碩士 / 國立中山大學 / 海洋資源學系 / 87 / The primary purpose of this research is (a) to examine the contents of water in the estuary area of the Puzi River, (b) to examine the contents of heavy metals and organic matter contained in the sediments of the water where it is affected by oysters'' shelves setting, oysters'' breeding, and other environmental factors, and (c) to find the existing form of the heavy metals in the sediments and understand the correlation between them. First, twelve stations were set up around the estuary area of the Puzi River. Then samples of water and sediments were collected separately during both the abundant and dried up season and analyzed. The water was analyzed for its contents which includes salinity, temperature, pH value, D.O., turbidity, total organic carbon (TOC), dissolved metals and so forth. The sediments were analyzed for its diffraction size, existing contents of organic matter, the contents of organic matter of different size, contents of full heavy metals, heavy metal of different diffraction size, and the contents of all different speciation of heavy metals.
The result shows that although the contents of total organic carbon is higher, the D.O. is obviously higher in the estuary stations than in other stations along the river (P1 and P2). This is because particulate organic matter degrades relatively slower and also because the ocean water dilutes oxygen-consuming materials from the upper stream. Because organic matter consumes oxygen and degrades itself, the pH value in the water reduces in the upper stream stations. However, because of the mixture of seawater in the estuary stations, the pH value is controlled by carbonate buffer. The pH value gets higher when it is closer to the ocean. The pH value has obvious correlation with turbidity, total organic carbon of the water sample, and organic matter in the sediments. This correlation is caused by particulate of the sediments affected by tide, oyster breeding, and oysters'' shelves setting. The mean of diffraction size (D50) in the estuary station is less than the other stations located along the river or in the ocean. Its diffraction size is less than 63 μm and its contents contained value is higher than full contents contained value of organic matter in the sediments.
The concentration of dissolved metals is higher in estuary stations than in stations located in the upper stream along the river. This is due to the desorption of heavy metals from suspended particulate caused by salinity variation. The contents of heavy metal in sediments increases when it is closer to the estuary area. This is related to the contents of organic matter. Therefore, it is concluded that oyster breeding also affects the sediments of the estuary area. The contents of heavy metals is higher in sediments with diffraction size less than 63 μm. This is because sediments with smaller diffraction size attach heavy metals easier than larger ones. The main part of different chemical speciation of heavy metal in the sediments is organic matter fraction and the contents of heavy metal in this part has a good correlation with the contents of organic matter in the sediments. The second part is residual fraction and Fe-Mn oxides fraction; the carbonate fraction and exchangeable fraction are lesser than the other fractions.
| Identifer | oai:union.ndltd.org:TW/087NSYSU277020 |
| Date | January 1999 |
| Creators | Shih-Ping Liu, 劉士萍 |
| Contributors | Wei-Shien Wang, 王維賢 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 107 |
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