TY - JOUR
T1 - Secondary Organic Aerosol Formation from Urban Roadside Air in Hong Kong
AU - Liu, Tengyu
AU - Zhou, Liyuan
AU - Liu, Qianyun
AU - Lee, Berto P.
AU - Yao, Dawen
AU - Lu, Haoxian
AU - Lyu, Xiaopu
AU - Guo, Hai
AU - Chan, Chak K.
N1 - Funding Information:
C.K.C. acknowledges the support of the Environment and Conservation Fund (ECF Project 81/2016) and the Science Technology and Innovation Committee of Shenzhen Municipality (project no. JCYJ20160401095857424). H.G. acknowledges the support of the Research Grants Council of the Hong Kong Special Administrative Region via grant CRF/C5004-15E, and the Strategic Focus Area (SFA) scheme of The Research Institute for Sustainable Urban Development at The Hong Kong Polytechnic University (PolyU) (1-BBW9). We thank the Hong Kong Observatory for providing the CO2 data at Hok Tsui.
Funding Information:
C.K.C. acknowledges the support of the Environment and Conservation Fund (ECF Project 81/2016) and the Science Technology and Innovation Committee of Shenzhen Municipality (project no. CYJ20160401095857424). H.G. acknowledges the support of the Research Grants Council of the Hong Kong Special Administrative Region via grant CRF/C5004- 15E, and the Strategic Focus Area (SFA) scheme of The Research Institute for Sustainable Urban Development at The Hong Kong Polytechnic University (PolyU) (1-BBW9). We thank the Hong Kong Observatory for providing the CO2 data at Hok Tsui.
Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/3/19
Y1 - 2019/3/19
N2 - Motor vehicle emissions are an important but poorly constrained source of secondary organic aerosol (SOA). Here, we investigated in situ SOA formation from urban roadside air in Hong Kong during winter time using an oxidation flow reactor (OFR), with equivalent atmospheric oxidation ranging from several hours to several days. The campaign-average mass enhancement of OA, nitrate, sulfate, and ammonium upon OFR aging was 7.0, 7.2, 0.8, and 2.6 μg m-3, respectively. To investigate the sources of SOA formation potential, we performed multilinear regression analysis between measured peak SOA concentrations from OFR and the concentrations of toluene that represent motor vehicle emissions and cooking OA from positive matrix factorization (PMF) analysis of ambient OA. Traffic-related SOA precursors contributed 92.3%, 92.4%, and 83.1% to the total SOA formation potential during morning rush hours, noon and early afternoon, and evening meal time, respectively. The SOA production factor (PF) was approximately 5.2 times of primary OA (POA) emission factor (EF) and the secondary particulate matter (PM) PF was approximately 2.6 times of primary particles EF. This study highlights the potential benefit of reducing secondary PM production from motor vehicle emissions in mitigating PM pollutions.
AB - Motor vehicle emissions are an important but poorly constrained source of secondary organic aerosol (SOA). Here, we investigated in situ SOA formation from urban roadside air in Hong Kong during winter time using an oxidation flow reactor (OFR), with equivalent atmospheric oxidation ranging from several hours to several days. The campaign-average mass enhancement of OA, nitrate, sulfate, and ammonium upon OFR aging was 7.0, 7.2, 0.8, and 2.6 μg m-3, respectively. To investigate the sources of SOA formation potential, we performed multilinear regression analysis between measured peak SOA concentrations from OFR and the concentrations of toluene that represent motor vehicle emissions and cooking OA from positive matrix factorization (PMF) analysis of ambient OA. Traffic-related SOA precursors contributed 92.3%, 92.4%, and 83.1% to the total SOA formation potential during morning rush hours, noon and early afternoon, and evening meal time, respectively. The SOA production factor (PF) was approximately 5.2 times of primary OA (POA) emission factor (EF) and the secondary particulate matter (PM) PF was approximately 2.6 times of primary particles EF. This study highlights the potential benefit of reducing secondary PM production from motor vehicle emissions in mitigating PM pollutions.
UR - http://www.scopus.com/inward/record.url?scp=85062545945&partnerID=8YFLogxK
U2 - 10.1021/acs.est.8b06587
DO - 10.1021/acs.est.8b06587
M3 - Journal article
C2 - 30790521
AN - SCOPUS:85062545945
SN - 0013-936X
VL - 53
SP - 3001
EP - 3009
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 6
ER -
