Jump to main content
Jump to site search

Issue 8, 2019
Previous Article Next Article

Assessing indoor gas phase oxidation capacity through real-time measurements of HONO and NOx in Guangzhou, China

Author affiliations

Abstract

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.

Graphical abstract: Assessing indoor gas phase oxidation capacity through real-time measurements of HONO and NOx in Guangzhou, China

Back to tab navigation

Supplementary files

Publication details

The article was received on 25 Apr 2019, accepted on 03 Jul 2019 and first published on 04 Jul 2019


Article type: Paper
DOI: 10.1039/C9EM00194H
Environ. Sci.: Processes Impacts, 2019,21, 1393-1402

  •   Request permissions

    Assessing indoor gas phase oxidation capacity through real-time measurements of HONO and NOx in Guangzhou, China

    J. Liu, S. Li, J. Zeng, M. Mekic, Z. Yu, W. Zhou, G. Loisel, A. Gandolfo, W. Song, X. Wang, Z. Zhou, H. Herrmann, X. Li and S. Gligorovski, Environ. Sci.: Processes Impacts, 2019, 21, 1393
    DOI: 10.1039/C9EM00194H

Search articles by author

Spotlight

Advertisements