Environment topic(civil engineering)-PHYTOREMEDIATION

1. PHYTOREMEDIATION
DAYAL KURIAN VARGHESE

2. OVERVIEW
 INTRODUCTION OF
PHYTOREMEDIATION
 NEED FOR THE NEW
REMEDIATION TECHNIQUE
 VARIOUS PHYTOREMEDIATION
PROCESSES
 PHYTOREMEDIATION BY
AQUATIC PLANTS
 ADVANTAGES AND
DISADVANTAGES
 CONCLUSION

3. INTRODUCTION
 Phytoremediation can be
defined as the use of green
plants to remove the
contaminants from the
environment or to render
them harmless.
 “Phyto”= Plant (in Greek)
 “Remediare”= To remedy
(in Latin)

4. NEED FOR THE NEW REMEDIATION
TECHNIQUE
Microbial/ Biological Measures
These approaches are ecological and economically sound but
physical removal/ cleaning up of contaminants does not occurs
as contaminants remain in the soil system
Chemical Measures
Chemical extraction procedures have been suggested but they
are not cost effective.
So, these constraints have forced the researcher to think of
using plants for cleaning up their own support system which
will eco-friendly and cost effective. This new approach is
“Phytoremediation”.

5. VARIOUS PHYTOREMEDIATION
PROCESSES
Phytoextraction
 Rhizofiltration
Phytostabilization
Phytotransformation
Rhizosphere
Bioremediation

6. PHYTOEXTRACTION
 Phytoextraction uses
plants or algae to remove
contaminants from soils,
sediments or water into
harvestable plant biomass.
 The main advantage of
phytoextraction is
environmental friendliness.

7. PHYTOSTABILISATION
 Phytostabilization is the use of plants to prevent the
migration of contaminants through control of the hydraulic
gradient or by reinforcing the soil structure.

8. PHYTOTRANSFORMATION
 chemical modification of
environmental substances
as a result of
plant metabolism resulting
in their inactivation,
degradation
(phytodegradation) or
immobilization
(phytostabilization).

9. RHIZOFILTRATION
 Filtering water through a
mass of roots to remove
toxic substances or
excess nutrients.
 The pollutants remain
absorbed in or adsorbed to
the roots.
Chernobyl - sunflowers were grown in
radioactively contaminated pools

10. RHIZOSPHERE BIOREMEDIATION
 Enhancement of soil
microbial activity for
the degradation of
contaminants, typically
by organisms that
associate with roots.
 Rhizosphere = soil +
root + microbes.
 Also known as
Phytostimulation.

11. PHYTOREMEDIATION BY AQUATIC
PLANTS
Aquatic plants are those plants living in and adapted to
aquatic environments, which can only grow in water or
permanently saturated soil.
Eurasian Watermilfoil (Myriophyllum spicatum)
Water Hyacinth (Eichhornia crassipes )
Duckweed (Lemna trisulca L.)
Fool's Watercress (Apium nodiflorum)

12. Water Hyacinth
 Floating plant with broad ,thick,
and glossy leaves that the plant
body can grow as much as 1m high.
 Able to phytoaccumulate metal
pollutants contain Ag, Pb, Cd and
Zn in municipal and agricultural
wastewater.
 Known as one of the plants with
fastest growth rate that can double
population in 2 weeks.
 High invasive potential.

13. Case Study: Removal of Cadmium and Zinc by Water Hyacinth
 The stock solution was prepared in distilled water with analytical grade
CdCl2. 2½ H2O and ZnSO4.7H2O which was later diluted as required. The
plants were maintained in tap water with concentrations of 0.5, 1, 2, 4 mg/L
of Cd and 5, 10, 20, 40 mg/L of Zn.
 The test durations were 0 (two hours), 4, 8 and 12 days.
 Relative growth, metal accumulation, and bioconcentration factor (BCF)
are evaluated.
Relative growth (above) and BCF (below)

14. Zn
CdCd
Zn
Cd
Zn
(Lu et al., 2004)
Relative plant growth Metal Accumulation BCF

15. Duckweed
 Has a very simple structure that
lacks obvious stems or leaves, with
small plate-shaped structure floating
on water surface.
 Reproduction is mainly rely on
asexual budding.
 High pollutant removal potential
due to small size, fast growth, and
easy to cluture.
(Kara and Kara, 2004)

16.  The duckweed obtained from
natural lake was acclimatized to
laboratory conditions for one week
before starting research.
 Solution of Cadmium was
prepared using Cd(NO3)2 and
contact with plant sample for
different length.
 After absorption, water samples
were analyzed by AAS at 228.8nm.
Case Study: Removal of Cadmium by Duckweed
Cd removal efficiencies
(Kara and Kara, 2004)

17. ADVANTAGES AND DISADVANTAGES
Advantages Disadvantages
Cost effective when compared to other
more conventional methods.
Slow rate and difficult to achieve
acceptable levels of decontamination.
 “natural” method, more aesthetically
pleasing.
Possibility of contaminated plants
entering the food chain.
minimal land disturbance.  Possible spread of contaminant
through falling leaves.
 reduces potential for transport of
contaminants by wind/soil erosion.
Trees and plants require care.
 multiple contaminants can be removed
with the same plant.
Contaminant might kill the tree.
It is one of the least harmful method. Degradation product could be worse
than original contaminant.
The possibility of recovery and reuse of
valuable metals.(Phyto mining)
 Only surface soil (root zone) can be
treated.
Cleanup takes several years.

18. 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 aesthetics and the potential for
ecosystem restoration.

19. REFERENCES:
 Majeti Narasimha Vara Prasad,et al, “Metal hyperaccumulation in plants -
Biodiversity prospecting for phytoremediation technology”, Electronic
Journal of Biotechnology 6(3),2003,450 -458.
 Yeşim Kara,et al, ” Removal of Cadmium from Water Using Duckweed
(Lemna
trisulca L.)”, International Journal Of Agriculture & Biology 4,2005,660-662.
 Angela Pierre Vitória,et al, ” Structural and Ecophysiological Alterations of
the Water Hyacinth [Eichhornia crassipes (Mart.) Solms] Due to
Anthropogenic Stress in Brazilian Rivers”, Brazilian Archives Of Biology And
Technology 54(5),2011, 1059-1068.
 Mesania Rizwana,et al, ” Phytoremediation of Textile Waste Water Using
Potential Wetland Plant: Eco Sustainable Approach”, International Journal of
Interdisciplinary and Multidisciplinary Studies (IJIMS) 1(4),2014,130-138.

20. REFERENCES(CONTD.)
 Divya Singh,et al, “Phytoremediation of lead from wastewater using aquatic
plants”, Journal of Agricultural Technology 8(1),2012,1-11.
 Honey Aggarwal,et al, “Phytoremediation of some heavy metals by agronomic
crops”, Developments in Environmental Science 5,2007,79-98.
 Hiromichi Morikawa,et al, “Basic processes in phytoremediation and some
applications to air pollution control”, Chemosphere 52,2003, 1553-1558.
 Hongyu Wang,et al, “An Application of Phytoremediation to River Pollution
Remediation”, Procedia Environmental Sciences 10 ,2011 ,1904 – 1907.

21. T H A N K S !
Any questions?