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Photomineralization of aqueous salicylic acids. Photoproducts characterization and formation of light induced secondary OH precursors (LIS-OH)
- Source :
- 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⟩
- Publication Year :
- 2016
-
Abstract
- 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.
- Subjects :
- 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
Subjects
Details
- ISSN :
- 18792448 and 00431354
- Volume :
- 106
- Database :
- OpenAIRE
- Journal :
- Water research
- Accession number :
- edsair.doi.dedup.....88143ca25b2ef1e74863b19d576c2311