Main Air Pollutants

Example 8.1 Calculate the partition coefficient of aniline between 1-octanol and air. 

One looks up the Kio w for aniline and its water/air partition coefficient. Often times such data are found in logarithmic form as log Kia,b. (See Goss and Schwarzenbach, 2003 and any CRC Handbook of Chemistry and Physics). 

Effects of Pollutants on the Chemistry of the Atmosphere, Hydrosphere, and Lithosphere 

In turn, these products may react to form C02 in the atmosphere. The main hazard of CO is its toxicity since it can substitute dioxygen uptake in hemoglobin. 

In turn, S02 can react photochemically with dioxygen to yield S03  

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It is easily understood that whereas ducted emissions can be rather easily treated, the other two kinds of emissions can only be prevented or minimized. For example, agricultural emissions are very difficult to control. The main air pollutants are the following. 

It is easily concluded from the above that road transport and combustion installations are the main sources of air pollutants. In Table 1.11, the releases of the main air pollutants in connection to the main activities as covered in EPER are presented (transport is not covered). 

The releases of the main air pollutants from the industrial sector in Europe (2001)... 

Table 2.50 Contribution of anthropogenic sources to main air pollutants x - significant, (x) - minor importance, - negligible or zero.

SO3), NH3, O3, and some volatile organie speeies (VOCs) sueh as toluene. The major sourees of these contaminants are vehiele exhaust, industrial emissions, and agrieultural activities. In speeial eases sueh as military applieations, battlefield eontaminants released from either ehemieal warfare or normal warfare, or both, should also be considered. These eontaminants inelude Sarin, sulfur mustard, eyanogen ehloride, hydrogen eyanide, and so on, whieh eould eause signifieant irreversible performance drops. Sinee NOx and SOx are the main air pollutants, in this seetion we will mainly diseuss NOx and SOx contamination. Contamination caused by other pollutants will also be touehed upon. 

NOj is one of the main air pollutants, emitted mainly from internal eombustion engine vehicles. The NO,c concentration in air fluetuates, espeeially in an urban environment. During rush hour traffic, the NO coneentration is mueh higher than at other times of the day. The eoncentration ehange may result in eonfusion during fuel cell evaluation when comparing data obtained at different sites or different times on the same day. 

Air. Studies have shown that 2500 years ago lead pollution caused by Greek and Roman silver smelters was a significant problem (4). Based on analysis of lake sediments and Greenland s ice, it was found that lead contamination from smelters in southern and central Europe was carried throughout the northern hemisphere. As long ago as the thirteenth century, air pollution has been linked to the burning of coal (4). The main concern was the smell from the sulfur in the coal and the effects of the soot. It was not until many years later that the effects of air pollution on people s health were discovered. 

Vinyhdene chloride is hepatotoxic, but does not appear to be a carcinogen (13—18). Pharmacokinetic studies indicate that the behavior of vinyl chloride and vinyhdene chloride in rats and mice is substantially different (19). No unusual health problems have been observed in workers exposed to vinyhdene chloride monomer over varying periods (20). Because vinyhdene chloride degrades rapidly in the atmosphere, air pollution is not likely to be a problem (21). Worker exposure is the main concern. Sampling techniques for monitoring worker exposure to vinyhdene chloride vapor are being developed (22). 

A primary concern in coal-fired power generation is the release of air pollutants. Limits on SO2 output, 0.52 g/MJ equivalent of coal input to a new plant, have been estabflshed. Eor a bituminous coal of 27.9 MJ/kg there is thus an upper limit of 0.72% sulfur content. Relatively few coals can meet this requirement. The U.S. Department of Energy indicated recoverable reserves of 420 x 10 t in 1987 (2) that were categorized by sulfur content 33.5% had 0.6% S or less, 15.4% had between 0.61% and 0.83% S, 16.1% had between 0.84 and 1.67% S, 12.4% had between 1.68 and 2.50% S, and 22.6% had more than 2.5% S. The lowest sulfur coal, 86%, is found west of the Mississippi River, mainly in Montana and Wyoming, quite distant from the electric power demand centers in the East. A trend to utilization of the western coals has developed. 

Human-made sources cover a wide spectrum of chemical and physical activities and are the major contributors to urban air pollution. Air pollutants in the United States pour out from over 10 million vehicles, the refuse of over 250 million people, the generation of billions of kilowatts of electricity, and the production of innumerable products demanded by eveiyday living. Hundreds of millions of tons of air pollutants are generated annu ly in the United States alone. The five main classes of pollutants are particulates, sulfur dioxide, nitrogen oxides, volatile organic compounds, and carbon monoxide. Total emissions in the United States are summarized by source categoiy for the year 1993 in Table 25-10. 

As the name implies, these operations, if uncontrolled, can cause a serious air pollution problem. The main problem is the odors associated with the process. Examples of such industries are tanning works, rendering plants, and many of the food processing plants such as fish meal plants. In most cases, the emissions of particulates and gases from such plants are not of concern, only the odors. Requiring these industries to locate away from the business or residential areas is no longer acceptable as a means of control. 

The main philosophical question that arises with respect to air quality standards is what to consider an adverse effect or a cost associated with air pollution. Let us examine several categories of receptors to see the judgmental problems that arise. 

In a fertilizer plant, the main source of potential air pollution is dusts and fiunes from spills, operating upsets, and dust emissions. It is essential that tight operating procedures be in place and that close attention be paid to constant cleanup of spills and to other housecleaning measures. 

Higher incomes, higher automobile ownership, and a decline in the population and workplaces that can be sciwcd by mass transit has lead to the declining mass transit demand. Criticism of this shift toward the private automobile comes mainly because the individual driver receives the short-term benefits (privacy, comfort, speed, and convenience), while the negative social consequences (air pollution, traffic jams, and resource depletion) are shared by all. Moreover, if people drove less, and drove more-fuel-efficient vehicles, the positive national goal of less dependence on imported oil would be achieved. 

The columns of V are the abstract factors of X which should be rotated into real factors. The matrix V is rotated by means of an orthogonal rotation matrix R, so that the resulting matrix F = V R fulfils a given criterion. The criterion in Varimax rotation is that the rows of F obtain maximal simplicity, which is usually denoted as the requirement that F has a maximum row simplicity. The idea behind this criterion is that real factors should be easily interpretable which is the case when the loadings of the factor are grouped over only a few variables. For instance the vector f, =[000 0.5 0.8 0.33] may be easier to interpret than the vector = [0.1 0.3 0.1 0.4 0.4 0.75]. It is more likely that the simple vector is a pure factor than the less simple one. Returning to the air pollution example, the simple vector fi may represent the concentration profile of one of the pollution sources which mainly contains the three last constituents. 

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