bioremediation and phytoremediation

1. Bioremediation &Phytoremediation
Name –MALAYA GHOSH
ROLL NO-21
PG-3RD SEM
DEPT OF LS
ASSAM UNIVERSITY,SILCHAR

2. Bioremediation :
Bioremediation has been derived from two words “bios”
meaning life and “remedy” meaning to solve problems together
meaning to solve problems with the help of living organisms .
Bioremediation is a waste management
technology involved in the process of treating environmental
pollution with the use of living organisms .It is mainly involved in
removing contaminants,restoring contaminated sites and
preventing further pollution .

3. Factors influencing bioremediation :
Microbial population
Oxygen
Nutients
PH,Water
Temperature ,etc

4. Types of bioremediation:
 On the basis of type of degradation-
Biotransformation.
Biodegradation.
Mineralization.
 On the basis of type of micro-organism used-
Bacterioremediation
Mycoremediation
Phytoremediation
Compost bioremediation

5. CONTD…..
On the basis of strategies involved –
In-situ bioremediation
Ex-situ bioremediation

6. In situ bioremediation :
In situ bioremediation is the treatment of
contaminated material at the site.This process is
usually recommended because it requires less
materials to be moved and is less expensive .
It is of two types viz-
Intrinsic bioremediation
Engineered in situ bioremediation

7. Techniques involved in bioremediation :
Bioventing
Biosparging
Biostimulation
Bioaugmentation

8. Ex-situ bioremediation :
It involves removal of contaminated material to be
treated elsewhere .However this technique is less
time consuming as compared to those of traditional
methods .
On the basis of phases of contaminated
materials under treatment they are of two types :
Solid phase system
Slurry phase system.

9. Solid phase system :
Solid phase system involves treatment of various
solid wastes such as leaves , animal manures ,
agricultural waste , municipal solid waste , etc.It
mainly involves the process of composting .

10. Solid phase system :

11. Slurry phase system :
Slurry phase system involves processing of contaminated
soil or water through the use of engineered system like
bioreactors so as to increase the rate of biodegradation .This
system is actually a triphasic system involving three major
components such as water , suspended particulate matter
and air .
The process involves three types of bioreactors-
 Aerated lagoons
 Low-shear airlift reactors
 Fluidized bed soil reactor.

12. Slurry phase treatment :
aerated lagoons

13. Contd :
low – shear airlift bioreactor

14. Reactions involved in bioremediation:
Aerobic reactions
Anaerobic reactions

15. Aerobic metabolism :
Organic
chemical
(benzene)
oxygen
Co2+H2O+biomass
(increased number
of bacteria )

16. Anaerobic metabolism :
Organic
chemical
(toluene)
Nitrate
CH4+N2+
H2O+Biomas
s

17. phytoremediation
Phytoremediation is defined as the in situ use
of plants to stabilize , remediate and reduce
or restore contaminated soil , water,
sediments etc. The plants used for removal of
polluting metal are able to accumulate heavy
metal in their tissues and thus cause increase
in dry weight of plant tissue.

18. Techniques of phytoremediation :
 Phytoextraction or Phytoaccumulation:
It is the process by which the plants accumulate contaminants into the
roots or other tissues thereby reducing the remediation cost by
accumulating low level of contaminants from a widespread area . Eg-
transgenic cotton wood with E.coli gene accumulates mercury , Indian
mustard (Brassica juncea)accumulates Pb , S , Se,and such other metals.
 Phytotransformation or Phytodegradation:
It refers to the breakdown of accumulated heavy metals and organics
into less toxic or simpler forms by the metabolic activities of the
microbes .as for example :metal Cr is reduced from hexavalent to
trivalent Cr which is less mobile and non-carcinogenic form

19. Contd :
 Phytostabilization :
Plants immobilize the heavy metal present in soil or ground
water and accumulate in the root and precipitate within the
root zone .eg –transgenic Arabidopsis carries a bacterial
gene that transforms mercury into a gaseous state .
 Phytovolatilization :
Plants take up the heavy metal from soil and volatilize them
and ultimately releases to atmosphere via transpiration .

20. Contd :
 Rhizofiltration :
It is a water remediation technique that involves uptake of
contaminants such as heavy metals etc from wetlands and
estuary areas.
 Rhizodegradation :
It is the breakdown of contaminants through the activity of
the existing in the rhizospere .This activity is due to the
enzymes and proteins that are produced by the plants and
the microbes such as yeast , bacteria , etc .it is actually a
symbiotic relationship .

21. Advantages :
 Bioremediation is useful to complete destruction of a wide
variety of contaminants .Many compounds that are
legally considered to be hazardous can to transformed to
non –hazardous forms .
 Instead of transferring contaminants from one medium to
another environmental medium such as soil to water or
such ,the technology helps in treating the contaminants on
site itself.
 It is proved to be less expensive than other technologies .

22. Disadvantages :
Bioremediation is limited only to those
compounds that are biodegradable.
Biological processes are often highly specific .It
mainly depends on the proper bacterial
population and the various factors responsible
for their proliferation
It is time consuming process.

23. Conclusion :
Bioremediation is being successfully used to treat a
wide range of contaminants in a broad range of
environment .Contaminants which require
bioremediation includes crude oil and refined
petroleum products , halogenated solvents ,
pesticides, herbicides etc . By aiding natural
selection and making small adjustments of the local
environment to encourage growth of remediating
microbes the process not only lowers the expenses
but also very environment friendly .

24. References :
 Alexander , Martin (1994 ).Biodegradation and Bioremediation , .New York :
Academic press.
 Sharma P.D , Ecology and Environment , 11th edition,345-373
 Mina U , Kumar P , Life Sciences , Fundamentals and Practice II,5th edition,580-581
 Panda S.K , Talukdar A.D , Phytoremediation Technology , A review

25. Thank you 