| 其他摘要 | At present, international studies of atmospheric aerosols remains a lower level in the environmental organic geochemistry and it is still a blank in China. This dissertation is aimed at energy pollution problems demanding prompt solution related to coal, petroleum in our country. The lipid composition, source, and distribution in the atmosphere of aerosols from several cities in China were first systematically investigated by applying some concepts and indexes such as the distributions of homologous compounds, carbon preference index (CPI), and molecular markers etc. in organicygeochemistry and petroleum geochemistry. This dissertation described how to recognize atmospheric pollution produced from using and storing various kinds of fossil fuels. At the same time, it presented the distribution regularity of the pollutants in different region and climate band in China, and sampling heights, season effect atmospheric pollution. This will be very helpful for recognizing serious atmospheric pollution in China and effect factors. Twenty-eight aerosol samples are acquired from the suburb and urban sites in Beijing, Guangzhou, Guiyian and Shuicheng by filtration of ambient air using a standard air sampler. There are some samples eming from stationary sources such as coking factory, refining plants and tyre factory, and background region. All of collected sample filters are ultrasonically extracted in organic solvents. The extracts are esterified and then separated by TLC to yield the hydrocarbon, ester, aldehyde and ketone, and alcohol fractions. The alcohol fractions were converted to trimethylsilyl esters. Finally, compound molecular structure of the fractions were characterized by GC and GC/MS. Environmental organic geochemistry study of the analytical indicates: (1) There are close relationship between the different pollution sources and background site with the composition of atmospheric aerosols. The composition of lipids of aerosolsat stationary sources obviously reflect anthropogenic characterization and in background mainly demonstrate biogenic characteristcs. It is found that the burning products of coal (especially soft coal) contain numerous heterocyclic aromatic hydrocarbons and their oxygenated products, and waster gas of automobile and oil refining plant contain more triterpenoids. Complicated series of alkyl benzen compounds are found in the aerosol derect from petroleum products; (2) Normal alkanes, fatty acids, fatty alcohols, aromatic hydrocarbons, sesterdi- and triterpenoids, and steranes are commonly present in the atmospheric aerosols of four cities in China. These compounds derived from natural biogenic, geologic, synthetic sources, and are present in different proportion. The composition of lipids in the various city aerosols have much to do with their industry development, traffic and population density, and geographic conditions. Generally, the pollution level of suburbs atmosphere is much lower than that in urban; (3) The sampling height is a factor affecting the composition of lipids and the distribution of homologous of aerosols. Some apparent fractionation phenomena of lipid yields of aerosols are observed in samples from different heights above ground. (4) Season is also an important factor impact on the composition of aerosols. Samples in summer contain more biogenic lipids than that in winter. |
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