| Summary: | 碩士 === 國立屏東科技大學 === 環境工程與科學系 === 87 === To identify the spilled oil types, ages and concentrations of the petroleum -contaminated soils is the primary work of scheduling a program for contaminated site treatment. This study plans to find the optimum petroleum-contaminated soils analytical parameters. Investigate whether the TPHs weathering rate is influenced by the soil moisture content and soil properties. And to identify the spilled oil types and ages by the changes of petroleum compositions.
Microwave extraction system can be used to extract the TPHs of diesel contaminated soils contain 0~10% moisture with recovery more than 93%. Low temperature thermal desorption is optimum to desorb the 95-unlead gasoline contaminated soils and is not influenced by the moisture content. Mechanical stirring extraction is optimum to extract both 95-unlead gasoline and diesel contaminated soils between 0~30% moisture content and is less expensive than the others.
Both lab and outdoor experiments showed that 95-unlead gasoline and diesel TPHs weathering rates were accelerated when moisture contents were raised. Soil properties have no obviously effect on TPHs weathering of petroleum-contaminated soils.
TPHs GC diagram match with n-C19/TPHs concentraction ratio could be used to identify the oil types of both 95-unlead gasoline and diesel contaminated soils. After 90 days weathering, both lab and outdoor experiments showed that average n-C19/TPHs concentration ratio is 0.12±0.0063 and is not change obviously with weathering time for diesel-contaminated soils. Due to the weathering resistant of n-C19, we can use the TPHs GC diagram and n-C19/TPHs concentraction ratio on identifying the oil types of both 95-unlead gasoline and diesel contaminated soils. Analysis of the diesel-contaminated site showed TPHs GC diagram as a bell sharp. The n-C19/TPHs concentration ratio is 0.13 with an error of 8.33% compared with the average ratio 0.12.
Because of the short weathering time, the TPHs of the diesel is not decreased obviously. Diesel-contaminated soils spilled age can not be identified. But in 95-unlead gasoline contaminated soils, BTEX/TPHs concentration ratio changes with weathering time as the equation Y＝0.23e-0.06X, where Y is the BTEX/TPHs concentration ratio and X is the weathering time (day). When analysis of the in-situ 95-unlead gasoline contaminated soil, the BTEX/TPHs concentration ratio is 0.09. We can get a spilled age of 16 days with an error of 6.67%.
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