Doctor of Philosophy (PhD)


Plant, Environmental Management and Soil Sciences

Document Type



Chemical manufactures are often associated with a negative publicity due to chemical spills that can cause human health problems and environmental pollution. Innovative methods such as phytoremediation in lieu of traditional remediation methods are being researched to determine environmentally friendly options for remediation. Phytoremediation was studied as an alternative remediation method for removal of chemicals in a contaminated groundwater plume in Louisiana. The main constituents of concern in the plume were cumene and 4-cumylphenol. Two pilot phytotoxicity studies were funded to determine an optimum tree species for removal and control of the constituents of concern. A greenhouse and hydroponic system were constructed to test Taxodium distichum, Salix nigra, Juniperus virginiana, Pinus glabra, Populus deltoids, and Quercus nigra for their phytoremediation capabilities. Both phytotoxicity pilot studies covered a nine month growing period. Trees in the first study were subjected to six water treatments from three of the contaminated groundwater plume monitoring wells. Treatments included undiluted well water containing the constituents of concern; well water containing high salinity levels (above 2.0mS); and several dilutions of each. Three water treatments were tested in the second pilot study, high, low, and deionized water. The high and low water treatments were based on historically recorded high levels of contamination in the plume water. Trees were evaluated monthly for possible health affects of the constituents of concern. Monthly height, trunk diameter, and foliage visual ratings were taken. Initial and final tissue (root and shoot) and soil samples were collected and analyzed for the potential presence and concentrations of the constituents of concern in the tissue and potting media. Monthly water input and discharge samples were collected and analyzed for the constituents of concern. Results from the pilot studies indicated that both the Salix nigra and Taxodium distichum species were acceptable phytoremediation choices. However, Taxodium distichum was selected for the full scale planting over the groundwater plume because it was tolerant of the contaminated water treatments and salinity levels present in the groundwater. Additionally, Taxodium distichum was a low maintenance tree with a conical form that complied with security restrictions at the chemical facility.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Edward Bush