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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Concentrations and sources of polycyclic aromatic hydrocarbons in sediment cores of Kaoping submarine canyon

Chang, Wei-kai 08 August 2005 (has links)
Cores and sediment traps collected from Kao-ping Canyon were used to reconstruct historical record of PAHs contamination and find out the possible sources, distributions, trends and flux of PAHs. The sedimentary record of PAHs shows that the average concentration of total PAHs was 310 ng/g dry wt. (264¡ã364 ng/g) which was lower than coasts of the other countries. According to diagnostic ratios and statistical analysis, we identify sources of PAHs and suggest that all up-cores were dominated by petrogenic sources, but all down-cores except for C980 and S1 were tended to pyrogenic or mixed sources. In contrast, both C980 and S1 were showed higher perylene/£UPAHs (%), which suggests that biogenic sources dominate in C980 and S1. In comparison with sediment quality guidelines (SQGs), the PAHs concentrations of all sediment cores weren¡¦t exceeded the criteria, which suggests that no evident adverse biological effects exist caused by PAHs in Kao-ping Canyon. It shows that the transition from coal to petroleum fuel use corresponding to the total concentrations of PAHs decrease recorded during 1893-1935 period in the sediment core. A PAHs concentration peak also recorded during the World War ¢º, 1893-1935. Because of increase of importing fossil fuel and the growth of heavy industrials in Kao-Ping area, the total concentrations of PAHs were shown evidence of increase again since 1950s in the core from Kao-ping Canyon. The average PAHs flux in the upper and lower mooring deployed in Kao-ping Canyon were 66 and 108 £gg/m2/d, respectively, which were higher than coasts of the other countries. The PAHs sources of sinking particles were dominated by petrogenic sources which were as similar sources as all up-cores.

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