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Titel |
Heterogeneous ozonation kinetics of 4-phenoxyphenol in the presence of photosensitizer |
VerfasserIn |
S. Net, L. Nieto-Gligorovski, S. Gligorovski, H. Wortham |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 4 ; Nr. 10, no. 4 (2010-02-15), S.1545-1554 |
Datensatznummer |
250008101
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Publikation (Nr.) |
copernicus.org/acp-10-1545-2010.pdf |
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Zusammenfassung |
In this work we have quantitatively measured the degradation of
4-phenoxyphenol adsorbed on silica particles following oxidative
processing by gas-phase ozone. This was performed under dark
conditions and in the presence of 4-carboxybenzophenone under
simulated sunlight irradiation of the particles surface.
At the mixing ratio of 60 ppb which corresponds to strongly polluted
ozone areas, the first order of decay of 4-phenoxyphenol is
k1=9.95×10−6 s−1. At a very high ozone
mixing ratio of 6 ppm the first order rate constants for
4-phenoxyphenol degradation were the following:
k1=2.86×10−5 s−1 under dark conditions
and k1=5.58×10−5 s−1 in the presence of
photosensitizer (4-carboxybenzophenone) under light illumination of
the particles surface. In both cases, the experimental data follow
the modified Langmuir-Hinshelwood equation for surface reactions.
The Langmuir-Hinshelwood and Langmuir-Rideal mechanisms for
bimolecular surface reactions are also discussed along with the
experimental results.
Most importantly, the quantities of the oligomers such as
2-(4-Phenoxyphenoxy)-4-phenoxyphenol and
4-[4-(4-Phenoxyphenoxy)phenoxy]phenol formed during the heterogeneous
ozonolysis of adsorbed 4-phenoxyphenol were much higher under solar light
irradiation of the surface in comparison to the dark conditions. |
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