The objective of this study was to investigate the spatial and temporal trends of a phytoremediation system comprised of poplar trees designed to control groundwater flow and remove primarily polycyclic aromatic hydrocarbons (PAHs). Several lab and field studies have demonstrated the success of poplar trees in effectively decreasing concentrations of volatile hydrocarbons, but few have demonstrated effects on PAH concentrations. Thus, the focus of this report will be the response of the poplar trees in relation to hydrophobic, nonvolatile polycyclic aromatic hydrocarbons (acenapthene, acenapthylene, anthracene, chrysene, fluoranthene, naphthalene, phenanthrene, and pyrene) in a shallow, surficial aquifer. This field study was conducted on a 1.7-acre site in Oneida, Tennessee contaminated with creosote that was once used for railroad cross-tie treatment. Spatial analysis was used to divide the site into areas based on contaminant levels and a layer of coal that served as a layer of low permeability at an approximate depth of 2 feet. The semi-impermeable coal layer does have an adverse impact on tree growth, while the contamination does not appear to adversely affect tree growth. The rate of growth is also impacted by the age of the tree at planting where younger trees grow faster than the older trees. A steady decrease in PAH concentrations has occurred at the multi-level samplers surrounded by a root zone that has penetrated the contamination. PAH compounds present at relatively high concentrations in the soil and groundwater do not appear to affect tree growth to a greater or lesser extent than lower PAH concentrations. While further research is required to affirm the positive effects of poplar trees at this site, the tree stand has responded well to the high PAH levels. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/37132 |
| Date | 07 July 2000 |
| Creators | Lawrence, Matthew S. |
| Contributors | Civil Engineering, Widdowson, Mark A., Novak, John T., Dymond, Randel L. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Master's project |
| Format | application/pdf, application/pdf, application/pdf, application/pdf, application/pdf |
| Rights | I hereby grant to Virginia Tech or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University Libraries in all forms of media, now or hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. |
| Relation | AppendixA.PDF, AppendixB.PDF, AppendixC.PDF, PaperETD.PDF, Vita.pdf |
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