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Phytoremediation as Green Infrastructure and a Landscape
of Experiences
Frank Sleegers, University of
Massachusetts,
Amherst,
MA
Selenium Enhanced Retirement of Mercury from Aquatic and
Terrestrial Ecosystems
Mark P. Elless, Edenspace Systems Corporation,
Dulles,VA
Nicholas V.C. Ralston, University of
North Dakota,
Grand Forks,
ND
Seaweed Bloom Soaks Up PCBs from Superfund Site in
New Bedford Harbor,
Massachusetts
Donald Cheney, Northeastern
University,
Boston, MA
Nina Farley, Boston College,
Boston, MA,
Scott Greenwood, University of
New Hampshire,
Durham,
NH
Deana Aulisio, University of
New Hampshire,
Durham,
NH
Kevin Gardner, University of
New Hampshire,
Durham,
NH
Pilot Phytoremediation of Lead Contamination at the
Former Skeet Range
in the Town of
Sprague, CT
Julia Kuzovkina, The University of
Connecticut,
Storrs,
CT
Olena Zhivotovsky, The University of
Connecticut,
Storrs,
CT
Isolation and Characterization of Genes Involved in
Arsenic and DDE Metabolism in Plants
Om Parkash, University of Massachusetts,
Amherst,
MA
Bibin Paulose, University of Massachusetts,
Amherst,
MA
Sudesh Chikkara, University
of Massachusetts,
Amherst, MA
Jason White,
The Connecticut Agricultural
Experiment Station,
New Haven CT
Use of Short-Lived Positron Emitting Radioisotopes to
Study the Effects of Belowground Contaminants on Plant
Growth and Function
Richard A. Ferrieri, Brookhaven National Laboratory,
Medical Department,
Upton,
NY
Phytoremediation as Green Infrastructure and a Landscape
of Experiences
Frank Sleegers, University
of Massachusetts,
Department of Landscape Architecture and Regional
Planning, Amherst, MA 01003, Email:
sleegers@larp.umass.edu
The idea of reconciling landscapes
through remediation is not new to our discipline.
However the potential of using transformative
remediation to build urban form as a large-scale
landscape network and that makes the process of
remediation part of an urban landscape experience is
still underdeveloped in theory and practice. This paper
examines how a remediation process could be exhibited
and become a design element, and how landscapes of
cleaning can become part of the urban infrastructure to
create new neighborhoods for research, education,
working, and living. The paper proposes a general
framework for how remediation could become an artistic,
aesthetically pleasing intervention with environmental
value.
Urban
brownfields are a challenging and a common landscape
especially in industrial and post-industrial cities.
They inhibit economical growth and impair the ecological
systems. Their industrial heritage often isolates them
from the urban fabric and creates physical barriers.
However the sensual, aesthetic quality that goes along
with derelict land has been discovered by our
profession. While there are successful examples of urban
park developments that are remediated landscapes they
are still not well integrated into their larger urban
context. A systematic and strategic approach to
remediation landscapes that are connected from the
regional to the local scale and that tie into the urban
fabric as a continuous network and as a part of a green
infrastructure framework is still underdeveloped.
Another
objective of this research is the exploration to reveal
phytoremediation as an aesthetic experience. How can
plants as the primary medium determine each phase of the
cleaning process as a sensual experience and create a
unique and meaningful landscape? The proposal is made to
understand phytoremediation as a process-oriented tool
for an evolving green infrastructure network that
defines new landscapes.
The long-term time requirement for
phytoremediation can also provide an opportunity:
Changing and growing plant communities can be staged,
each step of the cleaning process can transform into
specific landscape typologies that build up the
framework for urban form and green urban infrastructure
and that is simultaneously a landscape of experiences.
Thus phytoremediation as an
experience and framework calls for:
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Re-creation of systematic connectivity - from
isolation to network in a flexible framework that
structures a multi – layered urban infrastructure.
-
Visible
transformation of toxics and contaminants as a
sensual
experience through the dynamic media of the
landscape.
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Landscapes to support environmental education and
interpretation.
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Remediation as a tool to build new districts and
neighborhoods on former brownfields and a chance for
economic growth and revitalization.
The example
of two adjacent sites on the contaminated Elbe – Island
in Hamburg -
Wilhelmsburg, Germany discusses how the purification
process of water and soils can be showcased and
experienced by the public and how the landscape
framework becomes part of the urban infrastructure.
Strategies and
visions were developed under my direction in the UMASS
Urban Design Laboratory 2007 - 2008. The scientific
framework was established in collaboration with Prof.
PHD Guy Lanza,
Department of Environmental Sciences, UMASS.
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Key words:
connectivity, experience, education, green
infrastructure, green urbanism, landscape urbanism,
phytoremediation.
Selenium Enhanced Retirement of Mercury from Aquatic and
Terrestrial Ecosystems
Mark P. Elless,
Edenspace Systems Corporation, 3810 Concorde
Parkway, Suite 100, Dulles, VA, 20151-1131 Tel:
703-961-8700, Fax: 703-961-8939, Email:
elless@edenspace.com
Nicholas V.C. Ralston, Energy and Environmental Research
Center, University of North Dakota, 15 North 23rd
Street, Grand Forks, ND, 58202-9018 Tel. 701-777-5066,
Fax 701-777-5181, Email: nralston@eerc.org
Because mercury (Hg) poses significant public health
challenges, reducing its levels in air, soil, and water
is an international priority. Global redistribution of
Hg through the atmosphere makes current methods of
addressing Hg contamination, such as excavation and
replacement of soil or pump-and-treat techniques for
water, too expensive to be practical given the typically
large scale of remediation activity required. This
research sought to develop an innovative, low cost
method of extracting Hg from soil and water using two
recently-identified Hg-hyperaccumulating plant species,
one terrestrial (Rabbit’s foot grass) and one aquatic
(water hyacinth). The Hg stored in the plant leaves,
stems, and roots may then be harvested for disposal, or
allowed to remain on-site in an extremely refractory
(highly stable) chemical form that is biologically
unavailable and poses no health risks. This process
depends on the presence of selenium (Se), a
nutritionally essential trace element that is naturally
taken up from soil by plants. Previous studies have
shown Hg and Se coaccumulate in a high molecular weight
fraction, potentially indicating formation of a mercury
selenide (HgSe) complex. Because the solubility of HgSe
is extremely low (<10-58), it is expected that Hg in
this form becomes permanently retired from biological
cycling. Preliminary results have shown high plant
uptake of Hg and Se by both plant species, suggesting
the potential for in planta HgSe formation. The end
result of the project will be to establish the
foundation for a low-cost, solar powered method of
removing and stabilizing mercury over large areas of
soil and large volumes of water.
Seaweed Bloom Soaks Up PCBs from Superfund Site
in
New Bedford Harbor,
Massachusetts
Donald Cheney, Biology Dept.
and Marine Science Center, Northeastern University,
Boston, MA 02115, Email: d.cheney@neu.edu
Nina Farley, Biology Dept.,
Boston
College, Chestnut Hill, MA 02467, Email: farleyn@bc.edu
Scott Greenwood, Environmental
Research Group, University
of New Hampshire,
Durham,
NH Tel:
603-862-4334,
Email: scott.greenwood@unh.edu
Deana Aulisio, Environmental Research Group,
University of New Hampshire,
Durham,
NH Tel: 603-862-4334, Email:
deana.aulisio@unh.edu
Kevin Gardner, Environmental Research Group, Dept. Civil
Engineering, University of New Hampshire, Durham, NH,
Tel: 603-862-4334, Email: kevin.gardner@unh.edu
New
Bedford Harbor, in southeastern Massachusetts, is unlike any other
estuarine-harbor system in the world. Its lower harbor
is home to one of the busiest fishing ports found along
the US’s
eastern seaboard, while its upper harbor is home to one
of the worst polluted Superfund sites found in the
US.
Its Superfund site is unique both because of the
extremely high levels of PCBs reported in its sediments,
and because it is home to a remarkable seaweed bloom
that takes up and concentrates PCBs to a level not
previously known. In the summer of 2007, we discovered
that a bloom of the common green alga
Ulva is
growing in the Superfund site area, and that it
takes up and concentrates PCBs to levels as high as 98
ppm, which is over 1000X the concentration in the
seawater. Furthermore, we know from uptake experiments
in the field, that it is capable of taking up PCBs at an
extremely rapid rate; as much as 4 ppm per day. We
estimate that there is at least 50 tons of
Ulva growing in the Superfund site. PCB concentrations in
Ulva are
correlated with distance from the old Aerovox plant,
where PCBs were used in the manufacture of electrical
transformers and capacitors from ca. 1940 to 1977. While
the full environmental impact of the seaweed bloom is
still under investigation, we recently discovered that
Ulva is a
major source of food for the most abundant, intermediate
food chain level fish species in the system,
Fundulus
heteroclitus (mummichog). These findings raise
questions about
Ulva’s potential role in the transfer of PCBs up the
system’s food chain to top predator species that feed on
Fundulus like
striped bass, blue fish, egrets and blue herons, as well
as on humans that consume these fish species caught in
New Bedford
and near by waters.
Pilot Phytoremediation of Lead Contamination at
the Former Skeet
Range in the
Town of
Sprague, CT
Julia Kuzovkina, Ph.D., Department of Plant Science
and Landscape Architecture, The
University of
Connecticut, 1376 Storrs Rd. Unit 4067,
Storrs,
CT
06269, Tel:
860-486-3438, Fax: 860-486-0682
Olena Zhivotovsky, Department of Plant Science
and Landscape Architecture, The University of
Connecticut, 1376 Storrs Rd. Unit 4067,
Storrs,
CT
06269, Tel:
860-486-2174, Fax: 860-486-0682
A pilot phytoremediation project was conducted at the
Mukluk site, Town of Sprague, CT in
2008- 2009 by the Plant Science Department of the University of Connecticut.
This study was primarily an exploratory
investigation that sought to collect important
preliminary data to be used to asses the possibilities
of how to remediate the Mukluk site. A total area of
12-14 acres is currently contaminated by lead shot and
requires remediation. A series of experiments were
conducted to investigate if phytoremediation and
specifically phytoextraction or phytostabiilzation
can be implemented at the site to remediate the
soil to below regulatory limits. Greenhouse screening of
plants for lead resistance and accumulation using field
soil was proposed as the initial step prior to the field
installation to identify which plants could be used
successfully at the Mukluk site. Plant species with
known phytoextraction capabilities included Indian
mustard, blue fescue grass and willows.
Based on the results of the screening
experiments, only willows and Indian mustard, and
various soil amendments were selected for the field
installation in May 2008. Indian mustard grew poorly in
most of the treatments and
lead accumulation by this species was low in all
treatments. In contrast, willows showed tolerance to
very high lead concentrations present in the soil and
were able to survive and uptake and translocate lead
into above ground tissues. However, lead content which
had accumulated in plant tissues was relatively low and
the post
harvest soil analyses indicated that no significant
difference in lead concentrations had occurred at the
site after one season’s planting and harvesting.
More field research is required to confirm the
phytoextraction abilities of willows over a period of
3-4 years. The combination of biomass production and the
phytoremediation of soil with willows should be further
explored.
Isolation and Characterization of Genes Involved in
Arsenic and DDE Metabolism in Plants
Om Parkash (Dhankher), Bibin Paulose, and Sudesh
Chikkara; Dept. of Plant, Soil and Insect Sciences,
University
of Massachusetts,
Amherst, MA-01003, USA,
Tel: 413-545-5231, Email: parkash@psis.umass.edu
Jason White,
The Connecticut Agricultural
Experiment Station,
123 Huntington St. Box 1106, New Haven CT- 06504, Email:
Jason.White@po.state.ct.us
Environmental pollutants including heavy metals,
metalloids and persistent organic pollutants such as DDE
are major sources of food chain contamination and
thereby endanger human health. Arsenic (As) is an
extremely toxic carcinogenic metalloid pollutant that
adversely affects the health of millions of people
worldwide. Considerable concern exits globally about
arsenic contamination in drinking water and soil.
Phytoremediation renders an eco-friendly and sustainable
method to remediate the As and DDE polluted sites.
However, the progress in this regard is seriously
hampered by to the lack of proper understanding of the
molecular and biochemical mechanisms of uptake and
detoxification of these pollutants in plants. Crambe (Crambe
abyssinica) - a non-food high biomass crop, is
reported to be able to tolerate and accumulate high
amount of As. Understanding the molecular mechanism of
As tolerance is essential to improve the efficiency of
uptake thereby exploiting the plant for commercial
phytoremediation. We have isolated As-induced genes from
Crambe seedlings by PCR-Select Suppression Subtraction
Hybridization approach. After differential screening,
105 positive cDNA clones from the subtracted library
were sequenced. The sequences were categorized based on
their similarity with reported sequences in the
databases. We grouped the cDNA sequences into different
families based on the sequence similarity. Most of the
substracted cDNA belongs to families of oxidoreductases,
peptidases, transferases, transcription factors, metal
ion transporters, heat shock proteins and novel unknown
genes. Semi-quantitative RT-PCR confirmed their
up-regulation in response to arsenic exposure. Selected
genes were expressed in arsenic sensitive yeast strains
lacking arsenate reductase, ACR2, arsenite transporter,
ACR3, and vacuolar transport pump, YCF1, to evaluate
their functional role in arsenic uptake and metabolism.
The results showed that the ectopic expression of the
genes altered the phenotype of the mutant strains in
presence of arsenic indicating their potential role in
arsenic metabolism. The candidate genes will be
functionally characterized in plants using both forward
and reverse genetic approaches.
Persistent organic pollutants (POPs) are of great
environmental concern because of their toxicity, global
distribution, and resistance to remediation.
Cucurbita pepo
ssp pepo
(zucchini, pumpkin) roots have been shown to
phytoextract significant amounts of DDT/DDE, chlordane,
and PCBs from soil, followed by effective translocation
to aboveground tissues. Similar to As strategy, A PCR
select suppression subtraction hybridization approach
was employed to identify and isolate the differentially
expressed genes in DDE treated Zucchini (C.
pepo ssp pepo)
as compared to DDE treated Squash (C.
pepo ssp
ovifera). After differential screening, 46 cDNAs
clones (40 cDNAs isolated from shoot and 6 cDNAs
isolated from roots) were sequenced. Out of 40 shoot
cDNA sequences, 34 cDNAs are similar to different parts
of Phloem filament protein 1 (PP1) and few novel unknown
genes, whereas, in root, out of 6 cDNAs, 2 are similar
to Cytochrome P450 like proteins, one as putative
senescence associated protein and rest are novel unknown
genes. RT-PCR analysis confirmed the up regulation of
these genes in response to DDE exposure. These candidate
genes will be further characterized by both forward and
reverse genetic approach for their role in uptake of
DDEs in plants.
Use of Short-Lived Positron Emitting Radioisotopes to
Study the Effects of Belowground Contaminants on Plant
Growth and Function
Richard A.
Ferrieri,
Brookhaven National Laboratory, Medical Department,
Upton,
NY
11772
One of the major challenges facing plant biology at the
beginning of the 21st century is to
understand plant responses to environmental perturbation
and stress. This understanding is needed from the scale
of the single cell to that of the entire organism.
Such an understanding requires the measurement of
plant responses across these levels of organization on a
time scale from minutes to even days.
Unlike many questions of plant response that can
be studied using cell culture and/or destructive
techniques, the integration of plant stress responses
requires an in
vivo approach that allows repeated measurements from
a single plant.
An approach is needed that not only addresses the
integration of physiological processes, but allows
visualization and quantification of molecular movement
of substrates across the scale of the entire plant.
By using short-lived positron emitting isotopes
such as carbon-11 (half-life: 20.4 min) and nitrogen-13
(half-life: 9.97 min) in combination with PET imaging
and autoradiography, we can visualize quantitatively the
assimilation, transport and disposition of carbon and
nitrogen containing substrates in plants exposed to a
variety of types of environmental stress under true
tracer conditions. Often, we are interested in measuring
changes in C/N allocation, as sugars and amino acids,
between source-and-sink tissues in response to
contaminant exposure. These kinds of measurements can be
carried out by administering doses of 11CO2
or 13NH3 gas to intact leaves.
Other times we are interested in measuring contaminant
uptake and biodistribution. Through complex
radiochemistry, it is often possible to incorporate
appropriate radioactive tags either into organic
contaminants, or even as radiometals that are ionic or
chelated, enabling visualization of their uptake by
roots and transport to leaves.
An overview of this technology will be presented
with highlights on the phytoremediation of chlorocarbon
contaminants by
Populus.
This research is supported by the U.S. Department
of Energy through the Office of Biological and
Environmental Sciences.
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