Characteristics of water-soluble inorganic chemical components in size-resolved airborne particulate matters - Sheffield, UK

Abstract

To characterise the water-soluble inorganic components of PM(10) in the urban area of Sheffield, size-resolved aerosol samples were collected using an electric low pressure impactor (ELPI) during a 13-day sampling campaign in October and November 2006. Cl(-), NO(3)(-), SO(4)(2-), and NH(4)(+) were determined by ion chromatography, and Na(+), K(+), Mg(2+), and Ca(2+) by inductively coupled plasma-mass spectrometry. Back trajectories analyses revealed that the air masses could be classified into two main groups. In the "maritime regime", the air masses moved mostly over the sea and just short distances (ca. 100 to 150 km) over land; in the "terrestrial regime", the air masses had moved long distances (ca. 300 to 600 km) over land before reaching the sampling site. The chemical composition of the particles was strongly influenced by the origins of the air masses. Air mass belonging to the maritime regime brought more sea-salt species such as Na(+), Cl(-), and Mg(2+). Air mass belonging to the terrestrial regime carried more K(+) and secondary components like SO(4)(2-), NO(3)(-), and NH(4)(+). Sulfate showed bimodal distribution, peaking both in the fine mode (particle size <0.96 microm) and the coarse mode (particle size >0.96 microm). Nitrate exhibited a bimodal distribution in the terrestrial regime but only a coarse mode in maritime regime. Ammonium displayed a unimodal size distribution, peaking in the fine size range, mainly bound to sulfate and nitrate. In the maritime regime, chloride showed a unimodal distribution, peaking in the coarse size range. In the terrestrial regime, chloride appeared to be bimodal with one peak in the fine mode, reflecting the presence of chloride sources from industries, and another one in the coarse mode, mainly from sea spray. Although in general the air mass trajectories can be grouped into "maritime" and "terrestrial" regimes, the results suggest that air masses reaching Sheffield have been impacted by both maritime and terrestrial sources.

Insights into factors affecting nitrate in PM2.5 in a polluted high NOx environment through hourly observations and size distribution measurements

“…Formation pathways of aerosol nitrate have been discussed in a number of studies [e.g., Seinfeld and Pandis , ; Zhuang et al ., , ; Xie et al ., ; Pathak et al ., , ]. These studies conclude that the fine mode NO 3 − is formed through two pathways: (1) homogeneous gas‐phase transformation of NO 2 to HNO 3 (g) , followed by reaction with ammonia to form NH 4 NO 3 (reverse reaction of ), and (2) heterogeneous hydrolysis of N 2 O 5 on the preexisting particles .…”

“…Increase in temperature or drop in RH could release gaseous HNO 3 . The subsequent reactions of gaseous HNO 3 with coarse soil and sea‐salt particles ( and ) could shift nitrate to coarse particles and thereby change size distributions of nitrate [ Xie et al ., ]: …”

“…In Bondville, Illinois, in the U.S., the fine mode NH 4 NO 3 was the dominant contributor to particle NO 3 − in winter [ Lee et al ., ]. In Sheffield, central England, size distribution characteristics of NO 3 − were strongly influenced by air mass origins: when the air masses had traveled long distances over land before reaching the sampling site, NO 3 − exhibited a bimodal distribution; when the air masses moved mostly over the sea and just short distances over land, only the coarse mode was observed [ Xie et al ., ]. In past studies conducted in HK, Zhuang et al .…”

“…Production of NO 3 − in fine mode is mainly via two pathways, i.e., homogeneous reaction and heterogeneous reaction . The homogeneous reaction is believed to be the dominant contributor while the heterogeneous reaction plays a more important role during nighttime [ Xie et al ., ]. In recent studies, Pathak et al .…”

Quantification of Low Pressure Impactor Wall Deposits during Zinc Nanoparticle Sampling

“…They are widely used in various fields for characterizing aerosols, such as environmental dust and haze (e.g., Kang et al, 2013), coals (e.g., Wang et al, 2007;Kazanc et al, 2013), urban aerosols (e.g., Maenhaut et al, 2002;Salma et al, 2002;Wagner et al, 2008;Xie et al, 2009), drugs (e.g., Klemmer et al, 2013;McBride et al, 2013;Sultana et al, 2013;Zhu et al, 2014), and bacterial aerosols (e.g., Simon et al, 2013;Li 2013). In addition, impactors are commonly used for characterizing workplace environments (e.g., Cohen and Powers 2000;Chen et al, 2007;Wu and Vincent, 2007;Dahlin et al, 2008a;Dahlin et al, 2008b;Dall'Osto et al, 2008;Linnainmaa et al, 2008;Birch et al, 2011;Yang 2011;Coggins et al, 2012;Ehrlich et al, 2013).…”