This work consists of constructing a model that combines an understanding of physical transport processes and the biological mechanisms involved in the uptake, transport and sequestration of contaminants by a hyperaccumulator, alpine pennycress (Thlaspi caerulesciens), a non-accumulator, field pennycress (Thlaspi arvense), and a maize. Specifically, the model uses a Michaelis-Menten formulation to describe uptake, and transpiration-driven translocation into aboveground biomass. Model simulations indicate that, despite its small biomass and slow growth, the hyperaccumulator alpine pennycress is a reasonable choice for phytoextraction due to the fast uptake rate as well as high metal tolerance, specifically in the aboveground biomass. In contrast, the field pennycress, which has a similar small biomass, but can only tolerate cadmium at much lower levels and does not translocate cadmium into aboveground biomass, is not an ideal candidate for phytoextraction. Although maize has a much larger biomass, phytoextraction using maize requires chemical treatment that mobilizes cadmium into the surrounding environment, and it has negative features similar to those of the field pennycress. Further studies that account for diurnal and seasonal variations in moisture and radiation may be required; however, the relative performance between those three species is not expected to change.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-12092008-132028 |
| Date | 02 January 2009 |
| Creators | Takahashi, Maria |
| Contributors | Dr. David Jon Furbish, Dr. James A. Clarke |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-12092008-132028/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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