Secondary Organic Aerosol Formation Potential from Vehicular Non-tailpipe Emissions under Real-World Driving Conditions

作者：Jinsheng Zhang, Jianfei Peng, Ainan Song, Zhuofei Du, Jiliang Guo, Yan Liu, Yicheng Yang, Lin Wu, Ting Wang, Kai Song, Song Guo, Don Collins, Hongjun Mao · 发表于：Environmental Science & Technology · 年份：2024 · DOI：10.1021/acs.est.3c06475 · 被引用次数：19 · 研究领域：Air Quality and Health Impacts、Atmospheric chemistry and aerosols、Vehicle emissions and performance

Traffic emissions are a dominant source of secondary organic aerosol (SOA) in urban environments. Though tailpipe exhaust has drawn extensive attention, the impact of non-tailpipe emissions on atmospheric SOA has not been well studied. Here, a closure study was performed combining urban tunnel experiments and dynamometer tests using an oxidation flow reactor in situ photo-oxidation. Results show a significant gap between field and laboratory research; the average SOA formation potential from real-world fleet is 639 ± 156 mg kg fuel –1, higher than the reconstructed result (188 mg kg fuel –1 ) based on dynamometer tests coupled with fleet composition inside the tunnel. Considering the minimal variation of SOA/CO in emission standards, we also reconstruct CO and find the critical role of high-emitting events in the real-world SOA burden. Different profiles of organic gases are detected inside the tunnel than tailpipe exhaust, such as more abundant C 6 –C 9 aromatics, C 11 –C 16 species, and benzothiazoles, denoting contributions from non-tailpipe emissions to SOA formation. Using these surrogate chemical compounds, we roughly estimate that high-emitting, evaporative emission, and asphalt-related and tire sublimation share 14, 20, and 10% of the SOA budget, respectively, partially explaining the gap between field and laboratory research. These experimental results highlight the importance of non-tailpipe emissions to atmospheric SOA.