Published In

Building and Environment

Document Type

Post-Print

Publication Date

6-1-2018

Subjects

Surface chemistry, Ozone, Reactivity (Chemistry), Ventilation -- Effect on ozone reactivity, Mass accretion

Abstract

In indoor environments, accretion of mass to materials may provide sites for surface chemistry that differ from those of the original material. Since indoor surfaces are a major sink of oxidant gases, surface mass accretion may impact indoor O3 chemistry. In this study, the effect of surface mass accretion on O3 surface deposition was tested by deploying cleaned borosilicate glass plates in two types of indoor environments: a mechanically ventilated ( MV ) office and a naturally ventilated ( NV ) residence located in Singapore. In each environment, seven replicate glass plates and one field blank were deployed for between 7 - 56 days and examined in a laboratory chamber for O3 deposition rate and surface reaction probability. Average mass accretion to plates, deployed in a horizontal position and including deposited particles, was 10.6 mg/ ( m2 d ) in the MV office vs. 18.5 mg/ ( m2 d) in the NV residence and the comparison is at the threshold of statistical significance ( p = 0.054 ) . Ozone reactivity to the plates increased in magnitude and persistence with longer plate deployment. Ozone reaction probabilities to cleaned plates prior to deployment ranged [ 0.06–0.74 ] × 10-6 for two hours of observable removal whereas plates deployed for 56 days ranged [ 0.15–1.2 ] × 10-6 for four hours of observable removal. Regressions of cumulative O3 removed during chamber tests vs. mass accreted show removal of 4.3 nmol O3 / mg for the NV residence and 2.4 nmol O3 / mg for the MV office. These results imply that accretion of mass to surfaces may alter indoor O3 transformation pathways.

Description

© 2018 This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

This is the author’s accepted version. A definitive version was subsequently published in Building and Environment. Changes may have been made to this work since it was submitted for publication.

DOI

10.1016/j.buildenv.2018.04.030

Persistent Identifier

https://archives.pdx.edu/ds/psu/26700

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