Types of Air Pollutants

What is clean air Unpolluted air is a concept of what the air would be if humans and their works were not on earth, and if the air were not polluted by natural point sources such as volcanoes and forest fires. The true composition of unpolluted air is unknown because humans have been polluting the air for thousands of years. In addition there are many natural pollutants such as terpenes from plants, smoke from forest fires, and fumes and smoke from volcanoes. Table 4.1 lists the components that, in the absence of such pollution, are thought to constitute clean air. 

Gaseous Pollutants. These substances are gases at normal temperature and pressure as well as vapors evaporated from substances that are liquid or solid. Among pollutants of greatest concern are carbon monoxide (CO), hydrocarbons, hydrogen sulfide (H2S) 

Particulate Pollutants. Fine solids or liquid droplets can be suspended in air. Some of the different types of particulates are defined as follows  

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There are two different types of air pollution problems in urban areas. One is the release of primary pollutants (those released directly from sources). The other is the formation of secondary pollutants (those that are formed through chemical reactions of the primary pollutants). 

What are the two types of air pollution problems found in urban areas ... 

To develop an emission inventory for an area, one must (1) list the types of sources for the area, such as cupolas, automobiles, and home fireplaces (2) determine the type of air pollutant emission from each of the listed sources, such as particulates and SO2 (3) examine the literature (9) to find valid emission factors for each of the pollutants of concern (e.g., "particulate emissions for open burning of tree limbs and brush are 10 kg per ton of residue consumed") (4) through an actual count, or by means of some estimating technique, determine the number and size of specific sources in the area (the number of steelmaking furnaces can be counted, but the number of home fireplaces will probably have to be estimated) and (5) multiply the appropriate numbers from (3) and (4) to obtain the total emissions and then sum the similar emissions to obtain the total for the area. 

List the major types of air pollution control devices used for particulate removal. Visit the Web and make a list of equipment suppliers for these hardware. 

Sensitive Receptor the aqrv, or part thereof, that is the most responsive to or the most easily affected by the type of air pollution in question. For example, at Great... 

There are two types of air pollution. One is the presence of particulate matter and the other is the presence of unwanted or too highly concentrated gases. These are usually treated as two different separation problems, although sometimes the same equipment can be used to remove both types of pollution. 

Beny, C. R. The differential sensitivity of eastern white pine to three types of air pollution. J. Can. Forest. Res. 3 543-547, 1973. 

Pattern recognition has been applied In many forms to various types of chemical data (1,2). In this paper the use of SIMCA pattern recognition to display data and detect outliers In different types of air pollutant analytical data Is Illustrated. Pattern recognition Is used In the sense of classification of objects Into sets with emphasis on graphical representations of data. Basic assumptions which are Implied In the use of this method are that objects In a class are similar and that the data examined are somehow related to this similarity. 

In the following discussion, three types of air pollutant analytical data will be examined using principal component analysis and the K-Nearest Neighbor (KNN) procedure. A set of Interlaboratory comparison data from X-ray emission trace element analysis, data from a comparison of two methods for determining lead In gasoline, and results from gas chromatography/mass spectrometry analysis for volatile organic compounds In ambient air will be used as Illustrations. 

Under USEPA s BIF mle, manufacturers are required to closely monitor numerous conditions in the kiln and to observe limits on the following aspects of the process (a) the maximum feed rate of hazardous waste fuel (b) the maximum feed rate of metals from both raw materials and fuels (c) the maximum feed rate of chlorine from raw materials and fuels (d) the maximum feed rate of raw materials (e) the maximum temperature at the inlet to the air pollution control devices (f) the maximum concentration of carbon monoxide and total hydrocarbons in the flue gas (g) the maximum temperature in the combustion zone or minimum temperature at the kiln inlet and (h) any decrease of pressure at the baghouses or any decline in the strength of the electric field of electrostatic precipitators (both are types of air pollution control devices). 

In urban areas, there are three major types of air pollution found (EEA, 2003) ... 

Generally, you would connect Athens and London, respectively, to which of the following types of air pollution ... 

Photochemical air pollution is characterized by the formation of a so-called "photochemical oxidant" and the reduction of visibility due to the simultaneous production of aerosol particles or particulates. This type of air pollution is commonly known as "photochemical smog. ... 

In some parts of the world, there is more acid in the rain than normal. This type of rain is called acid rain. Scientists believe that one cause of acid rain is sulfur dioxide. Sulfur dioxide is a type of air pollution produced by burning fuels that contain sulfur atoms. When... 

Desalination processes may be characterized by their effluents emitted to the environment, the land and atmosphere nearby, and the sea. Desalination is highly dependent on energy, and generally uses fossil energy. All types of air pollution associated with energy production, namely, the emission of NOx, S02, volatile compounds, particulates and C02, also exist through the use of electricity produced by conventional power stations or by a dedicated power station. Using gas turbines may increase efficiency and therefore reduce pollutants. 

Photochemical smog Type of air pollution due photochemical reaction in the atmosphere. 

Sulfite and sulfate both can be metabolized by plant tissue. Sulfite can be oxidized to sulfate, and this ability may be correlated with resistance (7). On the other hand, sulfate can be reduced all the way to sulfide (8). Sulfur dioxide is generally considered to generate a reducing type of air pollution, but in terms of the latter pathway of metabolism it should... 

The lack of a correlation was also appreciated in a follow-up study in which the data presented in the Dutch report20 (particulate concentration, water content, carbon monoxide concentration, furnace temperature, etc.) were compared with the PCDD/F emissions using statistical regression techniques.21 The aim was to determine which operating and emission parameters were strongly related to PCDD/F emissions. The data set was divided into two groups on the basis of the type of air pollution control device installed ... 

However, this cost in 1991 dollars has to be escalated to 2001 dollars. As shown in Problem 18.2, the escalated cost is the product of the base cost and the escalation factor. The costs of gas absorbers can be escalated via one of the Vatavuk Air Pollution Control Cost Indexes (VAPCCIs). Updated quarterly since 1994 and published in Chemical Engineering, the VAPCCIs have been developed for gas absorbers and eight other types of air pollution control devices. The annual indices for gas absorbers for the years 1994 and 2001 are 100.8 and 114.4, respectively. In addition, the EPA study documenting the development of the VAPCCIs showed that gas absorber prices increased by 5.06% from 1991 to 1994 [Ref. 7]. Combining this increase with the VAPCCI data, we get... 

Sources. There are three types of air pollution sources point, area, and line sources. A point source is a single facility that has one or more emissions points. An area source is a collection of smaller sources such as emissions from residential heating witliin a particular geographic area. A line source is a one-dimensional, horizontal configuration such as a roadway. Alost emissions emanate from a specific stack or vent. Emissions emanating from sources other than stacks, eg, storage piles or unpaved lots, are classified as fugitive emissions. 

The particular type of air pollution model required depends on its expected uses. Models can be classified according to ... 

It is important to know whether molecules being released in the lower atmosphere can reach the stratosphere and affect the amount of ozone in it. Certain types of air pollution give rise to radicals that catalyze ozone depletion. A radical is a chemical species that contains an odd (unpaired) electron, and it is usually formed by the rupture of a covalent bond to form a pair of neutral species. One pressing concern involves chlorofluorocarbons (CFCs)—compounds of chlorine, fluorine, and carbon used as refrigerants and as propellants in some aerosol sprays. CFCs are nonreactive at sea level but can photodissociate in the stratosphere ... 

Various problems of human health, including respiratory problems, hospitalization for heart or lung diseases, and premature deaths are caused by air pollution. Children, who spend more of their time outdoors while their lungs are still developing, are more susceptible to the risk. Elderly people and people with heart or lung diseases are also sensitive to several types of air pollution (U.S. EPA, 2002). 

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