Ammonia emission from real-world in-use vehicle fleets in a megacity in China - based on tunnel measurement

作者：Jiliang Guo, Jinsheng Zhang, Ainan Song, Hui Tong, Jingchun Tang, Ning Yang, Zhuofei Du, Qijun Zhang, Ting Wang, Lin Wu, Jianfei Peng, Hongjun Mao · 发表于：Journal of Environmental Sciences · 年份：2025 · DOI：10.1016/j.jes.2025.03.069 · 被引用次数：6 · 研究领域：Vehicle emissions and performance、Air Quality and Health Impacts、Air Quality Monitoring and Forecasting

Ammonia (NH 3 ) has been widely recognized as a key precursor of atmospheric secondary aerosol formation. Vehicle emission is a major source of urban atmospheric NH 3 . With the tightening of emission standards and the growing trend of vehicle fleet electrification, it is imperative to update the emission factors for NH 3 from real-world on-road fleets. In this study, a tunnel measurement was conducted in the urban area of Tianjin, China. The fleet-average NH 3 emission factor (EF) was 11.2 mg/(km·veh), significantly lower than those in previous studies, showing the benefit of emission standard updating. Through a multiple linear regression analysis, the EFs of light-duty gasoline vehicles, light-duty diesel vehicles, and heavy-duty diesel vehicles (HDDVs) were estimated to be 5.7 ± 0.6 mg/(km·veh), 40.8 ± 5.1 mg/(km·veh), and 160.2 ± 16.6 mg/(km·veh), respectively. Based on the results from this study, we found that HDDVs, which comprise <3 % of the total vehicles may contribute approximately 22 % of total NH 3 emissions in Tianjin. Our results highlight NH 3 emissions from HDDVs, a previously potentially overlooked source of NH 3 emissions in urban areas. The actual on-road NH 3 emissions from HDDVs may exceed current expectations, posing a growing concern for the future.