Sulfate, particulate

Acid deposition refers to the transport of acid constituents from the atmosphere to the earth s surface. This process includes dry deposition of SO2, NO2, HNO3, and particulate sulfate matter and wet deposition ("acid rain") to surfaces. This process is widespread and alters distribution of plant and aquatic species, soil composition, pH of water, and nutrient content, depending on the circumstances. 

FINE PARTICULATE SULFATE AND NITRATE > 0l-2.0>im DIAMETER NH4NO3 (NH4)2 SO4... 

Fenner (11) has pointed out that short-lifetime constituents of the atmosphere such as nitrogen oxides, carbon monoxide, and nonmethane hydrocarbons may also play roles related to global warming because of their chemical relations to the longer-lived greenhouse gases. Also, SO, with a very short life interacts with ozone and other constituents to be converted to particulate sulfate, which has effects on cloud droplet formation. 

Many deleterious effects have been associated with photochemically polluted air ozone is deflnitely associated with respiratory problems, plant damage, and material damage PAN has deflnitely been associated with plant damage, and some other members of this class of chemical compounds have been associated with eye irritation the hydroxyl radical is considered to be an important factor in the conversion of gas-phase intermediates to end products, such as sulfur dioxide to particulate sulfate the particulate complex is responsible for haze formation and has also been associated with eye irritation and respiratory effects. The aldehydes have been associated with eye irritation. Ozone and PAN themselves do not cause eye irritation. For purposes of control, much more research is needed, in order to relate the laboratory data about the concentrations of these various materials that have significant effects to their formation in the atmosphere from emission and their atmospheric distribution. The lack of convenient measurement methods has hindered progress in gaining this understanding. 

Henry, R. C. and Hidy, G. M. (1979). "Multivariate Analysis of Particulate Sulfate and Other Air Quality Variables by Principal Components," Atmospheric Environment, 13, 1581. 

Eatough, D. J., L. J. Kewis, M. Eatough, and E. A. Lewis, Sampling Artifacts in the Determination of Particulate Sulfate and S02(g) in the Desert Southwest Using Filter Pack Samplers, Environ. Sci. Technol., 29, 787-791 (1995). 

Matsumoto, K., H. Tanaka, I. Nagao, and Y. Ishizaka, Contribution of Particulate Sulfate and Organic Carbon to Cloud Condensation Nuclei in the Marine Atmosphere, Geophys. Res. Lett., 24, 655-658 (1997). 

Stohl A (1996) Trajectory statistics - a new method to establish source-receptor relationships of air pollutants and its application to the transport of particulate sulfate in Europe. Atmos Environ 30 579-587... 

High efficiency denuders that concentrate atmospheric S02 were coupled to an ion chromatograph to yield detection limits on the order of 0.5 ppt (106). A newer approach has been introduced for the quantitative collection of aerosol particles to the submicrometer size (107). When interfaced to an inexpensive ion chromatograph for downstream analysis, the detection limit of the overall system for particulate sulfate, nitrite, and nitrate are 2.2,0.6, and 5.1 ng/m3, respectively, for an 8-min sample. A two-stage membrane sampling system coupled with an ion trap spectrometer has been utilized for the direct analysis of volatile compounds in air, with quantitation limits to low ppt levels (108). Toluene, carbon tetrachloride, tricholoroethane, and benzene were used in these studies. The measurement of nitrogen dioxide at ppb level in a liquid film droplet has been described (109) (see Air pollution). A number of elements in environmental samples have been determined by thermal ionization ms (Table 6). The detection limit for Pu was as low as 4 fg. 

Many studies have demonstrated increase in the response of animals to S02 in the presence of particulate matter and elevations of relative humidity. Thus, H2S04 mist and some particulate sulfates enhance the reactions of animals to S02, suggesting that alteration of S02 to a higher oxidation state may increase its irritability in animals. These interactions have important implication in air pollution control, as the rate of conversion of S02 to acid sulfates may have greater health significance than the concentration of S02 in the air. 

Estimating the deposition velocities of gaseous species is considerably more complex than estimating those for substances in particles, in part due to the uncertainties in the sticking and reaction probabilities. Such estimates have not been made but the potential effects of some of the typical gases can be surmised from available data on surface accumulation rates, e.g. sulfate accumulation on indoor zinc and aluminum surfaces is predominantly a result of particulate sulfate deposition rather than a corrosion reaction involving sulfur dioxide (0. 

Simultaneous materials-deterioration and aerometric measurements are made at one location. Correlations of deterioration parameters with varying atmospheric physical and chemical parameters will be examined using multivariate statistical methods when sufficient data are accumulated. Deterioration parameters being measured include rates of surface erosion, surface chemical changes, and microstructural alterations. Atmospheric monitoring includes particulate sulfate, nitrate, and sulfur dioxide concentrations, as well as temperature, relative humidity, and parameters of wind and water erosion. 

Fig. 3-13. Left Vertical distribution of carbonyl sulfide and sulfur dioxide in the stratosphere. [From data of Maroulis et al. (1977), Sandalls and Penkett (1977), Torres el al. (1980), Mankin et al. (1979), Inn et al. (1979, 1981) for COS, and from Jaeschke et al. (1976), Maroulis et al. (1980), Georgii and Meixner (1980), Inn et al. (1981) for S02.] Curves represent calculations of Turco et al. (1980, 1981a) for an assumed cutoff of COS photodissociation of 312 nm. Right Vertical distribution of gaseous and particulate sulfuric acid. Solid squares and circles are from mass spectrometric measurements of Arijs et al. (1982) and Viggiano and Arnold (1983), respectively. Open circles with error bars (one standard deviation) are from filter collections of Lazrus and Gandrud (1977). The range given by the thin lines indicates the seasonal variability of particulate sulfate. The solid line indicates the vapor pressure of H2S04 over a 75% H2S04/25% H20 mixture.

In estimating the rate of gas-to-particle conversion involving S02 from anthropogenic sources, Peterson and Junge (1971) assumed that 66% is converted to sulfate and the rest is removed by dry deposition. In addition, it was assumed that sulfate is completely neutralized to ammonium sulfate. An emission rate of 160 Tg S02/yr from the combustion of fossil fuels then gives a production rate for particulate sulfate of 220 Tg/yr. In 1971 the rate of sulfur compound emissions from natural sources was less well known... 

In combustion chambers, a small fraction of S02 is further oxidized to S03, which reacts readily with water vapor and is emitted as sulfate. Ryaboshapko (1983) estimated the direct emission of particulate sulfate to reach 12TgS/yr. This figure appears too high, however. American studies reviewed by Robinson and Homolya (1983) show that the average ratio of SOr to S02 in power-plant flue gases is close to 0.03. The corresponding global release rate of primary sulfate then is 3 Tg S/yr, a comparably minor fraction of total sulfur emissions. 

Field studies of S02 oxidation have been performed mostly in the downwind regions of sufficiently isolated sources. The favored objects were stacks of electric power plants, whose plumes often are identifiable at distances up to 300 km from the source, and larger cities. S02 and particulate sulfate were measured and the data were analyzed in terms of the concentration ratio (S04-)/(S02) + (S04 ) as a function of time or a combination of wind speed and distance. Sampling was done mostly by aircraft, although urban plumes have also been studied by ground-based measurements. Table 10-11 presents results from a variety of such investigations. 

Fig. 10-3. Distribution of (a) SO, and (b) particulate sulfate over Europe, in units of pg S/m [Adapted from Ottar (1978).]...

Fig. 10-4. Distribution of (a) S02 and (b) particulate sulfate in the northeastern U.S.A., in units of p.g S/m3. [Adapted from Mueller el al. (1980).] S02 emission densities in various states are indicated by heavy stipples, 20-30 g/m2 yr light stipples, 10-20 g/m2 yr no stipples, less than 10g/m2yr (from Husar and Patterson, 1980).

Fig. 10-6. Vertical distribution of (a, c) S02 and particulate sulfate in the atmosphere over the continents, and of (b) S02 over the Atlantic Ocean. Tropopause levels are indicated.

Table 10-12. Sulfur Dioxide and Particulate Sulfate in the Remote Troposphere (outside the Boundary Layer)... 

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