Seasonal variation characteristics of hydroxyl radical pollution and its potential formation mechanism during the daytime in Lanzhou
| Autor: | Xiuli Niu, Shiming Jia, Shangrong Ma, Ruihong Li, Guoying Wang, Xuefu Chen, Gaofeng Shi, Zhijun Wu |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Pollution
Environmental Engineering Ozone 010504 meteorology & atmospheric sciences Radical media_common.quotation_subject 010501 environmental sciences 01 natural sciences Atmosphere chemistry.chemical_compound Environmental Chemistry Nitrogen dioxide 0105 earth and related environmental sciences General Environmental Science media_common Pollutant Air Pollutants Hydroxyl Radical General Medicine chemistry Atmospheric chemistry Environmental chemistry Particulate Matter Hydroxyl radical Seasons Environmental Monitoring |
| Zdroj: | Journal of Environmental Sciences. 95:58-64 |
| ISSN: | 1001-0742 |
| DOI: | 10.1016/j.jes.2020.03.045 |
| Popis: | Hydroxyl free radicals (OH radicals) play the main role in atmospheric chemistry and their involving reactions are the dominant rate determining step in the formation of secondary fine particulate matter and in the removal of air pollutants from the atmosphere. In this paper, we studied the seasonal variation characteristics of OH radicals during the daytime in Lanzhou and explored the potential formation mechanism of high concentration OH radicals. We found that the OH radicals in four seasons was 2.7 × 106, 2.6 × 106, 3.1 × 106, and 2.2 × 106 cm−3, respectively. Since the rainfall was concentrated in summer, the wet deposition had a significant effect on removing OH radicals. Among the four pollutants (including ozone (O3), volatile organic compounds (VOCs), nitrogen dioxide (NO2) and fine particulate matter (PM2.5)), the variation of OH radicals were closely related to ozone concentration especially in spring and summer. In autumn, the correlation between PM2.5 and OH radicals were the closest among the observing pollutants and its formation mechanism was different conventional regeneration pathway. In Event 1, high concentration of ozone was the main source of OH radicals; under the high humidity condition, except for ozone, the multiple factors including VOCs, NO2 and PM2.5 interplayed and leaded to the Event 2. |
| Databáze: | OpenAIRE |
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