Fossil Fuel Combustion-Related Emissions Dominate Atmospheric Ammonia Sources during Severe Haze Episodes: Evidence from <sup>15</sup>N-Stable Isotope in Size-Resolved Aerosol Ammonium

Pan, Yuepeng; Tian, Shili; Li, Dongwei; Fang, Yunting; Zhu, Xiaodong; Zhang, Qiang; Zheng, Bo; Michalski, Greg; Wang, Yuesi

doi:10.1021/acs.est.6b00634

Cited by 289 publications

(282 citation statements)

References 37 publications

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“…For example, the emissions of SO 2 , NO x , and NH 3 in China are estimated to be about 22 Tg S y −1 , 19 Tg N y −1 , and 15 Tg N y −1 in 2010, respectively (48). In addition, traffic emissions have been suggested to represent an important urban NH 3 source (49). High emissions of these organic and inorganic PM precursors result in large secondary production of SO 4 2− , NO 3 − , NH 4 + , and SOA in China (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Also, because of the second-order nature of NO 2 in the aqueous SO 2 oxidation (i.e., reactions 1 and 2), reduction of the NO x level is likely effective in lowering sulfate formation. In light of large contributions to urban NO x , VOC, and NH 3 levels from transportation (1,21,49), regulatory actions in minimizing traffic emissions may represent the critical step in mitigating severe haze in China. These measures are clearly supported by our experimental results, showing no particle growth or sulfate formation at high RH when oxalic acid particles were exposed to high levels of SO 2 in the absence of NH 3 , NO 2 , or both (SI Appendix, Table S4).…”

Section: Resultsmentioning

confidence: 99%

“…Because of increasingly high SO 2 , NO x , VOC, and basic species (NH 3 and amine) emissions in many developing countries (1,38,48,49), the synergetic sulfate formation pathway identified in our work is likely widespread globally, contributing not only to air quality problems but also to enhanced nitrogen (i.e., NH 4 + or NO 3 − ) or acid (in the absence of basic species) deposition, with major implications for the ecosystem vitality, greenhouse gas budgets, and biological diversity (48). Our results highlight the necessity for comprehensive understanding of the atmospheric aerosol chemistry in the development of effective pollution mitigation policies (1), to minimize the impacts of fine PM on visibility, human health, ecosystems, weather, and climate.…”

Section: Resultsmentioning

confidence: 99%

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Persistent sulfate formation from London Fog to Chinese haze

Wang

Zhang

Gómez

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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1,161

922

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Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO 2 by NO 2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH 3 neutralization or under cloud conditions. Under polluted environments, this SO 2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH 3 and NO 2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world.sulfate aerosol | severe haze | pollution | human health | climate

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Persistent sulfate formation from London Fog to Chinese haze

Wang

Zhang

Gómez

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

1,161

922

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show abstract

“…Comparable NH3 levels have been measured at multiple stations over the NCP during the winter months Liu et al, 2017a;Zhao et al, 2016), indicating that ammonia-rich conditions are very common. The NHx sources include agriculture, fossil fuel use, and green space, and their contributions vary in different environments Sun et al, 2017;Teng et al, 2017;Pan et al, 2016). We note however that the similar behavior of CO and total NHx does not imply necessarily similar emission sources.…”

Section: Driving Factors For Particle Ph 25mentioning

confidence: 87%

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

Song¹,

Gao²,

Xu³

et al. 2018

Preprint

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Abstract. pH is an important property of aerosol particles but is difficult to measure directly. Several studies have estimated the pH values for fine particles in North China winter haze using thermodynamic models (i.e., E-AIM and ISORROPIA) and ambient measurements. The reported pH values differ widely, ranging from close to 0 (highly acidic) to as high as 7 (neutral).In order to understand the reason for this discrepancy, we calculated pH values using these models with different assumptions 25 with regard to model inputs and particle phase states. We find that the large discrepancy is due primarily to differences in the model assumptions adopted in previous studies. Calculations using only aerosol phase composition as inputs (i.e., reverse mode) are sensitive to the measurement errors of ionic species and inferred pH values exhibit a bimodal distribution with peaks between −2 and 2 and between 7 and 10. Calculations using total (gas plus aerosol phase) measurements as inputs (i.e., forward mode) are affected much less by the measurement errors, and results are thus superior to those obtained from the reverse mode 30 calculations. Forward mode calculations in this and previous studies collectively indicate a moderately acidic condition (pH from about 4 to about 5) for fine particles in North China winter haze, indicating further that ammonia plays an important role in determining this property. The differences in pH predicted by the forward mode E-AIM and ISORROPIA calculations may be attributed mainly to differences in estimates of activity coefficients for hydrogen ions. The phase state assumed, which can be either stable (solid plus liquid) or metastable (only liquid), does not significantly impact pH predictions of ISORROPIA. 35Atmos. Chem. Phys. Discuss., https://doi

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“…Dew has a prominent scavenging effect on atmospheric particulates, meanwhile, air quality deteriorates rapidly, and aerosol load and relative humidity increase significantly during fog-haze days [9,10]. In recent years, research on fog-haze weather process, dew amount in urban areas, and water quality has been gaining increasing attention among scholars [11 ÷ 13], especially the transformation of particulates during fog-haze days, which is a recent hot topic.…”

Section: Introductionmentioning

confidence: 99%

Influence of Fog-Haze on Dew Condensation in Urban Areas

Xu¹,

Zhu

Pan

et al. 2018

Teh. vjesn.

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Abstract:In recent years, fog-haze weather has frequently occurred in urban ecosystem, with accompanied dew condensation in the surface layer. Dew formation plays an important role in air purification, which takes fine aerosols in the atmosphere as the condensation nuclei. However, the influence of fog-haze on dew condensation remains unclear. Thus, this study aims to evaluate the influences of fog-haze days on the frequency, intensity, and duration of dew condensation, to reveal the factors relevant to dew condensation during weather pollution, and to improve the air quality in fog-haze days. The monitor-based direct weighing method was employed in this study to observe the vapour condensation in urban greenbelt under fog-haze and normal weather conditions during the frost-free season (April-October 2017) in Changchun, China. The differences in dew condensation intensity and frequency were discriminated under different weather conditions. Then, the influences of fog-haze days on the vapour condensation were analyzed by monitoring the velocity and duration of dew condensation in polluted weather. Finally, a program for improving air quality was proposed based on the analysis of major meteorological factors that affect the dew condensation during the fog-haze days. Results show that the dew condensation velocity decreases significantly (P < 0.01) from 0.0067 mm/h in normal weather to 0.0026 mm/h in a fog-haze day, whereas the condensation duration is prolonged. The dew condensation intensities are 0.064, 0.045, and 0.051 mm/d under fog, haze, and normal weather conditions, respectively, and the fog-haze weather has no significant effect on the frequency or intensity of dew condensation (P > 0.05). The particulate matter concentration, wind speed, air pressure, relative humidity, and solar radiation are the main factors that affect the vapour transport during the fog-haze days. Artificial increase of surface layer vapours can promote the particulates to absorb vapours fully and settle to the ground in the form of dew, thereby reducing the particulate matter concentration within the scope of human activities. The present study supplements the eigenvalues for dew condensation in urban areas during special pollution periods and reveals the influence of fog-haze on the night time vapour condensation in urban areas. Findings of this study provide theoretical basis for further developing the programs for controlling fog-haze weather and improving urban air quality.

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Fossil Fuel Combustion-Related Emissions Dominate Atmospheric Ammonia Sources during Severe Haze Episodes: Evidence from ¹⁵N-Stable Isotope in Size-Resolved Aerosol Ammonium

Cited by 289 publications

References 37 publications

Persistent sulfate formation from London Fog to Chinese haze

Persistent sulfate formation from London Fog to Chinese haze

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

Influence of Fog-Haze on Dew Condensation in Urban Areas

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Fossil Fuel Combustion-Related Emissions Dominate Atmospheric Ammonia Sources during Severe Haze Episodes: Evidence from 15N-Stable Isotope in Size-Resolved Aerosol Ammonium

Cited by 289 publications

References 37 publications

Persistent sulfate formation from London Fog to Chinese haze

Persistent sulfate formation from London Fog to Chinese haze

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

Influence of Fog-Haze on Dew Condensation in Urban Areas

Contact Info

Product

Resources

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Fossil Fuel Combustion-Related Emissions Dominate Atmospheric Ammonia Sources during Severe Haze Episodes: Evidence from ¹⁵N-Stable Isotope in Size-Resolved Aerosol Ammonium