Atmospheric degradation of 2- nitrobenzaldehyde: Photolysis and reaction with OH radicals. (December 2017)

• Record Type: Journal Article
• Authors: Bouya, H.; Al Rashidi, M.; Roth, E.; Salghi, R.; Chakir, A.
• Is Part Of: Atmospheric environment. Volume 171(2017)
• Page Start: 221
• Page End: 228
• Publication Date: 2017-12
• Subjects: 2-Nitrobenzaldehyde -- Kinetics -- UV absorption cross-sections -- Rate coefficient -- Tropospheric lifetimes -- Photolysis -- Mechanism -- OH radicals; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2017.10.021
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: This work presents an experimental study of the gas phase kinetics of 2-nitrobenzaldehyde (2-NBA) photolysis and oxidation by OH radicals. The experiments were carried out in an atmospheric simulation chamber coupled to an FTIR spectrometer and CG/MS. The UV spectra of 2-NBA were also measured and the experimentally determined absorption cross sections were used to estimate the atmospheric photo-dissociation constant of 2-NBA with a global quantum yield of 0.5. The obtained results indicate that 2-NBA is a highly photolysable. A mechanism of 2-NBA photolysis was proposed based on the identification of photolysis degradation products. The kinetics of oxidation of 2-NBA by OH radicals was investigated over the temperature range 308–352 K. The obtained rate coefficients exhibits slight negative temperature dependence and the Arrhenius expression obtained is as follows: kOH+2-NBA (T)= (7.00 ± 3.40) × 10 −12 exp (577 ± 156/T) cm 3 molecule −1 s −1 . The calculated rate coefficients lead to tropospheric lifetimes of 2-NBA that are in the order of a few minutes, relative to photolysis, or a few hours, relative to oxidation by OH radicals. Graphical abstract: Highlights: The UV absorption of 2-nitrobenzaldehyde (2-NBA), in gas phase, have been measured. This work provides the kinetic of the photolysis and OH reaction of 2-NBA. A possible degradation products for photolysis of 2-NBA were identified. The kinetic study with OH was carried out over the temperature range 308–352 K. The tropospheric lifetimes of this compound is estimated.