碩士 / 元智大學 / 化學工程與材料科學學系 / 95 / Recently, the artificial cultivation of oysters (e.g. Crassostrea gigas) has become important aquatic products around west coastline of Taiwan. Due to the industries development and industrial wastewater, the amount of heavy metals in oysters cultivated in some area of Taiwan has become very significant compared to other areas of the world. Therefore, the present study has selected cities around northern west coastline area of Taiwan, where the industries are well developed. In addition, Hi-tech Science Parks are also sited as sampled district to investigate the pollution impact of water quality, precipitate contamination in stream, and aquatic lives.
Experimentally, collecting environmental background data from September 2003 to November 2006, analyzing of marine water quality, sediment contamination, and Crassostrea gigas (2004~2006) were conducted. The analytical experiments including in situ measurement of water temperatures, salinity, analyses of the heavy metals (Cu, As, Zn, Cd, Cr, and Pb) in streamwater, stream precipitates or oyster shell by ICP/MS, volatile organic compounds concentration of streamwaters, precipitates or tissues of Crassostrea gigas by GC/MS, fine structures of metal ions in oyster tissues by XANES/EXAFS, and FTIR were also performed.
The heavy metals were absorbed and accumulated in soils and plants in Ke-Ya stream, but the correlation between Cu ions and estuary water quality is low found in the present study. However, the Cu ion concentration in soil is still at a certain level around estuary area, it reveals that the industrial Cu-contaminated wastewater still influence the stremwaters and stream precipitates concentration. The San-Xing stream with cemented river bank, and the streamwater does not come into contact with soil, plant and ponds to settle down or absorb heavy metals. Copper ion generated from the industrial discharge at middle- and down- stream was higher than other sections of the river and may be the major heavy metal sources. According to the experimental result on precipitates, the averaged enrichment factor of Cu ions was 2.4 and Zn (6.51), Cd (5.23), Cr(1.74) or Pb element was 10.92, repectively. The result proves both the enrichment phenomenon of heavy metals and artificial pollution, especially Zn, Cd, and Pb ions with the most obvious enrichment phenomenon. The abnormal increasing of Al concentration in sediment in August 2005 and the calculation of abnormal enrichment factor as well were found. It indicated that the Al compounds was leached out by acid rains and deposited during the water transferring processes.
The Cu concentration of artificial cultivated Crassostrea gigas was from 103 to 1409 ppm, and it is closely correlated with the water quality of both Ke-Ya and San-Xing streams. However, Ke-Ya stream is the major source of the contaminants in oysters. The Cu concentration related to the precipitates of Crassostrea gigas reached the highest value in spring and the lowest one in summer. The averaged concentration decreased from 470.6 ppm (April, 2006) to 195.5 ppm (July, 2006) and the bioaccumulation factor decreased from 4.56×105 to 9.0×104 in April, 2006, respectively. The changes on As concentrations were also related to polluated precipitates. The major sources of As are from water and precipitates of San-Xing stream. There is no specific way for the Crassostrea gigas to absorb As in the environment, and it is As-phile rather than As-repelling. The Zn concentration of Crassostrea gigas was from 107 to 722 ppm, its bioaccumulation factor was between 2.66 and 5.11×104. This result showed that the very sufficient supply of Zn ions was from aquatic environment eventually. The Cu and Zn ion in Crassostrea gigas tissues having the same consistency was observed. The average concentration of Cu ions was lower than Zn ones in the tissues of Crassostrea gigas. The concentrations of Cd, Cr and Pb ions in the tissues of Crassostrea gigas were quite low. In addition, the concentration variation of Crassostrea gigas shell was highly related to the seasonal difference during 2006. Compared As and Cr ions with other heavy metals, the concentration difference in shell and soft issue of Crassostrea gigas is several times due to their elemental characteristics.
According to our analyses of VOCs concentration in Crassostrea gigas and precipitates from breed area, toluene was detected with a very low concentration. Consulting with the MSDS data, it is unlikely to cause toluene poisoning by appropriately intake of the oysters. The FTIR analyses of Crassostrea gigas tissues, the highest possibility was amino acid of protein and toluene. In terms of precipitate analyses, the most possible species were hydrocarbon compounds and water. However, there are some correspondings to the VOC analyses. Based on the analyses of X-ray absorption near edge structure spectra (XANES), the Cu ion in Crassostrea gigas is partially bonded to postulated organic sulfur (Cu-S) of thiol.
| Identifer | oai:union.ndltd.org:TW/095YZU05159029 |
| Date | January 2007 |
| Creators | Wei-Cheng Shih, 石偉成 |
| Contributors | Kuen-Song Lin, 林錕松 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 225 |
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