The goal of this study was to use molecular biology techniques to access and monitor the efficacy of bioremediation on a trichloroethene (TCE) polluted site. We added emulsified hydrogen releasing materials to stimulate onsite microbial growth and the biodegradation of TCE. This process was known as enhanced bioremediation. In this study, there were two bioremediation sites had been treated anaerobically. Groundwater samples were taken periodically for microbial analysis. Denaturing gradient gel electrophoresis (DGGE) was used to evaluate the variations in microbial community structures during the in situ groundwater remediation. The DGGE DNA bandings were sequenced to determine the 16S rRNA gene sequences and identify the dominate bacterial species. In addition, we used Dehalococcoides spp. 16S rRNA genes as the targets to do real-time PCR. Results show that the emulsified hydrogen releasing materials could enhance anaerobic reductive dechlorination. After addition of emulsified hydrogen releasing materials, we found that the volatile organic compounds concentrations (i.e., TCE, 1, 1-DCE and VC) were decreased. In microbial analysis, the diversities of the microbial community were increased after nutrient supplement. According to the DNA sequencing results, there were 31 bacterial species had been found that related to TCE degradation (i.e., Acidovorax sp., Burkholderiales, Pseudomonas sp., £]-proteobacterium, Comamonadaceae, Iron-reducing bacterium, Hydrogenophilaceae, Clostridium sp., Geobacter sp., Rhodoferax ferrireducens, Dehalospirillum multivorans and Dehalococcoides spp.). Dehalococcoides spp. can be used as a biomarker to evaluate the efficacy of anaerobic bioremediation on a TCE contaminated site. Therefore, we quantified Dehalococcoides populations to explain the capacity of bioremediation after addition of emulsified hydrogen releasing materials to groundwater. Results reveal that Dehalococcoides cell numbers of site A were 4.47¡Ñ103-8.26¡Ñ104 CFU/liter, site B were 4.60¡Ñ102-9.31¡Ñ107 CFU/liter. This data indicated that the addition of emulsified substrate would increase the growth of total Dehalococcoides population under anaerobic conditions. Overall, results from this study demonstrated that the microbial analysis and quantities of Dehalococcoides at different time points can provide useful information to proceed with bioremediation methods.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0711111-164054 |
| Date | 11 July 2011 |
| Creators | Li, Kuan-hsun |
| Contributors | Jong-kang Liu, Chi-Hsin Hsu, Chih-ming Kao |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0711111-164054 |
| Rights | restricted, Copyright information available at source archive |
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