| Title: | Secondary Organic Aerosol Formation from Ambient Air at an Urban Site in Beijing: Effects of OH Exposure and Precursor Concentrations |
| Author(s): | Liu J; Chu B; Chen T; Liu C; Wang L; Bao X; He H; |
| Address: | "State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China. College of Environmental Science and Engineering , North China Electric Power University , Beijing 102206 , China. Center for Excellence in Regional Atmospheric Environment , Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021 , China. University of Chinese Academy of Sciences , Beijing 100049 , China. School of Resources and Environmental Engineering , Panzhihua University , Panzhihua 617000 , China. Hebei Provincial Academy of Environmental Sciences , Shijiazhuang 050051 , China" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "Secondary organic aerosol (SOA) is an important component of atmospheric fine particles (PM(2.5)), while the key factors controlling SOA formation in ambient air remain poorly understood. In this work, the SOA formation in Beijing urban ambient air was investigated using an oxidation flow reactor (OFR) with high concentrations of OH radicals. The SOA formation potential increased significantly with the increase of ambient PM(2.5) concentration during the observation. The optimum ambient exposure time, which is the aging time equivalent to atmospheric oxidation (with similar OH exposure) associated with the peak SOA formation, varied between 2 and 4 days in this study. The OA enhancement in this study was much higher than that of developed countries under different environmental conditions. The higher OA enhancement is probably due to the higher concentrations of volatile organic compounds (VOCs) in the urban air of Beijing. This might also have occurred because fragmentation did not dominate in the oxidation of OA, and did not result in negative OA enhancement on highly polluted days compared to relatively clean days with similar exposure time. These results suggested that under typical ambient conditions, high concentrations of VOC precursors might contribute to sustained organic aerosol growth and long duration haze events in Beijing" |
| Keywords: | Aerosols *Air Pollutants Beijing *Volatile Organic Compounds; |
| Notes: | "MedlineLiu, Jun Chu, Biwu Chen, Tianzeng Liu, Changgeng Wang, Ling Bao, Xiaolei He, Hong eng Research Support, Non-U.S. Gov't 2018/05/19 Environ Sci Technol. 2018 Jun 19; 52(12):6834-6841. doi: 10.1021/acs.est.7b05701. Epub 2018 May 25" |
