| Summary: | 碩士 === 國立中興大學 === 環境工程學系所 === 100 === The objective of this study was to use Solid Phase Microextraction (SPME) as a tool to assess the bioavailability of benzene and naphthalene in soil. The SPME extractable contaminants would be employed to compare to the actual biodegradable amount of contaminants. These experiments were conducted by a series of batch soil reactor with various conditions, including different soil textures, organic contents, multi-contaminants, and pollutant concentrations.
When benzene or naphthalene concentration reached 5000 μg/g-soil, toxic effect was observed in soils containing only indigenous microorganism. Experimental results indicated that when the sandy loam soil was contaminated by benzene, the biodegradation rate decreased with an increase in concentrations, but the biodegradation extents were remarkable enhanced with the addition of seeded microorganism. The bioavailability and the biodegradation rate of benzene in soils decreased with an increase in SOM contents.
The result of multi-contaminants (benzene and naphthalene) degradation tests showed that the soil textures and SOM contents had no effects on the bioavailability. However, the result demonstrated that the biodegradation extent of naphthalene was much higher than that of benzene and so of the biodegradation rate due to the properties of microorganisms and chemicals.
For all tested samples, the correlation between SPME extractable contaminants and biodegradable contaminants revealed that SPME overestimated the actual amount of biodegradation. Especially the result inferred that SPME could not properly estimate the bioavailability of benzene in soils contaminated by benzene only or by both benzene and naphthalene. Contrast with benzene, SPME is more accurate assess the biodegradeation of naphthalene
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