'Shock Therapy' Exceeds Expectations In Cleaning Up Contaminated Soils

March 31, 1999

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™ technology, which uses electrical current fed to electrodes 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 soil to move toward the electrodes and into the treatment zones where iron filings mixed with clay destroy (dechlorinate) the trichloroethylene carried by the water. All the materials used in the electrodes and treatment zones "are innocuous to the environment and are designed to be left in place after the cleanup is completed," claims the research article.

The Lasagna testing, done in collaboration with the U.S. Department of Energy and the U.S. Environmental Protection Agency, was conducted at the Paducah Gaseous Diffusion Plant in Paducah, Ky., which produces enriched uranium. The U.S. Department of Energy, original owner of the plant, is responsible for environmental restoration of the plant's land, consisting mostly of low permeability clay that is "very difficult to treat with other technologies," notes Ho.

Kentucky officials initially had called for concentrations of trichloroethylene in the soil at the Paducah site, which ranged as high as 300 parts per million (ppm) prior to the Lasagna treatment, to be reduced to no more than five ppm. Following treatment, the contamination levels were as low as 0.2 ppm in some cases.

Lasagna treatment should range from $45 to $80 per cubic yard for contaminated sites of about one acre, compared to $200 to $1,000 for traditional excavation and incineration treatment, says Ho.
(The online versions of the two research papers cited below are available on the American Chemical Society's ASAP (As Soon As Publishable) web site. Journalists desiring full access to papers at the ASAP site must submit their requests in writing to n_blount@acs.org in the ACS Office of News & Information.)

A nonprofit organization with a membership of nearly 159,000 chemists and chemical engineers, the American Chemical Society publishes scientific journals and databases, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.

American Chemical Society

Related Technology Articles from Brightsurf:

December issue SLAS Technology features 'advances in technology to address COVID-19'
The December issue of SLAS Technology is a special collection featuring the cover article, ''Advances in Technology to Address COVID-19'' by editors Edward Kai-Hua Chow, Ph.D., (National University of Singapore), Pak Kin Wong, Ph.D., (The Pennsylvania State University, PA, USA) and Xianting Ding, Ph.D., (Shanghai Jiao Tong University, Shanghai, China).

October issue SLAS Technology now available
The October issue of SLAS Technology features the cover article, 'Role of Digital Microfl-uidics in Enabling Access to Laboratory Automation and Making Biology Programmable' by Varun B.

Robot technology for everyone or only for the average person?
Robot technology is being used more and more in health rehabilitation and in working life.

Novel biomarker technology for cancer diagnostics
A new way of identifying cancer biomarkers has been developed by researchers at Lund University in Sweden.

Technology innovation for neurology
TU Graz researcher Francesco Greco has developed ultra-light tattoo electrodes that are hardly noticeable on the skin and make long-term measurements of brain activity cheaper and easier.

April's SLAS Technology is now available
April's Edition of SLAS Technology Features Cover Article, 'CURATE.AI: Optimizing Personalized Medicine with Artificial Intelligence'.

Technology in higher education: learning with it instead of from it
Technology has shifted the way that professors teach students in higher education.

Post-lithium technology
Next-generation batteries will probably see the replacement of lithium ions by more abundant and environmentally benign alkali metal or multivalent ions.

Rethinking the role of technology in the classroom
Introducing tablets and laptops to the classroom has certain educational virtues, according to Annahita Ball, an assistant professor in the University at Buffalo School of Social Work, but her research suggests that tech has its limitations as well.

The science and technology of FAST
The Five hundred-meter Aperture Spherical radio Telescope (FAST), located in a radio quiet zone, with the targets (e.g., radio pulsars and neutron stars, galactic and extragalactic 21-cm HI emission).

Read More: Technology News and Technology Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.