Phytoremediation of Arsenic-Contaminated Soils
Edenspace Systems Corporation
15100 Enterprise Court, Suite 100
Dulles, VA 20151-1217
Telephone: 877-961-8777
http://www.edenspace.com
Environmental Problem
Weathered lumber in decks, docks, playground
equipment, and gardens can leach significant
amounts of arsenic into soil and water, where it
poses health risks to people and animals. By 1990,
the United States used approximately 37 million lb
of arsenic annually in the production of chromated
copper arsenate {CCA), a wood preservative. Cur-
rently, there is no cost-effective method to clean up
arsenic-contaminated soils. The levels of arsenic
found in soil under CCA-treated decks have been
as high as 20 times the background level and sub-
stantially above most state and federal standards.
Although EPA regulations now limit the use of CCA
to the treatment of wood in forest products and
other primarily nonresidential applications, the
existing stock of CCA-treated wood products (con-
taining more than 600,000 metric tons of arsenic)
will continue to leach arsenic into the soil for years
to come. In situ phytoremediation of contaminated
soil could greatly reduce the amount of soil sent to
hazardous waste landfills by collecting and concen-
trating the arsenic in a much smaller volume of
plant biomass.
SBIR Technology Solution
With support from EPAs SBIR Program, Edenspace
Systems Corporation developed an arsenic phytore-
mediation technology for in situ treatment of soils
contaminated with CCA. With this technology, ferns
accumulate arsenic in their harvestable fronds at lev-
els up to 100 times the underlying soil concentra-
tion, facilitating efficient removal and disposal of
CCA-derived arsenic while preserving topsoil. The
plants then are harvested for recycling or landfill dis-
posal.
Edenspace Systems has demonstrated two methods
using fluid extraction for concentrating and refining
recovered arsenic for storage and future recycling,
with recovery rates greater than 70%. Phytoextrac-
tion and recycling of CCA arsenic for reuse in indus-
try offers two major benefits: (1) recapture and
proper disposal of arsenic leached to the environ-
ment from CCA-treated lumber; and (2) reduced
primary production (mining) of arsenic, thereby
reducing the total level of anthropogenic arsenic in
the environment.
This technology is scalable from very small sites {e.g.,
gardens) to large sites (e.g., lumber storage areas). An
acres-wide storage site for CCA lumber can be treat-
ed with high-volume agricultural techniques, whereas
a small area under a wood deck can be addressed
using home gardening skills. Edenspace Systems is
particularly interested in developing the technique for
use by individual homeowners, enabling them direct-
ly and flexibly to address CCA risks in the "microenvi-
ronment" around their homes. EPA has indicated that
such activities are covered by the Household Waste
Exclusion to the Resource Conservation and Recovery
Act, allowing the ferns to be disposed of as ordinary
waste in the same way that soil contaminated by
lead-based paint may be disposed of, facilitating the
reduction of environmental risk to the homeowner.
Commercialization Information
There is a strong customer interest in phytoremedia-
tion of soil arsenic deposited from CCA-treated wood,
with a projected U.S. market of $162-$194 million
Ferns following transplantation for remediation of
CCA: (a) over an entire area, and (b) closeup of ferns.
SBIR Success Stories
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4 years after product introduction. Currently, there is
no commercial competition for Edenspace Systems'
CCA arsenic phytoremediation. For the foreseeable
future, the innovation of this technology, combined
with Edenspace Systems' existing intellectual prop-
erty protection, should provide the company with
an excellent competitive position.
Edenspace Systems is marketing the arsenic extract-
ing fern under the trade name edenfern™. Sales of
edenfern™ to government agencies, businesses, and
homeowners totaled $22,000 in the initial year of
sales. Treatability studies are being conducted for six
potential arsenic-contaminated sites, and a multiyear
field cleanup is underway with the U.S. Army Corps
of Engineers at Spring Valley in Washington, DC.
Potential customers include wood treatment compa-
nies and distributors, homeowners, farmers, trans-
portation and utility companies, schools, and other
industry and government organizations.
Company History and Awards
Incorporated in Delaware in October 1998, and
headquartered in Dulles, Virginia, Edenspace
Systems Corporation is a leader in the commercial
use of living plants in innovative systems to remove
lead, arsenic, uranium, chlorides (salts), and other
minerals from the environment. As of December
31, 2004, Edenspace Systems had 9 employees and
revenues of $1.1 million. Edenspace Systems owns
or licenses 1 7 patents. In 2003, Edenspace an-
nounced a strategic partnership with Fujita Corpora-
tion, a large Japanese environmental contractor, to
introduce Edenspace Systems' phytoremediation
technology in Japan.
Current Edenspace Systems customers include EPA,
the Departments of Agriculture and Energy, US.
Army Corps of Engineers, National Institutes of
Health, state environmental agencies, universities,
private companies, and homeowners in the United
States and Japan. Edenspace Systems received the
1999 DaimlerChrysler Environmental
Excellence Award for saving the auto-
motive company more than $1 million
through a lead phytoextraction project.
V
A
SBIR Impact
EPA regulations now limit the use of chromated copper arsenate (CCA),
but the existing stock of CCA-treated wood products will continue to
leach arsenic into the soil for years to come.
Edenspace Systems developed an arsenic phytoremediation technology using
edenfern™, for in situ treatment of soils contaminated with CCA.
No other method of arsenic remediation offers such great potential for
recovering captured arsenic.
Sales of edenfern™ were made to government agencies, businesses,
and homeowners in the initial year of sales.
SBIR Success Stories
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