze: | OpenAIRE |
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