Humidity-Dependent Phase State of Gasoline Vehicle Emission-Related Aerosols
| Autor: | K.X. Liu, Hui Wang, Shiyi Chen, Zhijun Wu, Xiangxinyue Meng, Yuechen Liu, Taomou Zong, Limin Zeng, Mattias Hallquist, Min Hu, Song Guo, Shijin Shuai, Wenbin Zhang, Zhou Zhang |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Environmental Science & Technology. 55:832-841 |
| ISSN: | 1520-5851 0013-936X |
| Popis: | The phase states of primarily emitted and secondarily formed aerosols from gasoline vehicle exhausts were investigated by quantifying the particle rebound fraction (f). The rebound behaviors of gasoline vehicle emission-related aerosols varied with engines, fuel types, and photochemical aging time, showing distinguished differences from biogenic secondary organic aerosols. The nonliquid-to-liquid phase transition of primary aerosols emitted from port fuel injection (PFI) and gasoline direct injection (GDI) vehicles started at a relative humidity (RH) = 50 and 60%, and liquefaction was accomplished at 60 and 70%, respectively. The RH at which f declined to 0.5 decreased from 70 to 65% for the PFI case with 92# fuel, corresponding to the photochemical aging time from 0.37 to 4.62 days. For the GDI case, such RH enhanced from 60 to 65%. Our results can be used to imply the phase state of traffic-related aerosols and further understand their roles in urban atmospheric chemistry. Taking Beijing, China, as an example, traffic-related aerosols were mainly nonliquid during winter with the majority ambient RH below 50%, whereas they were mostly liquid during the morning rush hour of summer, and traffic-related secondary aerosols fluctuated between nonliquid and liquid during the daytime and tended to be liquid at night with increased ambient RH. |
| Databáze: | OpenAIRE |
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