Title page for etd-0721115-163333


[Back to Results | New Search]

URN etd-0721115-163333
Author Jian-Yu Lin
Author's Email Address No Public.
Statistics This thesis had been viewed 5385 times. Download 0 times.
Department Biological Sciences
Year 2014
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Studies on chemical leaching and bioremediation of mercury polluted soil
Date of Defense 2015-07-20
Page Count 111
Keyword
  • mercury
  • merA gene
  • chemical leaching
  • bioremediation
  • induction
  • Abstract Three mercury resistant bacteria strains were isolated from a mercury polluted site located in Southern Taiwan. The B37 strain is closely related to Enterobacter cloacae while A45 and A46 are associated with Pseudomonas sp. In previous studies, the existence of merA gene in these strains where confirmed by RT-PCR and real time PCR. The ability of mercury ion reduction by these three strains was also approved by microcosm studies. The objective of this study was to apply these three mercury resistant bacteria combined with chemical leaching pretreatment to remediate mercury contaminated soils. Chemical leaching compounds were added into growth media to test the inhibition effect on the growth of these 3 strains. Result showed that ammonium thiosulfate and sodium thiosulfate had comparatively less affection to the growth of bacteria, therefore were used in the following experiments. Microcosm studies exhibited that soil leaching by 0.3M ammonium thiosulfate for 24 hours then followed by the treatment of three mercury resistant bacteria resulted the best removal rete, 62.5% for the soil and 79.18% for the leachate. Calcium chloride, magnesium chloride, and zinc chloride were tested for the induction effect of the merA gene. From real time PCR analysis, the expression of merA gene was induced prominently by Mg2+ (650mg/L and 1300mg/L) and Ca2+ (200 mg/L and 400mg/L). The best induction effect was 650mg/L Mg2+ (12.28 folds) and 200 mg/L Ca2+ (11.13 folds) for A45 strain. A final microcosm study consisted all of the optimum conditions was performed. Result showed the mercury removal rate for the soil was 26%. This study provides a feasible way to treat mercury contaminated soils by a process of combined of chemical leaching with bioremediation.
    Advisory Committee
  • Jimmy C. M. Kao - chair
  • Lei Yang - co-chair
  • Jong-Kang Liu - advisor
  • Files
  • etd-0721115-163333.pdf
  • Indicate in-campus at 99 year and off-campus access at 99 year.
    Date of Submission 2015-08-21

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys