Abstract: Trees Suck… BTEX Compounds from Shallow Soils and Groundwater

BLAKE, KAREN, OXY USA, Inc, Houston, TX 

Under many oil field sites shallow soils and groundwater are contaminated with benzene, toluene, ethylbenzene, and xylene compounds. I propose using phytoremediation, specifically Liriodentdro tulipifera, Yellow Poplar, in the cleanup of the site.

Phytoremediation processes include enhanced rhizosphere biodegradation, hydraulic control, phyto-degradation and phyto-volatilization. Plant roots supply nutrients to the microorganisms within the soil, increasing microbial activity, which includes biodegradation of organic contaminants. Root growth and degeneration loosen soils, providing aeration and water transport pathways. Water uptake and transpiration processes move large quantities of water through the contaminated zones, allowing trees to become sinks for contaminants and providing for some hydraulic control. Initial core sampling will provide information on the hydraulic conductivity, thus refining the solute transport models.

Phytoremediation processes and groundwater parameters must be understood to refine the remediation effort. Once collected, data will be analyzed to obtained the following: Estimation of the natural attenuation rate. Spatial understanding of the hydraulic conductivity. Spatial-temporal relationship of water uptake and root activity. Spatial-temporal degradation rate of contaminants in soils and groundwater.

The effectiveness of phytoremediation with respect to benzene, toluene, ethylbenzene, and xylene compounds in shallow soils and groundwater will be determined. If successful, phytoremediation will be a cost effective, aesthetically pleasing method of remediation with wide applications.

AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California