Abstract：
This study aims to investigate the characteristics of carbonaceous aerosols and estimate emission factor (EF) based on roadway tunnel measurements, from two distinct vehicular fleets: an all light-duty vehicle (LDV) fleet, and a mixed fleet of 80% LDV and 20% heavy-duty vehicle (HDV). Carbonaceous content (organic carbon: OC and elemental carbon: EC) in total fine particles (PM2.5) accounted for 41% ± 6.8% in LDV fleet and 48% ± 7.2% in mixed fleet. While higher volatile OC dominated in the LDV fleet emissions, in mixed fleet, lower volatile OC and EC emissions dominated due to the presence of higher HDV and super-emitter (SE) fractions which led to significantly higher optically active absorbing aerosols. Reconstructed HDV fleet EF was higher than LDV fleet by 36 times (PM2.5), 19 times (OC) and 51 times (EC). Our findings emphasize the significance of implementing vehicle inspection and maintenance programs, coupled with decarbonization of HDVs to mitigate on-road vehicular emissions in India.
摘要：
这项研究旨在研究碳质气溶胶的特征，并根据巷道隧道测量估算排放因子（EF），来自两个不同的车队：全轻型车辆(LDV)车队，以及由80%LDV和20%重型车辆(HDV)组成的混合车队。总细颗粒（PM2.5）中的碳质含量（有机碳：OC和元素碳：EC）在LDV船队中占41％±6.8％，在混合船队中占48％±7.2％。虽然较高的挥发性OC在LDV车队排放中占主导地位，在混合舰队中，较低的挥发性OC和EC排放占主导地位，这是由于存在较高的HDV和超级发射体（SE）部分，从而导致明显较高的光学活性吸收气溶胶。重建后的HDV机队EF比LDV机队高36倍（PM2.5），19倍(OC)和51倍(EC)。我们的发现强调了实施车辆检查和维护计划的重要性，再加上HDV的脱碳，以减轻印度的道路车辆排放。
