Open AccessCharacterizing particulate polycyclic aromatic hydrocarbon emissions from diesel vehicles using a portable emissions measurement system
Author(s) -
Xuan Zheng,
Ye Wu,
Shaojun Zhang,
Jingnan Hu,
K. Max Zhang,
Zhenhua Li,
Liqiang He,
Jiming Hao
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-017-09822-w
Subject(s) - pyrene , diesel fuel , polycyclic aromatic hydrocarbon , environmental science , particulates , environmental chemistry , emission inventory , diesel exhaust , hydrocarbon , environmental engineering , air pollution , chemistry , waste management , engineering , organic chemistry
Particulate polycyclic aromatic hydrocarbons (p-PAHs) emitted from diesel vehicles are of concern because of their significant health impacts. Laboratory tests, road tunnel and roadside experiments have been conducted to measure p-PAH emissions. While providing valuable information, these methods have limited capabilities of characterizing p-PAH emissions either from individual vehicles or under real-world conditions. We employed a portable emissions measurement (PEMS) to measure real-world emission factors of priority p-PAHs for diesel vehicles representative of an array of emission control technologies. The results indicated over 80% reduction in p-PAH emission factors comparing the China V and China II emission standard groups (113 μg kg −1 vs. 733 μg kg −1 ). The toxicity abatement in terms of Benzo[a]pyrene equivalent emissions was substantial because of the large reductions in highly toxic components. By assessing real traffic conditions, the p-PAH emission factors on freeways were lower than on local roads by 52% ± 24%. A significant correlation (R 2 ~0.85) between the p-PAH and black carbon emissions was identified with a mass ratio of approximately 1/2000. A literature review indicated that diesel p-PAH emission factors varied widely by engine technology, measurement methods and conditions, and the molecular diagnostic ratio method for source apportionment should be used with great caution.