Particle Concentration and Characteristics near a Major Freeway with Heavy-Duty Diesel Traffic

详细信息    查看全文

• 作者：Leonidas Ntziachristos ; Zhi Ning ; Michael D. Geller ; Constantinos Sioutas
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：April 1, 2007
• 年：2007
• 卷：41
• 期：7
• 页码：2223 - 2230
• 全文大小：205K
• 年卷期：v.41,no.7(April 1, 2007)
• ISSN：1520-5851

文摘

This study presents the number, surface and volumeconcentrations, and size distribution of particles next tothe I-710 freeway during February through April 2006. I-710has the highest ratio (up to 25%) of heavy-duty dieselvehicles in the Los Angeles highway network. Particleconcentration measurements were accompanied bymeasurements of black carbon, elemental and organiccarbon, and gaseous species (CO, CO₂). Using the incrementalincrease of CO₂ over the background to calculate thedilution ratio, this study makes it possible to compare particleconcentrations measured next to the freeway to concentrations measured in roadway tunnels and in vehicle exhaust.In addition to the effect of the dilution ratio on themeasured particle concentrations, multivariate linearregressions showed that light and heavy organic carbonconcentrations are positively correlated with the particlevolume in the nucleation and accumulation modes,respectively. Solar radiation was also positively correlatedwith the particle surface concentration and the particlevolume in the accumulation (40-638 nm) mode, presumablyas a result of secondary particle formation. The methodsdeveloped in this study may be used to decouple the effectof sampling position, meteorology, and fleet operation onparticle concentrations in the proximity of freeways, roadwaytunnels, and in street canyons.