Measurements of particle number and mass concentrations and size distributions in a tunnel environment
Measurements of particle number and mass concentrations and size distributions in a tunnel environment
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DOI：
10.1021/es050360s
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发表时间：
2005-11-15
影响因子：
11.4
通讯作者：
Sioutas, C
中科院分区：
文献类型：
--
作者：
Geller, VD;Sardar, SB;Sioutas, C
2004年8月和9月，在加利福尼亚州北部的卡尔德科特隧道的两个钻孔中测量了颗粒物排放。一个孔(孔1)对重型和轻型车辆开放，而重型车辆禁止进入第二个孔(孔2)。连续四天在每个孔的入口和出口附近记录颗粒物数量和质量尺寸分布、化学成分和气态共润滑剂。确定了颗粒物数量、颗粒物质量、元素碳、有机碳(OC)、硫酸盐、硝酸盐和选定元素的尺寸分辨排放系数。两个孔的尺寸分布都显示出迁移率直径约为15-20 nm的单个大模，偶尔也有约100 mm的小模。重型车的PM10质量排放系数是轻型车的14.5倍。与轻型车相比，柴油车排放的颗粒物中元素碳含量更高，占PM10排放量的70.9%。相反，在轻负荷排放中发现的有机碳比例高于重负荷排放。与之前在卡尔德科特隧道进行的研究相比，与7年前相比，车辆排放的颗粒物质量更少，但颗粒物数量更多。
Particulate matter emissions were measured in two bores of the Caldecott Tunnel in Northern California during August and September 2004. One bore (Bore 1) is open to both heavy- and light-duty vehicles while heavy-duty vehicles are prohibited from entering the second bore (Bore 2). Particulate matter number and mass size distributions, chemical composition, and gaseous copollutants were recorded for four consecutive days near the entrance and exit of each bore. Size-resolved emission factors were determined for particle number, particle mass, elemental carbon, organic carbon (OC), sulfate, nitrate, and selected elements. The size distributions in both the bores showed a single large mode at roughly 15-20 nm in mobility diameter, with occasional smaller modes around 100 mm. The PM10 mass emission factor for heavy-duty vehicles was 14.5 times higher than that of light-duty vehicles. The particles derived from diesel are more abundant in elemental carbon, 70.9% of PM10 emissions, as compared to the light-duty vehicles. Conversely, a greater percentage of OC was found in light-duty emissions than heavy-duty emissions. In comparison to previous studies at the Caldecott Tunnel, less particle mass but more particle numbers are emitted by vehicles than was the case 7 years ago.