Mishra V K, Aggarwal M L, Berghmans P, Frijns E, Int Panis L, Chacko K M
Shriram Institute for Industrial Research, 19 University Road, Delhi, India.
VITO, Flemish Institute for Technological Research, Boeretang 200, 2400, Mol, Belgium.
Environ Monit Assess. 2015 Dec;187(12):756. doi: 10.1007/s10661-015-4948-x. Epub 2015 Nov 18.
Size-segregated ultrafine particles from motor vehicles were investigated in the Craeybeckx tunnel (E19 motorway, Antwerp, Belgium) at two measurement sites, at 100 and 300 m inside the tunnel, respectively, during March 2008. It was observed that out of the three size modes, nucleation, Aitken, and accumulation, Aitken mode was the most dominant size fraction inside the tunnel. The diurnal variation in ultrafine particle (UFP) levels closely follows the vehicular traffic inside the tunnel, which was maximum during office rush hours, both in the morning and evening and minimum during night-time around 3 am. The tunnel data showed very high growth rates in comparison with free atmosphere. The average condensation sink during the growth period was 14.1-17.3 × 10(-2) s(-1). The average growth rate (GR) of geometric mean diameter was found to be 18.6 ± 2.45 nm h(-1). It was observed that increase in Aitken mode was related to the numbers of heavy-duty vehicles (HDV), as they emit mainly in the Aitken mode. The higher Aitken mode during traffic jams correlated well with HDV numbers. At the end of the tunnel, sudden dilution leading to fast coagulation was responsible for the sudden drop in the UFP number concentration.
2008年3月，在比利时安特卫普E19高速公路的克雷贝克克斯隧道中，于两个测量点分别对机动车排放的粒径分级超细颗粒物进行了研究，这两个测量点分别位于隧道内100米和300米处。观察发现，在成核、艾肯和积聚这三种粒径模式中，艾肯模式是隧道内最主要的粒径组分。超细颗粒物（UFP）水平的日变化与隧道内的车辆交通密切相关，在早晚办公高峰时段最高，凌晨3点左右的夜间时段最低。与自由大气相比，隧道数据显示出非常高的增长率。生长期间的平均凝结核沉降率为14.1 - 17.3×10⁻² s⁻¹。几何平均直径的平均增长率（GR）为18.6±2.45纳米/小时。观察发现，艾肯模式的增加与重型车辆（HDV）的数量有关，因为它们主要在艾肯模式下排放。交通拥堵期间较高的艾肯模式与重型车辆数量密切相关。在隧道末端，突然稀释导致快速凝聚，这是超细颗粒物数量浓度突然下降的原因。
