Superfund Research Program
New Electroosmotic Pulse Process for Phytoremediation
Project Leader: Thomas D. Rogers
Grant Number: R43ES011877
Funding Period: Phase I: 2002-2005
The decontamination of soils and wastes polluted with heavy metals presents one of the most difficult problems for soil cleanup. Recently, a new technology that uses metal-accumulating plants has been explored for its ability to remove, contain, or render harmless various metals from contaminated soil. This new technology, phytoremediation, is an attractive approach for cleanup of soil because it is a low-cost and low-maintenance technology that can be applied for the treatment of a variety of contaminants. However, it also has a distinct limitation. Because the cleanup depth is strictly determined by the length of the plant roots, the application of phytoremediation is limited to surface contamination only.
Another soil remediation technique, electrokinetic soil processing, is an in situ technique where the contaminants are mobilized by the application of an electric field between strategically placed electrode wells, resulting in electroosmotic flow in the pore fluid within the soil structure. This technique also has its drawbacks. Treating over an extended period of time results in the formation of chemical species such as protons and hydroxide ions that interfere with the charged surface of the soil, causing flow reversal that severely limits the mobility of the metals and destroys the plants.
In this project, Lynntech aims to demonstrate a new approach to soil remediation and cleanup using a combination of electrokinetics and phytoremediation to concentrate, then bioaccumulate toxic heavy metal contaminants. Lynntech's advanced electrokinetic processes have been proven to mobilize metals through electroosmosis, electromigration and electrophoresis induced transport. Metal contaminants are mobilized into the root ozone where they can be accumulated in the plants as they grow.
The first phase of this project will demonstrate Lynntech's technology in a series of post field test beds before performing a 14-month field demonstration at Fort George Meade, MD. Phase two will utilize information gathered in phase one to perform a full-scale site decontamination study.