Thessaly master plan- WWF presentation_18.04.24.pdf
Phytoremediation
1.
2. Introduction
Phytoremediation as a cleaning tool
Different mechanisms of Phytoremediation
Plant as phytoremediator and requirements for
effective Phytoremediation
Applications
Case studies in support of soil and water remediation
Advantages
Disadvantages
Conclusion
3. What is it ?
Phytoremediation is a process that uses plants to remove, transfer,
stabilize, and destroy contaminants from soil, water and sediments.
phyto-remediation can be broadly categorized as:
To treat Organic contaminants
Phytodegradation
Phytovolatilization
Phytostimulation
To treat Metal contaminants
Phytoextraction
Rhizofiltration
Phytostabilization
4. Phytoremediation as a cleaning tool
• Phytoremediation is the direct use of green plants to
degrade, contain, or render harmless various environmental
contaminants, including recalcitrant organic compounds or
heavy metals.
•Plants are especially useful in the process of bioremediation
because they prevent erosion and leaching that can spread the
toxic substances to surrounding areas
•Phytoremediation of heavy metals from the environment
serves as an excellent example of plant-facilitated
bioremediation process and its role in removing
environmental stress.
5. Categories of Phytoremediation
• Phytostabilization
• Phytoextraction
• Rhizofiltration
• Phytovolatilization
• Phytodegradation
• rhizodegradation
( Snehal Saurav Pandey et al 2013 )
6. .
Phytostabilization
The immobilization of contaminants in soil through absorption and
accumulation by roots, adsorption onto roots or precipitation within the root
zone.
It not only prevent contaminant migration into the ground water or air by
reducing leaching and controlling erosion.
reduce the bioavailability of the contaminants.
Target Area’s are large bare surfaces caused by mining operations or arial
deposition of metals from metal smelters.
( http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2265025/ ) (http://enfo.agt.bme.hu/drupal/sites/default/files/ARuttens.pdf)
7. Phytoextraction
Plant roots uptake metal contaminants from the soil and
translocate them to their above soil tissues.
Once the plants have grown and absorbed the metal pollutants
they are harvested and disposed off safely.
This process is repeated several times to reduce contamination to
acceptable levels.
Hyper accumulator plant species are used on many sites due to
their tolerance of relatively extreme levels of pollution.
Avena sp. , Brassica sp.
8. Rhizofiltration
It is concerned with the remediation of contaminated
groundwater.
The contaminants are either adsorbed onto the root surface or are
absorbed by the plant roots.
1
• Plants are hydroponically grown in clean water rather than
soil, until a large root system has developed
2
• Water supply is substituted for a polluted water supply to
acclimatize the plant
3
• They are planted in the polluted area where the roots uptake
the polluted water and the contaminants along with it
4
• As the roots become saturated they are harvested and
disposed of safely
(Source:https://www.google.co.in/search?q=bioremediation+images)
9. Phytovolatilization
Plants uptake contaminants which are
water soluble and release them into the
atmosphere as they transpire the water.
Phytovolatilization has mainly been
applied to groundwater, but it can be
applied to soil, sediments, and sludges.
Contaminants could be transformed to
less toxic form such as elemental mercury
and dimethyl selenite gas.
Poplar trees volatilize up to 90% of the
TCE they absorb.
(https://www.google.co.in/search?q=bioremediation+images
10. Phytodegradation
It is the degradation or breakdown of organic contaminants by
internal and external metabolic processes driven by the plant.
Metabolic processes hydrolyze organic compounds into
smaller units that can be absorbed by the plants
Mechanisms:
Plant enzymatic activity:
oxygenases- hydrocarbons degradation.
nitroreductases- explosives degradation
Phytodegradation is used in the treatment of soil, sediments,
sludges, groundwater and surface water
11. Used in breakdown of ammunition wastes, chlorinated
solvents such as TCE (Trichloroethane), degradation of
organic herbicides.
Enzyme bacterial mercuric ion reductase has been
engineered into Arabidopsis thaliana and the resulting
transformant transgenic plant is capable of degrading and
volatilising mercuric ions.
(Cunningham and Owe, 2009)
Cont.
12. Rhizodegradation
Rhizodegradation is the breakdown of an organic
contaminant in soil through microbial activity that is
enhanced by the presence of the root zone.
Rhizodegradation is also known as plant-assisted
degradation, plant- assisted bioremediation, plant-
aided in situ biodegradation, and enhanced rhizosphere
biodegradation.
15. Plants as Phytoremediator
Plants that are able to decontaminate soils does one or more of the
following characteristics:
1- plant uptake of contaminant from soil particles or soil liquid into their
roots.
2- bind the contaminant into their root tissue, physically or chemically
3- transport the contaminant from their roots into growing shoots and
prevent or inhibit the contaminant from leaching out of the soil
4- accumulate, degrade or volatilize the contaminants.
5- grow quickly in different environmental conditions.
6-easily harvested . ( Annie Melinda Paz-Alberto et al .2013)
16. Requirements for effective Phytoremediation
• firstly making an assessment to the site,
correctly selecting plant species, and
• implementing a suitable plant or crop
management regime.
• Soil amendments may need to be added to
enhance plant growth and/or contaminant
uptake or degradation
(Kokyo Oh et al 2014)
17. • Phytoremediation technology is applicable to a broad range of
contaminants, including
• metals and radionuclides
• organic compounds like chlorinated solvents
• polycyclic aromatic hydrocarbons
• Pesticides
• explosives, and surfactants.
(Annie Melinda et al 2012.)
19. Selenium biofortification is an agricultural process that increases the
accumulation of Se in crops, through plant breeding, genetic engineering, or
use of Se fertilizers.
Selenium Phytoremediation is a green biotechnology to clean up Se-
contaminated environments, primarily through Phytoextraction and
Phytovolatilization.
By integrating Se Phytoremediation and biofortification technologies, Se-
enriched plant materials harvested from Se Phytoremediation .
can be used as Se-enriched green manures or other supplementary
sources of Se for producing Se-bio-fortified agricultural products.
Zhilin Wu et al . 2015
Cont.
21. Cont.
Phytoremediation of toxic metals and metalloids has been reported by
researchers using a variety of plants.
The efficiency of Phytoremediation can be enhanced by the assistance of
plant growth promoting (PGP) bacteria.
These bacteria transform metals into bioavailable and soluble forms
through the action of siderophores, organic acids, biosurfactants,
biomethylation, and redox processes.
in addition, PGP bacteria possess growth-promoting traits, including
phosphorus solubilization, nitrogen fixation, iron sequestration, and
phytohormone and ACC (1-aminocyclopropane-1-carboxylic acid)
deaminase synthesis, which improve plant growth and increase plant
biomass, in turn assisting Phytoremediation.
26. conclusion
The Eichhornia plant reduce pH 10 to 8, TDS 4500 mg/L to
26 00 mg/L and other parameters also reduced 17-28%.
Phytoremediation is suitable and low cost technology to
remove or degrade the pollution from industrial effluent like
tannery effluent.
The Eichhornia Crassipes is an extraordinary tool for
effluent treatment if it is properly concentrated on
Phytoremediation technology.
it could be utilized the benefits and safe of our environment
29. The results indicated that Glossostigma elatinoides was a
good
phytoremediator for Cd whereas Hemianthus callitrichoides
was a good phytoremediator for Cu.
The expected outcome of this research is to introduce cost-
effective and eco-friendly technology to cater environmental
pollution.
Cont.
30. Advantages
• Amendable to a variety of organic and inorganic compounds.
• Easy to implement and maintain
• cost effective
• less destructive to the environment.
• It also reduces soil erosion and dust emissions.
• Make a site more attractive, and improve surrounding air
quality.
• Most suitable for developing countries
( Snehal Saurav Pandey et al 2013 )
( Senthil kumar.R et al 2015 )
31. Advantages cont.
• Natural and in situ remediation system does not induce
secondary contamination
• Reduce movement of contaminants towards groundwater
• Sustain soil structure
• Enhance soil quality & productivity
• Prevent loss of soil resources
( Kokyo Oh et al 2014 )
32. Disadvantages
The process of bioremediation is slow. Time required is in day
to months.
Heavy metals are not removed completely.
For in situ bioremediation site must have soil with high
permeability.
It does not remove all quantities of contaminants.
Requires large surface area of land.
33. Disadvantages cont.
• Growing conditions required by the plants( i.e. climate , geology
,altitude and temperature)
• Geological conditions of site to be cleaned
• And accessibility for agricultural equipment
• Tolerance of the plant to the contaminant
• Time taken to remediate sites far exceeds that of other technologies
( Kokyo Oh et al 2014 )
34. References
1) kokyo et al. Study on Application of Phytoremediation Technology inManagement and
Remediation of Contaminated Soils, Journal of Clean Energy Technologies, Vol. 2, 2014.
2) Subhashini V et al. Phytoremediation: Emerging and green technology for the uptake of
3) Cadmium from the contaminated soil by plant species, international journal of environmental
sciences,vol 4, 2013.
4) Senthil kumar.R et al. Phytoremediation of Tannery Effluent by Water Hyacinth- GJRA, vol-
4,2015.
5) Gratao et.al. Phytoremediation: green technology for the cleanup of toxic metals in the
environment.2005.
6) Snehal Saurav Pandey et al. Phytoremediation an Alternative, International Journal of
Environmental Engineering and Management,vol 4, pp 483-488, 2013.
7) Zhilin Wu et al . 2015. Biofortification and Phytoremediation of selenium in China.PMC,
2015 .
8) Abid Ullah et al. Phytoremediation of heavy metals assisted by plant growth promoting (PGP)
bacteria: A review. ELSEVIER ,2015
Schematic showing phytostabilization mechanisms including precipitation of metals by bacterial and root surfaces, precipitation of metals by bacterial and root exudates, bacterial uptake and sequestration of metals, and root uptake of metals. In phytostabilization, accumulation of metals in plant shoot tissues is undesirable.
Contaminants removed:
Metal compounds that have been successfully phytoextracted include zinc, copper, and nickel.