Trace emission factor

Emission factors have been estimated for the release of trace metals to water from various source categories and these have been used to estimate inputs of these metals into the aquatic ecosystem. The global anthropogenic input of nickel into the aquatic ecosystem for 1983 is estimated to be between 33 and 194 million kg/year with a median value of 113 million kg/year (Nriagu and Pacyna 1988). 

Hasanen, E., Aunela-Tapola, L. et al. 1997. Emission factors and annual emissions of bulk and trace elements from oil shale fuelled power plants. The Science of the Total Environment, 198, 1-12. 

Anderson, D., Emission Factors for Trace Substances, EPA Document... 

Similarly, different results have been found for the impact of brake wear particles. While unequivocally a strong enrichment of brake-related chemical trace elements (Sb, Ba, Cu) is found at trafficked sites [63], the quantification of overall PM contribution from brake wear is associated with uncertainties. An even wider range of emission factors was found for re-suspension of road dust (cf. Table 4). It should be noted that re-suspension may be a strong source of PM during wintertime when de-icing salt is spread out. For a traffic site in southern Germany exceedance of the daily PM limit value could be tracked back to road salting in 12 of 43 cases [66]. 

Bukowiecki N, Lienemann P, Hill M et al (2009) Real-world emission factors for antimony and other brake wear related trace elements size-segregated values for light and heavy duty vehicles. Environ Sci Technol 43 8072-8078... 

Another source of metallic contamination in the studied region comes from the residual oil combustion used for electric utilities and fluvial and terrestrial transportation. Using the selected emission factors (quantity of trace element released by quantity of material consumed) given by Nriagu and Pacyna (1988) and Nriagu (1989), the electric-power production installed in the Amazonian states and the fuel consumption used for transportation (Ministerio de Minas... 

Laursen K. K., Ferek R. J., and Hobbs P. V. (1992) Emission factors for particulates, elemental carbon, and trace gases from the Kuwait oil fires. J. Geophys. Res. 97,14491 -14497. 

With respect to contributions of other mobile sources to the atmospheric burden of trace metals, very few data are available. The National Aeronautics and Space Administration in 1974 published calculated annual average ambient concentrations at or near airports of 49 trace elements attributable to aircraft most values were less than numbers. Of interest, however, are the estimates for the environmentally important metals, titanium, vanadium, and cadmium these were given as 24 ng/m , 0.12 ng/m and < 14 ng/m , respectively (56). EflForts to characterize aircraft emissions and to develop emissions factors by means of dynamometer tests are under way. One such experiment is being performed at Pratt and Whitney under contract to the Environmental Protection Agency results from this study should be available in mid-1978 (57). 

Skeaff JM, Dubreuil AA. 1997. Calculated 1993 emission factors of trace metals for Canadian non-ferrous smelters. Atmos Environ 31(10) 1449-1457. 

This contribution comprehensively reviews the literature reported for particulate emissions of motor vehicles operated under real-world conditions. This article will mainly focus on the results published for size segregated emissions factors of particle mass, elemental and organic carbon, crustal components and selected trace metals, since information is important for health effects studies and source reconciliation modeling efforts. 

The emission rates derived from the tunnel studies conducted so far show that the amount of emitted partieulate matter is in the order of tens to hundreds of mg veh km . The emission factors determined for individual species varied from several mg veh km for main components to some pg veh km for trace metals, indieating that particulate emissions from motor vehicles are dominated by carbonaceous speeies and mineral components. A compilation of most relevant PMio studies is presented in Table 2 corresponding data for the PM fraction smaller than 2.5 pm (PM2.5) is summarized in Table 3. 

Environmental Aspects. Airborne particulate matter (187) and aerosol (188) samples from around the world have been found to contain a variety of organic monocarboxyhc and dicarboxyhc acids, including adipic acid. Traces of the acid found ia southern California air were related both to automobile exhaust emission (189) and, iadirecfly, to cyclohexene as a secondary aerosol precursor (via ozonolysis) (190). Dibasic acids (eg, succinic acid) have been found even ia such unlikely sources as the Murchison meteorite (191). PubHc health standards for adipic acid contamination of reservoir waters were evaluated with respect to toxicity, odor, taste, transparency, foam, and other criteria (192). BiodegradabiUty of adipic acid solutions was also evaluated with respect to BOD/theoretical oxygen demand ratio, rate, lag time, and other factors (193). 

Fig. 19.7 Laser emission of R6G (2 mM) in different solvents using a high Q factor OFRR the spectra are acquired from the scattered light. Traces are shifted vertically for clarity. Reprinted from Ref. 20 with permission. 2008 International Society for Optical Engineering...

Acoustic emission from fluid flow through an orifice plate inserted in a pipeline contains a wealth of information, which can be used to predict, for example composition, flow or density [5]. Acoustic signatures from fluid flow are affected by several physical factors such as flow rate differential pressure over the orifice plate static pressure as well as chemical-physical factors - density, composition, viscosity. It is the objective of PLS modeling to extract the relevant features from the acoustic spectra and make use of these embedded signals in indirect multivariate calibration [1,2]. Several successful examples, including prediction of trace concentrations of oil in water, have been reported [5]. 

Cluster analysis Is used to determine the particle types that occur in an aerosol. These types are used to classify the particles in samples collected from various locations and sampling periods. The results of the sample classifications, together with meteorological data and bulk analytical data from methods such as instrunental neutron activation analysis (INAA). are used to study emission patterns and to screen samples for further study. The classification results are used in factor analysis to characterize spatial and temporal structure and to aid in source attribution. The classification results are also used in mass balance comparisons between ASEM and bulk chemical analyses. Such comparisons allow the combined use of the detailed characterizations of the individual-particle analyses and the trace-element capability of bulk analytical methods. 

The samples were analyzed for trace metals and sulfate as well as for three fractions of particulate organic matter (POM) using sequential extraction with cyclohexane (CYC), dichloromethane (DCM) and acetone (ACE). Factor analysis was used to identify the principal types of emission sources and select source tracers. Using the selected source tracers, models were developed of the form POM = a(V) + b(Pb) + - - -, where a and b are regression coefficients determined from ambient data adjusted to constant dispersion conditions. The models for CYC and ACE together, which constitute 90% of the POM, indicate that 40% (3.0 pg/m ) of the mass was associated with oil-burning, 19% (1.4 pg/m ) was from automotive and related sources and 15% (1.1 pg/m ) was associated with soil-like particles. 

In developing a multiple regression model for apportioning sources of TSP in New York City, Kleinman, et al.(2) selected Pb, Mn, Cu, V and SO, as tracers for automotive sources, soil-related sources, incineration, oil-burning and secondary particulate matter, respectively. These were chosen on the basis of the results of factor analysis and a qualitative knowledge of the principal types of sources in New York City and the trace metals present in emissions from these types of sources. Secondary TSP, automotive sources and soil resuspension were found to be the principal sources of TSP in 1974 and 1975 ( ). 

Internal standards are also used in trace metal analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) techniques. An internal standard solution is added to ICP-MS and ICP-AES samples to correct for matrix effects, and the response to the internal standard serves as a correction factor for all other analytes (see also chapter 2). 

If no fluorophore exists in a given area of the thin-layer plate, then no emission signal can be obtained. The fluorescence of the sample is then an absolute quantity relative to this zero signal and proportional to the number of emitting species present in the sample. However, in practice, the adsorbent does contain trace amounts of fluorescent impurities and thus background noise is observed, but usually at a lower level than experienced in absorption measurements. The low background noise is an important factor in the high sensitivity of fluorescence. 

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