碩士 / 國立海洋大學 / 海洋生物研究所 / 90 / Abstract
Chloroethylenes (CEs) has been used extensively as solvent for dry cleaning, metal degreaser and fumigant. Because of its widespread use and persistence, CEs are often detected in polluted soils, sediments, and groundwater throughout the world. Because of its potential for adverse health effects following exposure, many researches have been conducted to use effective bioremediation methods to clean up the polluted sites. Previous research indicated that highly chlorinated compounds could be reductive dechlorinated much faster than less chlorinated compounds in anoxic environments. However, in the case of CEs, the less chlorinated compounds e.g. vinyl chloride (VC) and dichloroethylene (DCE) are more toxic than trichloroethylene (TCE) and perchloroethylene (PCE). In order to evaluate the potential to use reductive dechlorination methods to clean up CEs polluted sites, in this study, PCE, TCE , cDCE, and VC were added to sediment slurries amended with lactate, acetate, or methanol under methanogenic and denitrifying conditions. We also used denaturing gradient gel electrophoresis (DGGE) to investigate the microbial communities in the sediment slurries under different conditions and at different times.
The results indicated that PCE could be reductively dechlorinated to ethene via TCE, cDCE, and VC in sediment slurries under methanogenic conditions. Addition of lactate and acetate increased reductive dechlorination of PCE and TCE by increasing dechlorination rates of their intermediate products, cDCE and VC, to ethene. Addition of methanol increased reductive dechlorination of PCE, but inhibited dechlorination of TCE and cDCE. However, the extent and the rates of reductive dechlorination of CEs were low under denitrifying conditions.Addition of lactate, acetate, and methanol could enhance dechlorination rates but not the extent of dechlorination of CEs under denitrifying conditions.
The results of DGGE indicated that the original microbial communities in the sediment slurries changed by adding CEs and different electron donors. Further researches are needed to find the microorganisms involved in the dechlorination of CEs.
| Identifer | oai:union.ndltd.org:TW/090NTOU0270009 |
| Date | January 2002 |
| Creators | Huang Chin Ming, 黃俊敏 |
| Contributors | Liu shiu Mei, 劉秀美, 李志源 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 76 |
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