 |
| Titel |
OH-initiated heterogeneous oxidation of tris-2-butoxyethyl phosphate: implications for its fate in the atmosphere |
| VerfasserIn |
Y. Liu, L. Huang, S.-M. Li, T. Harner, J. Liggio |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 22 ; Nr. 14, no. 22 (2014-11-19), S.12195-12207 |
| Datensatznummer |
250119174
|
| Publikation (Nr.) |
 copernicus.org/acp-14-12195-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| A particle-phase relative rates technique is used to investigate the
heterogeneous reaction between OH radicals and tris-2-butoxyethyl phosphate
(TBEP) at 298 K by combining aerosol time-of-flight mass spectrometry
(C-ToF-MS) data and positive matrix factor (PMF) analysis. The derived
second-order rate constants (k2) for the heterogeneous loss of TBEP is
(4.44 ± 0.45) × 10−12 cm3 molecule−1 s−1,
from which an approximate particle-phase lifetime was estimated to be
2.6 (2.3–2.9) days. However, large differences in the rate constants for TBEP relative to a reference compound were observed when comparing internally and
externally mixed TBEP/organic particles, and upon changes in the RH. The
heterogeneous degradation of TBEP was found to be depressed or enhanced
depending upon the particle mixing state and phase, highlighting the
complexity of heterogeneous oxidation in the atmosphere. The effect of
gas-particle partitioning on the estimated overall lifetime (gas + particle) for several organophosphate esters (OPEs) was also examined
through the explicit modeling of this process. The overall atmospheric
lifetimes of TBEP, tris-2-ethylhexyl phosphate (TEHP) and
tris-1,3-dichloro-2-propyl phosphate (TDCPP) were estimated to be 1.9, 1.9
and 2.4 days respectively, and are highly dependent upon particle size.
These results demonstrate that modeling the atmospheric fate of particle-phase toxic compounds for the purpose of risk assessment must include the
gas-particle partitioning process, and in the future include the effect of other
particulate components on the evaporation kinetics and/or the heterogeneous
loss rates. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|