BIOREMEDIATION
Dr. Veena Maheshwari
● SOURCES OF CONTAMINATION
● NATURE OF POLLUTANTS
● PARAMETERS INFLUENCING
BIOREMEDIATION
● BIOMAGNIFICATION
INTRODUCTION ● BINDING OF CONTAMINANT TO
SOIL
● BIOSORPTION
● DEGRADATION OF XENOBIOTICS
● POLLUTANTS DIFFICULT TO
DEGRADE
BIOREMEDIATION OF SYNTHETIC COMPOUNDS
1. Xenophobic referred as synthetic
2. Sources
● Direct use
● During production
● , spillage and disposal
● Wood treatment
● Combustion of polyaromatic hydrocarbons
3. Persistent in environment due to long half life
4. Persistent depend on environmental factors
5. Complexity in structure make it difficult to degrade
6. The level of recalcitrance depends on number of halogen
7. Mixture of isomers ate difficult to degrade
Examples of xenobiotic compounds
● Economical and sensitive method
to remediate pollutants
BIOREMEDIATIO ● Strategies for bioremediation in
soil and water:
N STRATEGIES ● Fungi, bacteria algae and plants
are useful in bioremediation.
● Soil and marine microorganisms
have great potential in
degradation of HC
Factors affecting bioremediation using indigenous microorganisms
● Factors that affect growth and metabolism
● Due to compound itself
● Structure of organic compound
● Toxicity of compound
● Type of Halogenated compound
● Availability of degradation
● Miscibility of compound
1. Stimulation of indigenous microbial growth
● Factors affecting growth and metabolism also influences degradation
● Requirement of other substrate
● Presence of other biodegradable material and inorganic compounds, heavy
metals and salts
● Environmental parameters
● Number and type of microorganisms
● Organisms needs to get acclimatise
● Aerobic metabolism and cometabolism are used for degradation
2. Bioaugmentation
● Addition of selected organisms to contaminated sites
● Specific nutrient that can be used by augmenting organism can only use
● It is less feasible as
● Limiting population of microorganisms
● Insufficient concentration of contaminant
● Presence of inhibitory substances in environment
● Utilization of other substrate
● Unreachable to contaminant
● Bioaugmentation in activated soil is more successful
● Bacteria and fungi participate in bioremediation
3. Stimulation of indigenous microbial growth
Reversible and irreversible binding of pollutant with
soil: example : TAT binds irreversible with soil and
humic acid.
Need of surfactants for immiscible pollutant
Soil washing for removal of sparingly soluble
compound
Removal of oil using liquid CO2
Bioremediation in situ
Remediation on site
1. Bioremediation on land:
Depends on
● Area contaminated
● Properties of compounds
● Concentration
● Time
Technique:Pump and treat
2. Land farming:
● Involves mixing of soil
● Useful for increasing oxygen level
● Nutrient addition enhances biodegradation
● 4-6 months for degradation
● Suitable for surface soil
3. Bioventing
● It combines an increased
supply of oxygen with
vapour extraction
● Vapours are finally treated
biologically ex:Use of
biofilters
4. Biosparging:
● Increased supply of pure oxygen
● Useful to treat heavily
contaminated site
● Used in bioremediation of
volatile compound
● Fate of degradation depends on
various parameters
Bioremediation: Ex situ
Excavation of pollutant from site and offsite treatment
Techniques of ex-situ bioremediation
1. Composting:
● Method of solid phase treatment.
● Piles or heaps of straw/bark/wood chips mixed with contaminated soil are
prepared.
● Process of operation: like normal composting
2. Biopiles:
● Soil is heaped into piles
● Covering with polyethylene
● Nutrient application on
surface
● Biofilters can be used to
restrict vapour limitation
Bioreactor:
● Rotating drum contactor
● Fluidised bed reactor
● Anaerobic sludge blankets
● Activated sludge process
augmented with special mixed
culture
Bioreactor
Bioremediation ex situ:Novel technology
Bioremediation ex situ:Novel technology
