Environmental remediation of HCB contaminated river sediment

• Main Authors: Chiung-Chiang Wang, 王炯強
• Other Authors: I-Ming Chan
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/68991106866360076823

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 the hexachlorobenzene (HCB) dechlorintion ability of indigenous microbes in Taiwan and Thailand, river and canal sediments were collected and introduced in the HCB dechlorination tests. Most sets by using anaerobic microbes from Er-Jen River and Ho-Tsin River slowly dechlorinated HCB with a longer lag phase more than 120 days, and only those sets that added powder-like HCB showed short lag phase. Futhermore, these microbes cannot dechlorinate polychlorinated biphenyls within 120 days of incubation. In contrast to the weak HCB dechlorination ability of Taiwan river sediment anaerobes, indigenous microbes from Thai canal sediments showed more active dechlorination. The reason for Thai canal bacteria possessing novel HCB dechlorination potential might because the Canal was found contaminated by HCB. The HCB dechlorination experiments by Thai Canal microbes included two stages. In the first stage, sediments from 10 different sites were collected and the HCB dechlorination ability of the sediment microbes was also tested. In the sets with yeast extracts (YE), all 10 sites of microbes showed dechlorination activity after 14 days of incubation and completed the dechlorination within 28 ~ 42 days. In the sets without YE, the lag phase was about 14 ~ 28 days. In the second stage, HCB dechlorination by treated and un-treated sediment slurries was investigated. The result showed that a higher sediment – water ratio lead to a higher dechlorinating activity for the sediment slurries. With or without filtration during the preparation of sediment slurries, the difference of dechlorination ability was not significant. In addition, the pre-anaerobic-treatment of sediment slurries improved the dechloriantion of sediment microbes. According to these findings, HCB dechlorinating consortia should be widespread along this Thai Canal, and it also suggested that the environmental remediation of HCB contamination is possible in natural polluted sites.