University of Florida | Soil & Water Science Department
SWSD: http://soils.ifas.ufl.edu
|
Center: http://www.eng.ufl.edu/
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Related Article: http://www.napa.ufl.edu/2001news/fern.htm
|
Newsletter: http://soils.ifas.ufl.edu/newsletter2/index.html
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The Soil and Water Science Department (SWSD) is going through
exciting and challenging times. We all know that optimal soil and water
quality is essential to sustainable agricultural productivity as well as
protection and conservation of natural resources. Nonpoint source pollution
of streams, rivers, groundwater, lakes, wetlands, and estuaries is linked
to the management practices used in agricultural, forest, range, and urban
land ecosystems.
Many current practices used in these ecosystems may not be adequate
to sustain the quality of natural resources. In the context of Florida
FIRST, the SWSD programs are designed to address critical issues related
to soil and water quality in these ecosystems.
The SWSD faculty continue to explore new opportunities by expanding
their programs and developing scientific knowledge that will help to protect
the quality of soil and water resources, while sustaining the productivity
of Florida’s ecosystems. We are addressing the critical needs of the State
of Florida through teaching courses on and off campus, timely research
and extension publications, serving on state sponsored task forces, conducting
in-service training and workshops, and consultations with clientele.
Here are a few examples of our recent activities:
-- Discovery of a ‘fern’ that hyper-accumulates arsenic offers excellent
opportunities to phyto remediate this important contaminant.
In this newsletter we feature one of our thrust areas,
‘Remediation of Contaminated Soils, Waters, and Aquifers.'
Dr. Lena Ma examines 'fern' | Pteris
vittata |
Newsletter: http://soils.ifas.ufl.edu/newsletter2/research.html
|
University of Florida scientists, led by Dr. Lena Ma, report discovering
a fern that soaks up arsenic from contaminated soil. The first plant
ever found to “hyper-accumulate” arsenic -- a carcinogenic
trace element often used as an herbicide the fern may prove useful in cleaning
up thousands of sites contaminated by arsenic from industrial, mining,
ag-ricultural or other operations around the world.
The research team, which included Ken Komar, Cong Tu, and Beth
Kennelley of the SWSD, and Weihua Zhang and Yong Cai of Florida International
University, Miami, found that the Brake fern, Pteris
vittata, soaks up arsenic with staggering efficiency. They
measured levels as much as 200 times higher in the fern than the concentrations
in contaminated soils where it was growing. In greenhouse tests using soil
artificially infused with arsenic, arsenic concentrations in the fern’s
fronds have reached 22,630 parts per million -- 2.3% of the plant was composed
of arsenic. The findings suggest that Brake fern has the potential to remediate
arsenic-contaminated soils, and could also aid in studies of arsenic uptake,
trans-location, speciation, distribution and detoxification in plants.
The fern is an easy-to-grow perennial that prefers a sunny environment
and alkaline soil. Results of this work were recently published in “Nature”
(Feb. 2001).
Kevin Boggs
Assistant Director, Life Sciences
University of Florida
Office of Technology Licensing
P.O. Box 115500
314 Walker Hall | Gainesville, FL 32611
Phone (352) 392-2577 | Fax (352) 392-6600 | kboggs@ufl.edu
|
-- The University holds use patnet
-- and is committed to bring the plant to public use
US Patent Office: http://www.uspto.gov
|
Info: http://www.uspto.gov/web/offices/pac/doc/general
|
First Gov: http://www.firstgov.gov/
|
Patent law: http://law.freeadvice.com/intellectual_property/patent_law
|
Brake Fern:
| http://www.amarillonet.com/stories/020201/usn_brakefern.shtml
|
Brake fern safely soaks up arsenic
By JEFF DONN The Associated Press
Friday, February 2, 2001
A common fern has been found to soak up extraordinary amounts of
arsenic without any ill effects, potentially offering a natural way
of cleaning up polluted soil and water.
The plant, known as the brake fern, grows naturally in the Southeast
and California.
“It looks lush green,” said Lena Ma, a soil chemist who
led the research at the University of Florida | Soil & Water Science
Department. “When I take people to my greenhouse to look at a fern with
8,000 parts per million of arsenic, they can't imagine it's toxic waste.”
The brake fern, whose scientific name is Pteris vittata, is the
first plant known to accumulate arsenic in extremely high concentrations
and still flourish, scientists said. The discovery was reported in Thursday's
issue of the journal Nature.
A crystalline chemical, arsenic is one of the best known poisons.
It has often been the poison of choice in the arts, as in the classic film
“Arsenic and Old Lace.”
Arsenic taints many sources of drinking water in the United States
and abroad. People who drink arsenic-contaminated water over long periods
are believed to run a higher risk of bladder, lung and skin cancer, as
well as other heart and lung ailments.
Some arsenic is naturally present in soil. It also comes from
some farm chemicals, wood preservatives and other industrial products.
Ma said that, unlike many ferns, this one likes the sun. It could
potentially be cultivated in water and act as a natural arsenic filter.
And the fern's arsenic-loving genes could potentially be spliced into other
plants.
“The fact that it can take something that is toxic at extremely
low concentration and accumulate it at high concentrations is very useful,”
said Stephen Ebbs, a plant researcher at Southern Illinois University.
Some plants are already used to remove other pollutants from the
environment, a process known as phytoremediation. But the plants
do not concentrate the toxins as strongly as the brake fern.
Other powerful accumulators are being tested, but these plants
are generally small and thus collect chemicals in small amounts.
By contrast, the brake fern collects the arsenic in fronds that
grow up to 5 feet long. Unlike roots - where some plants accumulate pollutants
- the fronds are easy to harvest when it is time to clear away the arsenic.
Scientists said more work is needed on how to dispose of the plants.
The report of the fern's special properties comes at a time of
intensified worry about arsenic in drinking water. Last year, a World Health
Organization study said that up to 77 million of Bangladesh's people are
at risk of poisoning from naturally occurring arsenic in drinking
water.
Two weeks ago, the Environmental Protection Agency announced
a much tighter standard for arsenic in American drinking water, forcing
about 3,000 communities to take stronger action.
The Florida researchers were looking for a plant that could take
in soil arsenic in high concentrations and then be hauled away. They tested
14 species from an abandoned lumber yard contaminated by arsenic in Archer,
Fla.
Their tests showed that the brake ferns growing there concentrated
up to 200 times the arsenic level in the soil. In other tests, the researchers
spiked soil with varying levels of arsenic and found that brake ferns absorbed
the poison at 10 to 64 times the original concentrations.
“She got incredibly lucky. She happened to pick the 14 and found
one good one,” said David Salt, a Northern Arizona University
biochemist who specializes in such pollution-absorbing plants.
It is unclear if the fern is taking in arsenic as a nutrient or for
some other reason.
Edenspace, a company in Dulles, Va., has bought rights and already
begun to market the fern commercially.
David Salt
a Northern Arizona University biochemist
who specializes in such pollution-absorbing plants.
David Salt: http://jan.ucc.nau.edu/
|
Stephen Ebbs
a plant researcher at Southern Illinois University
“The fact that it can take something that is toxic at
extremely low concentration and accumulate it at high concentrations is
very useful,” Stephen Ebbs, a plant researcher at Southern Illinois University.
Stephen Ebbs
A common fern has been found to soak up extraordinary amounts
of arsenic without any ill effects, potentially offering a natural way
of cleaning up polluted soil and water.
The plant, known as the brake fern, grows naturally in the southeast
United States and California.
“It looks lush green,” said Lena Ma, a soil chemist who led the
research at the University of Florida at Gainesville. “When I take
people to my greenhouse to look at a fern with 8,000 parts per million
of arsenic, they can't imagine it's toxic waste.”
The brake fern, whose scientific name is Pteris vittata, is the
first plant known to accumulate arsenic in extremely high concentrations
and still flourish, scientists said. The discovery was reported in Thursday's
issue of the journal Nature.
A crystalline chemical, arsenic is one of the best known poisons.
It has often been the poison of choice in the arts, as in the classic film
Arsenic and Old Lace.
Arsenic taints many sources of drinking water in the United States
and abroad. People who drink arsenic-contaminated water over long periods
are believed to run a higher risk of bladder, lung, and skin cancer, as
well as other heart and lung ailments.
Some arsenic is naturally present in soil. It also comes from
some farm chemicals, wood preservatives and other industrial products.
Ma said that, unlike many ferns, this one likes the sun. It could
potentially be cultivated in water and act as a natural arsenic filter.
And the fern's arsenic-loving genes could potentially be spliced into other
plants.
“The fact that it can take something that is toxic at extremely
low concentration and accumulate it at high concentrations is very useful,”
said Stephen Ebbs, a plant researcher at Southern Illinois University.
Some plants are already used to remove other pollutants from
the environment, a process known as phytoremediation. But the plants do
not concentrate the toxins as strongly as the brake fern.
Other powerful accumulators are being tested, but these plants
are generally small and thus collect chemicals in very small amounts.
By contrast, the brake fern collects the arsenic in fronds that
grow up to 5 feet long. Unlike roots - where some plants accumulate pollutants
- the fronds are easy to harvest when it is time to clear away the arsenic.
Scientists said more work is needed on how to dispose of the plants.
The report of the fern's special properties comes at a time of
intensified worry about arsenic in drinking water. Last year, a World Health
Organization study said that up to 77 million of Bangladesh's people are
at risk of poisoning from naturally occurring arsenic in drinking water.
Two weeks ago, the Environmental Protection Agency announced
a much tighter standard for arsenic in American drinking water, forcing
about 3,000 communities to take stronger action.
The Florida researchers were looking for a plant that could take
in soil arsenic in high concentrations and then be hauled away. They tested
14 species from an abandoned lumberyard contaminated by arsenic in Archer,
Florida.
Their tests showed that the brake ferns growing there concentrated
up to 200 times the arsenic level in the soil. In other tests, the researchers
spiked soil with varying levels of arsenic and found that brake ferns absorbed
the poison at 10 to 64 times the original concentrations.
Edenspace, a company in Dulles, Virginia, has bought rights and
already begun to market the fern commercially.
By Jeff Donn | The Associated Press.
GAINESVILLE, Fla. --- The solution to one of man’s most
vexing environmental problems may lie in one of nature’s most remarkable
plants.
Related Article: http://www.napa.ufl.edu/2001news/fern.htm
|
In an article scheduled to appear Thursday in the journal Nature,
University of Florida scientists report discovering a fern that soaks up
arsenic from contaminated soil. The first plant ever found to “hyperaccumulate”
arsenic -- a carcinogenic heavy metal often used as an herbicide -- the
fern may prove useful in cleaning up thousands of sites contaminated by
arsenic from industrial, mining, agricultural or other operations around
the world.
“It has great potential for remediating these contaminated soils,”
said Lena Ma, an associate professor at UF’s Institute of Food and Agriculture
Sciences and lead researcher on the project.
Ma’s research team found that the brake fern, Pteris vittata,
not only soaks up arsenic but does so with staggering efficiency. They
measured levels as much as 200 times higher in the fern than the concentrations
in contaminated soils where it was growing, Ma said.
In that example, from a site contaminated by lumber treated with
chromium-copper-arsenic solution, the soil had 38.9 parts per million of
arsenic, while the fern fronds had 7,526 parts per million of arsenic.
In greenhouse tests using soil artificially infused with arsenic,
concentrations of the heavy metal in the fern’s fronds have reached 22,630
parts per million -- meaning that a startling 2.3 percent of the plant
was composed of arsenic, Ma said.
To their surprise, the research team found the fern even accumulates
arsenic in soils that contain normal background arsenic levels of less
than 1 part per million. For example, the team measured 136 parts per million
of arsenic in fronds of a fern growing on UF campus in soil that contained
just .47 parts per million of the metal.
Levels of arsenic in the plant easily eclipse the threshold of
5 parts per million for classification as an industrial-level hazardous
waste based on the Environmental Protection Agency’s standard test, a jarring
fact when considered with the plant’s verdant appearance.
The findings are all the more remarkable because arsenic often
is used to kill weeds and other unwanted plants on golf courses and lawns,
said Ma, a specialist in trace metal chemistry in the IFAS soil and water
science department.
“Why it accumulates arsenic is a mystery,” she said, adding that
her future research will focus on how the plant takes up, distributes and
detoxifies the arsenic.
The findings suggest the fern could become a star player in a
burgeoning industry known as “phytoremediation,” or using
plants and trees to clean up toxic waste sites.
Currently, some 400 plants are known to accumulate toxins. Many
are used in a small but growing phytoremediation market estimated to be
climbing from a range of $16.5 million to $29.5 million in 1998 to a range
of $214 million to $370 million by 2005, according to published reports.
Because the fern accumulates 90 percent of the arsenic in its
fronds and stems, the strategy would be to grow the plant on toxic sites,
then harvest the fronds and stems -- its “above-ground biomass” -- and
transfer them to a designated hazardous waste facility.
The approach could help address a major problem in Florida and
worldwide, Ma said.
Earlier this century, cattle ranchers in Florida often used the
poison on their herds to combat fleas and other vermin. As a result of
this activity alone, the state has more than 3,200 known sites contaminated
by arsenic. Worldwide, there are tens of thousands of contaminated sites,
the result of mining, milling, combustion, wood preservation and pesticide
application, Ma said. The fern seems all the more promising to clean up
many sites because it is an easy-to-grow perennial that prefers a sunny
environment and alkaline soil.
Arsenic is more easily extractable chemically in alkaline conditions,
Ma said.
In the greenhouse tests the plant seems to fare better in soils
with arsenic than in soils without arsenic. But Ma said she is not ready
to conclude the plant needs arsenic to live.
Other scientists involved in the research are
-- Ken Komar, a former UF master’s student under Ma’s supervision;
-- Cong Tu, a postdoctoral student in Ma's group;
-- Weihua Zhang and Yong Cai of the Florida International University department
of chemistry; and
-- Elizabeth Kennelley at the IFAS Analytical Research Laboratory.
The research was supported by the Florida Center for Solid and Hazardous
Waste Management at the UF College of Engineering.
EPA: http://www.epa.gov/safewater/arsenic.html
|
The Safe Drinking Water Act requires EPA to revise the existing 50 parts
per billion (ppb) standard for arsenic in drinking water. In January
2001, EPA published a new standard for arsenic in drinking water that requires
public water supplies to reduce arsenic to 10 ppb by 2006. EPA
is reviewing this standard so that communities that need to reduce arsenic in
drinking water can proceed with confidence that the new standard is based
on sound science and accurate cost estimates.
On April 18, 2001, the Administrator announced the process by
which EPA will work with the National Academy of Sciences and the National
Drinking Water Advisory Council to review the science and cost estimates
behind the rule.
On May 22, 2001, EPA announced that it will delay the effective
date for the rule until February 22, 2002 allowing time to complete the
reassessment process outlined below and to afford the public a full opportunity
to provide further input.
EPA Fact Sheet on arsenic in drinking water:
| http://www.epa.gov/safewater/ars/ars_rule_factsheet.html
|
Edenfern by Edenspace: http://www.edenspace.com
|
Edenspace: http://www.edenspace.com
|
Edenspace is a systems technology company that uses living plants
to improve environmental quality and human health. With more than two dozen
field projects completed or underway, Edenspace is the commercial leader
in the use of plants as solar-powered pumps and filters to remove minerals
from water and the ground.
This exciting new approach, called phytoextraction, literally
grows a clean environment, offering substantially lower costs than alternative
methods as well as important environmental and aesthetic benefits. Headquartered
in northern Virginia near Washington, D.C., the company acquired Phytotech,
Inc., a pioneer in metal phytoextraction, in 1999.
How does it work: http://www.edenspace.com/
|
The Chinese brake fern (Pteris
vittata) is a fern that is native to Asia, Africa, and Australia.
It is an exotic in the United States. Researchers at UF - Gainesville has
found that the brake fern hyperaccumulates aresenic. This is incredibly
useful, since there is a whole lot of arsenic groundwater contamination
going on. Best of all, capitalism has capitalized, and you can now buy
these ferns exclusively under the trademark “edenfern”
from the company Edenspace.
Buy Ferns: http://www.edenspace.com/
|
To Order: http://www.edenspace.com/
|
Price per plant: $4.95 | 20 x $5.00 = $100 | Handling Charge 15% =
$15
Ferns are 4 to 6" tall | Wholesale / distributor ordes only.
Odered under exclusive license only for cultivation or resale.,
and not for propagation. Patent pending.
arsenic phytoremediation
| http://www.edenspace.com/
|
Arsenic contamination of soil and water poses significant health
risks to millions of people worldwide. Arsenic causes cancer, mutations
and birth defects, and has been linked to the development of diabetes and
problems with the immune system (NRC, 1977, 1999). Up to now, there has
been no cost-effective method to clean up arsenic-contaminated soils, and
the technologies currently used for the cleanup of arsenic-contaminated
drinking water have significant drawbacks, such as high cost, generating
high volumes of toxic sludge and brine, and low water recovery.
The Edenfern forms the basis of a solar-powered (photosynthetic)
technology that provides cost-effective, small-scale cleanup of arsenic-contaminated
soil and surface, ground, and drinking water.
Scientists from the University of Florida originally identified this
fern (Ma et al., 2001), for which Edenspace has licensed exclusive
rights for the cleanup of arsenic contaminated soil, sludge, and water.
Our research indicates that this fern accumulates an arsenic
concentration, in the above ground plant tissue, more than 200-fold higher
than any other plant species tested. We have also examined time-dependent
arsenic accumulation by Edenfern and Boston fern (N. exaltata). Under the
same growth conditions, Edenfern accumulated significantly higher shoot
arsenic concentration than Boston fern, a non-arsenic-accumulator. Edenfern,
a perennial plant species, grows very rapidly in arsenic contaminated soil,
regenerates substantial shoot biomass within three weeks following harvest
the shoots, and accumulates consistent high arsenic concentrations in its
shoots from successive harvesting.
| more: http://www.edenspace.com/
|
Contact Information ? For further information on effective
plant-based treatment of arsenic contaminated soils, groundwater, surface
water, or drinking water, please contact:
Michael Blaylock, PhD: Email: blaylock@edenspace.com
|
Ag Dictionary: http://www.agriculturelaw.com/links/dictionary.htm
|
Cultivate: http://www.dictionary.com/cgi-bin/dict.pl?term=Cultivate
|
1.
-- a.To improve and prepare (land),
as by plowing or fertilizing, for raising crops; till.
-- b.To loosen or dig soil around (growing plants).
2. To grow or tend (a plant or crop).
3. To promote the growth of (a biological culture).
4. To nurture; foster. See Synonyms at nurture.
5. To form and refine, as by education.
6. To seek the acquaintance or goodwill of; make friends with.
Propagation: http://www.dictionary.com/cgi-bin/dict.pl?term=propagation
|
1. Multiplication or increase, as by natural reproduction.
2. The process of spreading to a larger area or greater number;
dissemination.
3. Physics. The act or process of propagating, especially the process
by which a disturbance, such as the motion of electromagnetic or sound
waves, is transmitted through a medium such as air or water.
Arsenic-eating plant Pteris vittata could improve environment:
Study London Feb 01, 2001 14:30 Hrs (IST)
A fern that eats arsenic could help to clean up industrial, mining
and agricultural sites polluted with the poisonous metal, American scientists
said on Wednesday.
The fern, Pteris vittata, is easy to grow, likes a sunny environment
and soaks up arsenic from the soil quickly and efficiently.
“It has great potential for remediating these contaminated soils,”
Lena Ma, of the University of Florida, said in a statement.
Arsenic is often used as an herbicide to kill weeds and unwanted
plants. When the researchers tested the fern they found that it had arsenic
levels 200 times higher than the level of the metal found in the soil.
The scientists, whose research is published in the science journal
Nature, said there are tens of thousands of sites contaminated with arsenic
worldwide.
“Why it accumulates arsenic is a mystery,” Ma, a specialist in trace
metal chemistry, added.
Purdue: http://www.vet.purdue.edu/depts/addl/toxic/plant23.htm
|
Bracken remains toxic when dry, and is never safe for consumption.
PREVENTION: Grazing animals should not be allowed access to bracken
fern, especially if they have developed a taste for it. Provide supplemental
feed if the pasture is low in adequate forage. Never use hay or bedding
material that contains bracken.
Texes: http://www.hort.purdue.edu/newcrop/proceedings1993/v2-612.html
|
Slender Brake
Fern |
Natural History Museum:
| http://www.nhm.org/research/botany/wilsonferns/pte_vit.html
|
Pteris vittata
Horticulture: http://www.horticulturist.com/mastermag4/best4.htm
|
Pteris vittata
The danger of arsenic leaching from treated woods into
children's play areas has made the news in South Florida recently. The
problem of the heavy metal, arsenic, in the soil is much wider than this,
of course, since it is a by-product of many industrial and mining activities,
and has been a common component of weed killers and pesticides.
This has led to research on ways of cleaning soil, including
one very promising avenue of work at the University of Florida that
uses a common tropical fern, Pteris vittata or ladder brake, with
the ability to extract arsenic from soil and store it in its leaves. The
research was reported in the February 1st issue of Nature, but more
accessible to most of us is a summary in American Nurseryman of 15th
March 2001.
The fern has a staggering ability to extract and concentrate arsenic
from the soil. On one contaminated site with 38.9 parts per million
(ppm) of arsenic in the soil, the fern's fronds had 7,526 ppm of arsenic,
and under experimental conditions where soil was loaded with arsenic, the
fern accumulated 22,630 ppm of the heavy metal.
Mature plant of Pteris vittata
Even where the arsenic concentration in the soil is low, the
fern will seek it out and suck it up: a soil on the university campus with
just 0.47 ppm produced a fern with 136 ppm or arsenic in its fronds.
The promise appears to be high for subtropical areas where this fern
will thrive. Once the plants are established, the concentration of
the heavy metal in the leaves begins, and they can be harvested periodically
for disposal in some safe facility. The ferns are even an attractive addition
to the landscape.
California:
| http://www.csdl.tamu.edu/FLORA/cgi/calmap2_list?gen=Pteris
|
Pteridophytes
Family Pteridaceae
Genus Pteris
Pteris cretica L.
Pteris tremula R. Br.
| Pteris
vittata L. |
Arsenic-loving fern
|
A report from Florida in Nature for February 1, 2001, describes
a fern native to that state which is extremely efficient at extracting
arsenic from soils and concentrating it in its above ground structures.
The American brake fern, Pteris vittata, is claimed to be the first found
to function as an arsenic hyperaccumulator. It was discovered on a site
in Central Florida that was heavily contaminated with chromated copper
arsenate. Plants at the site were tested by atomic absorption spectroscopy,
but of 14 species investigated only the fronds of Pteris vittata contained
large amounts of arsenic (3,280 to 4,980 ppm). Plants from an uncontaminated
soil site (0.47 to 7.56 ppm arsenic) contained 11.8 to 64 ppm, and others
from an adjacent site (18.8 to 1,603 ppm) contained 1,442 to 7,526 ppm.
It is evident that, apart from being able to thrive in soils
containing up to 1,500ppm of arsenic, brake fern can accumulate large quantities
of the metal rapidly in its fronds. Concentrations in the roots were much
lower. Addition of 100ppm arsenic to growing ferns stimulated them with
an increase of 40 per cent biomass.
Almost all the element present was in relatively toxic inorganic compounds
with little organoarsenic. There was evidence that during translocation
from roots to fronds pentavalent arsenic was converted to trivalent forms.
Since the fern is versatile and hardy, preferring sunny and alkaline
environments, easy to propagate and perennial, it is believed to hold great
potential for the low-cost recovery of arsenic-contaminated soils.
Wahington State:
| http://www.wsu.edu/~mahbub/article1.html
|
The plant, (Pteris vittata), could be used to clean up land
and water that has been contaminated with the toxic element or its compounds.
Dr. Lena Ma, of the University of Florida, US, and colleagues
found the brake fern growing on a disused wood-preservation site that had
been poisoned with arsenic. When they examined its leaves, they found the
concentration of arsenic to be up to 200 times higher than in the surrounding
soil. The brake fern, say the researchers, is hardy, versatile and fast
growing. It has “great potential for the remediation of arsenic-contaminated
soils”, they write in the journal Nature.
Safely burnt
Brake fern is native to Africa, Asia and Australia, and is now
widely naturalized in warm parts of the Americas. Unusually for a fern,
it actually likes a sunny, open position. The plants growing in uncontaminated
soil were found by Dr Ma's team to have arsenic levels ranging from 11.8
to 64.0 parts per million. But those growing in contaminated soil at a
site in central Florida had arsenic levels of between 1,442 and 7,526 parts
per million, most of which was found in the plants' long-fingered green
leaves, or fronds. The fern is able to absorb arsenic and its compounds
very quickly, the team discovered. In lab tests, arsenic levels in ferns
rose by a factor of 126 in as little as two weeks when they were transplanted
into contaminated soil. Research is now under way to devise a method of
safely burning arsenic-enriched ferns that have been grown on contaminated
sites. This would provide a source of energy and enable the element to
be recovered in the form of a gas.
Water problems
Arsenic has wide industrial applications: it is used to remove
iron impurities during glass making, to manufacture semi-conductor wafers
and even in the production of some fireworks. But if the element or its
compounds leak into the environment, their toxicity can cause health problems.
Dr Ma said that brake fern held out promise for helping Bangladesh,
where between 35 and 77 million people out of a population of 125 million
are at risk of being exposed to arsenic in their drinking water. Many have
developed painful skin lesions; some cancers are also linked to the problem.
It all stems from the creation over the past two decades of tube wells
that have been drilled into shallow rock containing naturally occurring
arsenic. Dr Ma suggests the water in Bangladesh could flow through reservoirs
planted with brake fern to filter out the arsenic.
Green Cleaners | Science Now
| http://bric.postech.ac.kr/science/97now/01_1now/010131c.html
|
Ferns may be the key to cheap cleanup of soils contaminated with
arsenic. In the 1 February issue of Nature, scientists report that
brake fern (Pteris vittata) squirrels away so much of the toxic element
that arsenic concentrations in the fern's fronds can be more than 100 times
greater than in surrounding soil.
Arsenic occurs naturally in many environments, but soils contaminated
from old copper smelters or wood treatment factories can have levels that
are thousands of times higher. Long-term exposure to arsenic is thought
to cause bladder, liver, and skin cancer; high doses interfere with cells'
energy metabolism and can be deadly.
Currently, removing the soil is the only method for cleaning up contaminated
sites, but it can cost up to $2.5 million to dig up and safely truck away
the top 30 centimeters of soil from a site the size of a hectare, says
Rufus Chaney, a research agronomist with the U.S. Department of Agriculture
(USDA) in Beltsville, Maryland. “We haven't cleaned up large sites for
arsenic contamination because it's prohibitively expensive,” he says.
In the search for a cheaper, easier solution, Lena Ma, a soil
scientist at the University of Florida in Gainesville, turned to plants.
She and her colleagues tested 14 species growing at a site where wood had
been pressure-treated with a preservative that contained copper, chromium,
and arsenic. Soil levels of arsenic averaged about 150 parts per million
(ppm), whereas a nearby uncontaminated site had levels under 8 ppm.
Most plant species the team tested had less arsenic than the
contaminated soil they were growing in, but the first fern the team examined
contained 4300 ppm. “We were shocked,” says Ma. The shock quickly gave
way to delight. Her graduate student and co-author Kenneth Komar “was dancing
around--it's like hitting the lottery,” she adds. Subsequent experiments
in the greenhouse showed that in just 2 weeks, fronds of brake fern, an
Asian plant introduced into Florida more than 100 years ago, can accumulate
100 times more arsenic than is in the soil. The skyrocketing levels don't
seem to affect the plant.
Decontaminating soils using plants, a method known as phytoremediation,
requires planting, growing, and harvesting a species that “hyperaccumulates”
the contaminant. Finding a plant that can do so for arsenic “is an important
discovery,” USDA's Chaney says, and one that will be commercially valuable.
“This plant gives a whole new opportunity” to clean up arsenic waste, says
Chaney.
Ecolotree IA: http://www.ecolotree.com
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505 East Washington Street, Suite 300 Iowa City, Iowa 52240
Phone: 319-358-9753 Fax: 319-358-9773 e-mail: Info@Ecolotree.com
Ecolotree®, Inc. uses patented vegetative systems to contain
and clean up problem chemicals that can harm humans and the environment.
This technology is called “phytoremediation.” The plants, primarily hybrid
poplar trees, legumes, and grasses, can provide effective and economical
solutions to environmental problems. Incorporated in 1990, Ecolotree is
the oldest and most experienced phytoremediation company in America, with
55 sites planted across the United States and one in Europe. Planted locations
include landfills, contaminated soil and groundwater sites, municipal and
industrial wastewater treatment sites, 'brownfield' sites, agrochemical
spill areas, riparian stream filters, and animal feed lot perimeters.
Sierra: http://www.sierraclub.org/sierra/200105/lol6.asp
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Suck It Up Scientists at the University of Florida recently
discovered that a common fern found in the southeastern United States
and California has the capacity to soak up arsenic from soil without
keeling over dead. Pteris vittata, or brake fern, could potentially
be used to clean up the poison, which is both naturally occurring in soil
and unnaturally present in farm chemicals, wood preservatives, and other
products. Once the plant pulls the arsenic from the ground and into
its leaves, it can be harvested and safely disposed of. Arsenic, which
often leaches into groundwater, threatens many communities in the United
States and worldwide. Studies show that people who drink arsenic-contaminated
water over long periods run a higher risk of bladder, lung, and skin cancer.
Phytoremediation: http://www.engg.ksu.edu/HSRC/phytorem/home.html
|
Phytoremediation is an innovative technology that utilizes the
natural properties of plants in engineered systems to remediate hazardous
waste sites. This web page is a starting point for exploring the world
wide web for information related to research in this area. Erickson, et,
al. provides a brief introduction to the technology.
Bioremediation and Phytoremediation Glossary
This is a glossary terms related to bioremediation (biological treatment)
and phytoremediation (remediation using green plants) of environmental
pollutants. Links to other environmental glossaries are at the bottom of
the page.
Glossary: http://members.tripod.com/~bioremediation
|
RTDF: http://www.rtdf.org
|
The Remediation Technologies Development Forum (RTDF) was established
in 1992 by the U.S. Environmental Protection Agency (EPA) to identify what
government and industry can do together to develop and improve the environmental
technologies needed to address their mutual cleanup problems in the safest,
most cost-effective manner. The RTDF fosters public and private sector
partnerships to undertake research, development, demonstration, and evaluation
efforts focused on finding innovative solutions to high priority problems.
The RTDF has grown to include partners from industry, several federal and
state government agencies, and academia who voluntarily sharing knowledge,
experience, equipment, facilities, and even proprietary technology to achieve
common cleanup goals.
RTDF Action Team: http://www.rtdf.org/public/phyto/default.htm
|
The Phytoremediation of Organics Action Team, established in
1997, is one of the six active Action Teams under the Remediation Technologies
Development Forum (RTDF). The U.S. Environmental Protection Agency (EPA)
created the RTDF in 1992 to foster collaboration between the public and
private sectors in developing innovative solutions to mutual hazardous
waste problems. The Phytoremediation of Organics Action Team includes representatives
from industry, government, and academia who share an interest in further
developing and validating the of use of plants and trees to remediate organic
hazardous wastes in soil and water.
Research Lab: http://plantbio.berkeley.edu/~terry
|
Dr. Norman Terry is a Professor of Plant Biology at the University
of California, Berkeley. He runs a multi-disciplinary research laboratory
in the Department of Plant and Microbial Biology. There is a lot
of concern about the clean up of toxic pollutants from the environment.
Most of the remediation technologies that are currently in use are very
expensive, relatively inefficient, and sometimes generate a lot of waste
which has still to be disposed of. Phytoremediation is a novel, efficient,
environmentally friendly, low-cost technology which uses plants to clean
up heavy metals and other toxic compunds from contaminated environments.
The Terry lab is particularly interested in improving the efficiency with
which plants remove and detoxify toxic metals and metalloids like Arsenic,
Chromium, Lead, Selenium, Mercury, Cadmium etc., from contaminated soil,
sediments, water. For example, many plant species detoxify Chromium (VI),
which is a very toxic form of the element, to Chromium (III) which is essentially
non-toxic. Some plants can also convert toxic forms of Selenium, e.g.,
selenate and selenite, which are present in wastewaters and contaminated
soils and sediments, to volatile forms like dimethylselenide which is non-toxic.
EPA Citizens Guide: http://www.cluin.org/products/citguide/phyto2.htm
|
Phytoremediation can be used to clean up metals, pesticides,
solvents, explosives, crude oil, polyaromatic hydrocarbons, and landfill
leachates.
Journal: http://www.aehs.com/journals/phytoremediation
|
The International Journal of Phytoremediation is the first journal
devoted to the publication of current laboratory and field research describing
the use of plant systems to remediate contaminated environments. The journal
is a quarterly, international, peer reviewed publication designed to link
professionals in the many environmental disciplines involved in the development,
application, management and regulation of emerging phytoremediation technologies.
Market: http://www.channel1.com/dglassassoc/INFO/phytrept.htm
|
Phytoremediation, the use of plants, trees and other vegetation
to remove, sequester or degrade environmental contaminants from soil, groundwater,
wastewater and landfill leachate, has attracted a great deal of interest
in recent years. Drawing on the natural abilities of plants to accumulate
metals and other substances or take up and transpire large amounts of water,
phytoremediation is an effective, low-cost treatment technology that is
beginning to gain the attention of private and industrial site owners,
regulators, and the environmental engineering community.
Rice U: http://www.ruf.rice.edu/~aatdf/pages/phyto.htm
|
One of the technologies being tested in the AATDF program is , or
vegetation-enhanced bioremediation, of fuel-contaminated soil. Traditional
biological land treatment of fuel-contaminated soil can often result in
final concentrations that do not meet clean-up criteria. One potential
approach for the long-term management of fuel-contaminated soils is the
establishment of vegetation, because the presence of vegetation may enhance
the biodegradation of contaminants.
Mobot: > Cross, John W. (2005) "Phytoremediation"
http://www.mobot.org/jwcross
/phytoremediation/
Links: http://www.mobot.org/jwcross/phytoremediation/phytorem_links.htm
|
A research team at Purdue University has pioneered the use of plants
to help clean up soil contaminated with petroleum products. The team is
currently using their methods to clean several petroleum spill sites across
the United States with help from the Environmental Protection Agency and
the petroleum industry.” -- Environmental News Network, Tuesday, July 11,
2000 [ link
to article ]
PhytoKinetics UT: http://www.phytokinetics.com
|
Truly Innovative! Cost-effective Clean up of Hazardous Contaminants
Phytoremediation is the unique process of using specific plants
and planting techniques to remediate contaminated soils and groundwater.
The innovative technology treats both organic chemical contaminants and
in- organics, including heavy metals. Federal and state agencies responsible
for overseeing the cleanup of contaminated sites recognize the benefits
inherent within the technology. We are proud of having played a major role
in advancing both the technology and its approval within the scientific
community.
WOLVERTON: http://www.wolvertonenvironmental.com
|
Wolverton Environmental Services, Inc. (WES, Inc.) has developed
a line of phytoremediation technologies using plants and their root-associated
microbes for the treatment of domestic and industrial/agricultural wastewater,
stormwater runoff and numerous other applications. WES, Inc. is the world's
leader in using interior plants for improving indoor air quality.
Bibliography: http://www.clu-in.org/products/phytobib/biba-b.html
|
This bibliography is the work of the EPA Phytoremediation Handbook
Team in conjunction with the RTDF Phytoremediation Action Team.
Clu In 1997: http://www.clu-in.org/products/phytotce.htm
|
The potential use of plants to remediate contaminated soil and groundwater
has recently received a great deal of interest. EPA's Technology Innovation
Office (TIO) provided a grant through the National Network for Environmental
Management Studies (NNEMS) to assess the status of phytoremediation technologies
to clean up shallow groundwater. This report was prepared by a graduate
student from Duke University during the summer of 1997. It has been
reproduced to help provide federal and state project managers responsible
for hazardous waste sites with information on the current status of this
technology.
1997 Article: http://www.soils.wisc.edu/~barak/temp/opin_fin.htm
|
Phytoremediation of metal contaminated soils offers a lower
cost method for soil remediation and some extracted metals may be recycled
for value. Both the phytoextraction of metals and phytovolatilization of
Se or Hg by plants offer great promise of commercial development.
Utah State:
Phytoremediation is the use of plants to clean contaminated soil
and ground water. The Crop Physiology lab of Utah State University
is involved with several phytoremediation projects, including cooperative
research programs with the Utah Water Research Lab, Phytokinetics, Inc.,
and Idaho National Engineering and Environmental Laboratory.
USDA: http://www.ars.usda.gov/is/AR/archive/jun00/soil0600.htm
|
Kochian's cost-effective “green” technology uses plants to “vacuum”
heavy metals from the soil through their roots. He says, “Certain plant
species—known as metal hyperaccumulators—have the ability to extract elements
from the soil and concentrate them in the easily harvested plant stems,
shoots, and leaves. These plant tissues can be collected, reduced in volume,
and stored for later use.” While acting as vacuum cleaners, the unique
plants must be able to tolerate and survive high levels of heavy metals
in soils—like zinc, cadmium, and nickel.
US Army: http://www.wes.army.mil/el/phyto
|
Phytoremediation is the use of green plants to remove, contain,
or render harmless environmental contaminants. It is a promising technology
that addresses clean-up of organic solvents, PCBs, heavy metals, polyaromatic
hydrocarbons, explosives and energetics, or nutrients
Forbes: http://www.forbes.com/global/2001/0402/072_print.html
|
Dirty appetite
Spare the bulldozer. Let Mother Nature clean the filthiest sites.
In 1999 DaimlerChrysler wanted to turn a mothballed auto-parts
forge in Detroit, Michigan, into an axle factory.
Decades of parts-making had soaked the site's topsoil with lead.
In the old days, Daimler would have bulldozed the topsoil, mixed it with
concrete and hauled it off to a landfill. Instead, the company planted
beds of sunflowers and Indian mustard.
A year later, the plants had sucked enough lead from the soil
into their tissues to make the site clean enough to reopen. Lead concentrations
dropped from 1,100 parts per million (PPM) to 850. Instead of carting away
4,400 cubic meters of concrete, Daimler disposed of only a few cubic meters
of dead plants. The cost: $400,000—a saving of $1 million compared with
the brute-force method.
The concept of using trees and plants to purify polluted land, a
process called phytoremediation, is beginning to take root in America's
$30 billion-a-year remediation industry. Cleaning the U.S.' 217,000 polluted
sites with traditional techniques would cost an estimated $187 billion
and require more landfills. Plants can do it with less labor, noise and
waste. The cost savings can be tremendous. Mechanical pump-and-treat remedies
to keep underground petroleum plumes or toxic leachate from seeping into
groundwater cost an annual $1.7 million a hectare. Trees can do it for
$500,000.
A dozen or so small shops have sprung up to compete for phytoremediation
contracts. The market, just $50 million last year, could grow fivefold
by 2005, says David Glass, a phytoremediation consultant in Boston, Massachusetts.
“Everybody really likes this idea, except the guy who drives the bulldozer,”
says Michael Blaylock, the head scientist for Edenspace Systems, which
Daimler hired for its lead-removal job. Based in Reston, Virginia, the
company had revenue of $900,000 last year, making it one of the biggest
in the field.
Nature's antipollutant arsenal includes about 400 species of plants,
divided
into two categories:
1. hyperaccumulators,
which gobble up such toxic metals as arsenic, lead and mercury; and
2. root-level killers,
which break down such organic pollutants as petroleum below the ground.
Evolution likely favored these traits: One discourages predators
by dosing them with lethal metals; the other allows flora to adapt to harsh
soil.
The first phytoremediation study was conducted in 1948, when
Italian scientists noticed dense accumulations of nickel in the alyssum
vine. Uses date even further back. Miners in the 19th century found ore
deposits by looking for fields thick with the copper-loving mustard plant.
Now, in a neat bit of ecoefficiency, some green plants are being smelted
to recapture ores trapped in tissue.
New hyperaccumulators are found all the time. Two months ago
a biologist at the University of Florida discovered an arsenic-gobbling
fern called pteris vittata that, when planted in soil with 40 PPM
of arsenic, can suck up the metal so quickly that its new shoots show concentrations
of 7,500 PPM. Edenspace will sell a hydroponic version of the fern to smaller
cities for removing arsenic from drinking water.
In 1995 Chevron planted alfalfa grass and hundreds of poplars
on a two-hectare site in Ogden, Utah, once used as a transportation terminal
for petroleum products. At the time, a plume of benzene, ethylbenzene and
toluene compounds was moving toward the groundwater. Five years later,
the trees have removed the pollutants to safe levels, says Phytokinetics
in Logan, Utah, which engineered the cleanup.
Ecolotree, of Iowa City, Iowa, manages poplar groves on 15 landfills
in seven states. The trees cap the landfill, holding soil and water in
place and keeping the gunk inside. At a fill in Fort Madison, Iowa, 27
million liters of leachate, the nasty liquid that percolates out of landfills,
is sprayed onto a three-hectare poplar site annually.
Before, the leachate would have to be hauled to a wastewater
treatment plant. Ecolotree has also planted lots of poplars along streams
across the U.S. Midwest—the roots filter the runoff from farms, keeping
manure and pesticides out of the water. The company even sells kits—250
poplar seedlings for $240.
Phytoremediation has its share of drawbacks. For one thing, it's
slow. “Often sites need to be cleaned faster than plants can grow,” says
Lucinda Jackson, Chevron's director of bioremediation.
The time pressure threatens one promising new find. The root
systems of mulberry and Osage orange trees were recently shown to break
down one of the most toxic and insoluble pollutants, polychlorinated biphenyls,
PCBs, used for decades as insulation and lubrication in electrical products.
It takes mulberry trees a decade to reach maturity, compared with two years
for poplars. Genetic engineers hope to transfer mulberry trees' PCB-busting
power to faster growers.
Some of the biggest companies remain skeptical of phytoremediation's
benefits. General Electric, which spends $100 million annually on remediation
efforts, studied phytoremediation of PCBs but recently ended its program
because of doubts about the process's long-term efficacy.
American industry and government have a hard time putting their
faith in anything but chemicals and machines. Unless they get behind phytoremediation,
its potential may wither over time.
