Smokestack emissions

Typical examples of gaseous samples include automobile exhaust, emissions from industrial smokestacks, atmospheric gases, and compressed gases. Also included with gaseous samples are solid aerosol particulates. 

Air Pollution Control Device Meehanism or equipment that eleans emissions generated by a source (e.g., an incinerator, industrial smokestack or an automobile exhaust system) by removing pollutants that would otherwise be released to the atmosphere. 

Nitrogen oxide is a pollutant commonly found in smokestack emissions- One way to remove it is to react it with ammonia. 

Sulfur dioxide emissions from power plants can be reduced by spraying a water solution of calcium hydroxide directly into the smokestack. This "scrubbing" operation brings about the reaction... 

Sulfur dioxide can be removed from the smokestack emissions of power plants by reacting it with hydrogen sulfide, producing sulfur and water. What volume of hydrogen sulfide at 27°C and 755 mm Hg is required to remove the sulfur dioxide produced by a power plant that bums one metric ton of coal containing 5.0% sulfur by mass How many grams of sulfur are produced by the reaction of H2S with S02 ... 

Acid precipitation, or acid rain, can causes significant impacts on freshwater, coastal, and forested ecosystems (e.g.. Likens et ai, 1996). Both NOi", from NO emissions, and SO from SO2 emissions contribute significantly to acid rain. The relative ratio of SO /NOf in precipitation will be substantially determined by the regional emissions of SO2/NO3. In developed countries, uncontrolled combustion of coal and high-sulfur fuel oil led to significant emissions of SO2, relative to NO Due to strict control of smokestack SO2 emissions in some regions and increasing NO emissions from automobiles, the relative contribution of NOi is expected to increase (Sirois, 1993 Mayewski et ai, 1990). 

Proximity to the smokestacks of metal smelters is positively associated with increased levels of lead in the hair (manes) of horses and in tissues of small mammals, and is consistent with the results of soil and vegetation analyses (USEPA 1972). Lead concentrations were comparatively high in the hair of older or chronically impaired horses (USEPA 1972). However, tissues of white-tailed deer (Odocoileus virginianus) collected near a zinc smelter did not contain elevated levels of lead (Sileo and Beyer 1985). Among small mammals near a metal smelter, blood ALAD activity was reduced in the white-footed mouse but normal in others, e.g., the short-tailed shrew (Beyer et al. 1985). The interaction effects of lead components in smelter emissions with other components, such as zinc, cadmium, and arsenic, are unresolved (USEPA 1972) and warrant additional research. 

Uses. In construction materials manufacture of steel, aluminum, and magnesium as a scrubbing agent to remove sulfur dioxide emissions from smokestacks manufacmre of glass, paper, and industrial chemicals in fungicides, insecticides, and lubricants... 

Armstrong et al, (28) describe a unique approach of attaching sampling equipment to tethered balloons which are maneuvered from the ground into the plume of smokestack emissions. Aircraft sampling in plumes ( 9) has long been used, but it is expensive and difficult. 

Transmissometers in simplest form consist of a light source and a detector located some distance along the axis of the light beam. Among their applications, these devices are commonly used at airports to provide data in visual ranging conditions and are used to measure particle loadings in smokestacks. When calibrated for the type of particles present in this aerosol, a semiquantitative measure of the particulate emissions can be made, with knowledge of the volumetric gas flow. 

Emission Pollution discharged into the atmosphere from smokestacks, other vents, and surface areas of commercial or industrial facilities from residential chimneys and from motor vehicles, locomotives, or air craft exhausts. 

Secondly I think one has to look very carefully at transport phenomena. Several speakers in this Study Week have referred to the effect of the introduction of tall stacks which permit an increased dilution of emissions from power plants. The inclusion of a tall stack at a power plant does not cut the deposition in the vicinity of that stack — and you can use the term vicinity in any way you like — to zero and the deposition at a distance of 500 kilometers to 100%. A very substantial fraction of the deposition associated with emission from a particular source, even with the tall stack, occurs relatively near to that source and again, the question of how near is one, that is extremely difficult to get solid answers for — one simply does not have that kind of information. If you want to take an applied mathematician and send him into shock, you ask him to model the flow from a tall smokestack over a distance of about ten or twenty kilometers — that is just something that is not done. The overall transport phenomenon in acid rain is an extraordinarily complex multi-scale phenomenon. So far as the chemistry is concerned, I think that, too, varies dramatically with the climate, with the season, with the presence of oxidants of various types in the atmosphere, and I fear that there can be no single generalization concerning acid rain and the mitigation of acid deposition worldwide. This is something that has to be handled on a scale which in fact I think will be much smaller. 

FIGURE 4-10 Emission of pollutants from a smokestack, a typical continuous source, under a variety of meteorological conditions. The dry adiabatic lapse rate is represented as a dashed line and the actual measured lapse rate as a solid line in the left panels. Vertical mixing is strongest when the adiabatic lapse rate is less than the actual measured lapse rate and the atmosphere is unstable (top). Weak lapse is a term used to express the existence of a stable atmosphere, which results in less vigorous vertical mixing. An inversion, in the third panel from the top and in part of the last three panels, results in a very stable atmospheric layer in which relatively little vertical mixing occurs (Boubel et al, 1994). 

The smallest spatial scale at which outdoor air pollution is of concern corresponds to the air volume affected by pollutant chemical emissions from a single point source, such as a smokestack (Fig. 4-24). Chemicals are carried downwind by advection, while turbulent transport (typically modeled as Fick-ian transport) causes the chemical concentrations to become more diluted. Typically, smokestacks produce continuous pollutant emissions, instead of single pulses of pollutants thus, steady-state analysis is often appropriate. At some distance downwind, the plume of chemical pollutants disperses sufficiently to reach the ground the point at which this occurs, and the concentrations of the chemicals at this point and elsewhere, can be estimated from solutions to the advection-dispersion-reaction equation (Section 1.5), given a knowledge of the air (wind) velocity and the magnitude of Fickian transport. 

One classic Gaussian plume model for smokestack emissions is the Pas-quill-Gifford model, which applies for steady emissions of a chemical over relatively level terrain. If no chemical sinks exist in the air (i.e., no reactions are degrading the chemical) and if there is an unlimited mixing height (i.e., no atmospheric inversion exists, and the plume can be mixed upward indefinitely), the Pasquill- Gifford model can be expressed in the form... 

Some air pollutants are transported far beyond their points of release. For example, otherwise pristine areas have received acid precipitation originating from industrial smokestack emissions hundreds of miles away. Dust from the Sahara Desert in Africa has been detected in South America, and radioactive debris from the Chernobyl nuclear reactor meltdown has been deposited in countries throughout Europe. 

Understanding heterogeneous chemistry (4) the structure of natural organic matter (2) air sources and characterization of toxics (1) speciation of toxic metals (1) smokestack emissions beyond SOx and NOx (1) chemical sources of toxicity of fine particulate matter (PM2.5) (1) environmentally persistent free radicals (1) understanding of greenhouse gases in the atmosphere (carbon cycles and sinks)... 

In addition to the fiber sensors, there have been numerous reports on remote fiberless optical detection of pollution from stationary sources. Mobile remote sensors can have cost advantages over on-site instruments and also are much more versatile. Pollutants in smokestack emissions have been identified by irradiation with a laser from a mobile unit equipped with a telescope, a monochromator, and low-noise detection electronics. The gases and particles in the plume scatter the laser light in various directions. A fraction is scattered back to the receiver and analysed to detect the amount and type of gas in the plume. Many of these methods await their application to fiber-optic sensing schemes which are inherently safer than direct laser spectroscopic schemes. 

The 2002 General Assembly passed the Clean Smokestacks Bill (SB 1078) a multi-pollutant strategy that requires a 77% reduction in utility NO emissions by 2009, year-round. The bill also would require substantial reductions in SOj emissions, the primary cause of haze, acid rain and fine... 

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