Distribution And Occurrence Of Polycyclic Aromatic Hydrocarbons In Coal Combustion Environment And Its Impact On The Environment In Shougang District

It has been systematically studied on the species, contents, distribution and occurrence of the polycyclic aromatic hydrocarbons (PAHs) in raw coal, waste water from the power plant and coke plant, the particulate matter (PM) emitted from the coal combustion and the suspended PM near the plants by way of organic geochemistry, environmental chemistry and organic pollution chemistry. The change of PAHs in solution leached from coal and fly ash has been investigated as well. The environmental effect of the PAHs has been evaluated, which providing the scientific evidence for an evaluation on the organic contamination around the circumstance of the coal combustion. The leached rate and distribution of PAHs from coal and fly ash has been researched making use of many analysis techniques. The mechanisms of the transportation and the transformation of PAHs have firstly been studied by the carbon isotope and the fluorescence spectrum as well as the distribution and the formation mechanism of PAHs around the coal combustion environment have been studied.It mainly lies on the degree of the coal combustion and the capability of thermal reaction of compounds, which affects the contents and species of PAHs in fly ash and bottom ash from the power plant. The different source and component of the dropping dust may causes the different contents of PAHs between the dropping dust from the power plant, which mainly originated from the fly ash, and the dropping dust from the coke plant, which made up of the fine coal and coke. The amount of the suspended PM from coke plant is more than 565.1 u g/m ,but it is only 73.0 u g/mjat the east gate. So it is very necessary to pay more attention to the harm of the suspended PM from the coke plant to the circumstance.The source of the suspended PM has been estimated. To the suspended PM, the more contents of PAHs, the more positive of the carbon isotope. According to the carbon isotope, the values of the carbon isotope of PAHs from the coal combustion tend to be negative, and more negative of the values of the carbon isotope, more complete of coal combustion. There are similar changing regularities of the fluorescence spectrum and the fluorescence intensity in PAHs from the same source of PM. The fluorescence alteration turns from the negative-positive to the negative.It indicates that PAHs can be released from coal and fly ash by leaching, and the content and species of PAHs reduce with the leaching solution from the sulfuric acid, acetic acid to distilled water. The content of PAHs from waste water at the coke plant is more than those of the power plant, and more dangerous as well.The difference of the content of PAHs depends on the source of the suspended PM. The suspended PM at the coke plant is mainly from the coke plant, and PAHs mainly come from the fine coal of the coke plant and partly from the sinter plant and the iron-making plant. However, the source of the suspended PM at the east gate is very complex, including the production of Shougang Group and the auto waste gas.There are many aspects for the influence of PAHs in the suspended PM from the coal combustion or the coal carbonization on circumstance. The first is that the inhaled PM directly enters the organ and the second is that PAHs of the PM are released to the water system, to the biology chain, and resulting in the harmful impact on human being.