Element in aerosols

Table V Methods of Identifying Sources of Elements in Aerosols and Surface Dust...

Rahn, K. A. Sources of trace elements in aerosols, an approach to clean air. Doctoral dissertation. University of Michigan, Ann Arbor, Michigan. (1971). 

Table I. Mean abundances of crustal elements in aerosols, soil, and road dust in a rural area near Champaign, IL.

Abundances. Additional evidence of possible multiple sources comes from an examination of the mass percentages (abundances) of crustal elements in aerosol samples. Figures 6 through 11 show abundances for Al, Si, K, Ca, Ti, and Fe. 

Rahn, K. A., Sources of Trace Elements in Aerosols—An Approach to... 

The multivariate autocorrelation function (MACF) was computed for each particle-size fraction of the data set, consisting in the concentrations of 23 elements in aerosol samples taken weekly over a period of 60 weeks. 

Fig. 7-18. Left Enrichment factors for volatile elements in aerosols from volcanoes. Data were compiled from Cadle el al. (1973) and Duce et al. (1976) for the volcano Kilauea Mroz and Zoller (1975) for Heimaey Lepel era/. (1978) for St. Augustine Buat-Menard and Arnold (1978) for Etna. Right Enrichment factors for volatile elements in background aerosols. Data are from Duce et al. (1976), triangles, Buat-Menard and Chesselet (1979), diamonds, Zoller et al. (1974), circles, and Maenheut et al. (1979), vertical bars.

Results for elements in aerosol samples which are obtained by multielement techniques from data sets from which information about the sources of the components can be extracted (Gordon 1980). Such methods which make use of data obtained at receptor points are called receptor models. The most important receptor models are chemical mass balances (CMB), enrichment factors, time series correlation, multivariate models and spatial models (Cooper and Watson 1980 Gordon 1988). Dispersion modeling has also been used to explain the... 

McLaren et al. (1995) analyzed water samples for production of standard reference materials and determine 16 elements with detection limits in the subng/g range. Garbe-Schoenberg (1993), Guo and Lichte (1995) and Guenther et al. (1997) determine a number of elements in aerosols, soils and rock standard reference materials. Detection limits for lanthanides reached 0.002 p,g/g and were 0.01 p.g/g for the rest of the elements. 

ETAAS is used to determine about 15-20 elements in aerosol filters, usually after acid extraction. Preconcentration adds about five to six more elements. In soils and plants the method permits the direct determination of about ten to 15 elements after dissolution of the samples. 

Arimoto R, Ray BJ, Duce RA et al (1990) Concentrations, sources, and fluxes of trace-elements in the remote marine atmosphere of New Zealand. J Geophys Res 95 22389-22405 Arimoto R, Duce RA, Savoie DL et al (1992) Trace-elements in aerosol-particles from Bermuda and Barbados—concentrations, sources and relationships to aerosol sulfate. J Atmos Chem 14 439 57... 

Other lesser mechanisms that result in aerosol removal by filters are (1) gravitational settling due to the difference in mass of the aerosol and the carrying gas, (2) thermal precipitation due to the temperature gradient between a hot gas stream and the cooler filter medium which causes the particles to be bombarded more vigorously by the gas molecules on the side away from the filter element, and (3) Brownian deposition as the particles are bombarded with gas molecules that may cause enough movement to permit the aerosol to come in contact with the filter element. Browruan motion may also cause some of the particles to miss the filter element because they are moved away from it as they pass by. For practical purposes, only the three mechanisms shown in Fig. 29-1 are normally considered for removal of aerosols from a gas stream. 

In Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), a gaseous, solid (as fine particles), or liquid (as an aerosol) sample is directed into the center of a gaseous plasma. The sample is vaporized, atomized, and partially ionized in the plasma. Atoms and ions are excited and emit light at characteristic wavelengths in the ultraviolet or visible region of the spectrum. The emission line intensities are proportional to the concentration of each element in the sample. A grating spectrometer is used for either simultaneous or sequential multielement analysis. The concentration of each element is determined from measured intensities via calibration with standards. 

Table in Proposed Sources of Elements in Remote Aerosols ... 

Since the majority of the elements in surface dust arise from deposited aerosol and added soil it is not surprising to find strong linear relationships between the concentrations of the elements in an atmospheric dust and street or house dust. This is illustrated by the two examples given in Fig. 8 for remote house dust vs urban atmospheric dust and street dust vs rural atmospheric dust. As discussed above crustal/soil material is a major component of atmospheric dust and the soil based elements in the atmospheric dust are Al, Ca, Fe, Mg, Mn, Ni, K, Si and Ti. The elements As, Br, Cd, Cl, Co, Cu, Pb, Rb, Se, V, and Zn are, on the other hand, enriched in atmospheric dust. The same elemental distribution applies to surface dust, but in this case their concentrations (compared on a mass basis) are reduced presumably due to dilution with soil. However, the elements enriched in the atmosphere remain enriched in the surface dusts. 

Mizohata, A.and Mamuro, T., (1979) "Chemical Element Balances in Aerosol Over Sakai, Osaka", Annual Report of the Radiation Center of Osaka Prefecture, 20, 55-69. 

The second difference is that the correlations between samples are calculated rather than the correlations between elements. In the terminology of Rozett and Peterson ( ), the correlation between elements would be an R analysis while the correlation between samples would be a Q analysis. Thus, the applications of factor analysis discussed above are R analyses. Imbrle and Van Andel ( 6) and Miesch (J 7) have found Q-mode analysis more useful for interpreting geological data. Rozett and Peterson (J ) compared the two methods for mass spectrometric data and concluded that the Q-mode analysis provided more significant informtlon. Thus, a Q-mode analysis on the correlation about the origin matrix for correlations between samples has been made (18,19) for aerosol composition data from Boston and St. Louis. 

Hopke, P.K. Gladney, E.S. Gordon, G.E. Zoller, W.H. Jones, A.G. "The Use of Multivariate Analysis to Identify Sources of Selected Elements in the Boston Urban Aerosol," Atmos. Environ. 1976,... 

Estimates of the relative concentations of selected elements in fine particles collected upstream from the FGD system are listed in Table II. The values listed are some of the highest concentrations yet reported in the literature for fine coal- derived aerosols, especially those of V, Cr, and 2n, which lie in the tenth-percent range. Additional enhancements in the concentration of these elements resulting from FGD were about a factor of 2 for V, U, W, and As, a factor of 4 for Cr and Mn, and a factor of 15 for Se. If, as predicted by vapor-deposition models, the mass of there constituents resides in 0.02-ym-thick surface layers (10), then the surface concentration would be yet another 5 times greater, yielding concentrations of V, Zn, Cr, and Se in the range of 1 to 5%. 

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