5.1 In Situ Techniques
In the in situ technology, the pollutants are treated at the contaminated site by
simulating the microorganism’s metabolism as well as nutrients and optimized
environmental conditions (Ahmad et al. 2018). The pollutants are effectively treated
on site, thereby avoiding any site excavation or damage to the ecological structure. In
this process, the pollutants undergo microbial decomposition under natural conditions and produce carbon dioxide, water, and other less toxic by-products
(Doolotkeldieva et al. 2018; Abatenh et al. 2017). The method is conducive to
feasible, economical, environmentally friendly, and sustainable to achieve detoxification of contaminated sites. The most common in situ strategies are bioventing,
bioaugmentation, biopiles, biosparging, biostimulation, and natural attenuation.
5.1.1 Bioventing
Bioventing involves the supply of nutrients and air through wells to stimulate the
native bacteria of the contaminated soil. Bioventing provides low oxygen flow
necessary for the biodegradation and accelerates the elimination and degradation
of toxic compounds.
5.1.2 Bioaugmentation
Bioaugmentation is used to biodegrade specific soil and groundwater pollutants. It
involves adding cultured microbial population into the particular subsurface environment to biodegrade the desired pollutants.
5.1.3 Biopiles
Biopiles provide a favorable environmental conditions for endemic aerobic and
anaerobic microbial diversity to remove pollutants by controlling losses of the
pollutants by volatilization and leaching.
5.1.4 Biosparging
Biosparging is the process in which air (oxygen) and nutrients are injected to
increase groundwater oxygen concentrations and biological activity of naturally
occurring microorganisms. This technique accelerates the biodegradation of the
toxic organic compounds.
8 Bioremediation: Efficient Technology to Combat Pesticide Pollutants in. . .
159
In the in situ technology, the pollutants are treated at the contaminated site by
simulating the microorganism’s metabolism as well as nutrients and optimized
environmental conditions (Ahmad et al. 2018). The pollutants are effectively treated
on site, thereby avoiding any site excavation or damage to the ecological structure. In
this process, the pollutants undergo microbial decomposition under natural conditions and produce carbon dioxide, water, and other less toxic by-products
(Doolotkeldieva et al. 2018; Abatenh et al. 2017). The method is conducive to
feasible, economical, environmentally friendly, and sustainable to achieve detoxification of contaminated sites. The most common in situ strategies are bioventing,
bioaugmentation, biopiles, biosparging, biostimulation, and natural attenuation.
5.1.1 Bioventing
Bioventing involves the supply of nutrients and air through wells to stimulate the
native bacteria of the contaminated soil. Bioventing provides low oxygen flow
necessary for the biodegradation and accelerates the elimination and degradation
of toxic compounds.
5.1.2 Bioaugmentation
Bioaugmentation is used to biodegrade specific soil and groundwater pollutants. It
involves adding cultured microbial population into the particular subsurface environment to biodegrade the desired pollutants.
5.1.3 Biopiles
Biopiles provide a favorable environmental conditions for endemic aerobic and
anaerobic microbial diversity to remove pollutants by controlling losses of the
pollutants by volatilization and leaching.
5.1.4 Biosparging
Biosparging is the process in which air (oxygen) and nutrients are injected to
increase groundwater oxygen concentrations and biological activity of naturally
occurring microorganisms. This technique accelerates the biodegradation of the
toxic organic compounds.
8 Bioremediation: Efficient Technology to Combat Pesticide Pollutants in. . .
159