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RESEARCH ARTICLE

PM2.5 acidity during haze episodes in Shanghai, China

Tianhao Zhang A C , Bingqing Lu A C , Xiang Quan A , Na Wu A , Jiandong Shen B D and Xiang Li https://orcid.org/0000-0002-0434-3057 A D
+ Author Affiliations
- Author Affiliations

A Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.

B Hangzhou Ecological Environment Monitoring Center of Zhejiang, Hangda Road 4, Hangzhou 310007, China.

C These authors contributed equally to this work.

D Corresponding authors. Email: Sjiandong@gmail.com; lixiang@fudan.edu.cn

Environmental Chemistry 18(4) 168-176 https://doi.org/10.1071/EN21087
Submitted: 24 June 2021  Accepted: 4 August 2021   Published: 27 August 2021

Environmental context. Aerosol acidity, or aerosol aqueous phase pH, can affect various environmental processes. Based on high frequency measurements of particulate compositions, along with thermodynamic calculations, this work studies particle acidity in the course of severe episodes of haze in Shanghai and considers the effect of this on the production of nitrate. The results will provide new perspectives on our interpretation of PM2.5 acidity during haze episodes in megacities.

Abstract. Aerosol acidity is one of the most important parameters that can influence climate change and human health, which has been inadequately analysed in China. Here, hourly measurements of particulate compositions and the E-AIM II model (assuming thermodynamic equilibrium) were used to study particle acidity during severe episodes of haze in Shanghai. The total concentration of sulfate, nitrate and ammonium was 138.9 ± 50.6 μg m−3, maximum 241.3 μg m−3; and the PM2.5 to PM10 (PM2.5/PM10) ratio was 0.60. The fine particles detected were somewhat acidic, with a pH range of 0.04–4.50, average 2.34, which is higher than in some areas of the US and China. The relatively low particle acidity is attributed to particle water content levels. Furthermore, the growth rate of sulfate, nitrate and ammonium during a haze episode (Case 2) was faster than that during a clean episode (CE), owing to exacerbated effects of PM2.5 acidity in the event of high relative humidity (RH) on hazy days. Finally, the detected significant correlations of [NO3]/[SO42−] with [NH4+]/[SO42−] in conditions of abundant NH4+ indicate that NO3 in Shanghai is primarily formed through homogeneous reaction between ambient NH3 and HNO3. These findings provide new perspectives on our interpretation of PM2.5 acidity during haze episodes in megacities.

Keywords: PM2.5 acidity, haze, E-AIM II model, Shanghai.


References

Adams PJ, Seinfeld JH, Koch DM (1999). Global concentrations of tropospheric sulfate, nitrate, and ammonium aerosol simulated in a general circulation model. Journal of Geophysical Research, D, Atmospheres 104, 13791–13823.
Global concentrations of tropospheric sulfate, nitrate, and ammonium aerosol simulated in a general circulation model.Crossref | GoogleScholarGoogle Scholar |

Behera SN, Betha R, Liu P, Balasubramanian R (2013). A study of diurnal variations of PM2.5 acidity and related chemical species using a new thermodynamic equilibrium model. The Science of the Total Environment 452–453, 286–295.
A study of diurnal variations of PM2.5 acidity and related chemical species using a new thermodynamic equilibrium model.Crossref | GoogleScholarGoogle Scholar | 23523726PubMed |

Bougiatioti A, Nikolaou P, Stavroulas I, Kouvarakis G, Weber R, Nenes A, Kanakidou M, Mihalopoulos N (2016). Particle water and pH in the eastern Mediterranean: source variability and implications for nutrient availability. Atmospheric Chemistry and Physics 16, 4579–4591.
Particle water and pH in the eastern Mediterranean: source variability and implications for nutrient availability.Crossref | GoogleScholarGoogle Scholar |

Chan CK, Yao X (2008). Air pollution in mega cities in China. Atmospheric Environment 42, 1–42.
Air pollution in mega cities in China.Crossref | GoogleScholarGoogle Scholar |

Cheng YF, Zheng GJ, Wei C, Mu Q, Zheng B, Wang ZB, Gao M, Zhang Q, He KB, Carmichael G, Poschl U, Su H (2016). Reactive nitrogen chemistry in aerosol water as a source of sulfate during haze events in China. Science Advances 2, e1601530
Reactive nitrogen chemistry in aerosol water as a source of sulfate during haze events in China.Crossref | GoogleScholarGoogle Scholar |

Clegg SL, Brimblecombe P, Wexler AS (1998). Thermodynamic model of the system H+-NH4+-SO42–-NO3–-H2O at tropospheric temperatures. The Journal of Physical Chemistry A 102, 2137–2154.
Thermodynamic model of the system H+-NH4+-SO42–-NO3-H2O at tropospheric temperatures.Crossref | GoogleScholarGoogle Scholar |

Dawei Z, Seip HM, Dianwu Z, Dongbao Z (1994). Pattern and cause of acidic deposition in the Chongqing region, Sichuan Province, China. Water, Air, and Soil Pollution 77, 27–48.
Pattern and cause of acidic deposition in the Chongqing region, Sichuan Province, China.Crossref | GoogleScholarGoogle Scholar |

Elser M, Huang RJ, Wolf R, Slowik JG, Wang QY, Canonaco F, Li GH, Bozzetti C, Daellenbach KR, Huang Y, Zhang RJ, Li ZQ, Cao JJ, Baltensperger U, El-Haddad I, Prevot ASH (2016). New insights into PM2.5 chemical composition and sources in two major cities in China during extreme haze events using aerosol mass spectrometry. Atmospheric Chemistry and Physics 16, 3207–3225.
New insights into PM2.5 chemical composition and sources in two major cities in China during extreme haze events using aerosol mass spectrometry.Crossref | GoogleScholarGoogle Scholar |

Fang T, Guo H, Zeng L, Verma V, Nenes A, Weber RJ (2017). Highly Acidic Ambient Particles, Soluble Metals, and Oxidative Potential: A Link between Sulfate and Aerosol Toxicity. Environmental Science & Technology 51, 2611–2620.
Highly Acidic Ambient Particles, Soluble Metals, and Oxidative Potential: A Link between Sulfate and Aerosol Toxicity.Crossref | GoogleScholarGoogle Scholar |

Ghio AJ, Carraway MS, Madden MC (2012). Composition of air pollution particles and oxidative stress in cells, tissues, and living systems. Journal of Toxicology and Environmental Health 15, 1–21.
Composition of air pollution particles and oxidative stress in cells, tissues, and living systems.Crossref | GoogleScholarGoogle Scholar | 22202227PubMed |

Guo B, Wang Y, Zhang X, Che H, Zhong J, Chu Y, Cheng L (2020). Temporal and spatial variations of haze and fog and the characteristics of PM2.5 during heavy pollution episodes in China from 2013 to 2018. Atmospheric Pollution Research 11, 1847–1856.
Temporal and spatial variations of haze and fog and the characteristics of PM2.5 during heavy pollution episodes in China from 2013 to 2018.Crossref | GoogleScholarGoogle Scholar |

Han JS, Moon KJ, Lee SJ, Kim YJ, Ryu SY, Cliff SS, Yi SM (2006). Size-resolved source apportionment of ambient particles by positive matrix factorization at Gosan background site in East Asia. Atmospheric Chemistry and Physics 6, 211–223.
Size-resolved source apportionment of ambient particles by positive matrix factorization at Gosan background site in East Asia.Crossref | GoogleScholarGoogle Scholar |

He K, Zhao Q, Ma Y, Duan F, Yang F, Shi Z, Chen G (2012). Spatial and seasonal variability of PM2.5 acidity at two Chinese megacities: insights into the formation of secondary inorganic aerosols. Atmospheric Chemistry and Physics 12, 1377–1395.
Spatial and seasonal variability of PM2.5 acidity at two Chinese megacities: insights into the formation of secondary inorganic aerosols.Crossref | GoogleScholarGoogle Scholar |

Hung HM, Hoffmann MR (2015). Oxidation of gas-phase SO2 on the surfaces of acidic microdroplets: Implications for sulfate and sulfate radical anion formation in the atmospheric liquid phase. Environmental Science & Technology 49, 13768–13776.
Oxidation of gas-phase SO2 on the surfaces of acidic microdroplets: Implications for sulfate and sulfate radical anion formation in the atmospheric liquid phase.Crossref | GoogleScholarGoogle Scholar |

Jang MS, Czoschke NM, Lee S, Kamens RM (2002). Heterogeneous atmospheric aerosol production by acid-catalyzed particle-phase reactions. Science 298, 814–817.
Heterogeneous atmospheric aerosol production by acid-catalyzed particle-phase reactions.Crossref | GoogleScholarGoogle Scholar |

Larssen T, Lydersen E, Tang D, He Y, Gao J, Liu H, Duan L, Seip HM, Vogt RD, Mulder J, Shao M, Wang Y, Shang H, Zhang X, Solberg S, Aas W, Okland T, Eilertsen O, Angell V, Liu Q, Zhao D, Xiang R, Xiao J, Luo J (2006). Acid rain in China. Environmental Science & Technology 40, 418–425.
Acid rain in China.Crossref | GoogleScholarGoogle Scholar |

Liu M, Song Y, Zhou T, Xu Z, Yan C, Zheng M, Wu Z, Hu M, Wu Y, Zhu T (2017). Fine particle pH during severe haze episodes in northern China. Geophysical Research Letters 44, 5213–5221.
Fine particle pH during severe haze episodes in northern China.Crossref | GoogleScholarGoogle Scholar |

Nemitz E, Sutton MA, Wyers GP, Jongejan PAC (2004). Gas-particle interactions above a Dutch heathland: I. Surface exchange fluxes of NH3, SO2, HNO3 and HCl. Atmospheric Chemistry and Physics 4, 989–1005.
Gas-particle interactions above a Dutch heathland: I. Surface exchange fluxes of NH3, SO2, HNO3 and HCl.Crossref | GoogleScholarGoogle Scholar |

Pakkanen TA, Kerminen VM, Hillamo RE, Makinen M, Makela T, Virkkula A (1996). Distribution of nitrate over sea-salt and soil derived particles – Implications from a field study. Journal of Atmospheric Chemistry 24, 189–205.
Distribution of nitrate over sea-salt and soil derived particles – Implications from a field study.Crossref | GoogleScholarGoogle Scholar |

Pathak RK, Louie PKK, Chan CK (2004). Characteristics of aerosol acidity in Hong Kong. Atmospheric Environment 38, 2965–2974.
Characteristics of aerosol acidity in Hong Kong.Crossref | GoogleScholarGoogle Scholar |

Pathak RK, Wu WS, Wang T (2009). Summertime PM2.5 ionic species in four major cities of China: nitrate formation in an ammonia-deficient atmosphere. Atmospheric Chemistry and Physics 9, 1711–1722.
Summertime PM2.5 ionic species in four major cities of China: nitrate formation in an ammonia-deficient atmosphere.Crossref | GoogleScholarGoogle Scholar |

Pathak RK, Wang T, Ho KF, Lee SC (2011). Characteristics of summertime PM2.5 organic and elemental carbon in four major Chinese cities: Implications of high acidity for water-soluble organic carbon (WSOC). Atmospheric Environment 45, 318–325.
Characteristics of summertime PM2.5 organic and elemental carbon in four major Chinese cities: Implications of high acidity for water-soluble organic carbon (WSOC).Crossref | GoogleScholarGoogle Scholar |

Shen Z, Arimoto R, Cao J, Zhang R, Li X, Du N, Okuda T, Nakao S, Tanaka S (2008). Seasonal variations and evidence for the effectiveness of pollution controls on water-soluble inorganic species in total suspended particulates and fine particulate matter from Xi’an, China. Journal of the Air & Waste Management Association 58, 1560–1570.
Seasonal variations and evidence for the effectiveness of pollution controls on water-soluble inorganic species in total suspended particulates and fine particulate matter from Xi’an, China.Crossref | GoogleScholarGoogle Scholar |

Song CH, Park ME, Lee KH, Ahn HJ, Lee Y, Kim JY, Han KM, Kim J, Ghim YS, Kim YJ (2008). An investigation into seasonal and regional aerosol characteristics in East Asia using model-predicted and remotely-sensed aerosol properties. Atmospheric Chemistry and Physics 8, 6627–6654.
An investigation into seasonal and regional aerosol characteristics in East Asia using model-predicted and remotely-sensed aerosol properties.Crossref | GoogleScholarGoogle Scholar |

Sun YL, Zhuang GS, Wang ZF, Wang Y (2006). Regional characteristics of spring Asian dust and its impact on aerosol chemistry over northern China. Atmospheric Chemistry and Physics Discussion 6, 12825–12864.
Regional characteristics of spring Asian dust and its impact on aerosol chemistry over northern China.Crossref | GoogleScholarGoogle Scholar |

Surratt JD, Lewandowski M, Offenberg JH, Jaoui M, Kleindienst TE, Edney EO, Seinfeld JH (2007). Effect of acidity on secondary organic aerosol formation from isoprene. Environmental Science & Technology 41, 5363–5369.
Effect of acidity on secondary organic aerosol formation from isoprene.Crossref | GoogleScholarGoogle Scholar |

Takahama S, Davidson CI, Pandis SN (2006). Semicontinuous measurements of organic carbon and acidity during the Pittsburgh air quality study: Implications for acid-catalyzed organic aerosol formation. Environmental Science & Technology 40, 2191–2199.
Semicontinuous measurements of organic carbon and acidity during the Pittsburgh air quality study: Implications for acid-catalyzed organic aerosol formation.Crossref | GoogleScholarGoogle Scholar |

Wang GH, Zhang RY, Gomez ME, Yang LX, Zamora ML, Hu M, Lin Y, Peng JF, Guo S, Meng JJ, Li JJ, Cheng CL, Hu TF, Ren YQ, Wang YS, Gao J, Cao JJ, An ZS, Zhou WJ, Li GH, Wang JY, Tian PF, Marrero-Ortiz W, Secrest J, Du ZF, Zheng J, Shang DJ, Zeng LM, Shao M, Wang WG, Huang Y, Wang Y, Zhu YJ, Li YX, Hu JX, Pan B, Cai L, Cheng YT, Ji YM, Zhang F, Rosenfeld D, Liss PS, Duce RA, Kolb CE, Molina MJ (2016). Persistent sulfate formation from London Fog to Chinese haze. Proceedings of the National Academy of Sciences of the United States of America 113, 13630–13635.
Persistent sulfate formation from London Fog to Chinese haze.Crossref | GoogleScholarGoogle Scholar |

Wang Q, Qiao L, Zhou M, Zhu S, Griffith S, Li L, Yu JZ (2018). Source Apportionment of PM2.5 Using Hourly Measurements of Elemental Tracers and Major Constituents in an Urban Environment: Investigation of Time-Resolution Influence. Journal of Geophysical Research: Atmospheres 123, 5284–5300.
Source Apportionment of PM2.5 Using Hourly Measurements of Elemental Tracers and Major Constituents in an Urban Environment: Investigation of Time-Resolution Influence.Crossref | GoogleScholarGoogle Scholar |

Xue J, Lau AKH, Yu JZ (2011). A study of acidity on PM2.5 in Hong Kong using online ionic chemical composition measurements. Atmospheric Environment 45, 7081–7088.
A study of acidity on PM2.5 in Hong Kong using online ionic chemical composition measurements.Crossref | GoogleScholarGoogle Scholar |

Yao XH, Ling TY, Fang M, Chan CK (2006). Comparison of thermodynamic predictions for in situ pH in PM2.5. Atmospheric Environment 40, 2835–2844.
Comparison of thermodynamic predictions for in situ pH in PM2.5.Crossref | GoogleScholarGoogle Scholar |

Zhang XY, Cao JJ, Li LM, Arimoto R, Cheng Y, Huebert B, Wang D (2002). Characterization of Atmospheric Aerosol over XiAn in the South Margin of the Loess Plateau, China. Atmospheric Environment 36, 4189–4199.
Characterization of Atmospheric Aerosol over XiAn in the South Margin of the Loess Plateau, China.Crossref | GoogleScholarGoogle Scholar |

Zhang Q, Jimenez JL, Worsnop DR, Canagaratna M (2007). A case study of urban particle acidity and its influence on secondary organic aerosol. Environmental Science & Technology 41, 3213–3219.
A case study of urban particle acidity and its influence on secondary organic aerosol.Crossref | GoogleScholarGoogle Scholar |

Zhang R, Wang G, Guo S, Zamora ML, Ying Q, Lin Y, Wang W, Hu M, Wang Y (2015a). Formation of urban fine particulate matter. Chemical Reviews 115, 3803–3855.
Formation of urban fine particulate matter.Crossref | GoogleScholarGoogle Scholar | 25942499PubMed |

Zhang RY, Wang GH, Guo S, Zarnora ML, Ying Q, Lin Y, Wang WG, Hu M, Wang Y (2015b). Formation of Urban Fine Particulate Matter. Chemical Reviews 115, 3803–3855.
Formation of Urban Fine Particulate Matter.Crossref | GoogleScholarGoogle Scholar |

Zhang Z, Guan H, Luo L, Zheng N, Xiao H, Liang Y, Xiao H (2020). Sources and transformation of nitrate aerosol in winter 2017–2018 of megacity Beijing: Insights from an alternative approach. Atmospheric Environment 241, 117842
Sources and transformation of nitrate aerosol in winter 2017–2018 of megacity Beijing: Insights from an alternative approach.Crossref | GoogleScholarGoogle Scholar |

Zhao M, Huang Z, Qiao T, Zhang Y, Xiu G, Yu J (2015). Chemical characterization, the transport pathways and potential sources of PM2.5 in Shanghai: Seasonal variations. Atmospheric Research 158–159, 66–78.
Chemical characterization, the transport pathways and potential sources of PM2.5 in Shanghai: Seasonal variations.Crossref | GoogleScholarGoogle Scholar |

Zhou Y, Xue L, Wang T, Gao X, Wang Z, Wang X, Zhang J, Zhang Q, Wang W (2012). Characterization of aerosol acidity at a high mountain site in central eastern China. Atmospheric Environment 51, 11–20.
Characterization of aerosol acidity at a high mountain site in central eastern China.Crossref | GoogleScholarGoogle Scholar |

Zhou M, Zhang Y, Han Y, Wu J, Du X, Xu H, Feng Y, Han S (2018). Spatial and temporal characteristics of PM2.5 acidity during autumn in marine and coastal area of Bohai Sea, China, based on two-site contrast. Atmospheric Research 202, 196–204.
Spatial and temporal characteristics of PM2.5 acidity during autumn in marine and coastal area of Bohai Sea, China, based on two-site contrast.Crossref | GoogleScholarGoogle Scholar |

Zhu W, Luo L, Cheng Z, Yan N, Lou S, Ma Y (2018). Characteristics and contributions of biogenic secondary organic aerosol tracers to PM2.5 in Shanghai, China. Atmospheric Pollution Research 9, 179–188.
Characteristics and contributions of biogenic secondary organic aerosol tracers to PM2.5 in Shanghai, China.Crossref | GoogleScholarGoogle Scholar |

Ziemba LD, Fischer E, Griffin RJ, Talbot RW (2007). Aerosol acidity in rural New England: Temporal trends and source region analysis. Journal of Geophysical Research: Atmospheres 112, D10S22
Aerosol acidity in rural New England: Temporal trends and source region analysis.Crossref | GoogleScholarGoogle Scholar |