Cost-Effective Approach Has Potential For Wide Use
Researchers have removed up to 99 percent of trichloroethylene from contaminated soil during the first field tests of an innovative remediation method called Lasagna buried in the ground.
Trichloroethylene is used for cleaning and degreasing metal, in the production of rubber and plastics, in dry cleaning processes and in household solvents. It has been associated with a possible increased risk of cancer in people.
The tests exceeded the researchers' expectations for remediation of the soil, according to two related research articles in the April 1 print edition of the peer-reviewed journal Environmental Science & Technology, published by the American Chemical Society, the world's largest scientific society.
Scientists from Monsanto, General Electric and DuPont describe the Lasagna technology as "very successful" and claim it is cost-effective in cleaning up trichloroethylene-contaminated soil in place. The research was initially published on the journal's web site Feb. 25.
Called "lasagna" because of the layered placement of 'treatment zones' within the buried electrodes, "the technology utilizes an electrical current to drive contaminants from soil into in situ treatment zones for destruction," says the report's lead author, Sa V. Ho, Ph.D., of the Monsanto Company in St. Louis, Mo. Doing the treatment in place, rather than moving it to a central remediation site, means "the technology has minimal disturbance to the environment, generates no waste, can be cost-effective and has the potential for wide application," he claims.
Applying electricity to the electrodes, which were buried up to 45 feet
deep in the larger of two field tests that were conducted, causes water in the
move toward the electrodes and into the treatment zones where iron filings mixed
with clay destroy (dechlorinate) the trichloroethylene carried by the water.
Contact: Charmayne Marsh
American Chemical Society