Institute of Landscape Ecology - Climatology, University of Münster, Heisenbergstr. 2, 48149, Munster, Germany.
Environ Sci Pollut Res Int. 2017 Oct;24(29):23279-23289. doi: 10.1007/s11356-017-9941-1. Epub 2017 Aug 23.
We conducted a 60-day roadside measurement campaign on a busy street in Münster, Germany, during summer 2016. We used gas and particle concentration measurements with high temporal resolution (10 Hz) to quantify both the emission ratios of nitrogen oxides per carbon dioxide (NO /CO) for over 70,000 individual exhaust plumes as well as the emission ratios for size-resolved particle numbers per carbon dioxide (d(PN CO)/dlogD) for about 10,000 plumes. The real-world fleet passing by the measurement station consisted of passenger cars (85%), buses (5.9%), light duty commercial vehicles (5.7%), trucks (1.7%), and motorcycles (1.6%). The median measured NO /CO ratio was 3.33 g kg. The median measured PN/CO emission ratio for particles with diameters between 0.03 and 10 μm was 5.6 × 10 kg. We compared our results with the Handbook Emission Factors for Road Transport (HBEFA) and the Euro 5 and Euro 6 emission standards by employing traffic counts, assuming the diesel-to-gasoline ratios of vehicles according to registration statistics, and estimating that stop-and-go traffic occurred 65% of the time. Using a conservative estimate, our median ratios exceeded the HBEFA data by more than 65% for NO /CO and by a factor of about 100 for PN/CO Furthermore, our median NO emission per kilometer travelled (NO km) exceeded the Euro 5 emission limit for diesel cars by a factor of 3 and exceeded the Euro 6 limit by almost a factor of 7. Additionally, our median particle number emission (PN km) exceeded the Euro 5 and Euro 6 limits of diesel cars by a factor of almost 150. These results confirm the presumption that the emissions of a real-world traffic fleet comprehensively exceed the legal limits. Very likely, the widespread presence of defeat devices in vehicle emission control systems plays a major role in this discrepancy. This has a strong impact on the apparent inability of authorities to comply with the legal limits of the NO concentrations in urban air.
我们在 2016 年夏季于德国明斯特的一条繁忙街道上进行了为期 60 天的路边测量活动。我们使用具有高时间分辨率（10 Hz）的气体和颗粒浓度测量来量化超过 70,000 个单个排气羽流的氮氧化物与二氧化碳的排放比（NO / CO），以及约 10,000 个羽流的二氧化碳分辨颗粒数的排放比（d(PN CO)/dlogD）。经过测量站的实际车队由乘用车（85%）、公共汽车（5.9%）、轻型商用车（5.7%）、卡车（1.7%）和摩托车（1.6%）组成。测量得到的中位 NO / CO 比为 3.33 g kg。测量得到的 0.03 至 10 μm 直径范围内颗粒的 PN/CO 排放比为 5.6×10 kg。我们通过交通计数、根据登记统计数据假设车辆的柴油到汽油比，并估计停车-启动交通占 65%的时间，将我们的结果与《道路运输排放因素手册》（HBEFA）和欧洲 5 号和 6 号排放标准进行了比较。使用保守估计，我们的中位比对于 NO / CO 超过 HBEFA 数据的 65%，对于 PN/CO 则超过 100 倍。此外，我们行驶每公里的氮氧化物排放量（NO km）超过了柴油车的欧洲 5 号排放限值的 3 倍，超过了欧洲 6 号限值的近 7 倍。此外，我们的中位颗粒数排放量（PN km）超过了柴油车的欧洲 5 号和 6 号限值的 150 倍左右。这些结果证实了这样的假设，即实际交通车队的排放全面超过了法定限制。很可能，车辆排放控制系统中广泛存在的失效装置在这种差异中起着重要作用。这对当局无法遵守城市空气中氮浓度的法定限制产生了强烈影响。
