Effect of ambient NH3 levels on PM2.5 composition in the Great Smoky Mountains National Park

Olszyna, Kenneth J.; Bairai, S. T.; Tanner, Roger L.

doi:10.1016/j.atmosenv.2005.04.011

Cited by 38 publications

(18 citation statements)

References 27 publications

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“…Our ammonia results are similar to levels found in Rome (Perrino et al, 2002), as well as to a swine production facility in eastern North Carolina, USA (Baek et al, 2004). Agricultural (Robarge et al, 2002) and suburban (Hu et al, 2008) areas show slightly lower concentrations, while the Great Smoky Mountains National Park, USA (Olszyna et al, 2005) and the urban area of North Birmingham, USA show concentrations below 2 µg/m 3 (Edgerton et al, 2007). The concentrations of ammonia in Santiago are among the highest, due to the large number and variety of sources (mobile sources, wastewater treatment plants, agricultural activities in the southwestern part of the city, rivers and channels with loads of organic matter, and wetlands) and adverse geographical and meteorological conditions for dispersion of gases and particles.…”

Section: Ammonia Concentration Levelssupporting

confidence: 71%

“…Through reactions with acid pollutants to form ammonium nitrate (NH 4 NO 3 ), ammonium sulphates (NH 4 HSO 4 and [NH 4 ] 2 SO 4 ) and ammonium chloride (NH 4 Cl) (Walker et al, 2004;Olszyna et al, 2005;Morales and Leiva, 2006), ammonia (NH 3 ) is a main contributor to secondary particulate matter. Additionally, those particulates can significantly contribute to visibility impairment and regional haze.…”

Section: Introductionmentioning

confidence: 99%

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Urban Atmospheric Ammonia in Santiago City, Chile

Toro

Canales

Flocchini

et al. 2014

Aerosol Air Qual. Res.

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To improve the current understanding of the ammonia distribution in the major urban area of Chile, measurements of atmospheric NH 3 were collected in Santiago during three sampling periods (25 April to 27 May, 11 to 26 June and 27 June to 31 July 2008). Additionally, air quality and meteorological data as well as NH 4 + , NO 3 -, SO 4 = and Ca +2 concentrations in fine particles were collected during the same period. NH 3 concentrations for the different sites in the three sampling periods varied from 7.7 ± 2.0 µg/m 3 to 19.8 ± 2.1 µg/m 3 . The results of one-way ANOVA and cluster analysis suggest that were no significant differences between the three sampling periods, but significant differences in NH 3 concentrations were detected between the sampling sites. Furthermore, two clusters were found with a pronounced difference between sampling sites located in the eastern part of the city and those located in the western part of the city. The results suggest that the distribution of ammonia in the western part of the city is due to the emissions of ammonia by agricultural areas, wetlands and the large sewage treatment plants, while in the eastern part of the city, ammonia emissions are governed by vehicular emissions. Fine particles (PM 2.5 ) chemical speciation showed NH 4 + /SO 4 = and NO 3 -/SO 4 = molar-equivalents ratios of 5.7 ± 0.3 and 1.8 ± 0.1, respectively. The results show that during the sampling period, complete neutralisation of H 2 SO 4 and HNO 3 occurred in the presence of excess of NH 4 + and NH 3 . Therefore, the atmosphere of Santiago can be considered to be ammonia-rich in the gas phase. Abundant NH 3 was present to neutralise the acid components, such as H 2 SO 4 and HNO 3 , and to form fine particulate ammonium salts, such as (NH 4 ) 2 SO 4 , NH 4 NO 3 and others. Relatively high humidity and low temperatures in the cold season support the formation of particulate ammonium nitrate.

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Section: Ammonia Concentration Levelssupporting

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Urban Atmospheric Ammonia in Santiago City, Chile

Toro

Canales

Flocchini

et al. 2014

Aerosol Air Qual. Res.

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“…Due to volatilization of NH 4 NO 3 , the equilibrium shifts towards the left with rise in temperature (Wang et al 2005). Olszyna et al 2005 observed that partial pressure products (Pr) of gas phase NH 3 and HNO 3 were 2-20 times below the threshold value for NH 4 NO 3 formation in PM 2.5 and 2-3 folds increase in NH 3 levels or 2°C drop in temperature was sufficient to produce NH 4 NO 3 aerosol. The present study shows that the concentrations of NH 4 + and NO 3 -gradually decreased from winter till monsoon.…”

Section: Secondary Ionic Speciesmentioning

confidence: 94%

Fine mode aerosol chemistry over a tropical urban atmosphere: characterization of ionic and carbonaceous species

et al. 2012

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An extensive aerosol sampling program was conducted during January-December 2006 over Kolkata (22º33′ N and 88º20′ E), a mega-city in eastern India in order to understand the sources, distributions and properties of atmospheric fine mode aerosol (PM 2.5 ). The primary focus of this study is to determine the relative contribution of natural and anthropogenic as well as local and transported components to the total fine mode aerosol loading and their seasonal distributions over the metropolis. The average concentrations of fine mode aerosol was found to be 71.2±25.2 μgm -3 varying between 34.5 μgm -3 in monsoon and 112.6 μgm -3 in winter. The formation pathways of major secondary aerosol components like nitrate and sulphate in different seasons are discussed. A long range transport of dust aerosol from arid and semiarid regions of western India and beyond was observed during pre-monsoon which significantly enriched the total aerosol concentration. Vehicular emissions, biomass burning and transported dust particles were the major sources of PM 2.5 from local and continental regions whereas seasalt aerosol was the major source of PM 2.5 from marine source regions.

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“…Traditional techniques employ passive samplers such as annular diffusion denuders with off-line analysis such as ion chromatography (Hoek et al, 1996;Burkhardt et al, 1998;Matsumoto and Okita, 1998;Erisman et al, 2001;Olszyna et al, 2005;Smith et al, 2007). Drawbacks of these methods often include low time resolution, poor sensitivity, and human-induced errors.…”

Section: Introductionmentioning

confidence: 99%

Atmospheric ammonia measurements in Houston, TX using an external-cavity quantum cascade laser-based sensor

et al. 2011

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Abstract. In order to improve the current understanding of the dynamics of ammonia (NH 3 ) in a major industrial and urban area, intensive measurements of atmospheric NH 3 were conducted in Houston during two sampling periods (12 February 2010-1 March 2010 and 5 August 2010-25 September 2010). The measurements were performed with a 10.4-µm external cavity quantum cascade laser (EC-QCL)-based sensor employing conventional photo-acoustic spectroscopy. The mixing ratio of NH 3 ranged from 0.1 to 8.7 ppb with a mean of 2.4 ± 1.2 ppb in winter and ranged from 0.2 to 27.1 ppb with a mean of 3.1 ± 2.9 ppb in summer. The larger levels in summer probably are due to higher ambient temperature. A notable morning increase and a mid-day decrease were observed in the diurnal profile of NH 3 mixing ratios. Motor vehicles were found to be major contributors to the elevated levels during morning rush hours in winter. However, changes in vehicular catalytic converter performance and other local or regional emission sources from different wind directions governed the behavior of NH 3 during morning rush hours in summer. There was a large amount of variability, particularly in summer, with several episodes of elevated NH 3 mixing ratios that could be linked to industrial facilities. A considerable discrepancy in NH 3 mixing ratios existed between weekdays and weekends. This study suggests that NH 3 mixing ratios in Houston occasionally exceeded previous modeling predictions when sporadic and substantial enhancements occurred, potentially causing profound effects on particulate matter formation and local air quality.

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Effect of ambient NH3 levels on PM2.5 composition in the Great Smoky Mountains National Park

Cited by 38 publications

References 27 publications

Urban Atmospheric Ammonia in Santiago City, Chile

Urban Atmospheric Ammonia in Santiago City, Chile

Fine mode aerosol chemistry over a tropical urban atmosphere: characterization of ionic and carbonaceous species

Atmospheric ammonia measurements in Houston, TX using an external-cavity quantum cascade laser-based sensor

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