Case studies of phytoremediation of petrochemicals and chlorinated solvents in soil and groundwater

The use of plants and the microbes associated with their growth to cleanup contaminated soils and water (phytoremediation) is an innovative technique approved by state and federal regulators for use in full-scale restoration of hazardous waste sites. Three case studies on the use of phytoremediation technologies for remediation of volatile organic contaminants (VOCs) in soil and groundwater are discussed. In Case Study #1 willow tress were planted over a petroleum spill and used to clean-up residual contamination in soils and the contaminated groundwater below. After three growing seasons 90% of the contamination was removed from the site. In Case Study #2, a combination of poplar and willows trees was used as a polishing step for a chlorinated solvent plume while in-situ chemical oxidation with potassium permanganate was used for source control. The parent chlorinated ethenes and chloroacetic acids (oxidative transformation products) were detected in the tree tissues at the end of the first growing season, confirming the uptake and phytodegradation of the contaminants. Case Study #3 focused on the assessment of the contribution of plants in the attenuation of a mixed-contaminant plume of hydrocarbons and chlorinated solvents at a hydrocarbon burn facility at the Kennedy Space Center in Florida. Analysis of the geochemical and hydrogeological data confirmed the attenuation of the plume in the natural wetland at the site.Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources Facult