Emissions trace metal oxides

The analytical performance of ICP-MS is compared with other analytical techniques for the determination of trace metal oxide particulates after the simulated detonation of an RDD [10]. Table 20.9 shows a comparison of the instrumental parameters used in inductively coupled plasma optical emission spectroscopy (ICP-OES) and an ICP-MS instrument. These two techniques were used to analyze Sr, Ti, and Ce in ceramic oxides that may be used in RDDs. ICP-MS provided lower detection limits for the metals than ICP-OES. Overall method performance was comparable with ICP-OES and instrumental neutron activation analysis (INAA), another well-established nuclear and radiological analytical technique. 

Emissions from other nonferrous metal facilities are primarily metal fumes or metal oxides of extremely small diameter. Zinc oxide fumes vary from 0.03 to 0.3 jiim and are toxic. Lead and lead oxide fumes are extremely toxic and have been extensively studied. Arsenic, cadmium, bismuth, and other trace metals can be emitted from many metallurgical processes. 

In roadside soils, lead was present in the more soluble forms such as PbCIBr and PbS04 from automobile emissions compared to soils near smelters or in mining sites (Adriano, 2001), which contained oxides, sulfides and carbonates (galena, anglesite and cerussite) with low solubility. However, after oxidation of sulfide into sulfate, the soils became very acidic, resulting in the increase in both solubility and bioavailability of the trace metals. 

Trace metals are introduced to the ocean by atmospheric feUout, river runoff, and hydrothermal activity. The latter two are sources of soluble metals, which are primarily reduced species. Upon introduction into seawater, these metals react with O2 and are converted to insoluble oxides. Some of these precipitates settle to the seafloor to become part of the sediments others adsorb onto surfaces of sinking and sedimentary particles to form crusts, nodules, and thin coatings. Since reaction rates are slow, the metals can be transported considerable distances before becoming part of the sediments. In the case of the metals carried into the ocean by river runoff, a significant fraction is deposited on the outer continental shelf and slope. Hydrothermal emissions constitute most of the somce of the metals in the hydrogenous precipitates that form in the open ocean. 

The production of coke by the carbonization of bituminous coal leads to the release of chemically complex emissions from coke ovens that include both gases and particulate matter of varying chemical composition. The chemical and physical properties of coke oven emissions vary depending on the constituents. The emissions include coal tar pitch volatiles (e.g., particulate polycyclic organic matter, polycyclic aromatic hydrocarbons, and polynuclear aromatic hydrocarbons), aromatic compounds (e.g., benzene and jS-naphthyl amine), trace metals (e.g., arsenic, beryllium, cadmium, chromium, lead, and nickel), and gases (e.g., nitric oxides and sulfur dioxide). 

A number of methods exist for the determination of parts-per-billion (ng/g) levels of chromium in aqueous media (Table 8.1). These are repeatedly reviewed as new techniques are introduced (4,5,6). Potentially all these techniques could be applied to petroleum samples after matrix destruction, but in practice, only a few have been utilized. After wet oxidation of a large sample (> 100 g), 10 to 50 fig of chromium may be determined by a colorimetric procedure with 1,5-diphenylcarbohydrazide after iron, copper, molybdenum, and vanadium are extracted as the cup-ferrates (3). In survey analyses, Cr levels as low as 5 ng/g have been measured by optical emission spectroscopy after ashing (2,3) or directly by neutron activation with extended irradiation and counting times (1). Concentrations of chromium above 100 ng/g in used lubricating oils have been measured directly by flame atomic absorption (8) for lower concentrations, heated vaporization atomic absorption (HVAA) has been utilized (9). In the Trace Metals Project, two procedures using this latter technique were evaluated for the determination of 10 ng Cr/g in a variety of petroleum matrices. 

Analysis of Trace or Minor Components. Minor or trace components may have a significant impact on quaHty of fats and oils (94). Metals, for example, can cataly2e the oxidative degradation of unsaturated oils which results in off-flavors, odors, and polymeri2ation. A large number of techniques such as wet chemical analysis, atomic absorption, atomic emission, and polarography are available for analysis of metals. Heavy metals, iron, copper, nickel, and chromium are elements that have received the most attention. Phosphoms may also be detectable and is a measure of phosphoHpids and phosphoms-containing acids or salts. 

Also, wood fuel is low in sulfur, ash, and trace toxic metals. Wood-fired power plants emit about 45% less nitrogen oxides, NO, than coal-fired units. Legislation intended to reduce sulfur oxides, SO, and NO emissions may therefore result in the encouragement of wood-burning or cofiring wood with coal. 

MetaUic impurities in beryUium metal were formerly determined by d-c arc emission spectrography, foUowing dissolution of the sample in sulfuric acid and calcination to the oxide (16) and this technique is stUl used to determine less common trace elements in nuclear-grade beryUium. However, the common metallic impurities are more conveniently and accurately determined by d-c plasma emission spectrometry, foUowing dissolution of the sample in a hydrochloric—nitric—hydrofluoric acid mixture. Thermal neutron activation analysis has been used to complement d-c plasma and d-c arc emission spectrometry in the analysis of nuclear-grade beryUium. 

The analysis methods are national in scope and address emissions from a wide variety of industrial and community source types. The materials reviewed are of widely disparate natures. They include metals, and bulk and trace hydrocarbons, including chlorinated and oxide derivatives of hydrocarbons. The analyses are intended to be preliminary screening analyses for use in scoping and prioritizing regulatory attention to toxic exposures from the chemicals studied. 

Acid rain is caused primarily by sulfur dioxide emissions from burning fossil fuels such as coal, oil, and natural gas. Sulfur is an impurity in these fuels for example, coal typically contains 2-3% by weight sulfur.1M Other sources of sulfur include the industrial smelting of metal sulfide ores to produce the elemental metal and, in some parts of the world, volcanic eruptions. When fossils fuels are burned, sulfur is oxidized to sulfur dioxide (SO2) and trace amounts of sulfur trioxide (SC>3)J21 The release of sulfur dioxide and sulfur trioxide emissions to the atmosphere is the major source of acid rain. These gases combine with oxygen and water vapor to form a fine mist of sulfuric acid that settles on land, on vegetation, and in the ocean. 

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