博士 / 國立海洋大學 / 海洋生物研究所 / 90 / Abstract
In this study, microorganisms in anoxic sediment slurries collected from the Tansui River and the Erjen River were used to test its ability to dechlorinate some polychlorinated biphenyl (PCB) congeners (3,3’,4,4’- tetrachlorobiphenyl (34-34 CB) , 3,4,4’,5-tetrachlrobiphenyl (345-4 CB) , 2,3’,4’,5-tetrachlrobiphenyl (25-34 CB) , 3,3’,4,4’,5- pentachlorobiphenyl (345-34 CB) , 3,3’,4,4’,5,5’-hexachlorobiphenyls (345-345 CB) ) and commercial PCBs (Aroclor 1221, 1248, 1260). Toluene-adapted sediment slurries or 3-chlorobenzoate-adapted sediment slurries, 4,4’-dibromo biphenyl (4-4 BB) , 2,6-dibromobiphenyl (26 BB) or Tween 20 was added to the sediment slurries in an attempt to stimulate the dechlorination of the PCB congeners. Dechlorination of commercial PCBs in sediment slurries from the Erjen River under sulfate reducing conditions and methanogenic conditions were compared.
Enhancement of the dechlorinaiton of commercial PCBs was tested by amendment of 2,3’,4’,5-tetrachlorobiphenyl (25-34 CB)-adapted sediment slurries, 3,4,4’,5-tetrachlorobiphenyl (345-4 CB)-adapted sediment slurries, bromobiphneyls or chlorobiphenyls to sediment slurries from the Erjen River. The change of the microorganism communities during dechlorination in sediment slurries from the Tansui River and the Erjen River was observed by using the denaturing gradient gel electrophoresis (DGGE) method.
Except 3,3’,4,4’,5,5’-hexachlorobiphenyls (345-345 CB) , all other congeners, e.g. 25-34 CB, 34-34 CB, 345-4 CB and 345-34 CB were dechlorinated by anaerobic microorganisms in sediment slurries from the Tansui River and the Erjen River. Chlorines at the para position of the biphenyl ring of PCB congeners were removed by microorganisms in sediment slurries from the Tansui River. However chlorines at both meta and para chlorines positions of the biphenyl ring of PCB congeners were removed by microorganisms in sediment slurries from the Erjen River. The dechloriantion rates of PCB congeners in sediment slurries from the Erjen River were greater than that from the Tansui River. Amendment of toluene-adapted sediment slurries or 3-chlorobenzoate-adapted sediment slurries, could enhance the dechloriantion of 34-34 CB and 345-4 CB in sediment slurries from the Tansui River. Amendment of 4-4 BB, 26 BB and Tween 20 colud not enhance the dechloriantion of 34-34 CB, 345-4 CB and 345-345 CB. Methanogen and sulfate reducing bacteria were involving in the dechlorination of PCB congeners in sediment slurries from the Tansui River, while sulfate reducing bacteria and eubacteria were involving in the dechlorination of PCB congeners in sediment slurries from the Erjen River.
The rates and the extent of dechlorination of Aroclor 1221, 1248, 1260 in sediment slurries under sulfate reducing conditions were greater than that under methanogenic conditions. Amendment of 25-34 CB- or 345-4 CB-adapted sediment slurries to sediment slurries from the Erjen River with or without addition of 25-34 CB or 345-4 CB affected the dechlorination rates of Aroclor 1221, 1248, 1260. Dechlorination rates of Aroclor 1221 were greater in sediment slurries without addition than in sediment slurries with addition of 25-34 CB or 345-4 CB. While dechlorination rates of Aroclor 1248 were greater in sediment slurries with addition than in sediment slurries without addition of 25-34 CB or 345-4 CB. No significant differences were observed in the dechlorination rates of Aroclor 1260 in sediment slurries with or without addition of 25-34 CB or 345-4 CB. Amendment of 26 BB, 4-4 BB, 25-3 BB, 25-34 CB, 345-4 CB could not enhance dechlorination of Aroclor 1221, 1248, 1260 in sediment slurries from the Erjen River. Amendment of 4-4 BB could enhance removal of chlorines at the para positions of Aroclor 1221, 1248. 1260. Amendment of 25-34 CB and 345-4 CB could enhance removal of chlorines at the meta and para, and chlorines at para positions of Aroclor 1248 respectively. Amendment of 26 BB could enhance removal of chlorines at the meta positions of Aroclor 1260. DGGE method was used to analyze the change of the microorganism communities during the dechlorination of 345-34 CB in sediment slurries from the Tansui River and the Erjen River.
The results indicated that microorganisms communities in the Tansui River and the Erjen River were different. P group were the major dechlorinating microorganisms in sediment slurries from the Tansui River, while L group were the major dechlorinating microorganisms in sediment slurries from Erjen River.
| Identifer | oai:union.ndltd.org:TW/090NTOU0270016 |
| Date | January 2002 |
| Creators | 郭加恩 |
| Contributors | 劉秀美 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 148 |
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