introduction to phytoremediation

1. Phytoremediation
Presented By
Muhammad Wahaj Javed

2. Phytoremediation
• Phyto (Greek Word) it means “Plant”, Remediare (Latin Word) it means “to
remedy”. Phytoremediation means, remedy through plants.
• Phytoremediation can be defined as “the efficient use of plants to remove,
detoxify or immobilize environmental contaminants in a growth matrix (soil,
water or sediments) through the natural biological, chemical or physical
activities and processes of the plants”
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3. Mechanism of Phytoremediation
Phyto Remediation
Phyto Extraction
Phyto Stabilization
Phyto Transformation
Phyto Stimulation
Phyto volatilization
Rhizofiltration
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4. Overview of processes
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5. Phytoextraction
• The uptake of contaminants by
plant roots and movement of these
contaminants from roots to the
above part of plants .
• Contaminant permanently removed
from soil.
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6. Phyto stabilization
• It refers to the immobilization of
contaminants in the soil through:
absorption and accumulation by
roots.
• The mobility of the contaminant is
reduced, migration to groundwater
is prevented and thus bioavailability
of metal into food chain is reduced.
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7. Phyto transformation
• Also known as phytodegradation, it
is the breakdown of contaminants
taken up plants by metabolic
processes within the plant.
• Remediate some organic
contaminants, such as chlorinated
solvents and herbicides.
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8. Phyto stimulation
• Breakdown of contaminants within
the plant root zone, or rhizosphere.
• Carried out by bacteria or other
microorganisms flourishing in the
rhizosphere.
• Microbes in rhizosphere transform
contaminant to non toxic product.
• Works well in the removal of
petroleum hydrocarbons
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9. Phytovolatilization
• Involves plants taking up
contaminants from soil,
transforming them into volatile
forms and transpiring them into
atmosphere.
• Works on organic compounds and
heavy metal and mercury is the
primary metal contaminant that
this process has been used for.
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10. Rhizofiltration
• Adsorption or precipitation onto
plant roots or absorption of
contaminants in the solution
surrounding the root zone.
• Compared to phytoextraction, here
the plants are used to address the
groundwater rather than soil.
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11. Time
The time depends on:
• Type and number of plants used
• Type and amount of harmful chemicals
present
• Size and depth of polluted area
• Type of soil and conditions present
Often, it takes many years to clean up a site
with phytoremediation.
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13. Types of plant used
• Plant species are selected for use based on factors such as:
• Ability to extract or degrade the contaminants of concern
• Adaptation to local climates
• High biomass
• Depth root structure
• Compatibility with soils
• Growth rate
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14. Examples of plants used in phytoremediation
Indian mustard
(Brassica juncea
L.)
Brassicaceae
species are
really useful
to accumulate
certain metals
Sunflower
(Helianthus
Annuus L.)
one month old
plants reached the
incredible goal of
removing more than
95% of uranium in
24 hours
lemongrass
(Cymbopogon citratus
(D.C.) Stapf.)
Based on translocation
factor, lemongrass acted as
potential phytostabilizer and
was found efficient in
translocation of Al, Zn, Cd,
Pb, Cr, As and Ni from roots
to shoot.
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15. Why should we used phytoremediation and
why should not!
Advantages
• Suited to remediation of large areas of soil
• Cost effective compared to conventional
methods
• Easy to implement and maintain and also
accepted by public
• Fewer spread of contaminants via air and
water
• Environmentally friendly and aesthetically
pleasing to public
Disadvantages
• Limited to shallow ground water, soil and
sediments
• Not as effective for sites with high
contamination
• Slower than conventional methods
• Contaminants may mobilized into ground
water
• Disposal of contaminants accumulated in
plants after harvesting-pollution again!
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