The goal of this study is to evaluate the potential of three plants, Thelypteris palustris (marsh fern), Asparagus sprengeri (asparagus fern), and Lolium perenne (perennial ryegrass) for use in phytoremediation of arsenic-contaminated soils. Specifically, the objectives of this study are to (1) confirm if arsenic accumulation occurs in the selected plants, (2) to examine morphological effects of arsenic in the selected plants, and (3) to evaluate the oxidation state of arsenic upon accumulation in the selected plants. The analytical method combination of ICP-MS, SEM, and XANES was used to accomplish the objectives of this study.
The results indicate marsh fern, asparagus fern, and perennial ryegrass all uptake arsenic. Bioaccumulation factors of all plants except ryegrass are > 1, indicating that they are accumulators of arsenic. The bioaccumulation factors of marsh fern were found to be in the range of the bioaccumulation factors (>10) of the known hyperaccumulator, Pteris vittata. After arsenic exposure, plants exhibited necrosis or vascular system degradation and collapse. All plants contained a mixture of the arsenic oxidation states of As (V), As (III), and/or As (0). Ryegrass was the only plant to contain As (III) chemically associated with sulfur. As (V) and/or As (0) were the dominant oxidation states in above-ground biomass of asparagus fern and ryegrass. As (V) was the dominant oxidation state in the roots of marsh fern.
In conclusion, marsh fern, asparagus fern, and ryegrass have the ability to survive arsenic exposure and accumulate arsenic into above-ground parts. Marsh fern is a good candidate for phytoextraction of areas contaminated with low levels of arsenic. Although, asparagus fern and ryegrass are not good candidates for phytoextraction, their potential in phytostabilization should be further investigated.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-04102007-160616 |
| Date | 11 April 2007 |
| Creators | Anderson, LaShunda L |
| Contributors | Maud Walsh, Margaret Reams, David Himelrick, Jim Wang, James Griffin |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-04102007-160616/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein 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 LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, 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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