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Vince
Gallardo, 513-569-7176, past SITE program manager (10 yrs) now with
the EPA's National Homeland Security Research Center). Date: Wed,
11 Feb 2004 12:15:51 -0500
From: Gallardo.Vincente@epamail.epa.gov, Keith, As discussed.Vince
U.S.
EPA Superfund Innovative Technology Evaluation (SITE) Program.
Request for Sites to Host Demonstrations / Evaluations of Innovative
Technologies for Hazardous Waste Cleanup http://www.epa.gov/ORD/SITE/solicitations.htm
Application http://www.epa.gov/ORD/SITE/HSA-07.pdf
Roles and responsibilities of the project participants (site owner,
technology vendor, and US EPA) are summarized
here.
EPA's
Environmental Technology Verification Program, National Homeland
Security Research Center
http://www.epa.gov/NHSRC/htm/etv.htm
Vince
recommended that I speak with Steve Rock, who I called (spoke with
him for 30 minutes) Rock.Steven@epamail.epa.gov, 513-569-7149, Steve
is a project manager for the SITE program, and the leading expert
on phytoremediation. http://www.epa.gov/ORD/SITE/solicitations.htm
Other
contacts from Vince:
Measuring and Monitoring Program, soil and sediments
Steve Billets: 702-798-2232
Eric Koglin 702-798-2332
Steve
Rock is an Environmental Engineer in the Remediation and Contaminant
Branch at EPA's National Risk Management Research Laboratory in
Cincinnati, Ohio. Steve manages field projects using phytoextraction,
phytodegradation, plume control and vegetative. He is the author
of several phytotechnology publications, including acting as team
leader on the EPA's Introduction to Phytoremediation, and a chapter
in the Standard Handbook of Environmental Engineering. He co-chairs
the RTDF Action Team on Phytoremediation, and has three subgroups
researching the phytoremediation issues of petroleum hydrocarbons,
chlorinated solvents, and vegetative covers for waste containment.
He participates in EPA in-house research, and provides technical
assistance to EPA regional staff on questions of phytoremediation.
Notes
from conversation with Steve Rock
Summary: we could submit a proposal to the SITE program. We need
to do the planting, or get a partner to do the planting. They will
do all the monitoring and analysis, scientific evaluation and write
up (cost over two years $50-100K). We'd need to get (1) Camp Pendleton
approval (and thru CP, the approval of our regional regulatory agencies:
EPA Region 9, DTSC, OSHA), (2) a technology matched to a problem,
and (3) a feasible site.
Contacts
given to me by Steve Rock
ApGen, David Glass; Researchers in Denmark, Conference held at University
of Washington, Stuart Strand; and the EPA Environmental Technology
Verification Program (ETV) Homeland Security--possible contact for
biomarkers.
They
give contracts to Batelle, SAIC, Tetratec and EQMI. He heard of
Parsons.com (the group on Camp Pendleton). Says a tribal focus would
be good
Applied
PhytoGenetics, Inc. ApGen,
(possible collaborator with us in a UCSD-CampPendleton proposal;
I sent a note to David Glass, CEO, Edenspace also a possibility)
http://www.appliedphytogenetics.com/apgen/index.htm
Applied
PhytoGenetics, Inc. (APGEN) is a new company pursuing a promising,
new remediation technology -- phytoremediation. Phytoremediation
is the use of plants, trees and grasses to remove hazardous materials
from the environment. APGEN can apply phytoremediation to a variety
of remediation scenarios involving both organic chemical contaminants
and heavy metals.
Company
Headquarters:
Applied PhytoGenetics, Inc.
Room 169, 110 Riverbend Road
Athens, GA 30602
Tel (706) 543-8083
For
more information, please contact:
David
J. Glass, Ph.D., Chief Executive Officer
c/o 124 Bird Street
Needham, MA 02492
Tel (617) 653-9945
Fax (781) 449-8045
DGlassAssc@aol.com
David
J. Glass, Chief Executive Officer, has twenty years’ experience
in management positions in biotechnology, and for the past ten years
has been widely recognized as one of the leading business analysts
of remediation markets and technologies. As an independent consultant,
Dr. Glass has advised companies in North America, Europe and Australia
on the structure of remediation markets, and has assisted firms
in North America, South America and Europe locate potential partners
or customers for remediation technologies. Dr. Glass is the author
of several market reports and articles on bioremediation and phytoremediation,
including "U.S. and International Markets for Phytoremediation,
1999-2000" (July 1999), "The 1998 United States Market
for Phytoremediation" (April 1998), "Bioremediation in
Germany" (co-authored with Thomas Raphael, June 1994), and
"The Promising Worldwide Bioremediation Market", published
by Decision Resources, Inc. in December 1993. Dr. Glass has been
a featured speaker at several major remediation conferences on U.S.
and international markets for site remediation, phytoremediation,
and bioremediation, and is a member of the Editorial Board of the
International Journal of Phytoremediation.
Dr.
Glass holds a B.S. degree in biological sciences from Cornell University
and a Ph.D. in biochemical sciences from Princeton University. From
1981 to 1990, Dr. Glass served in a succession of management roles
at BioTechnica International, culminating as Vice President, Government
and Regulatory Affairs for the company’s agricultural subsidiary.
At BioTechnica, he focused on the commercial uses and government
regulation of microorganisms in the environment, and he obtained
federal and state government approvals for some of the earliest
field tests of genetically modified microorganisms and plants in
the U.S. From 1991 to 2001, concurrently with carrying out his consulting
activities, Dr. Glass was associate director of the technology transfer
office at Massachusetts General Hospital in Boston, where he was
responsible for managing and providing strategic direction to the
hospital’s large portfolio of patent applications arising
from biomedical research, and for drafting and negotiating license,
option and research agreements with biotechnology, pharmaceutical,
medical device and agbiotech companies.
From:
DGlassAssc@aol.com
Date: Wed, 11 Feb 2004 21:57:19 EST
Subject: Re: SITE Demonstration Program
To: kpezzoli@ucsd.edu
--
APGEN is the exclusive licensee of Richard Meagher's work out of
the Univ.
of Georgia on transgenic plants for mercury remediation. We're focusing
on
mercury in the short term, but our longer term goal would be to
go after other
heavy metals, whether with transgenic plants or native plants.
--
In 2003, APGEN obtained three permits from the USDA for field testing
transgenic plants, at a total of 5 potential field sites. We began
field tests of
transgenic cottonwood for mercury remediation at two of these sites
in 2003
(in Connecticut and Alabama) and we'll likely begin a third trial
in 2004 at a
third site. These are the first commercial phytoremediation projects
using
transgenic plants done in the US (one of which is client-funded),
and we are by
far the commercial entity that is the farthest progressed towards
testing and
using commercially transgenic plants in phytoremediation.
--
APGEN also has commercial operations using native plants for
phytoremediation of other contaminants, mostly organic chemicals,
and this part of our
business gives us a lot of practical field experience in carrying
out
phytoremediation projects.
--USDA
APHIS Biotechnology Regulatory Services office, and their policies
and
procedures for regulating transgenic field tests. Note that, within
the past year,
USDA has decided that all phytoremediation applications using transgenic
plants must be done under the more extensive permit system rather
than the easy,
straightforward notification system. This imposes an extra burden
on applicants,
but it is one that is manageable with appropriate planning.
David
J. Glass, Ph.D.
Chief Executive Officer
Applied
PhytoGenetics, Inc.
110 Riverbend Road, Room 169
Athens, GA 30602
www.appliedphytogenetics.com
contact information for David Glass
124 Bird Street
Needham, MA 02492
Tel (617) 653-9945
Fax (781) 449-8045
DGlassAssc@aol.com or dglass@appliedphytogenetics.com
More
notes from Steve Rock:
Mercury
accumulatin via poplar trees
Arsenic Cadmium easy to bioaccumulate naturally, natural hyperaccumulators
Use of a ferns in Florida
Researchers
in Denmark are preparing to test a modified thale cress plant
that they say will turn red when planted near a landmine. The scientists
hope to use this technology to help locate and remove the estimated
100 million unexploded landmines in 75 countries around the world.
The
Workshop on Tools for Environmental Cleanup: Engineered Plants for
Phytoremediation
January 26 - 28, 2003
http://www.cfr.washington.edu/outreach/phyto2003/agenda.htm
Stuart E. Strand
College of Forest Resources, Box 352100, University of Washington,
Seattle WA 98195-2100
Department of Civil & Environmental Engineering, University
of Washington
Voice/Fax: 206-543-5350
Alt Fax: 206-543-3254
Email sstrand@u.washington.edu
Risk
Assessment Issues Associated with Transgenic Plants
Philip Sayre, U.S. Environmental Protection Agency, Office of Pollution
Prevention and Toxics,
1200 Pennsylvania Avenue NW (Mail code 7403M), Washington, D.C.
20460
sayre.phil@epa.gov
Currently,
there are few applications using transgenic plants for phytoremediation
which have been pursued in field tests. Risk assessment issues
for such transgenics are addressed by the U.S. Department of Agriculture.
Other risk assessment information can be gleaned from the U.S.
Environmental Protection Agency’s review of plants with
pesticidal properties, and from the current acceptability of phytoremediation
mediated by naturally-occurring plants. Recent policy and regulatory
developments in FDA, the White House, and the National Academy
of Sciences have sought to clarify risk assessment issues associated
with crops for food use. Further, issues surrounding transgenic
plants intended for pharmaceutical use, and research on risk issues
associated with transgenics, may improve the understanding of
plants intended for phytoremediation.
Integrated,
Redundant Approach Best Way to Biologically Confine Genetically Engineered
Organisms — National Academies National Research Council
Report: January 20, 2004
http://www4.nationalacademies.org/news.nsf/isbn/0309090857?OpenDocument
The panel that advises the U.S. government on scientific matters has
issued a report calling on developers of genetically enhanced organisms
to adopt more than one approach to “bioconfinement” —
such as induced sterility — to ensure that transgenic animals
and plants do not escape into natural ecosystems. Genetically
engineered organisms (GEOs) have been under development for more
than 20 years while GE crops have been grown commercially during
the last decade. During this time, a number of questions have cropped
up concerning the potential consequences that certain GEOs might
have on natural or managed ecosystems and human health. Interest
in developing methods to confine some GEOs and their transgenes
to specifically designated release settings has increased and the
success of these efforts could facilitate the continued growth and
development of this technology.
Biological
Confinement of Genetically Engineered Organisms examines biological
methods that may be used with genetically engineered plants, animals,
microbes, and fungi. Bioconfinement methods have been applied successfully
to a few non-engineered organisms, but many promising techniques
remain in the conceptual and experimental stages of development.
This book reviews and evaluates these methods, discusses when and
why to consider their use, and assesses how effectively they offer
a significant reduction of the risks engineered organisms can present
to the environment.
Interdisciplinary
research to develop new confinement methods could find ways to minimize
the potential for unintended effects on human health and the environment.
Need for this type of research is clear and successful methods could
prove helpful in promoting regulatory approval for commercialization
of future genetically engineered organisms.
Environmental
Technology Verification Program (ETV)
The
U.S. Environmental Protection Agency (EPA) is now engaged in identifying
and filling data and informational gaps by partnering with other
agencies, departments and the Office of Homeland Security. As part
of EPA's effort, the Environmental Technology Verification Program
(ETV) has been tapped to verify the performance of technologies
that can be used to monitor and ensure the quality of the Nation's
drinking water supplies, technologies for use in monitoring indoor
environments in buildings, and technologies for cleaning up contamination
from intentional acts.
Under
a funding agreement with EPA's Office of Water, three ETV centers
are being enlisted to develop protocols and test technologies related
to ensuring the safety and security of the Nation's water supplies:
The
Advanced Monitoring Systems Center in cooperation with Battelle
will develop protocols and test technologies for detecting chemical
and biological warfare agents in drinking water;
The ETV Drinking Water Systems Center, operated by NSF, International,
will develop protocols and test technologies for point of use treatment
of biological and chemical contaminants; and
The new ETV Water Quality Protection Center, also with NSF, International,
will develop protocols and test technologies for treating wastewater
resulting from decontamination of buildings that have been intentionally
contaminated.
Date: Wed, 11 Feb 2004 11:29:13 -0500
From: Gallardo.Vincente@epamail.epa.gov
Subject: SITE Demonstration Program
To: kpezzoli@ucsd.edu, Rock.Steven@epamail.epa.gov
Keith,
I am
forwarding your E-mail to Steve Rock who has done a lot of work
in
phytoremediation.
As to
your question about how to go about getting your technology tested
by the EPA' s SITE program: We normally don't accept technologies
into
the program but specific sites. Our approach has been to solicit
and
work with specific hazardous waste sites in need of innovative
technologies for environmental remediation. Once specific sites
have
been accepted into the SITE program, we determine the most promising
technologies that would likely be effective at the specific site
and
then conduct a field demonstration of those technologies at that
site.
It is envisioned that the result of a SITE demonstration will be
three
fold: 1) the site owner or other decision maker will be able to
make a
more informed choice on the clean up technology to use for larger
scale
work, 2) technology vendors and/or developers will have gained credible
data and much needed exposure for their process and 3) the environmental
community at large will gain a better understanding of the capabilities
and costs of new and promising technologies.
What
we normally tell technology vendors is to work with a specific site
and together apply to the SITE program. Currently we do not have
a
solicitation open, but if you are able to forge an arrangement with
a
specific site to apply to have your technology evaluated by the
SITE
program, then please contact us. The best person to contact is Randy
Parker at 513/569-7271 or parker.randy@epa.gov
Also,
although you did not ask this specifically, we are often asked
what the SITE program pays for; thus I thought it would be useful
to let
you know what we do and don't pay for. The SITE program does not
subsidize the technology vendors for expenses occurred during a
SITE
demonstration. No funding is awarded to the technology vendor. However
we do pay for the planning, sampling, analysis and for the writing,
publishing and deistribution of the final report of the demonstration.
Vince
Gallardo
513-569-7176
EDEN
Space
http://www.edenspace.com/overview.html
15100 Enterprise Court, Suite 100
Dulles, VA 20151-1217
Tel.: +1 703-961-8700
Fax: +1 703-961-8939
Dr.
Michael J. Blaylock [e-mail]
Director, Research and Development
Dr. Blaylock leads the Company’s research, analysis and development
team. Dr. Blaylock was Laboratory Head at Phytotech from 1997 to
1999, where he supervised a 14 -member research team of laboratory,
greenhouse and field personnel developing phytoremediation services.
He joined Phytotech as a Research Scientist in 1996, having completed
postdoctoral studies at Rutgers University and at the University
of Wyoming from 1992-1996. He received his Ph.D. in Soil Chemistry
from the University of Maryland in 1992, and his M.S. and B.S. in
Agronomy from Brigham Young University in 1988 and 1987.
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.
Current
contracts call for removing lead from residential sites; extracting
arsenic from soil at military and natural gas facilities; and reclaiming
tungsten from abandoned mines. With a partner, Edenspace is developing
ways of reaching deeper into the earth with electrokinetic techniques.
Future applications of the technology include removing arsenic from
drinking water, water desalination, increasing the mineral content
of fruits and vegetables, and reduction of atmospheric levels of
carbon dioxide.
Industry
Background:
The
EPA estimates that there are more than 30,000 sites throughout the
U.S that require environmental treatment. Heavy metals comprise
a particularly difficult component of this problem, because many
metal compounds resist chemical breakdown and because soil excavation
and removal is expensive. Depending on site conditions and metal
concentrations, solar-powered phytoremediation can cost as little
as 5% of alternative treatment methods.
Candidate sites for phytoremediation include homes contaminated
with lead paint or leaded gasoline, thousands of government and
private firing ranges, as well as industrial facilities used by
primary and secondary metal manufacturers, scrap metal recyclers,
paint manufacturers, battery recycling and production companies,
chemical and petrochemical manufacturers, automobile manufacturers,
utility companies, transportation companies, mining companies, and
landfill operators.
Edenspace
also uses phytoremediation to treat soil and water contaminated
with arsenic, an element used in pesticides and wood treatment,
and with radioactive elements, a problem at former weapon production
and fuel rod assembly sites estimated by the Department of Energy
at over $200 billion.
Technology
Background
After
several years of careful screening and selection, Edenspace scientists
have identified superior metal-accumulating plant lines from known,
well-characterized crop species such as Indian mustard and sunflowers.
Company researchers have shown that such plants can accumulate lead,
mercury, arsenic, chromium, uranium, cesium, strontium, gold, zinc,
selenium, manganese, calcium, iron, magnesium and other metals from
soils into harvestable leaves and shoots. When combined with proprietary
techniques involving soil amendments and hyperaccumulation inducing
agents, the plants can take up more than 3.5% of their dry weight
in heavy metals.
Rhizofiltration
is the use of plant roots to accumulate metals from water. Hydroponically
cultivated plants rapidly remove heavy metals from water and concentrate
them in the roots and shoots. Harvested plants containing heavy
metals can be disposed of or treated to recycle the metal. Edenspace
scientists have identified select species of plants demonstrating
high biomass production and metal removal capacity for a wide variety
of metals. Rhizofiltration has many of the benefits of other phytoextraction
techniques, including low cost and minimal environmental disruption.
A continuous flow system circulates the contaminated water through
specially designed plant containment units. Periodically, older
plants are harvested and replaced.
Patents
Edenspace
owns, or has exclusive license to, eleven patents relating to phytoextraction,
hyperaccumulation, and rhizofiltration, and numerous pending applications.
The substantial investment in proprietary technology reflected in
its patents and licenses reflects Edenspace's commitment to provide
its customers with top-quality service based on cutting-edge research.
Discuss
Your Needs
Should
you be interested in the applicability of phytoremediation techniques
to a particular manufacturing process or site, please contact us
by e-mail at Info@edenspace.com, by fax, or at the mailing address
above.
Phytoremediation
Articles
February
17, 2004, I spoke with Mark Elless
Some
collaboration between Edenspace and ApGen (Mark and David Glass
on transgenic tobacco plants).
Say
one needs four month lead time to get regulatory approval for use
of transgenics.
Mark
Elless (1984) is Senior Geochemist at Edenspace Systems Corporation,
a biosystems technology company located in Dulles, VA, that specializes
in phytoremediation --- that is the use of plants to hyperaccumulate
heavy metals and/or radionuclides from contaminated soils and waters.
Mark received his M.S. (Soil Science, 1987) at NDSU and his Ph.D.
(Soil Science, 1992) at the University of Maryland. Following his
Ph.D., he held a DOE-sponsored postdoctoral position at Oak Ridge
National Laboratory until November, 1995, when he then became a
Research Assistant Professor in the Department of Plant and Soil
Science at the University of Tennessee. He began working at Edenspace
in June, 1999, after working the previous three years at Phytotech,
Inc. At Edenspace, Mark is responsible for optimizing the availability
of a contaminant for plant uptake and removal from the soil.
Mark's work number is (703) 961-8700, cell: 703-505-2798
Dr.
Mark P. Elless [e-mail]
Senior Soil Scientist elless@edenspace.com
Dr. Elless heads the soil science effort at Edenspace. He was Environmental
Research Scientist and Project Manager at Phytotech from 1996 to
1999, where he specialized in the phytoremediation of radionuclides.
He was a Research Assistant Professor at the University of Tennessee
from 1995 to 1996 and a Postdoctoral Research Associate at Oak Ridge
National Laboratory from 1992 to 1995. He received his Ph.D. in
Soil Science from the University of Maryland in 1992, and his M.S.
and B.S. from North Dakota State University in 1987 and 1984.
Transgenic
Citrate-Producing Plants for Lead Phytoremediation
http://cfpub2.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/6104
EPA Contract Number: 68D03043
Title: Transgenic Citrate-Producing Plants for Lead Phytoremediation
Investigators: Elless, Mark P.
Small Business: Edenspace Systems Corporation
EPA Contact: Manager, SBIR Program
Phase: II
Project Period: May 1, 2003 through April 30, 2003
Project Amount: $225,000
RFA: SBIR - Phase II (2002)
Research Category: SBIR - Hazardous and Solid Waste
Description:
In 1991, the U.S. Secretary of Health and Human Services called
lead "the number one environmental threat to the health of
children in the United States." Lead exposure can cause premature
birth and impair a child's mental and physical development. In adults,
lead exposure can cause kidney damage, high blood pressure, and
other problems. The U.S. Environmental Protection Agency estimates
that 12,000,000 homes exceed the new 400 ppm standard for soil lead
in play areas. Soil lead at small arms firing ranges, manufacturing
plants, and other government and industrial sites poses similar
challenges.
A promising
alternative to excavation and replacement of lead-contaminated soil
is phytoremediation, whereby living plants remove lead from firing
ranges, industrial sites, and residences. Phytoremediation relies
on crop species and chelators that facilitate higher plant uptake
rates. The annual cost of chelators can range up to $20,000 per
acre. Furthermore, sites with sandy, well-drained soil may need
a water-impermeable liner to prevent slowly degrading chelators
such as ethylenediamine tetraacetic acid from leaching metals into
groundwater. Costs of a liner can double the total cost of phytoextraction,
rendering phytoremediation impractical for certain sites.
In this
Phase II project, Edenspace Systems Corporation seeks to demonstrate
the use of transgenic plants that exude significant amounts of a
rapidly biodegradable chelator-citric acid-from their roots, enabling
a cost savings of more than 70 percent in lead phytoextraction.
A citrate synthase (CS) transgene was placed under the control of
different plant promoters to overexpress the gene in roots. In Phase
I, 100 lines of CS-transgenic tobacco, Nicotiana tabacum, were created
and tested. Preliminary results with five hemizygous strains are
promising, suggesting that higher-performing homozygous strains
created at the end of Phase I may hyperaccumulate lead from soil
(bioconcentration factor >1). Significantly, little soluble lead
remained in the soil, indicating that the plants may successfully
address leaching concerns. In Phase II, the highest performing transgenic
lines will be demonstrated at a small arms firing range in Maryland
and a residential site in Massachusetts. Phase II objectives also
include concentrating lead in harvested plants to facilitate disposal
or recycling, and mating transgenic lines of a proven lead-accumulating
plant species, Brassica juncea.
At many
sites, applying rapidly biodegradable citric acid precisely at the
root/soil interface where metal uptake occurs may eliminate the
need for expensive chelating agents and liners. Attainment of the
project's goals therefore may reduce the substantial public health
hazard of soil lead by realizing phytoremediation's low-cost potential.
Supplemental
Keywords:
small
business, SBIR, lead, soil, phytoremediation, phytoextraction, chelator,
transgenic plants, Brassica juncea, Nicotiana tabacum, citrate synthase
transgene, citric acid, ethylenediamine tetraacetic acid, EPA. ,
INTERNATIONAL COOPERATION, RFA, Scientific Discipline, TREATMENT/CONTROL,
Waste, Water, Analytical Chemistry, Bioremediation, Contaminated
Sediments, Environmental Microbiology, Hazardous, Hazardous Waste,
Microbiology, Molecular Biology/Genetics, Treatment Technologies,
Brassica juncea, bioavailability, biochemistry, biodegradation,
bioremediation of soils, chlorinated organics, citric acid, contaminants
in soil, contaminated sediment, contaminated soil, contaminated
soils, degradation, lead, natural recovery, phytoremediation
Small
Business Innovation Research Grant
In-Situ Application of Near Infrared Reflectance Spectroscopy to
Soils
Phytoremediation of Arsenic-Contaminated Soil
Dr. Mark P. Elless
Edenspace Systems Corporation
15100 Enterprise Court, Suite 100
Chantilly, VA 20151-1217
$80,000/6 Months
Recent
Advances in Arsenic Phytoremediation, click
here to go to site
Charissa
Y. Poynton, Mark P. Elless and Michael J. Blaylock, Edenspace Systems
Corporation, 15100 Enterprise Court, Suite 100, Dulles, VA 20151,
Tel: 703 961 8700, Fax: 703 961 8939
The
health risks of arsenic (As) are now well documented, causing problems
such as various cancers and adversely affecting the immune system.
Arsenic occurs naturally in certain rocks, soils and the water in
contact with them, but it has also been elevated anthropogenically,
in particular from mining activities and from extensive application
of As containing herbicides and insecticides in the late 19th and
first half of the 20th centuries. The recent discovery of a fern,
Pteris vittata, which hyperaccumulates As raises the possibility
of in-situ phytoremediation of contaminated soils, rather than the
costly alternative of excavation and disposal of topsoil. This fern
can accumulate As in its fronds up to 21 g / kg after 6 weeks in
soil contaminated with 0.5 g / kg As. Phytoextraction of As from
various soils and the effect of altering the soil pH by liming and
different plant spacings have been examined, using several species
within the Pteris genus in both laboratory and field studies. The
national standard for As in drinking water has recently been lowered
from 50 to 10 µg / L, focusing attention on this health issue.
Pteris ferns may also be used to remove As from water by phytofiltration.
During the optimization of this technology, the effect of source
water quality (pH, dissolved ions, As oxidation state), Pteris species,
as well as growth and operating conditions on efficiency of As uptake
have been investigated. The results of recent technology advances
will be presented, including methods to treat the biomass produced
to allow low-cost disposal as non-hazardous material.
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