Element balance, chemical

Chemical Chemical differences Chemical element balance... 

More detailed statistical analyses (chemical element balance, principal component analysis and factor analysis) demonstrate that soil contributes >50% to street dust, iron materials, concrete/cement and tire wear contribute 5-7% each, with smaller contributions from salt spray, de-icing salt and motor vehicle emissions (5,93-100). A list is given in Table VII of the main sources of the elements which contribute to street dust. 

Watson, J. G., Chemical element balance receptor model methodology for assessing the sources of fine and total suspended particulate matter in Portland, Oregon, PhD Thesis, Oregon Graduate Center, Beaverton, Oregon, 1979. 

Kowalczyk GS, Gordon GE, Rheingrover SW. 1982. Identification of atmospheric particulate sources in Washington, D.C. using chemical element balances. Environmental Science and Technology 16 79-90. 

We start from the chemical element balance (CEB) method Z) of source resolution as a reference approach although it is not necessary to all of the discussion which follows. 

Chemical Element Balances Maximum Likelihood Method... 

Friedlander, S.K., (1973) "Chemical Element Balances and Identification of Air Pollution Sources,"... 

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. 

Watson, J.G., Jr., (1979) "Chemical Element Balance Receptor Model Methodology for Assessing the Sources of Fine and Total Suspended Particulate Matter in Portland, Oregon," Thesis, Ph.D., Department of Chemistry, Oregon Graduate Center, Beaverton, OR. 

Dzubay, T. G. Chemical Element Balance Method Applied to Dichotomous Sampler Data, Annals N. Y. Acad. Sci., 1980, 338. 126. 

A critical requirement for the success of receptor models for atmospheric particles Is that the compositions of particles from all major sources in an area be accurately known. Chemical element balances (CEBs) of 130 samples taken In Washington, D.C. and analyzed for 40 elements yielded nearly the same source strengths when 28 elements are used In the least-squares fit as when only nine carefully chosen elements are used. Certain elements are important to the stability of CEB fits (Na, Ca, V, Mn, As and Pb) and should be measured carefully In particles from sources. For three of the nine elements (Al, Fe and Zn), other elements can serve as surrogates (many lithophlles for Al and Fe, Sb and Cd for Zn). Measurements on many more sources of each Important type should be done In order that trends can be observed that will allow one to predict compositions of particles from unmeasured sources. Instack measurements should Include collections of at least two size fractions of particles plus vapor-phase species. Measurements of at least 20 elements plus some classes of carbonaceous material should be made. 

Table II. Summary of Chemical Element Balances for Washington, D.C. for Different Numbers of Marker... 

Chemical Element Balances of Atmospheric Particles In the Washington, D.C. Area", submitted to Environ. Scl. Technol. 

In an attempt to provide this focus, forty-seven active receptor model users from government, university, consulting and industry met for 2 1/2 days in February 1980 it. They addressed the models and the information required to use them in six separate task forces 1) Chemical Element Balance Receptor Models, 2) Multivariate Receptor Models, 3) Microscopic Identification Receptor Models, 4) Field Study Design and Data Management, 5) Source Characterization, and 6) Analytical Methods. The objectives of these interrelated task forces were to ... 

Watson, J.G. "Chemical Element Balance Receptor Model... 

Chemical Element Balance. To help resolve this dilemma, the results of a simple chemical element balance based on Ca and K are useful. The calculations were performed separately for each of the 36 vane samples collected, so a distribution of the results could be presented. The input data for these calculations included the mean abundances of the elements in the source materials (local bulk soil and road dust)... 

However, the results of the chemical element balance, based on assumed road and soil sources, were consistent with the multiple sources implied by the observed abundances, the seasonal variations in concentration, and the wind direction dependence. The chemical element balance shows that in summer 1978 roads contributed a mean of 12% to the local TSP and soils a mean of 39%. If these were the only Ca sources, this means that roads contributed 86% and soil 14% of the airborne Ca. 

The factor analysis technique used was unable to distinguish separate soil and road sources. Ca appeared with Al, Si, K, Ti, and Fe on a factor that can be characterized only as "crustal," including both soil and road materials. It appears that a chemical element balance should always be used as a check on factor analysis results, at least until a more sophisticated factor analysis method, such as target transformation factor analysis (14), can be shown not to require it. 

Chemical element balances and identification of air pollution sources in Washington, D.C. Atmos. Environ., 1978, 12, 1143-1153. 

DzubayTG. 1980. Chemical element balance method applied to dichotomous sampler data. Ann NY Acad Sci 338 126-144. 

The chemical mass balance (CMB) method depends on the inversion of (13.11) or (13.12) to obtain the source contributions mj or Anij. Values of pi are measured at a given sampling site. The matrix Cij should also correspond to the point of measurement. Usually, however, it is assumed that the value of c,-/ is equal to (he value at the source, and fractionation by exchange with (he gas phase or by sedimentation is neglected. Hence in carrying out the chemical element balance, it is necessary to choose elements for which fractionation is not tmportanl. 

TABLE 24.5 Average Results of Chemical Element Balances of 130 Samples from Washington, DC, Area... 

---