Bioremediation - Environment | Environment for UPSC 2024 (Pre & Mains) PDF Download

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BIOREMEDIATION 
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BIOREMEDIATION 
BIOREMEDIATION 
Bioremediation is the general name given to a set 
of practices that enlist plants, microorganisms, 
or their enzymes to degrade contaminants for 
the purpose of restoring ecosystem health. 
In many cases, bioremediation is less expensive 
and more sustainable than other remediation 
alternatives. 
The microorganisms may be indigenous to a 
contaminated area or they may be isolated from 
elsewhere and brought to the contaminated 
site. 
 
 
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BIOREMEDIATION 
BIOREMEDIATION 
Bioremediation is the general name given to a set 
of practices that enlist plants, microorganisms, 
or their enzymes to degrade contaminants for 
the purpose of restoring ecosystem health. 
In many cases, bioremediation is less expensive 
and more sustainable than other remediation 
alternatives. 
The microorganisms may be indigenous to a 
contaminated area or they may be isolated from 
elsewhere and brought to the contaminated 
site. 
 
 
BIOREMEDIATION 
Most bioremediation processes involve oxidation-reduction 
reactions where either an electron acceptor (commonly 
oxygen) is added to stimulate oxidation of a reduced 
pollutant (e.g. hydrocarbons) or an electron donor 
(commonly an organic substrate) is added to reduce 
oxidized pollutants (nitrate, perchlorate, oxidized metals, 
chlorinated solvents, explosives and propellants).  
In both these approaches, additional nutrients, vitamins, 
minerals, and pH buffers may be added to optimize 
conditions for the microorganisms.  
In some cases, specialized microbial cultures are added 
(bioaugmentation) to further enhance biodegradation.  
 
 
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BIOREMEDIATION 
BIOREMEDIATION 
Bioremediation is the general name given to a set 
of practices that enlist plants, microorganisms, 
or their enzymes to degrade contaminants for 
the purpose of restoring ecosystem health. 
In many cases, bioremediation is less expensive 
and more sustainable than other remediation 
alternatives. 
The microorganisms may be indigenous to a 
contaminated area or they may be isolated from 
elsewhere and brought to the contaminated 
site. 
 
 
BIOREMEDIATION 
Most bioremediation processes involve oxidation-reduction 
reactions where either an electron acceptor (commonly 
oxygen) is added to stimulate oxidation of a reduced 
pollutant (e.g. hydrocarbons) or an electron donor 
(commonly an organic substrate) is added to reduce 
oxidized pollutants (nitrate, perchlorate, oxidized metals, 
chlorinated solvents, explosives and propellants).  
In both these approaches, additional nutrients, vitamins, 
minerals, and pH buffers may be added to optimize 
conditions for the microorganisms.  
In some cases, specialized microbial cultures are added 
(bioaugmentation) to further enhance biodegradation.  
 
 
 
IN SITU BIOREMEDIATION 
 
It involves treatment of the contaminated material at the 
site. 
Bioventing 
 Supply of air and nutrients through wells to contaminated 
soil to stimulate the growth of indigenous bacteria.  
It is used for simple hydrocarbons and can be used where 
the contamination is deep under the surface. 
Biosparging 
 Injection of air under pressure below the water table to 
increase groundwater oxygen concentrations and enhance 
the rate of biological degradation of contaminants by 
naturally occurring bacteria 
Bioaugmentation 
 Microorganisms are imported to a contaminated site to 
enhance degradation process. 
 
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BIOREMEDIATION 
BIOREMEDIATION 
Bioremediation is the general name given to a set 
of practices that enlist plants, microorganisms, 
or their enzymes to degrade contaminants for 
the purpose of restoring ecosystem health. 
In many cases, bioremediation is less expensive 
and more sustainable than other remediation 
alternatives. 
The microorganisms may be indigenous to a 
contaminated area or they may be isolated from 
elsewhere and brought to the contaminated 
site. 
 
 
BIOREMEDIATION 
Most bioremediation processes involve oxidation-reduction 
reactions where either an electron acceptor (commonly 
oxygen) is added to stimulate oxidation of a reduced 
pollutant (e.g. hydrocarbons) or an electron donor 
(commonly an organic substrate) is added to reduce 
oxidized pollutants (nitrate, perchlorate, oxidized metals, 
chlorinated solvents, explosives and propellants).  
In both these approaches, additional nutrients, vitamins, 
minerals, and pH buffers may be added to optimize 
conditions for the microorganisms.  
In some cases, specialized microbial cultures are added 
(bioaugmentation) to further enhance biodegradation.  
 
 
 
IN SITU BIOREMEDIATION 
 
It involves treatment of the contaminated material at the 
site. 
Bioventing 
 Supply of air and nutrients through wells to contaminated 
soil to stimulate the growth of indigenous bacteria.  
It is used for simple hydrocarbons and can be used where 
the contamination is deep under the surface. 
Biosparging 
 Injection of air under pressure below the water table to 
increase groundwater oxygen concentrations and enhance 
the rate of biological degradation of contaminants by 
naturally occurring bacteria 
Bioaugmentation 
 Microorganisms are imported to a contaminated site to 
enhance degradation process. 
 
 
EX SITU BIOREMEDIATION 
 
It involves the removal of the contaminated material to be treated 
elsewhere. 
Land farming 
Contaminated soil is excavated and spread over a prepared bed and 
periodically tilled until pollutants are degraded. The goal is to stimulate 
indigenous biodegradative microorganisms and facilitate their aerobic 
degradation of contaminants. 
Biopiles 
It is a hybrid of land farming and composting. Essentially, engineered cells 
are constructed as aerated composted piles. Typically used for treatment 
of surface contamination with petroleum hydrocarbons. 
Bioreactors 
It involves the processing of contaminated solid material (soil, sediment, 
sludge) or water through an engineered containment system. 
Composting 
 Composting is nature’s process of recycling decomposed organic materials 
into a rich soil known as compost.