(Phytoremediation Technology)


Phytotech is an environmental biotechnology company that uses specially selected and engineered plants to treat soil and water contaminated with toxic metals such as lead and cadmium, as well as radionuclides. The treatment of soils or sediments with this technology is referred to as phytoextraction.

Phytoextraction offers an efficient, cost-effective, and environmentally friendly way to clean up heavy metal contamination. Plants are grown in situ on contaminated soil and harvested after toxic metals accumulate in the plant tissues. The degree of accumulation varies with several factors, but can be as high as 2 percent of the plants' aboveground dry weight, leaving clean soil in place that meets or exceeds regulatory cleanup levels.

After accumulation in the plant tissues, the contaminant metal must be disposed of, but the amount of disposable biomass is a small fraction of the amount of soil treated. For example, excavating and landfilling a 10-acre site contaminated with 400 parts per million (ppm) lead to a depth of 1 foot requires handling roughly 20,000 tons of lead-contaminated soil. Phytoextraction of a typical 10-acre site to remove 400 ppm of lead from the top 1 foot would require disposal of around 500 tons of biomass - about 1/400 of the soil cleaned. In the example cited, six to eight crops would typically be needed, with three or four crops per growing season.

Compared to traditional remedial technologies, phytoextraction offers the following benefits:


Phytotech's phytoextraction technology can be used to clean soil or sediments contaminated with lead, cadmium, chromium, cesium/strontium and uranium. Phytoremediation of other metals such as arsenic, zinc, copper, and thorium is in the research stage.


Phytotech was accepted into the SITE Demonstration Program in 1996. Under the SITE Program, Phytotech is demonstrating its phytoremediation technology at a former metal-plating facility in Findlay, Ohio where soil is contaminated with heavy metals. The site has been prepared and characterized; the contaminant metals are chromium, cadmium, nickel, zinc and lead. Two crops were planted and harvested in late summer 1996. Phytotech has also conducted several successful field trials of its phytoextraction technology at other contaminated sites in the U.S. and abroad.

Phytotech has conducted several field demonstrations of its rhizofiltration technology for the removal of (1) cesium/strontium at Chernobyl, and (2) uranium from contaminated groundwater at a DOE site in Ashtabula, Ohio. At Chernobyl, sunflowers were shown to extract 95 percent of the radionuclides from a small pond within 10 days. At the Ashtabula site, Phytotech ran a 9-month pilot demonstration during which incoming water containing as much as 450 parts per billion (ppb) uranium was treated to 5 ppb or less of uranium.


Steven Rock
National Risk Management Research
26 West Martin Luther King Drive
Cincinnati, OH 45268
Fax: 513-569-7105

Michael Blaylock or John Ehrler
One Deer Park Drive, Suite I
Monmouth Junction, NJ 08852
Fax: 908-438-1209
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