TY - JOUR
T1 - Assessing indoor gas phase oxidation capacity through real-time measurements of HONO and NO: X in Guangzhou, China
AU - Liu, Jiangping
AU - Li, Sheng
AU - Zeng, Jiafa
AU - Mekic, Majda
AU - Yu, Zhujun
AU - Zhou, Wentao
AU - Loisel, Gwendal
AU - Gandolfo, Adrien
AU - Song, Wei
AU - Wang, Xinming
AU - Zhou, Zhen
AU - Herrmann, Hartmut
AU - Li, Xue
AU - Gligorovski, Sasho
N1 - Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019/8
Y1 - 2019/8
N2 - The hydroxyl radical (OH) is one of the most important oxidants controlling the oxidation capacity of the indoor atmosphere. One of the main OH sources indoors is the photolysis of nitrous acid (HONO). In this study, real-time measurements of HONO, nitrogen oxides (NOx) and ozone (O3) in an indoor environment in Guangzhou, China, were performed under two different conditions: (1) in the absence of any human activity and (2) in the presence of cooking. The maximum NOx and HONO levels drastically increased from 15 and 4 ppb in the absence of human activity to 135 and 40 ppb during the cooking event, respectively. The photon flux was determined for the sunlit room, which has a closed south-east oriented window. The photon flux was used to estimate the photolysis rate constants of NO2, J(NO2), and HONO, J(HONO), which span the range between 8 × 10-5 and 1.5 × 10-5 s-1 in the morning from 9:30 to 11:45, and 8.5 × 10-4 and 1.5 × 10-4 s-1 at noon, respectively. The OH concentrations calculated by photostationary state (PSS) approach, observed around noon, are very similar, i.e., 2.4 × 106 and 3.1 × 106 cm-3 in the absence of human activity and during cooking, respectively. These results suggest that under "high NOx" conditions (NOx higher than a few ppb) and with direct sunlight in the room, the NOx and HONO chemistry would be similar, independent of the geographic location of the indoor environment, which facilitates future modeling studies focused on indoor gas phase oxidation capacity.
AB - The hydroxyl radical (OH) is one of the most important oxidants controlling the oxidation capacity of the indoor atmosphere. One of the main OH sources indoors is the photolysis of nitrous acid (HONO). In this study, real-time measurements of HONO, nitrogen oxides (NOx) and ozone (O3) in an indoor environment in Guangzhou, China, were performed under two different conditions: (1) in the absence of any human activity and (2) in the presence of cooking. The maximum NOx and HONO levels drastically increased from 15 and 4 ppb in the absence of human activity to 135 and 40 ppb during the cooking event, respectively. The photon flux was determined for the sunlit room, which has a closed south-east oriented window. The photon flux was used to estimate the photolysis rate constants of NO2, J(NO2), and HONO, J(HONO), which span the range between 8 × 10-5 and 1.5 × 10-5 s-1 in the morning from 9:30 to 11:45, and 8.5 × 10-4 and 1.5 × 10-4 s-1 at noon, respectively. The OH concentrations calculated by photostationary state (PSS) approach, observed around noon, are very similar, i.e., 2.4 × 106 and 3.1 × 106 cm-3 in the absence of human activity and during cooking, respectively. These results suggest that under "high NOx" conditions (NOx higher than a few ppb) and with direct sunlight in the room, the NOx and HONO chemistry would be similar, independent of the geographic location of the indoor environment, which facilitates future modeling studies focused on indoor gas phase oxidation capacity.
UR - http://www.scopus.com/inward/record.url?scp=85070802315&partnerID=8YFLogxK
U2 - 10.1039/c9em00194h
DO - 10.1039/c9em00194h
M3 - Article
C2 - 31322150
AN - SCOPUS:85070802315
SN - 2050-7887
VL - 21
SP - 1393
EP - 1402
JO - Environmental Sciences: Processes and Impacts
JF - Environmental Sciences: Processes and Impacts
IS - 8
ER -
