| Summary: | 碩士 === 國立交通大學 === 環境工程系所 === 92 === In this study, we use BOD bottles to perform a close-system algal(Raphidocelis subcapitata) test to assess the toxicity of PAHs photomodification products. we also analyze the photosynthesis mechanisms associated with photoinduced toxicity of anthracene to R.subcapitata
The toxic test was ended based on DO, final yield and growth rate methods. The cell density difference was used to calculate the final yield and growth rate. ANT photoproducts those were more toxic than the parent compound. The most toxic was 1,8-dhATQ. In contrast, ISO was the least toxic. ANT are rapidly photomodified in UV-A to products that are more water soluble and toxic to R. subcapitata. Compared to ANT photo-induced toxicity, toxicity was increased 10 times on GR. Furthermore, ANT was converted to ATQ, 1-hATQ, and one-ring aromatics after 6 h of UV-A exposure. After 24 and 48 h UV-A, photomodification of ANT had further generated of 1,8-dhATQ and 1,4-dhATQ. When compare with other species, BOD bottle test shows a higher sensitivity and a good correlation with the Duckweed assays. This study derives that sensitivity of the algae can be influenced with different major factors, and show precious data about the algae inhibition toxicity test.
In addition, a cut-off value approach is proposed to determine whether NOEC or EC10 should be chosen for estimating low toxic effects. The results indicate that NOEC offers better protection to test organisms than EC10.
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