Date of Award

2001

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Plant, Enviromental and Soil Sciences

First Advisor

Wayne H. Hudnall

Abstract

The goal of this project is to introduce a successful remediation and restoration plan for a wetland and pine forest contaminated by an oil well blowout. A field study focused on the effectiveness of ammoniated bagasse (ABG) to enhance the bioremediation of the contaminated wetland. A comprehensive soil and vegetation greenhouse study investigated the effects of oil and brine on loblolly pine tree seedlings and the effectiveness of ABG to remove and remediate oil contaminated forest soils. The most effective, ecologically sound, and economical plan to remove the oil from the wetland was to burn the area. Once the area was burned a combination of ABG, lime, and topsoil was applied in situ to 20 research plots in order to monitor the effectiveness of ABG to remediate the soils. The soil total petroleum hydrocarbon results of the study question the ability of ABG to remediate the site, as there was no statistically significant difference between treatments. The spatial variability of oil within the wetland made it difficult to prove the effectiveness ABG to promote bioremediation of the oil contaminated soils. Greenhouse studies investigated the effects of foliar and soil applications of unweathered crude oil and brine on two-year old loblolly pine seedlings. Results show that soil applied oil and brine had a greater negative effect (i.e. stress, death) than foliar applied oil and brine. Foliar applied brine had little or no effect on the trees. Foliar applied oil caused trees to show signs of stress when needle surface area coverage exceeded 50%. Nutrient analysis of seedlings treated with oil to cover 75--100% of the needle surface area show that the seedlings may have stressed and/or died as a result of the oil inhibiting the photosynthetic pathway. The effectiveness of ABG to remediate oil contaminated forest soils was demonstrated in this greenhouse study. When ABG was applied at rates of 1724 kg/ha, soil total petroleum hydrocarbon concentrations decreased from 18571 ppm to 574 ppm. Rates of ABG equal to or less than 431 kg/ha were not effective at remediating oil contaminated forest soils.

ISBN

9780493328423

Pages

137

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