This document discusses bioremediation, which uses microorganisms to degrade environmental contaminants into less toxic forms. It describes various methods of bioremediation including bioaugmentation, biostimulation, and intrinsic bioremediation. Bioaugmentation involves adding microbes that can degrade specific contaminants, biostimulation provides nutrients to promote existing microbial growth, and intrinsic bioremediation relies on natural microbial activity. The document also outlines the types of microbes used in bioremediation such as bacteria, fungi, algae, and plants. It concludes that bioremediation is an effective technique for reducing environmental toxicity and discusses using algae to treat wastewater and metal-hyperaccumulating plants for ph
3. Introduction
Bioremediation is simulation of microorganism to
degrade contaminants present either in soil or
water to environmentally safe components.
Microbes as well as plants are capable to reduce
environmental toxicities without human
interventions.
Advantages
Cost effective
Environmental friendly
Can be carried out on site of contamination itself
Traditional methods for remediation
High temperature incineration
Chemical decomposition
Disadvantages
Technological complexity
High cost maintenance
May increase the exposure to contaminant,
for both workers and near by residents
4. Bio-stimulation Bioaugmentation Intrinsic Bioremediation
• In this method bacteria are
motivated to start the
process of bioremediation
• With the contaminants
nutrient are supplied
which can promote the
growth of microbiota.
• As result bacteria and
other microorganisms
remove the contaminants
efficiently
• Microorganisms that can
clean up a particular
contaminant are added to
contaminated soil and water.
• Ex. Waste water treatment.
• Process takes place in soil
and water which are
contaminated.
• Microorganisms are used
to remove harmful
substance from soil and
water
• Ex underground petroleum
tank.
Methods for Bioremediation
5. Bioremediation
Microorganism
Bacteria
Fungi
(Mycoremediation)
Algae
(Phycoremediation)
Plants
(Phytoremediation)
Phytoextraction
Phytovolatilization
Phyto-stabiliization
Rhizo-degradation
Rhizofiltration
Fungi like Candida tropcalis, Aspergillus niger involved in chlorobenzoate
class herbicides
Plant root uptake metal contaminants and translocated in plants. Example:
Hypperacummlators. Ex. Alyssum sp.
Bacteria like Aerobic (Pesudonomas, Alcaligenes), Methanotrophs
(Methanococcus) etc.
Algal biomass can effectively reduce organic waste from wastewater. It is
also capable to in reducing heavy metal toxicity. Ex. Chlorella sp.
Scenedesmus sp.
Plant uptake water soluble contaminants and release them into atmosphere.
Ex. Arabidopsis thaliana, Astragalus sp. ,Cicer sp., Achillea sp.
Phytochemical complexation root zone. Example Al tolerant plants
Aluminium complexation
Plant excrete organic compound that increases rhizospheric microflora which
results in remediation. Ex genetically engineered rhizobium
Plant hydroponically
grown
In situ transferred to
wastewater
Transferred to
contaminated areas
Harvested when roots
become saturated and
replaced thereafter
6. Outcomes of Biodegradation
A minor change in an organic molecule leaving the main structure intact
Fragmentation
Complete mineralization
Ex:
2,6-Dichlorobenzonitrile
Dehalogenation
Beneze-1,3,5-triol
and
Methyl amine
H2O, 2Cl and NH3
7. Approaches for
Bioremediation
In-Situ Ex-Situ
• Allows treatments of a
large volume soil at once
• It involves methods of
supplying oxygen or
electron donor to
organism that degrade
the contaminants
• Ex. Bioventing, injection
of H2O2 or O2 releasing
compounds for aerobic
treatment
• Involving excavation of
contaminated soil and
treating in a treatment
plant located on the site
• Ex. Composting, Land
Farming
8. Static beds
• Heaps of soil that
can be
intermittently
irrigated , aerated
and mixed
Moving bed system
• It consists of
rotating cylindrical
and horizontal
screw that are
continuously
aerated and mixed
and intermittently
irrigated
Slurry bioreactors
• Contaminated soil
is present in the
form of slurry
subjected to
aeration and
agitation
Types of bioreactor
10. Conclusion
Contaminants in soil and water are hazardous to organism and disbalances the ecosystem.
Bioremediation is a proven technique by which reduction in toxicity can occur
Use of microbes for remediation such as :
1) Cultivation of algae in wastewater can prove to be beneficial as its biomass can be useful as in
biofuel production .
2) Use of Plant which can hyperaccumulate heavy metals can also be beneficial for revegetation
of in the areas of heavy metal polluted soil with a good public acceptance