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Identification of the major HO x radical pathways in an indoor air environment
Author(s) -
Mendez M.,
Amedro D.,
Blond N.,
Hauglustaine D. A.,
Blondeau P.,
Afif C.,
Fittschen C.,
Schoemaecker C.
Publication year - 2017
Publication title -
indoor air
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.387
H-Index - 99
eISSN - 1600-0668
pISSN - 0905-6947
DOI - 10.1111/ina.12316
Subject(s) - identification (biology) , environmental science , environmental chemistry , indoor air , engineering , waste management , environmental engineering , chemistry , ecology , biology
OH and HO 2 profiles measured in a real environment have been compared to the results of the INCA ‐Indoor model to improve our understanding of indoor chemistry. Significant levels of both radicals have been measured and their profiles display similar diurnal behavior, reaching peak concentrations during direct sunlight (up to 1.6×10 6 and 4.0×10 7 cm −3 for OH and HO 2 , respectively). Concentrations of O 3 , NO x , volatile organic compounds ( VOC s), HONO , and photolysis frequencies were constrained to the observed values. The HO x profiles are well simulated in terms of variation for both species (Pearson's coefficients: p OH =0.55, p HO 2 =0.76) and concentration for OH (mean normalized bias error: MNBE OH =−30%), HO 2 concentration being always underestimated ( MNBE HO 2 =−62%). Production and loss pathways analysis confirmed HONO photolysis role as an OH precursor (here up to 50% of the production rate). HO 2 formation is linked to OH ‐initiated VOC oxidation. A sensitivity analysis was conducted by varying HONO , VOC s, and NO concentrations. OH , HO 2 , and formaldehyde concentrations increase with HONO concentrations; OH and formaldehyde concentrations are weakly dependent on NO , whereas HO 2 concentrations are strongly reduced with increasing NO . Increasing VOC concentrations decreases OH by consumption and enhances HO 2 and formaldehyde.