PHYTOREMEDIATION.

1. Background
•“Phyto” = Plant, “Remediation” = restore balance
•The use of certain plants to remove toxins from the
environment. (e.g., metals in soil – Cu, Pb, Zn)
•“Green” technology
• Less environmental impact than excavation
•Cost-effective
These plants work
like a vacuum
cleaner!
Parts of the plant
can be removed
and the toxins
carefully
destroyed.

2. Question
•How is the final copper concentration in Elodea
affected by the starting copper concentration of the
water that it grows in?
•How does the copper concentration in Elodea plants
change over time?
Transport in Plants
High
copper in
water
Low
copper in
Low
copper in
water
High
copper in
Input
s
Outputs

3. Hypothesis
•Elodea will remove increasing amounts of copper from
the polluted water over 5 days.
•Elodea will be most effective at low and moderate
concentrations. High copper concentration will result in
plant death.
•Independent variable: Time (days)
•Dependent variable: Copper conc. in Elodea (ppm)

4. Experimental Setup
• Materials:
• Elodea plant
• Copper sulfate
• Beakers
• Aluminum foil
• Water with nutrients
• Pipet
• Copper test kit
• Measure copper levels by taking a sample of
water at one day intervals for 5 days.
• Use a copper test kit to measure copper levels.
– Mix water with reagent and look at color change
– Compare color change to a standard chart
• Calculate and graph the change in copper
concentration over 5 days for each beaker.
• Record the appearance of each plant to
determine health of the plant over 5 days
0 0.5 1 5 10 50 100
Initial copper concentration
(ppm)

5. Now I have answers…
• How is the final copper concentration in Elodea affected by
the copper concentration of the water that it grows in?
• How does the copper concentration in Elodea plants change
over time?
• How much copper metal can Elodea remove from polluted
water over 5 days?
• What is the range for effective phytoremediation?

6. Global Impact
• Soil and water contaminated with heavy metals and other toxins pose
large environmental and human health hazards.
• Phytoremediation can be used to decontaminate large areas without
damaging the land.
• “Phytoremediation of lead in residential soils in Dorchester, MA”
- Lead paint was widely used until 1978. Houses were built before 1980.
- Lead is highly toxic and can cause neurological problems.
- Federal limit: 400 ppm in children’s play area and 1200 ppm in non-play areas
- Use Indian mustard plant suitable for northeastern soil conditions

7. Questions?
• What type of plants can be used for photoremediation?
• “hyperaccumulators”
• fast growing, deep roots, easy to harvest.
• Sunflower, duckweed, kale, corn, broccoli etc.
• Do the toxins or metals prevent plant growth?
• Possibly, so this method may work best when there is
moderate contamination.
• Grow seeds in a nursery and transfer the plants only when
they are more mature.
• Can animals be poisoned if they eat these plants?
• Maybe, but the environmental risk is small compared to the
number of human lives that could be protected

8. Bibliography
• Chaney R.L., Phytoremediation: Using Plants to Clean Up Soils. USDA
Agricultural Research Magazine, 2006
• ITRC Workgroup, Emerging Technologies for the Remediation of
Metals in Soils. Interstate Technology & Regulatory Council, 2007
• Kirkwood NG, Here come the Hyperaccumulators!. Harvard Design
Magazine, 2002
• http://www.chemetrics.com/ (copper test kit)

9. Phytoremediation:
Phytoremediation
• describes the treatment of environmental problems through
the use of plants that
• mitigate the environmental problem without the need toexcavate
the contaminant material and dispose of it elsewhere.
• Phytoremediation consists of mitigating pollutan tconcentrations
in contaminated soils, water, or air, with plants able to contain,
degrade, or eliminate metals, pesticides,olvents, explosives,
crude oil and its derivatives, and variousother contaminants from
the media that contain them.
• 350 plant species naturally take up toxic materials. Sunflowers
used to remove radioactivecesium and strontium from Chrenobyl
site .Water hyacinths used to remove arsenic from water supplies
in Bangladesh, India.

13. MOBILIZATION
H -ATPase
+
H
+
H
+ SOIL
M
n+
M
M
n+
MALIC ACID
CITRIC ACID
CELL
WALL
M
ROOT UPTAKE
H+
H
+
M
n+
Mn+
M
M
M M
M
M
M
M
CELL
WALL
PLASMA
MEMBRANE
H -ATPase
+
VACUOLE
CITOSOLIC
CHELATORS
XILEMATIC TRANSPORT
M
n+
Mn+
Mn+
Mn+
Mn+
M
M
M
cell.
transfer
XILEM
PARENCHIMATIC
CELLS
DIFFUSION
floema
APOPLASTIC
LOADING
?
SYMPLASTIC
LOADING
HYSTOLOGICAL LOCALIZATION
Mn+
M
Mn+
M
M
TRICOMES
xilem
APOPLASTIC
TRANSPORT
SYMPLASTIC
TRANSPORT
CELL UPTAKE AND COMPARTIMENTATION
M
M
M
M M
M
M
M
M
M
M
GOLGI
NUCLEUS
PLASMA
MEMBRANE
metal-
chaperonines
VACUOLE

14. Alyssum serpyllifolium
Brassica juncea
Liriodendron tulipifera
Pteris vittata
Thlaspi
caerulescens
HYPERACCUMULATOR
SPECIES &
PHYTOREMEDIATION
PLANTS

15. Hyperaccumulator species = low biomass?
WHICH PLANT SPECIES FOR PHYTOEXTRACTION?
Thlaspi caerulescens, a Zn/Cd
hyperaccumulator, produces little biomass
(2-5 t/ha)
(McGrath et al. Adv. Agronom. 2002)
Alyssum bertolonii and Berkheya coddii, Ni
hyperaccumulators, produce up to 9-22 t/ha
biomass (Robinson, 1997)

16. Can high biomass compensate for lower accumulation?
WHICH PLANT SPECIES FOR PHYTOEXTRACTION?
Thlaspi caerulescens
can extract 2000 g Cd / ha / year
Cannabis sativa
Can extract 126 g
Cd / ha / year

17. Hemp as a high biomass plant for phytoextraction?
WHICH PLANT SPECIES FOR PHYTOEXTRACTION?
Zn toxicity on hemp plants
Phytoxicity?
Use of fibers after
phytoextraction?

18. Hemp as a high biomass plant for phytoextraction?
WHICH PLANT SPECIES FOR PHYTOEXTRACTION?
High biomass
Not hyperaccumulator
Could be used for phytoremediation if fibers can be
commercialized

19. COPPER SOIL CONTAMINATION
Copper is required for the physiology of the plant
An EXCESS of copper in the soil results in phytotoxic effects
Copper is an essential cofactor for many enzymatic activities in
animals too
An EXCESS of copper is excreted by animals (liver, bile)
Genetic diseases result in altered Cu homeostasis (Wilson
disease)
Exposure to the metal copper may increase the risk of
Alzheimer's disease

20. COPPER SOIL CONTAMINATION
Copper sulfate is used in
agricuture, including organic
farming
Possible copper build-up in the soil
which at high levels can be
harmful to earth worm populations.
In response to such environmental
concerns copper should be
phased out of usage as soon as
possible

21. The aim of this work is the
localization of Cu in hemp plants
grown in a copper-enriched solution
CuSO4

22. CELL WALL
VACUOLE
PLASTID
CITOLOGICAL
LOCALIZATION
OF
Cu

23. Hemp grown in hydoponics accumulates cooper in the leaves (tricomes)
Copper was not detected in fibers
Further work is needed to evaluate the fibers quality from hemp grown
in open field in the presence of copper sulfate
CONCLUSIONS