2. SOHAIL P.hD Scholar Department of Botany, PMAS-Arid Agriculture University, Rawalpindi.

3. Technology That Use Plants To Clean Up Contaminated Sites.

4. Contents Phytoremediation Over all Phytoremediation’s
Plants used for Phytoremediation's
How does it work?
Mechanisms
Phytotransformation/Phytodegradation
Phytoextraction
Phytostabilization
Rhizofiltration
Rhizosphere Bioremediation
Over all Phytoremediation’s
Transgenic Plants Use for Phytoremediation's
Aquatic plants for wastewater treatment
Effects of Some Heavy Metals on Human Health
Contaminant removal mechanisms
Advantages and Disadvamtages
Conclusions
References

5. Green technology that uses plants systems for remediation and restoration.
Consist of microbial degradation in rhizosphere as well as uptake, accumulation and transformation in the plant.

6. Current Methods
Current methods mainly remove and transport to land fill or pump and treat type systems.
Many sites are large and pollution is not high but still violates standards.
For secondary or tertiary treatment of waste water.

7. Phytoremediation
Phytoremediation is the direct use of living green plants for in situ, or in place, removal, degradation, or containment of contaminants in soils, sludge's, sediments, surface water and groundwater. Phytoremediation is:
It a low cost, use solar energy driven cleanup technique.
Most useful at sites with shallow, low levels of contamination.

8. Useful for treating a wide variety of environmental contaminants.
Effective with, or in some cases, in place of mechanical cleanup methods.

9. Plants used for Phytoremediation's

10. Conti…

11. How does it work? in the rhizosphere
- Plants in conjunction with bacteria and fungi
in the rhizosphere
transform, transport or store harmful chemicals.
- Plants attributes make them good candidates
root system surface area to absorb substances and efficient mechanisms to accumulate water, nutrients and minerals.
selectively take up ions
Plants developed diversity and adaptivity to tolerate high levels of metals and other pollutants.

12. Mechanisms Phytotransformation/Phytodegradation
Pollutant is taken up by the plant and
transformed in plant tissue (to be effective
must be transformed to a less toxic form).
Trichloroethylene (TCE), a prevalent ground
water contaminant, transformed to less toxic
metabolites by using hybrid poplar tree.

13. Air Force facility in Texas using cottonwoods to treat a large ground water plume of TCE.
EPA research lab using parrot feather (a common aquatic weed) for TNT (Treating New Targets) treatment.

15. Uptake of chemical by the plant.
Phytoextraction
Uptake of chemical by the plant.
Works well on metals such as lead, cadmium,
copper, nickel etc.
Detroit lead contaminated site was removed with
Sunflower and Indian Mustard.
- recently researchers at the University of
Florida have determined that a species of
fern, native to the south east, stores high
concentrations of arsenic in its fronds and
stems more than 200 times the concentration in the soil.

17. Phytostabilization
Involves the reduction of the mobility of heavy metals in soil.
Immobilization of metals can be accomplished by decreasing
wind-blown dust,
minimizing soil erosion,

18. Reducing contaminant solubility or bioavailability to the food chain.
Trees transpire large quantities of water (more than 15 gal/day) so pumping action prevents contaminants from migration into the water table.

20. Rhizofiltration Use the extensive root system of plants as a filter.
1995, Sunflowers were used in a pond near Chernobyl (City name).
- approx. 1 week they had hyperaccumulated
several thousand times the concentration of
cesium and strontium.
- hyperaccumulation can contain 100 times or
more of contaminant than normal plant.

22. Rhizosphere Bioremediation
- Increase soil organic carbon, bacteria, and
mycorrhizal fungi, all factors that
encourage degradation of organic chemical
in soil.
- The number of beneficial bacteria increased
in the root zone of hybrid poplar trees and
enhanced the degradation of BTEX, (benzene, toluene, ethylbenzene, and xylenes)
organic chemical, in soil.

24. Rhizofiltration Applicability
A suitable plant for rhizofiltration applications can remove toxic metals from solution over an extended period of time with its rapid-growth root system.
Various plant species have been found to effectively remove toxic metals such as Cu2+, Cd2+, Cr6+, Ni2+, Pb2+, and Zn2+ from aqueous solutions.
Low level radioactive contaminants also can be removed from liquid streams.

25. Rhizofiltration (cont.)
Limitations Rhizofiltration is particularly effective in applications where low concentrations and large volumes of water are involved.
Data Requirements - Depth of contamination,
- Types of heavy metal present,
- Level of contamination must be determined and
monitored.
- Vegetation should be aquatic, emergent, or
submergent plants.
- Hydraulic detention time and sorption by the plant
roots must be considered for a successful design.

26. Rhizofiltration (cont.)
The example of an experiment
The plant root immersed in flowing contaminated water until
the root is saturated.
The metal concentrated in the roots was analyzed on a dry weight basis using Atomic Absorption Spectrophotometry(AAS). 
The amount to metal taken up by the roots from various solutions was compared on the basis of recovery rate (µg metal in roots/µg metal in solution) and bioaccumulation coefficient (ppm metal in roots / ppm of metal in solution). 

27. Rhizofiltration (cont.)
Other factors that should be considered
- Potential of failure modes and contigencies
Rhizofiltration may not succeed for a number of reasons,
including mortality of plants for reasons such as
management, weather extremes, soil conditions or pest.
- Field studies
Field studies are required before full-scale application.
Specific information include rates of remediation, irrigation
requirements, rates of soil amendments, and plant selection.
Formulating clear objectives, appropriate treatments,
experimental units and planning are important considerations in field
studies.
- Economic
This technique should be less cost than traditional technologies such
as excavation, thermal desorption, landfilling etc.

28. Over all Phytoremediation’s

29. Transgenic Plants
Most recent advances in phytoremediation is the development of genetically modified plants able to take up and degrade contaminants.
With increased understanding of the enzymatic processes involved in plant tolerance and metabolism of xenobiotic chemicals,
there is new potential for engineering plants with increased phytoremediation capabilities.

30. Several transgenic plant species are being developed with phytoremediation applications in mind.
Tobacco plants containing a human P450 2E1 were able to transform up to 640 times the amount of TCE compared with control plants.

31. They also showed increased uptake and metabolism of ethylene dibromide, another halogenated hydrocarbon commonly found in groundwater.
Higher tolerance to the explosives.

33. Aquatic plants for wastewater treatment
Aquatic plants are chosen for absorb particular
nutrient and to remove pathogens, metals and
other contaminants from wastewater.
Aquatic plants have been shown to be very
effective as a secondary or tertiary state for
water treatment and nutrient removal.

34. Living Environment of Aquatic Plants
Rivers
Lakes
Where do they live?
Constructed Wetlands
Hydroponic systems

35. Mechanisms of aquatic plants phytoremediation
Inorganic pollutants
Rhizofiltration
Phytostabilization
Phytoextraction
Organic pollutants
Phytodegradation
Phytovolatilization
Rhizodegradation

36. Aquatic plant for waste water treatment
Water Lily has an extensive root system with rapid
growth rates, but is sensitive to cold temp, it is an ideal
plant for water treatment in warm climates.
Duckweed (Lemma spp.) has greater cold tolerance and a
good capacity for nutrient absorption.
Penny wort (Hydrocotyl spp) is relatively cold tolerant
with a very good capacity for nutrient uptake.
Water hyacint uptake of heavy metal eg.,Pb,Cu,Cd,Hg
from contaminated water.

37. Function of plants in aquatic treatment
Plant Parts
Functions
Roots and/or stem
in water column
Stem and/or
leaves at or above
water surface
Uptake of pollutants
surfaces on which bacteria grow
media for filtration and adsorption of
solids
Attenuate sunlight, thus can prevent
growth of suspended algae.
Reduce effects of wind on water
Reduce transfer of gases and heat
between atmosphere and water.

38. Heavy Metals Arsenic Lead Aluminum Beryllium Copper Iron Mercury
Nickel
These persist in soils and are toxic to animals even in small quantities

39. Effects of Some Heavy Metals on Human Health
Scope of Arsenic contaminaton

40. Scope of Nickle Contamination

43. Contaminant removal mechanisms
Physical Chemical Biological
Sedimentation Precipitation Bacterial metabolism
Filtration Adsorption Plant metabolism
Adsorption Hydrolysis reaction Plant absorption
Volatilization Oxidation reaction Natural die-off

44.  World Wide Projects on Bioremediation projects
Team
Year
Organism
Description
Peking University
2010
E.coli
Heavy metal decontamination of aquatic environments via binding proteins
UT Dallas
Establishing E.coli as a biosensor for environmental pollutants using fluorescence
METU Turkey
Designing a biosensor to detect CO as a dangerous pollutant
USeoul Korea
Using fluorescence proteins to detect various heavy metals in water
TU Delft
Enabling hydrocarbon degradation in aqueous environments
Michigan
2009
Sensing and degrading toluol
UQ Australia
Uptake and reduction of mercury in water
Cornell University
B.subtilis
Creating a cadmium sensor

45. Projects Working in Pakistan For Bioremediation's
Local Government and Rural Development Department (LGRDD) and Anjum-e-Takmeel-e-Maqased-e Insania (ATMI) ( )
Three of the above organizations contributed to introduce various components of ISFS/Bio-remediation in GanguJuma Village, Taxila.
The village reclaimed village wastewater was about 0.75 it covered about 3.5 acre of land,the land consumed for biological treatment of wastewater was about 0.75 acre and rest of the land restored for integrated farming activities.

46. ISFS/Bio-remediation Resource Centre Village GanguJuma, Taxila UNICEF Pakistan and Sardar Ahmed Khan Memorial Welfare Trust (SAK-MWT) ( ).
Established Bio-remediation Garden to reclaim sewerage water of NARC offices through bio-remediation.
Established Bio-remediation Orchard for treatment of 0.65 million gallons waste water of Shehzad Town, Islamabad.
Established integrated farming facilities through usage of reclaimed water at Bio-remediation Garden and Bio-remediation Orchard

47. Advantages Cost effective when compared to other more
conventional methods.
“nature” method, more aesthetically pleasing.
minimal land disturbance.
reduces potential for transport of
contaminants by wind, reduces soil erosion
hyperaccumulaters of contaminants mean a
much smaller volume of toxic waste.
multiple contaminants can be removed with the
same plant.

48. Disadvantages Slow rate and difficult to achieve acceptable
levels of decontamination.
Potential phase transfer of contaminant.
Possibility of contaminated plants entering
the food chain.
Disposal of plant biomass could be a RCRA
regulated hazard substances.
Possible spread of contaminant through
falling leaves.

49. Disadvantages (cont.) Decrease in action during winter months when
trees are dormant.
Trees and plants require care.
Contaminant might kill the tree.
Degradation product could be worse than
original contaminant.
Much testing is needed before a procedure
can be utilized (EPA approval)

50. Conclusion
Although much remains to be studied, phytoremediation will clearly play some role in the stabilization and remediation of many contaminated sites.
The main factor driving the implementation of phytoremediation projects are low costs with significant improvements in site and the potential for ecosystem restoration.

51. References
S a m c h e r i a n , and M . M a r g a r i d a O l i v e i R A Transgenic Plants in Phytoremediation: Recent Advances and New Possibilities. Environmental science & technology . Vol. 39, no. 24.
Martinoia, E., Grill, E., Tomasini, R., Kreuz, K., Amrehin, N. ATP-dependent glutathione S-conjugate ‘export’ pump in the vacuolar membrane of plants. Nature 1993, 364,
Ross, S.M.Toxic Metals in Soil-Plant Systems; Wiley: Chichester, UK, 1994.
De la Fuente, J. M., Ramirez-Rodriguez, V., Cabrera-Ponce, J. L., Herrera-Estrella,L.Aluminiumtoleranceintransgenicplants by alteration of citrate synthesis. Science 2010,276,

53. Any
Questions…?