TY - JOUR
T1 - High Gaseous Nitrous Acid (HONO) Emissions from Light-Duty Diesel Vehicles
AU - Liao, Songdi
AU - Zhang, Jiacheng
AU - Yu, Fei
AU - Zhu, Manni
AU - Liu, Junwen
AU - Ou, J.
AU - Dong, Huabin
AU - Sha, Qinge
AU - Zhong, Zhuangmin
AU - Xie, Yan
AU - Luo, Haoming
AU - Zhang, Lihang
AU - Zheng, Junyu
N1 - Funding Information:
The financial support by the National Natural Science Foundation of China (No. 41627809) and the National Key Research and Development Program of China (No. 2018YFC0213904) are gratefully acknowledged. We acknowledge the support received from all students in our laboratory.
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2021/1/5
Y1 - 2021/1/5
N2 - Nitrous acid (HONO) plays an important role in the budget of hydroxyl radical (•OH) in the atmosphere. Vehicular emissions are a crucial primary source of atmospheric HONO, yet remain poorly investigated, especially for diesel trucks. In this study, we developed a novel portable online vehicular HONO exhaust measurement system featuring an innovative dilution technique. Using this system coupled with a chassis dynamometer, we for the first time investigated the HONO emission characteristics of 17 light-duty diesel trucks (LDDTs) and 16 light-duty gasoline vehicles in China. Emissions of HONO from LDDTs were found to be significantly higher than previous studies and gasoline vehicles tested in this study. The HONO emission factors of LDDTs decrease significantly with stringent control standards: 1.85 ± 1.17, 0.59 ± 0.25, and 0.15 ± 0.14 g/kg for China III, China IV, and China V, respectively. In addition, we found poor correlations between HONO and NOx emissions, which indicate that using the ratio of HONO to NOx emissions to infer HONO emissions might lead to high uncertainty of HONO source budget in previous studies. Lastly, the HONO emissions are found to be influenced by driving conditions, highlighting the importance of conducting on-road measurements of HONO emissions under real-world driving conditions. More direct measurements of the HONO emissions are needed to improve the understanding of the HONO emissions from mobile and other primary sources.
AB - Nitrous acid (HONO) plays an important role in the budget of hydroxyl radical (•OH) in the atmosphere. Vehicular emissions are a crucial primary source of atmospheric HONO, yet remain poorly investigated, especially for diesel trucks. In this study, we developed a novel portable online vehicular HONO exhaust measurement system featuring an innovative dilution technique. Using this system coupled with a chassis dynamometer, we for the first time investigated the HONO emission characteristics of 17 light-duty diesel trucks (LDDTs) and 16 light-duty gasoline vehicles in China. Emissions of HONO from LDDTs were found to be significantly higher than previous studies and gasoline vehicles tested in this study. The HONO emission factors of LDDTs decrease significantly with stringent control standards: 1.85 ± 1.17, 0.59 ± 0.25, and 0.15 ± 0.14 g/kg for China III, China IV, and China V, respectively. In addition, we found poor correlations between HONO and NOx emissions, which indicate that using the ratio of HONO to NOx emissions to infer HONO emissions might lead to high uncertainty of HONO source budget in previous studies. Lastly, the HONO emissions are found to be influenced by driving conditions, highlighting the importance of conducting on-road measurements of HONO emissions under real-world driving conditions. More direct measurements of the HONO emissions are needed to improve the understanding of the HONO emissions from mobile and other primary sources.
UR - http://www.scopus.com/inward/record.url?scp=85097870733&partnerID=8YFLogxK
U2 - 10.1021/acs.est.0c05599
DO - 10.1021/acs.est.0c05599
M3 - Article
SN - 0013-936X
VL - 55
SP - 200
EP - 208
JO - Environmental Science & Technology
JF - Environmental Science & Technology
IS - 1
ER -