| Title: | Insight into the Primary and Secondary Particle-Bound Methoxyphenols and Nitroaromatic Compound Emissions from Solid Fuel Combustion and the Updated Source Tracers |
| Author(s): | Zhang B; Shen Z; He K; Sun J; Huang S; Xu H; Li J; Ho SSH; Cao JJ; |
| Address: | "Xi'an Key Laboratory of Solid Waste Recycling and Resource Recovery, Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710049, China. Divison of Atmospheric Sciences, Desert Research Institute, Reno NV89512, United States" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "Methoxyphenols and nitroaromatic compounds (NACs) have strong atmospheric radiative forcing effects and adverse effects on human health. They are emitted from the incomplete combustion of solid fuels and are secondarily formed through photochemical reactions. Here, an on-site study was conducted to determine the primary emission and secondary formation of particulate phase products from a variety of solid fuels through a potential aerosol mass-oxidation flow reactor. Emission factors for total quantified methoxyphenols and NACs (i.e., EF( summation operatorMethoxyphenols) and EF( summation operatorNACs)) varied by 2 orders of magnitude among different fuels, which were greatly influenced by volatile matter, incomplete combustibility, flame intensity, and combustion temperature. Guaiacol and 4-nitro-2-vinylphenol were used as tracers for primary organic aerosol due to the low aged-to-fresh ratios (0.21-0.97), while 4-methyl-guaiacol, 4-ethyl-guaiacol, eugenol, 4-methyl-syringol, isoeugenol, acetovanillone, syringaldehyde, homovanillin acid, vanillin acid, and syringic acid were identified as secondary organic aerosol (SOA) (aged-to-fresh ratios between 1.90 and 4.20). During simulated aging, the -CHO group reacted with the hydroxyl radical (*OH) to form the -COOH group, but there was no correlation between syringol and 4-nitrosyringol, implying that *OH is the main reactant rather than the nitriate radical (*NO(3)) in the atmospheric aging processes of methoxyphenols. Aging caused substantially different emission profiles due to variable photochemical reaction properties. The fresh EFs for guaiacol emitted from the biomass burning ranged from 3.80 +/- 0.44 to 26.2 +/- 5.40 mg.kg(-1), which were much higher than those in coal combustions (of 0.03 +/- 0.01 to 1.42 +/- 0.28 mg.kg(-1)). However, the aged EFs (EF(aged)) for guaiacol was 1.02 +/- 0.06 to 1.61 +/- 0.11 mg.kg(-1) in most biomass combustions, which were comparable with those of the bituminous chunk (1.20 +/- 0.16 mg.kg(-1)). Therefore, guaiacol, a traditional biomass marker, is not an ideal tracer for aged PM(2.5) emitted from biomass burning. Indeed, the syringol/guaiacol and syringol/4-nitrosyringol ratios were found to be more suitable and efficient to be used in source characterization" |
| Keywords: | Humans Aged *Pyrogallol *Aging Biomass Coal Pam-ofr emission factors methoxyphenols nitroaromatic compounds source tracer; |
| Notes: | "MedlineZhang, Bin Shen, Zhenxing He, Kun Sun, Jian Huang, Shasha Xu, Hongmei Li, Jianjun Ho, Steven Sai Hang Cao, Jun-Ji eng Research Support, Non-U.S. Gov't 2023/09/14 Environ Sci Technol. 2023 Sep 26; 57(38):14280-14288. doi: 10.1021/acs.est.3c04370. Epub 2023 Sep 14" |
