Investigation of PCBs contaminated sediments and bioremediation in river

• Main Authors: Sih-yu Huang, 黃思瑀
• Other Authors: Ji-ming Cian
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/98890634623999002600

碩士 === 嘉南藥理科技大學 === 環境工程與科學系碩士班 === 94 === In order to investigate polychlorinated biphenyls (PCBs) contamination in the river sediment in southern Taiwan, every 2 layers (the upper layer 0 ~ 30 cm, and the lower layer 30 ~ 60 cm, in depth) of sediments from 6 different sites were collected and analyzed the PCBs content. The results showed that in the upper layer of Site A, total PCBs concentration was 4.814 �嵱, 2,3,6,3’,4’-chlorobiphenyl (2,3,6,3’,4’-CB) was the most abundant congeners with a ratio of 15.25 %, and 2,4,3’,4’-CB and 2,4,5,3’,4’-CB were 13.74 %, 13.47 %, respectively. In site B and site C, there was no significant PCBs contamination. In Site D upper layer, 2,5,3’,5’-CB and 2,5,2’-CB were the major congeners with 12.41% and 11.76 % of weight ratio. Similar to the lower layer of Site E, 2,5,2’-CB and 2,5,3’,5’-CB were two most abundant congeners. However, in Site F lower layer, 2,3,4,5,2’,3’,4’-CB was congeners with the highest concentration of 21.69%, then 252''-CBp was of 7.85%. Except Site F lower layer, most of the layers with significant PCBs contamination showed the similar congener distribution with Aroclor 1242. While the investigation of PCBs contamination was completed, a Simulated Aquarium Box (SAB) was constructed in a purpose of evaluating PCBs dechlorination in natural sediment environment. Sediment columns amended with different PCBs congeners or mixture such as 2,3,4-CB, 2,5,3’,4’,-CB, 2,4,2’,5’-CB 2,4,5,2’,4’,5’-CB and Aroclor 1242 were introduced into SAB for PCBs dechlorination tests. After 3 months of incubation, 2,3,4-CB concentration decreased and 2,4-CB was found. It suggested that PCBs dechlorination happened in the sediment. In 2,5,3’,4’-CB and 2,4,2’,5’-CB columns, the concentration were both decreasing, and their dechlorination products, 3,4,2’-CB and 2,5,2’-CB were also produced. 2,4,5,2’,4’,5’-CB, a congener with 6 substituted chlorines was thought not easily dechlorinated, however in SAB, it’s dechlorination product such as 2,4,2’,4’-CB, 2,4,2’,5’-CB and 2,4,5,2’,4’-CB, 2,4,5,2’,5’-CB were produced during a 3 months of incubation.