碩士 / 國立臺灣海洋大學 / 海洋環境資訊學系 / 93 / In order to understand the geochemistry and pollution of Hg in the East China Sea (ECS), sediment samples were collected from the inner and middle shelves of the ECS during cruises 493, 499 and 551 by R/V Ocean Researcher I, and were analyzed the Hg content employed the cold-vapor atomic fluorescence spectrometry (CVAFS) in the present study. The analyzed results show that the concentrations of mercury in surface sediments of the inner and middle shelves of the ECS were in the range of 26.45-47.58 ng/g and 2.42-22.19 ng/g, respectively. The distribution of mercury concentration in the ECS showed gradual decrease with seaward. The closer the mouth of the Changjiang estuary, the higher the concentration of Hg in surface sediment. This result may suggest that the spatial distribution of Hg in the ECS was strongly influenced by the Changjiang estuary. However, the value of the enrichment factor, the calculation of Hg concentration normalized to Al concentration, in surface sediment of the all studied stations ranged from 0.07-0.55, and the spatial distribution of the value resembled the Hg distribution. This result may reveal that the contamination of Hg in the ESC was still slight.
The profiles of mercury concentration were more irregular in stations located in the inner shelf than those in the middle shelf. In addition, the Hg concentration in deeper depth showed nearly 2-4 times higher than that in surface sediment in two stations. This phenomenon is probably induced by occasionally polluted event from the Ningbo industrial zone or the inconsistent supply of the riverine suspended particulate matter of the Changjiang estuary. In contrast, the profile variation of Hg in the all studied stations of the middle shelf show relatively minor, suggesting that the sedimentation flux in this area was constant and the diagenetic processes was also minor. Finally, based on the results obtained in the present study and the data of mass accumulation rate (MAR) of the East China Sea from literature, the annual sedimentation rate and sedimentation flux of mercury were calculated. The calculated area, which is the highest MAR area in the ECS, is approximately 1/5 whole area of the ECS. The values of both estimations were in the range of 25.26-150 ng/cm2/y and 4.91-42.87 tons/y, respectively.
| Identifer | oai:union.ndltd.org:TW/093NTOU5282002 |
| Date | January 2005 |
| Creators | Ru-Yun Chen, 陳茹雲 |
| Contributors | Tien-His Fang, 方天熹 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 60 |
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