WEST LAFAYETTE, Ind. -- Plants have been quietly cleaning up behind us, recycling waste carbon dioxide into life-giving oxygen for as long as humans have been breathing.
Now Purdue University researchers are prodding them to take the cleanup a step further, to become phytoremediators -- plants that collect heavy metals and radioactive waste from polluted water and contaminated soils.
"Phytoremediation is only five or 10 years old," says Purdue horticulture Professor Peter Goldsbrough, "but there's a lot of hope that eventually plants can be used to restore sites and remove pollutants at a fairly low cost."
Initial commercial efforts at phytoremediation have been promising, but officials from the U.S. Department of Energy (DOE), which owns most toxic sites in the United States, are unsure about how well current processes will work on large projects -- and how much a large-scale operation would cost.
In one multinational effort, a New Jersey company is using plants to clean up nuclear contamination from the April 1986 nuclear accident at Chernobyl, Ukraine.
Using traditional technology to clean contaminated soil (such as removing, chemically treating or heating it) would cost several hundred dollars per ton of soil, according to DOE officials. That puts cleanup costs for contaminated soil in the United States at hundreds of billions of dollars. If phytoremediation reduced those cleanup costs by even 10 percent, an estimate Goldsbrough considers plausible, it would save taxpayers billions.
Goldsbrough, working with researchers from Australia, has been studying how plants
take up and store cadmium, a toxic heavy metal. It's both a natural and industrial
contaminant. Cadmium recently was found at high levels in livers of British sheep
grazing on a pasture fertilized for many years with sewage sludge. According to findings reported
at the annual meeting of the British Society of Animal Science, cadmium levels in
the sheep livers wer
Contact: Rebecca Goetz