A General Scavenging Rate Constant for Reaction of Hydroxyl Radical with Organic Carbon in Atmospheric Waters
| Autor: | S. Azechi, D. Handa, Ai Tsuhako, Youichi Miyagi, Cort Anastasio, Takemitsu Arakaki, Kouichirou Okada, Taro Kimura, Yuji Kotani, Hitomi Nakajima, Yukiko Kuroki |
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| Rok vydání: | 2013 |
| Předmět: |
Total organic carbon
Aqueous solution Atmosphere Hydroxyl Radical Chemistry Inorganic chemistry Water Free Radical Scavengers General Chemistry Photochemistry Carbon Aerosol Kinetics chemistry.chemical_compound Reaction rate constant Dissolved organic carbon Environmental Chemistry Hydroxyl radical Sink (computing) Scavenging |
| Zdroj: | Environmental Science & Technology. 47:8196-8203 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es401927b |
| Popis: | Hydroxyl radical (OH) is an important oxidant in atmospheric aqueous phases such as cloud and fog drops and water-containing aerosol particles. We find that numerical models nearly always overestimate aqueous hydroxyl radical concentrations because they overpredict its rate of formation and, more significantly, underpredict its sinks. To address this latter point, we examined OH sinks in atmospheric drops and aqueous particles using both new samples and an analysis of published data. Although the molecular composition of organic carbon, the dominant sink of OH, is extremely complex and poorly constrained, this sink behaves very similarly in different atmospheric waters and even in surface waters. Thus, the sink for aqueous OH can be estimated as the concentration of dissolved organic carbon multiplied by a general scavenging rate constant [kC,OH = (3.8 ± 1.9) × 10(8) L (mol C)(-1) s(-1)], a simple process that should significantly improve estimates of OH concentrations in atmospheric drops and aqueous particles. |
| Databáze: | OpenAIRE |
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