monoaromatic compounds and linear alkanes (above 180
C), torrefaction (in the
case of high carbon content), pyrolysis or aerobic cracking (beyond 205
C), and
pyrolysis and sintering with temperatures above 500
C (Fig. 3.1) (Hiester et al.
2013).
The main advantages and disadvantages of ISTT compared to other pollution
clean-up approaches are described below (Baker et al. 2004, 2016; Colombano et al.
2010; Falta et al. 2005a, b; Kawala and Atamanczuk 1998; Kingston et al. 2014;
McGuire et al. 2006; Smith and Hinchee 1993; Unified Facilities Criteria 2006;
U.S. Army Corps of Engineers 2014).
• Advantages
– Shorter remediation times (a few months)
– Broad applicability (to both volatile and semi-volatile pollutants)
– Largely tested and implemented in situ at full scale
– Some techniques are less sensitive to geological heterogeneity of treated sites
(i.e., TCH, ERH, and RFH)
– Very high treatment yields (in some cases above 99%)
– Reduced discharges from pollution sources
• Disadvantages
– Potentially high installation and operating costs (due to high energy consumption in particular); therefore, often limited to removal of most concentrated
pollution sources.
– Difficult to implement in residential and commercial areas (warrants specific
safety procedures).
– Requires advanced engineering skills to design, operate, and maintain.
– In case of faulty design or implementation, pollutants may migrate to
unpolluted soil.
– Requires consideration of impact on the surrounding area:
Physical impact on soil: Perturbation of soil mechanical properties; appearance of shrinkage cracks in wet and fine soils; and soil settlement, which
can affect the stability of any super- or infrastructures on or near the
treated zone.
Impact on water table: Elevation of the water table temperature and changes in
the prevailing physical, chemical, and biological conditions; degradation of
organic matter during heating may release nonvolatile, adsorbed pollutants
and increase their solubility and bioavailability after treatment.
Direct impact on infrastructure, networks, and buried pipes.
Ecological and microbiological impact: Destruction or disturbance of microorganisms and soil organisms in and around treated zones; possible damage
to vegetation in the treated zones.
– Possible detrimental effect on treatment yields due to medium heterogeneity,
presence of organic matter, and nonvolatile and almost insoluble pollutants.
– Lengthy posttreatment duration (months to years).
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S. Colombano et al.
C), torrefaction (in the
case of high carbon content), pyrolysis or aerobic cracking (beyond 205
C), and
pyrolysis and sintering with temperatures above 500
C (Fig. 3.1) (Hiester et al.
2013).
The main advantages and disadvantages of ISTT compared to other pollution
clean-up approaches are described below (Baker et al. 2004, 2016; Colombano et al.
2010; Falta et al. 2005a, b; Kawala and Atamanczuk 1998; Kingston et al. 2014;
McGuire et al. 2006; Smith and Hinchee 1993; Unified Facilities Criteria 2006;
U.S. Army Corps of Engineers 2014).
• Advantages
– Shorter remediation times (a few months)
– Broad applicability (to both volatile and semi-volatile pollutants)
– Largely tested and implemented in situ at full scale
– Some techniques are less sensitive to geological heterogeneity of treated sites
(i.e., TCH, ERH, and RFH)
– Very high treatment yields (in some cases above 99%)
– Reduced discharges from pollution sources
• Disadvantages
– Potentially high installation and operating costs (due to high energy consumption in particular); therefore, often limited to removal of most concentrated
pollution sources.
– Difficult to implement in residential and commercial areas (warrants specific
safety procedures).
– Requires advanced engineering skills to design, operate, and maintain.
– In case of faulty design or implementation, pollutants may migrate to
unpolluted soil.
– Requires consideration of impact on the surrounding area:
Physical impact on soil: Perturbation of soil mechanical properties; appearance of shrinkage cracks in wet and fine soils; and soil settlement, which
can affect the stability of any super- or infrastructures on or near the
treated zone.
Impact on water table: Elevation of the water table temperature and changes in
the prevailing physical, chemical, and biological conditions; degradation of
organic matter during heating may release nonvolatile, adsorbed pollutants
and increase their solubility and bioavailability after treatment.
Direct impact on infrastructure, networks, and buried pipes.
Ecological and microbiological impact: Destruction or disturbance of microorganisms and soil organisms in and around treated zones; possible damage
to vegetation in the treated zones.
– Possible detrimental effect on treatment yields due to medium heterogeneity,
presence of organic matter, and nonvolatile and almost insoluble pollutants.
– Lengthy posttreatment duration (months to years).
152
S. Colombano et al.