Seasonal variation in atmospheric aerosols concentration covering northern Kyushu, Japan and Seoul, Korea

Tsai

et al. 2007

Environ Geochem Health

In 2004, airborne particulate matter (PM) was collected for several aerosol episodes occurring in the southern region of Taiwan. The particulate samples were taken using both a MOUDI (Micro-orifice Uniform Deposit Impactor) and a nano-MOUDI sampler. These particulate samples were analyzed for major water-soluble ionic species with an emphasis to characterize the mass concentrations and distributions of these ions in the ambient ultrafine (PM0.1, diameter <0.1 microm) and nano mode (PMnano, diameter <0.056 microm) particles. Particles collected at the sampling site (the Da-Liao station) on the whole exhibited a typical tri-modal size distribution on mass concentration. The mass concentration ratios of PMnano/PM2.5, PM0.1/PM2.5, and PM1/PM2.5 on average were 1.8, 2.9, and 71.0%, respectively. The peak mass concentration appeared in the submicron particle mode (0.1 microm < diameter <1.0 microm). Mass fractions (percentages) of the three major water-soluble ions (nitrate, sulfate, and ammonium) as a group in PMnano, PM0.1, PM1, and PM2.5 were 18.4, 21.7, 50.0, and 50.7%, respectively. Overall, results from this study supported the notion that secondary aerosols played a significant role in the formation of ambient submicron particulates (PM0.1-1). Particles smaller than 0.1 microm were essentially basic, whereas those greater than 2.5 microm were neutral or slightly acidic. The neutralization ratio (NR) was close to unity for airborne particles with diameters ranging from 0.18 to 1 microm. The NRs of these airborne particles were found strongly correlated with their sizes, at least for samples taken during the aerosol episodes under study. Insofar as this study is exploratory in nature, as only a small number of particulate samples were used, there appears to be a need for further research into the chemical composition, source contribution, and formation of the nano and ultrafine mode airborne particulates.

Section: Neutralization Ratio Of Airborne Particlessupporting

confidence: 65%

Water-soluble inorganic ions in airborne particulates from the nano to coarse mode: a case study of aerosol episodes in southern region of Taiwan

Tsai

et al. 2007

Environ Geochem Health

Journal of the Air & Waste Management Association

“…The partial anthropogenic origin of Cl is clearly evidenced from the Cl/Na excess in some peak events. Conversely, in summer, a Cl/Na deficit was detected probably because of the well-known volatilization of ammonium chloride by interaction of ammonium nitrate and sodium chloride 36,37 As mentioned previously, the time series of local pollutants, such as As, Cu, Ni, P, and V ( Figure 4) and Cd, Co, Pb, Sb, Se, Sn, Ti, Tl, and Zn, were characterized by random peak concentrations associated with specific pollution episodes. Some elements, such as Cu, As, Zn, and P or Ni and V (Figure 4) show a parallel time evolution because of their common origin or the fact that they are emitted by close industrial plants.…”

Section: Pm 10 and Pm 25 Chemistrymentioning

confidence: 99%

Identification and Chemical Characterization of Industrial Particulate Matter Sources in Southwest Spain

Alástuey

Querol

Plana

et al. 2006

A detailed physical and chemical characterization of coarse particulate matter (PM 10 ) and fine particulate matter (PM 2.5 ) in the city of Huelva (in Southwestern Spain) was carried out during 2001 and 2002. To identify the major emission sources with a significant influence on PM 10 and PM 2.5 , a methodology was developed based on the combination of: (1) real-time measurements of levels of PM 10 , PM 2.5 , and very fine particulate matter (PM 1 ); (2) chemical characterization and source apportionment analysis of PM 10 and PM 2.5 ; and (3) intensive measurements in field campaigns to characterize the emission plumes of several point sources. Annual means of 37, 19, and 16 g/m 3 were obtained for the study period for PM 10 , PM 2.5 , and PM 1 , respectively. High PM episodes, characterized by a very fine grain size distribution, are frequently detected in Huelva mainly in the winter as the result of the impact of the industrial emission plumes on the city. Chemical analysis showed that PM at Huelva is characterized by high PO 4 3Ϫ and As levels, as expected from the industrial activities. Source apportionment analyses identified a crustal source (36% of PM 10 and 31% of PM 2.5 ); a traffic-related source (33% of PM 10 and 29% of PM 2.5 ), and a marine aerosol contribution (only in PM 10 , 4%). In addition, two industrial emission sources were identified in PM 10 and PM 2.5 : (1) a petrochemical source, 13% in PM 10 and 8% in PM 2.5 ; and (2) a mixed metallurgical-phosphate source, which accounts for 11-12% of PM 10 and PM 2.5 . In PM 2.5 a secondary source has been also identified, which contributed to 17% of the mass. A complete characterization of industrial emission plumes during their impact on the ground allowed for the identification of tracer species for specific point sources, such as petrochemical, metallurgic, and fertilizer and phosphate production industries.

Aerosol Science and Technology

“…The influence of these artefacts on PM levels may be highly significant as carbonaceous aerosols may represent up to 70% of the fine PM mass (Turpin et al 2000). Sampling artefacts are also known to affect inorganic species, such as the loss of ammonium nitrate by volatilization (Schaap et al 2004;Wieprecht et al 2004), adsorption of water vapor, sulphation of CaCO 3 or nitrification of CaCO 3 or NaCl (Harrison and Kito 1990;Wakamatsu et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Influence of Sampling Artefacts on Measured PM, OC, and EC Levels in Carbonaceous Aerosols in an Urban Area

Viana¹,

Chi²,

Maenhaut³

et al. 2006

Sampling of particulate matter (PM) with filter media is subject to the influence of positive and negative artefacts. The complexity of these measurements derives from the use of different instrumentation, face velocities, and filter types. Carbonaceous compounds are one of the main PM chemical components affected by these artefacts. In this study, two main types of artefacts were evaluated at an urban site in Ghent (Belgium) during the summer period: those related to the sampling procedure (high-or low-volume samplers) and those related to the adsorption and/or volatilization of carbonaceous species. For their measurement, two high-volume (PM10 and PM2.5) samplers with single quartz fiber filters and two low-volume PM2.5 samplers (one of them coupled to an annular diffusion denuder) with double quartz fiber filters (front and backup) were used. PM2.5 mass concentrations measured by means of the lowvolume sampler (front filter) were, on average, 31% higher than those registered with the high-volume sampler. PM2.5 mass concentrations registered with the low-volume sampler coupled to the diffusion denuder represented 88% of the PM2.5 mass collected with the undenuded low-volume sampler. Similar values for organic carbon (OC) were recorded for the high-and low-volume samplers. Front filter OC levels for the denuded samples represented 66% of the front filter OC mass on the undenuded samples. Using the backup filter OC data to apply a correction to the front filter data as suggested by Mader et al. (2003) only marginally reduced the discrepancy between the undenuded and denuded OC data, indicating that such correction does not result in consistent OC data for an urban area in Western Europe during summer.