Characterizing PM_2.5 in Beijing and Shanxi Province using terahertz radiation

Abstract

Particles of aerodynamic diameter≤2.5 μm (PM_2.5) caused extremely severe and persistent haze pollution is of concern in many cities. In this study, samples of PM_2.5 were collected from atmosphere environment of Beijing and Shanxi Province, and analyzed using terahertz (THz) radiation. The transmission spectrum of PM_2.5 in Shanxi Province had two distinct absorption peaks at 6.0 and 6.7 THz, and the curve was increasing on the whole. However, the transmission spectrum of PM_2.5 in Beijing had obviously different variation tendency and the absorption peak was studied by monitoring PM_2.5 masses in conjunction with two-dimensional correlation spectroscopy (2DCOS). By comparing the pollutant species and concentrations of Shanxi Province and Beijing over the time of collecting samples, the concentrations of sulfate and ammonium were similar, which contributed to emerge absorption bands in the same position. While the concentrations of organic matter (OM), nitrate, chloride and elemental carbon (EC) were different. Furthermore, dust and some other inorganic ion are unique to Shanxi province, which lead to different variation tendency of the transmission spectrum of PM_2.5. These results will be of importance for environmental monitoring and for controlling PM emissions. According to this research, optical techniques, and especially spectral methods, should be considered for PM_2.5 monitoring.

Keywords

PM_2.5 / terahertz / two dimensional correlation spectroscopy (2DCOS)

References

[1] Huang R J, Zhang Y, Bozzetti C, Ho K F, Cao J J, Han Y, Daellenbach K R, Slowik J G, Platt S M, Canonaco F, Zotter P, Wolf R, Pieber S M, Bruns E A, Crippa M, Ciarelli G, Piazzalunga A, Schwikowski M, Abbaszade G, Schnelle-Kreis J, Zimmermann R, An Z, Szidat S, Baltensperger U, El Haddad I, Prévôt A S. High secondary aerosol contribution to particulate pollution during haze events in China. Nature, 2014, 514(7521): 218–222

[2] http://news.xinhuanet.com/mrdx/2012-12/20/c_132051703.html (in Chinese), <Date>accessed on 20 December 2012</Date>

[3] Yao L, Yang L, Yuan Q, Yan C, Dong C, Meng C, Sui X, Yang F, Lu Y, Wang W. Sources apportionment of PM_2.5 in a background site in the North China Plain. Science of the Total Environment, 2016, 541: 590–598

[4] Zhou X, Cao Z, Ma Y, Wang L, Wu R, Wang W. Concentrations, correlations and chemical species of PM_2.5/PM₁₀ based on published data in China: potential implications for the revised particulate standard. Chemosphere, 2016, 144: 518–526

[5] Ferm M, Sjöberg K. Concentrations and emission factors for PM_2.5 and PM₁₀ from road traffic in Sweden. Atmospheric Environment, 2015, 119: 211–219

[6] Han S, Youn J S, Jung Y W. Characterization of PM₁₀ and PM_2.5 source profiles for resuspended road dust collected using mobile sampling methodology. Atmospheric Environment, 2011, 45(20): 3343–3351

[7] Liu J, Zhang X. Terahertz radiation-enhanced-emission-of-fluorescence. Frontiers of Optoelectronics, 2014, 7(2): 156–198

[8] Su T, Yu B, Han P, Zhao G, Gong C. Characterization of spectra of lignin from midribs of tobacco at THz frequencies. Frontiers of Optoelectronics in China, 2009, 2(3): 244–247

[9] Feng X, Wu S, Zhao K, Wang W, Zhan H, Jiang C, Xiao L, Chen S. Pattern transitions of oil-water two-phase flow with low water content in rectangular horizontal pipes probed by terahertz spectrum. Optics Express, 2015, 23(24): A1693–A1699

[10] Ge L N, Zhan H L, Leng W X, Zhao K, Xiao L Z. Optical characterization of the principal hydrocarbon components in natural gas using terahertz spectroscopy. Energy & Fuels, 2015, 29(3): 1622–1627

[11] Zhan H, Wu S, Bao R, Zhao K, Xiao L, Ge L, Shi H. Water adsorption dynamics in active carbon probed by terahertz spectroscopy. RSC Advances, 2015, 5: 14389–14392

[12] Zhan H, Wu S, Bao R, Ge L, Zhao K. Qualitative identification of crude oils from different oil fields using terahertz time-domain spectroscopy. Fuel, 2015, 143: 189–193

[13] Zhan H, Li Q, Zhao K, Zhang L, Zhang Z, Zhang C, Xiao L. Evaluating PM_2.5 at a construction site using terahertz radiation. IEEE Transactions on Terahertz Science and Technology, 2015, 5(6): 1028–1034

[14] Li Q, Zhao K, Zhang L, Liang C, Zhang Z, Zhang C, Han D. Probing PM_2.5 with terahertz wave. Science China Physics, Mechanics & Astronomy, 2014, 57(12): 2354–2356

[15] Yang Y, Harsha S S, Shutler A J, Grischkowsky D R. Identification of genistein and biochanin A by THz (far-infrared) vibrational spectra. Journal of Pharmaceutical and Biomedical Analysis, 2012, 62: 177–181

[16] Meng T, Du R, Hou Z, Yang J, Zhao G. THz spectra-based SVM prediction model for Yungang Grottoes samples. Journal of Archaeological Science, 2015, 55: 280–285

[17] Chen Z, Jiang Y, Jiang L, Ma H. Terahertz absorption spectra and potential energy distribution of liquid crystals. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2016, 153: 741–745

[18] Hu M, Mu K, Zhang C, Gu H, Ding Z. Broadband THz pulse emission and transmission properties of nanostructured Pt thin films. Physica B, Condensed Matter, 2015, 474: 64–69

[19] Kansiz M, Domínguez-Vidal A, McNaughton D, Lendl B. Fourier-transform infrared (FTIR) spectroscopy for monitoring and determining the degree of crystallisation of polyhydroxyalkanoates (PHAs). Analytical and Bioanalytical Chemistry, 2007, 388(5-6): 1207–1213

[20] Burnett A D, Fan W, Upadhya P C, Cunningham J E, Hargreaves M D, Munshi T, Edwards H G M, Linfield E H, Davies A G. Broadband terahertz time-domain spectroscopy of drugs-of-abuse and the use of principal component analysis. Analyst, 2009, 134(8): 1658–1668

[21] Isaksson T. Methods to extract exclusively linear relationships in generalized two-dimensional correlation spectroscopy (2DCOS). Vibrational Spectroscopy, 2004, 36(2): 251–259

[22] Meng Z Y, Jiang X M, Yan P, Lin W L, Zhang H D, Wang Y. Characteristics and sources of PM_2.5 and carbonaceous species during winter in Taiyuan, China. Atmospheric Environment, 2007, 41(32): 6901–6908

Acknowledgements

This work was supported by the National Basic Research Program of China (No. 2014CB744302), the Specially Funded Program on National Key Scientific Instruments and Equipment Development (No. 2012YQ140005), and the National Natural Science Foundation of China (Grant No. 11574401).

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2016 Higher Education Press and Springer-Verlag Berlin Heidelberg