Characterization of single scattering albedo and chemical components of aged toluene secondary organic aerosol

Experimental results demonstrated that theretrieved real part of RI for aged toluene SOA was 1.452 ± 0.002, which is consistent with the reported data.The measured SSA of aged toluene SOA was 0.78 ± 0.02, slightly lower than that of organic aerosols associatedwith biomass burning (BBOA), and the k-value (imaginary part of RI, corresponding to the absorption extent ofSOA particles) was 0.024 ± 0.002, larger than that of fresh toluene SOA, indicating that the absorbing ability ofSOA increased with increasing oxidation level.

📌 3 Key Takeaways

🎯

Objective & Hypothesis:Secondary organic aerosol (SOA) can influence the radiative balance of the atmosphere via its optical properties.The single-scattering albedo (SSA) and complex refractive index (RI) are the basic optical parameters of theaerosol particles.

📊

Key Findings & Data:Experimental results demonstrated that theretrieved real part of RI for aged toluene SOA was 1.452 ± 0.002, which is consistent with the reported data.The measured SSA of aged toluene SOA was 0.78 ± 0.02, slightly lower than that of organic aerosols associatedwith biomass burning (BBOA), and the k-value (imaginary part of RI, corresponding to the absorption extent ofSOA particles) was 0.024 ± 0.002, larger than that of fresh toluene SOA, indicating that the absorbing ability ofSOA increased with increasing oxidation level.

💡

Conclusion & Impact:These would provide experimental basis for refine theradiative forcing estimates of anthropogenic SOA for certain regions.

🔬Design:Research Article

📍Scope:Comprehensive Sample

⚙️Variables:Domain Parameters

Özet

Secondary organic aerosol (SOA) can influence the radiative balance of the atmosphere via its optical properties.The single-scattering albedo (SSA) and complex refractive index (RI) are the basic optical parameters of theaerosol particles. Toluene SOA particles were formation and aging with extreme amounts of OH radicals withoutNOx in flow reactor chamber in this study, cavity-enhanced aerosol single-scattering albedometer, UV–Visspectrometer, and liquid chromatography-mass spectrometry (LC-MS) were utilized to measure the opticalproperties and components of the aged toluene SOA, respectively. Experimental results demonstrated that theretrieved real part of RI for aged toluene SOA was 1.452 ± 0.002, which is consistent with the reported data.The measured SSA of aged toluene SOA was 0.78 ± 0.02, slightly lower than that of organic aerosols associatedwith biomass burning (BBOA), and the k-value (imaginary part of RI, corresponding to the absorption extent ofSOA particles) was 0.024 ± 0.002, larger than that of fresh toluene SOA, indicating that the absorbing ability ofSOA increased with increasing oxidation level. The obtained UV absorption and electrospray ionization massspectrum shown that carboxylic acids are identified as the principal constituents of aged toluene SOA, which areresponsible for the decreased SSA and increased k-value measured by the albedometer when compared to thefresh SOA. As the rate of production of SOA is greater than that of BBOA, the aged SOA particles may contributeremarkably to the radiative balance of the atmosphere. These would provide experimental basis for refine theradiative forcing estimates of anthropogenic SOA for certain regions.

🔖

Cite This Article

FENG, Z., HUANG, M., CAİ, S., XU, X., YANG, Z., ZHAO, W., HU, C., GU, X., ZHANG, W. (2019). Characterization of single scattering albedo and chemical components of aged toluene secondary organic aerosol. Atmospheric Pollution Research, Cilt: 10 - Sayı: 6, 1736–1744. https://ajindex.com/articles/351339

References (12)

Andreae, M.O., 2009. A new look at aging aerosols. Science 326, 1493–1494.
Atkinson, R., Arey, J., 2003. Atmospheric degradation of volatile organic compounds. Chem. Rev. 103, 4605–4638.
Cappa, C.D., Che, D.L., Kessler, S.H., Kroll, J.H., Wilson, K.R., 2011. Variations in organic aerosol optical and hygroscopic properties upon heterogeneous OH oxidation. J. Geophys. Res-Atmos. 116 (D15204), 1–12.
Carlton, A.G., Turpin, B.J., Altieri, K.E., Seitzinger, S., Reff, A., Lim, H.J., Ervens, B., 2007. Atmospheric oxalic acid and SOA production from glyoxal: results of aqueous photooxidation experiments. Atmos. Environ. 41, 7588–7602.
Dehghani, M., Fazlzadeh, M., Sorooshian, A., Tabatabaee, H.R., Miri, M., Baghani, A.N., Delikhoon, M., Mahvi, A.H., Rashidi, M., 2017. Characteristics and health effects of BTEX in a hot spot for urban pollution. Ecotoxicol. Environ. Saf. 155, 133–143.
George, I.J., Abbatt, J.P.D., 2010. Chemical evolution of secondary organic aerosol from OH-initiated heterogeneous oxidation. Atmos. Chem. Phys. 10, 5551–5563.
Hallquist, M., Wenger, J., Baltensperger, U., Rudich, Y., Simpson, D., Claeys, M., Dommen, J., Donahue, N., George, C., Goldstein, A., 2009. The formation, properties and impact of secondary organic aerosol: current and emerging issues. Atmos. Chem. Phys. 9, 5155–5236.
Hildebrandt Ruiz, L., Paciga, A.L., Cerully, K.M., Nenes, A., Donahue, N.M., Pandis, S.N., 2015. Formation and aging of secondary organic aerosol from toluene: changes in chemical composition, volatility, and hygroscopicity. Atmos. Chem. Phys. 15 (14), 8301–8313.
Hinks, M.L., Montoya-Aguilera, J., Ellison, L., Lin, P., Laskin, A., Laskin, J., Shiraiwa, M., Dabdub, D., Nizkorodov, S.A., 2018. Effect of relative humidity on the composition of secondary organic aerosol from the oxidation of toluene. Atmos. Chem. Phys. 18, 1643–1652.
Hall IV, W.A., Pennington, M.R., Johnston, M.V., 2013. Molecular transformations accompanying the aging of laboratory secondary organic aerosol. Environ. Sci. Technol. 47, 2230–2237.
Huang, M.Q., Hao, L.Q., Cai, S.Y., Gu, X.J., Zhang, W.X., Hu, C.J., Wang, Z.Y., Fang, L., Zhang, W.J., 2017. Effects of inorganic seed aerosols on the particulate products of aged 1,3,5- trimethylbenzene secondary organic aerosol. Atmos. Environ. 152, 490–502.
Huang, M.Q., Xu, J., Cai, S.Y., Liu, X.Q., Hu, C.J., Gu, X.J., Zhao, W.X., Fang, L., Zhang, W.J., 2018. Chemical analysis of particulate products of aged 1,3,5-trimethylbenzene secondary organic aerosol