Plants That Clean A Mess Of Messes
PLANTS THAT USUALLY DON'T GET MUCH RESPECT--LIKE cattails and ragweed--are coming into their own as low-cost pollution vacuums. Using vegetation to soak up toxic wastes was proposed in 1980 by Rufus Chaney, a U.S. Agriculture Dept. agronomist. But the idea caught on only in the past few years, says Douglas D. Randall, a University of Missouri biochemist and co-organizer of a conference in April that attracted 35 researchers from around the world.
Chevron Corp., for instance, is using cattails to soak up selenium discharged from its Point Richmond (Calif.) oil refinery (photo). Some of the selenium is expelled into the air in nontoxic quantities. Cattails containing selenium can be reaped and spread over soil that's deficient in the metal. That should cost a fraction of the hundreds of millions of dollars that would be required to dredge and bury or burn the sediments, according to University of California at Berkeley plant biologist Norman Terry.
In Ukraine, Ilya Raskin, a Rutgers University biochemist, is testing the Indian mustard plant to soak up radioactive wastes from soil near the Chernobyl nuclear power plant. And in Athens, Ga., Environmental Protection Agency researchers are studying how plants such as parrotfeather and stonewort can soak up and decompose TNT.