Yang Dongsen, Zhu Shengnan, Ma Yan, Zhou Liujun, Zheng Feixue, Wang Lin, Jiang Jingkun, Zheng Jun
School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
NUIST Reading Academy, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Environ Sci Technol. 2022 May 3;56(9):5440-5447. doi: 10.1021/acs.est.2c00555. Epub 2022 Apr 11.
Emissions of NH and nine nitrogen-containing volatile organic compounds (NVOCs) (C-amines, C-amides, and C-imines) from motor vehicles powered by gasoline, diesel, and natural gas under low-speed driving conditions from roadside in situ measurements were characterized using a water-cluster chemical ionization mass spectrometer and trace gas monitors. The total emission strength of diesel trucks was the greatest followed by those of gasoline cars and natural gas cars. NH emission per vehicle was found to be 2-3 orders of magnitude greater than that of all NVOCs, regardless of the type of vehicle. Although much lower than the emissions of amides or imines, emissions of amines were sufficient to produce atmospheric concentrations exceeding the threshold level for amines to enhance atmospheric nucleation by several orders of magnitude. Different engine emission reduction technologies (e.g., three-way catalytic converter vs selective catalytic reduction) can lead to different NH and NVOC emission profiles. During the lifetime of a vehicle, its emission level was most likely to increase with its mileage. Source profiles of NH and NVOC emissions from the three types of vehicles were also obtained from the measurements. These profiles can be a valuable contribution to the air pollution management system in terms of source apportionment, elucidating the emission contributions from a specific type of vehicle.
使用水团簇化学电离质谱仪和痕量气体监测仪，对在路边原位测量的低速行驶条件下由汽油、柴油和天然气驱动的机动车排放的NH和九种含氮挥发性有机化合物（NVOCs）（C-胺、C-酰胺和C-亚胺）进行了表征。柴油卡车的总排放强度最大，其次是汽油车和天然气车。无论车辆类型如何，每辆车的NH排放量都比所有NVOCs的排放量高2 - 3个数量级。尽管胺的排放量远低于酰胺或亚胺的排放量，但足以使大气浓度超过胺增强大气成核的阈值水平几个数量级。不同的发动机减排技术（例如，三元催化转化器与选择性催化还原）会导致不同的NH和NVOC排放特征。在车辆的使用期限内，其排放水平很可能随着行驶里程的增加而上升。通过测量还获得了这三种类型车辆的NH和NVOC排放源特征。就源分配而言，这些特征可为空气污染管理系统做出宝贵贡献，阐明特定类型车辆的排放贡献。
