84
A.A. Juwarkar et al.
Bioventing
Natural attenuation
In situ bioremediation
Phytoremediation
Biostimulation
Air-sparging
Fig. 5.2 In situ bioremediation technologies
5.2.1.1
Bioventing
Bioventing is the one of the most common in situ treatment technique. This
technology is designed primarily to treat soil contamination by fuels,
nonhalogenated volatile organic compounds (VOCs) and semi-volatile organic
compounds (SVOCs), pesticides, and herbicides. The technology requires presence
of indigenous organisms capable of degrading the contaminants of interest, as well
as nutrients necessary for growth. This is an aerobic process involving air supply for
the biodegradation while minimizing volatilization and release of contaminants to
the atmosphere. Table 5.1 shows several advances in the field of bioventing during
last decade.
5.2.1.2
Biostimulation
Biostimulation is one of the in situ treatment techniques for treatment of subsurface
region by addition of water-based solutions carrying nutrients, electron acceptor, or
other amendments. These technologies are designed primarily to treat soil and
groundwater contamination by fuels, nonhalogeneted VOCs, SVOCs, pesticides,
and herbicides. The technology requires the presence of indigenous organisms
capable of degrading the contaminants of interest. Coupling biostimulation process
with advanced tools and techniques enhances the bioremediation process as shown
in Table 5.1.
5.2.1.3
Air Sparging
Air sparging is an in situ treatment process which usually applies to contaminated
ground water by injecting air below the water table. This technology is designed
primarily to treat groundwater contamination by fuels, nonhalogenated VOCs,
SVOCs, pesticides, organics, and herbicides. The technology requires presence of
indigenous organisms capable of degrading the contaminants of interest, as well as
nutrients necessary for growth and specific contaminant availability. Table 5.1
shows some of the findings in air-sparging field in the last decade.