Bioremediation, phytoremediation, biostimulation

1. Dr.AB Jadhav, SSAC,AC,Pune
Lecture no.32-34
Bio-Remediation
Dr. AB Jadhav
Assistant professor
Soil Science & Agricultural Chemistry
College of Agriculture, Pune

2. Dr.AB Jadhav, SSAC,AC,Pune
Bio-remediation Techniques
• Bioremediation
• Biostimulation
• Phyto-remediation
• Phyto-decontamination
• Phyto-extraction
• Phyto-volatilization
• Phyto-degradation
• Rhizo-degradation
• Composting
• Incineration
• Dilution
• Oxidation
• Land farming
• Precipitation
• Ion exchange
• neutralization

3. Dr.AB Jadhav, SSAC,AC,Pune

4. Dr.AB Jadhav, SSAC,AC,Pune
Suitable species of
microbes with
population
Oxygen Enough to
support aerobic
degradation
Water (50-60%) and
Nutrients (N,P, S)
Temperature (20-400C)
pH 6.5 to 7.5
Essential Factors for Microbial Bioremediation

5. Dr.AB Jadhav, SSAC,AC,Pune
Biodegradation Process for Inorganic Contaminants
The goal of microbial remediation of heavy metal contaminated soils and
sediments are to immobilize the metal in-situ to reduce bioavailability and
mobility or to remove the metal from the soil ….BY
Adsorption of living or dead cell walls
Ion exchange at the cell wall
Extracellular precipitaion
Forming organo-metallic complexes or chelate
Using the metal as an electron accepter during metabolism
Microbes Element Uptake (%)
Zooglea Spp. CO 25
Ni 13
Citrobactor Cd 170
Bacillus Spp. Cu 15
Zn 14
Aspergillus Spp P 10
Hg 54
Source: Rajendran (2003)

6. Dr.AB Jadhav, SSAC,AC,Pune
Bioremediation
• Describes several technologies and processes or
practices that take advantages of natural
systems and processes to clean-up pollution.
• It is a strategy or a process that uses micro-
organisms, plants or plant enzymes to detoxify
the contaminants in soil and other
environments.
• These bioremediation technologies are
considerably less expensive than traditional
cleanup methods and their proper
implementation results in complete
destruction, removal or stabilization of
pollutants
• Detoxification Involves the enzymatic
hydroxylation of relatively insoluble organic
compounds to make them more soluble for
further breakdown
• Organism must have catabolic activity to
degrade the contaminant at a rate to bring
down the concentration
• Target contaminant must be bio-available and
site of process must have conductive conditions
to microbial/plant growth or enzyme activity
Bio-stimulation
• Involves some stimulation of the
numbers and activities of natural
populations, usually bacteria and
fungi, so they can better breakdown
the pollutants into harmless products.
• Bio-stimuation is based on the
assumption that a polluted medium
(Soil/water/Air) already contains
microbes that are capable of
destroying or detoxifying particular
pollutant in that medium.
• Bio-stimulation. The addition of
nutrients to stimulate the growth of
innate oil-degrading microbes to
increase the rate of remediation.
Bio-augmentation: The injection of a
small amount of oil-degrading
microbes into an affected area.

7. Dr.AB Jadhav, SSAC,AC,Pune
Phyto-remediation
• It is defined as "the use of green plants and the associated microorganisms,
along with proper soil amendments and agronomic techniques to either
contain, remove or render toxic environmental contaminants harmless“. The
term is an amalgam of the Greek phyto (plant) and Latin remedium (restoring
balance). Although attractive for its cost, phyto-remediation has not been
demonstrated to redress any significant environmental challenge to the extent
that contaminated space has been reclaimed.
• Phyto-remediation is proposed as a cost-effective plant-based approach
of environmental remediation that takes advantage of the ability of plants to
concentrate elements and compounds from the environment and to detoxify
various compounds. The concentrating effect results from the ability of certain
plants called hyper-accumulators to bio-accumulate chemicals.
• The remediation effect is quite different. Toxic heavy metals cannot be
degraded, but organic pollutants can be and are generally the major targets for
phyto-remediation. Several field trials confirmed the feasibility of using plants
for environmental cleanup.

8. Dr.AB Jadhav, SSAC,AC,Pune
Plant Families Acts as hyper-accumulatores
Element Families
Cadmium Brassicaceae
Cobalt Laminnaceae, Scrophulariceae
copper Laminnaceae, Poaceae, Cuperaceae
manganese Apocynaceae, cunoiaceae
Nickel Brassicaceae, Euphorbiaceae

9. Dr.AB Jadhav, SSAC,AC,Pune
Advantages
– the cost of the phyto-
remediation is lower than
that of traditional
processes both in situ and ex
situ
– the possibility of the
recovery and re-use of
valuable metals (by
companies specializing in
"phyto-mining")
– it preserves the topsoil,
maintaining the fertility of
the soil Increase soil health,
yield, and plant
phytochemicals
– the use of plants also
reduces erosion and metal
leaching in the soil.
Limitations
• Phytoremediation is limited to the surface area
and depth occupied by the roots.
• with plant-based systems of remediation, it is
not possible to completely prevent the leaching
of contaminants into the groundwater (without
the complete removal of the contaminated
ground, which in itself does not resolve the
problem of contamination)
• the survival of the plants is affected by the
toxicity of the contaminated land and the
general condition of the soil
• bio-accumulation of contaminants, especially
metals, into the plants can effect consumer
products like food and cosmetics, and requires
the safe disposal of the affected plant material
• when taking up heavy metals, sometimes the
metal is bound to the soil organic matter, which
makes it unavailable for the plant to extract[
Phyto-remediation

10. Dr.AB Jadhav, SSAC,AC,Pune
4] Rhizo-degradation [Rhizosphere degradation]-
Plant roots, their associated microflora and /or external products destroy the
contaminant in the root zone
3] Phyto-degradation- Plants take up the contaminants and metabolize it to
an environmentally safe material
1] Phyto-extraction- Absorption of the contaminant in to the plant tissue and
subsequent harvesting for destruction
2] Phyto-volatilization- Plants or their associated microbial activity helps to
increase the rate of volatilization of a contaminenet from the contaminated soils
Phyto-decontamination- It is a subject of phytoremediation in which the
concentration of contaminants of concerned in the soil is reduced to an
acceptable level through the action of plants, their associated micro flora and
agronomic soil techniques

11. Dr.AB Jadhav, SSAC,AC,Pune
Incineration
• Incineration is a waste treatment process that involves the combustion of
substances contained in waste materials. Industrial plants for waste
incineration are commonly referred to as waste-to-energy facilities.
• Incineration of waste materials converts the waste into ash, flue gas and
heat. The ash is mostly formed by the inorganic constituents of the waste
and may take the form of solid lumps or particulates carried by the flue gas.
The flue gases must be cleaned of gaseous and particulate pollutants before
they are dispersed into the atmosphere. In some cases, the heat that is
generated by incineration can be used to generate electric power.
• Incineration with energy recovery is one of several waste-to-
energy technologies such as gasification, pyrolysis and anaerobic digestion.
• Incinerators reduce the solid mass of the original waste by 80%–85%

12. Dr.AB Jadhav, SSAC,AC,Pune
Dilution
• Disposal by Dilution:
• In this method, the raw sewage or
the treated sewage (or the effluent
from treatment plants) is
discharged into natural water
bodies such as streams or rivers,
lakes, sea, etc., having large
quantity of water.
• n this process, the raw sewage or
the partially treated sewage is
thrown into natural waters having
large volume. The sewage in due
course of time is purified by what
is known as the self-purification
capacity of natural waters.
Oxidation
• Wet oxidation
• also known as wet air
oxidation, refers to a
process of oxidizing
suspended or dissolved
material in liquid phase
with dissolved oxygen at
elevated temperature. It is
a method for treatment of
waste streams that are too
dilute to incinerate and too
concentrated for biological
treatment.

13. Dr.AB Jadhav, SSAC,AC,Pune

14. Dr.AB Jadhav, SSAC,AC,Pune
Source: Google

15. Dr.AB Jadhav, SSAC,AC,Pune
Ex-situ Bioremediation Techniques:
These techniques involve excavating pollutants from polluted sites and subsequently
transporting them to another site for treatment.
Example:
Ex-situ bioremediation techniques are usually considered based on
: the cost of treatment and depth of pollution
Biopile:
Biopile mediated bioremediation involves above-ground piling of excavated polluted
soil, followed by nutrient amendment and sometimes aeration to enhance
bioremediation by basically increasing microbial activities.

16. Dr.AB Jadhav, SSAC,AC,Pune
The periodic operations like during ex-siru bioremediation…...
 Turning of polluted soil,
 Together with addition of water bring about increase in aeration,
 Uniform distribution of pollutants, nutrients and microbial degradative activities.
Windrows:
As one of ex situ bioremediation techniques, windrows rely on periodic turning of piled
polluted soil to enhance bioremediation by increasing degradation activities of
indigenous and/or transient hydrocarbonoclastic bacteria present in polluted soil.
Bioreactor:
As the name implies, is a vessel in which raw materials are converted to specific product(s)
following series of biological reactions.
Batch Type
Fed-batch
Sequencing
batch
Continuous
and multistage
Bioreactor Types

17. Dr.AB Jadhav, SSAC,AC,Pune
Sequencing Batch Reactor Process

18. Dr.AB Jadhav, SSAC,AC,Pune
Bioreactor for solid and liquid waste

19. Dr.AB Jadhav, SSAC,AC,Pune
Enhanced in situ bioremediation
Bioventing
This technique involves controlled stimulation of airflow by delivering oxygen to
unsaturated zone in order to increase bioremediation, by increasing activities of
indigenous microbes.
In bioventing, amendments are made by adding nutrients and moisture to enhance
bioremediation with the ultimate goal being to achieve microbial transformation of
pollutants to a harmless state.
Biosparging
This technique is very similar to bioventing in that air is injected into soil subsurface
to stimulate microbial activities in order to promote pollutant removal from polluted
sites.
Composting:
In this organic waste material is composted either by aerobic or anaerobic
with effective microbial culture. This compost can be used to enhance the
fertility status of soil.

20. Dr.AB Jadhav, SSAC,AC,Pune
Land farming-
It is an ex-situ waste treatment process that is performed in the upper soil zone
or in bio-treatment cells. Contaminated soils, sediments, or sludge's are
transported to the land farming site, mixed into the soil surface and periodically
turned over (tilled) to aerate the mixture. Land farming commonly uses
a clay or composite liner to intercept leaching contaminants and
prevent groundwater pollution, however, a liner is not a universal requirement.

21. Dr.AB Jadhav, SSAC,AC,Pune
Thank you
Save natural Resources