| Title: | [Characteristics of Ozone and Source Apportionment of the Precursor VOCs in Tianjin Suburbs in Summer] |
| Author(s): | Luo RX; Liu BS; Liang DN; Bi XH; Zhang YF; Feng YC; |
| Address: | "State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China" |
| DOI: | 10.13227/j.hjkx.202005096 |
| ISSN/ISBN: | 0250-3301 (Print) 0250-3301 (Linking) |
| Abstract: | "From June to August 2018, a 1-hr resolution concentration dataset of ozone and its gaseous precursors (volatile organic compounds(VOCs) and NO(x)), and meteorological parameters were synchronously monitored by online instruments of the Nankai University Air Quality Research Supersite. The relationships and variation characteristics between ozone and its precursors were analyzed. According to the photochemical age, the initial concentrations of VOCs were calculated, and the photochemical loss of the concentration of VOCs during the daytime (06:00-24:00) was corrected. The initial and directly monitored concentrations of VOCs were incorporated into the PMF model for source apportionment. The results indicated that the mean concentration of O(3) in Tianjin in summer was (41.3+/-25.7)x10(-9), while that of VOCs was (13.9+/-12.3)x10(-9). The average concentration of alkane (7.0+/-6.8)x10(-9) was clearly higher than that of other VOC species. The species with high concentrations of alkanes were propane and ethane, accounting for 47% of the total alkane concentration. The average ozone formation potential (OFP) in summer was 52.1x10(-9), and the OFP value of alkene was the highest and its contribution reached 57%. During the daytime, alkene loss accounted for 75% of the total VOC loss. The major sources of VOCs that were calculated based on the initial concentration data were the chemical industry and solvent usage (25%), automobile exhaust (22%), combustion source (19%), LPG/NG (19%), and gasoline volatilization (15%), respectively. Compared with the apportionment results based on directly monitored concentrations, the contribution of the chemical industry and solvent usage decreased by 4%, while automobile exhaust decreased by 5%. By combining the results of PMF apportionment and the OFP model to analyze the relative contributions of emission sources to ozone formation, and we found that the highest contribution source of ozone was the chemical industry and solvent usage (26%) in summer. Compared with the analysis results based on the directly monitored concentrations, the OFP values of the chemical industry and solvent usage decreased by 7%, while that of NG/LPG apparently decreased by 13%" |
| Keywords: | initial volume fraction ozone positive matrix factorization (PMF) source apportionment volatile organic compounds (VOCs); |
| Notes: | "PubMed-not-MEDLINELuo, Rui-Xue Liu, Bao-Shuang Liang, Dan-Ni Bi, Xiao-Hui Zhang, Yu-Fen Feng, Yin-Chang chi English Abstract China 2020/12/30 Huan Jing Ke Xue. 2021 Jan 8; 42(1):75-87. doi: 10.13227/j.hjkx.202005096" |
