• picture
  • picture
PRI's Environmental News Magazine

Emerging Science Note/Cleaning Contaminants

Air Date: Week of March 31, 2006

stream/download this segment as an MP3 file

What do algae, ultrasonic waves, and mercury contamination have in common? Emily Taylor reports on a possible savior for polluted rivers.

Transcript

TAYLOR: Goodbye, heavy metal. Hello, soft rock.

Scientists at Ohio State University have come up with a new combination of technologies that they hope will someday be used to clean heavy metals out of riverbeds contaminated by pollution.

By using ultrasonic waves, researchers Ziqi He and Linda Weavers were able to shake mercury loose from sediment particles resting in water in their lab. But they quickly found themselves with a new problem. Because the mercury had been vibrated loose, it was now contaminating the water. So, Weavers and He turned to their colleague Richard Sayre, a professor of plant, cellular and molecular biology.

Sayre and his team had genetically modified a species of algae designed to absorb certain heavy metals. Then the two teams put their two technologies to the test. They used an ultrasonic probe in a beaker filled with water, contaminated sediment, and algae. As predicted, the mercury was vibrated free, and within seconds the algae had absorbed up to 60 percent of the mercury from the water. After the first few minutes, 30 percent of the mercury in the sediment was gone.

Although other technologies exist to remove metals from sediment, this system is more efficient because the algae has been modified to absorb a single metal group, rather than all metals, making it five times more absorptive. The researchers hope to put the technology to use in contaminated river beds where sediment could be removed, cleaned, then replaced without greatly harming wildlife.

That’s this week’s Note on Emerging Science, I’m Emily Taylor.

 

 

Living on Earth wants to hear from you!

P.O. Box 990007
Prudential Station
Boston, MA, USA 02199
Telephone: 1-617-287-4121
E-mail: comments@loe.org

Donate to Living on Earth!
Living on Earth is an independent media program and relies entirely on contributions from listeners and institutions supporting public service. Please donate now to preserve an independent environmental voice.

Newsletter
Living on Earth offers a weekly delivery of the show's rundown to your mailbox. Sign up for our newsletter today!

Major funding for Living on Earth is provided by the National Science Foundation.

Committed to healthy food, healthy people, a healthy planet, and healthy business.

Innovating to make the world a better, more sustainable place to live.

Kendeda Fund, furthering the values that contribute to a healthy planet.

The Grantham Foundation for the Protection of the Environment: Committed to protecting and improving the health of the global environment.

Contribute to Living on Earth and receive, as our gift to you, an archival print of one of Mark Seth Lender's extraordinary hummingbird photographs. Follow the link to see Mark's current collection of photographs.