vvEPA
United States
Environmental Protection
Agency
EPA/540/M5-89/004
April 1989
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin
In-Situ Soil Stabilization
International Waste Technologies
TECHNOLOGY DESCRIPTION: In in-situ
stabilization technology immobilizes organics and
inorganic compounds in wet or dry soils by using
reagents (additives) to polymerize with the soils and
sludges producing a cement-like mass. Two basic
components of this technology are the Geo-
Con/DSM Deep Soil Mixing System, a system
capable of delivering and mixing chemicals with the
soil in-situ, and the batch mixing plant that supplies
the proprietary treatment chemicals (Figure 1).
The Geo-Con/DSM Deep Soil Mixing System,
incorporating mechanical mixing and injection,
consists of one set of cutting blades and two sets of
mixing blades attached to a vertical drive auger,
which rotate at approximately 15 rpm. Two conduits
in the auger allow for the injection of the additive
slurry and supplemental water. Additive injection is on
the downstroke, with further mixing occurring upon
auger withdrawal. The treated soil columns, whose
diameter is 36 inches, are positioned to provide an
overlapping pattern. In each sector, alternating
primary and secondary soil columns exist, with all
primary columns prepared before the secondary
columns are augered.
The developer states that their proprietary additive
generates a complex crystalline connective network
of inorganic polymers and that the structural bonding
in the polymer is mainly covalent. Furthermore, in the
process, there is a two-phased reaction in which the
contaminants are complexed first in a fast-acting
reaction and then in a slow-acting reaction where
the building of macromolecules continues over a long
period of time. For each type of waste, the quantity of
additives used varies and must be optimized.
WASTE APPLICABILITY: This technology can be
applied to soils, sediments, and sludge-pond
bottoms contaminated with organic compounds and
metals.
DEMONSTRATION RESULTS: The IWT stabilization
demonstration took place at a PCB-contaminated
site in Hialeah, Florida. The preliminary results of the
SITE demonstration showed that the processes
produced a solidified mass with good physical
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i
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Flow Line
Control Line
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Figure 1. In-situ stabilization batch mixing plant process diagram.
-------
vvEPA
United States
Environmental Protection
Agency
EPA/540/M5-89/004
April 1989
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin
In-Situ Soil Stabilization
International Waste Technologies
TECHNOLOGY DESCRIPTION: In in-situ
stabilization technology immobilizes organics and
inorganic compounds in wet or dry soils by using
reagents (additives) to polymerize with the soils and
sludges producing a cement-like mass. Two basic
components of this technology are the Geo-
Con/DSM Deep Soil Mixing System, a system
capable of delivering and mixing chemicals with the
soil in-situ, and the batch mixing plant that supplies
the proprietary treatment chemicals (Figure 1).
The Geo-Con/DSM Deep Soil Mixing System,
incorporating mechanical mixing and injection,
consists of one set of cutting blades and two sets of
mixing blades attached to a vertical drive auger,
which rotate at approximately 15 rpm. Two conduits
in the auger allow for the injection of the additive
slurry and supplemental water. Additive injection is on
the downstroke, with further mixing occurring upon
auger withdrawal. The treated soil columns, whose
diameter is 36 inches, are positioned to provide an
overlapping pattern. In each sector, alternating
primary and secondary soil columns exist, with all
primary columns prepared before the secondary
columns are augered.
The developer states that their proprietary additive
generates a complex crystalline connective network
of inorganic polymers and that the structural bonding
in the polymer is mainly covalent. Furthermore, in the
process, there is a two-phased reaction in which the
contaminants are complexed first in a fast-acting
reaction and then in a slow-acting reaction where
the building of macromolecules continues over a long
period of time. For each type of waste, the quantity of
additives used varies and must be optimized.
WASTE APPLICABILITY: This technology can be
applied to soils, sediments, and sludge-pond
bottoms contaminated with organic compounds and
metals.
DEMONSTRATION RESULTS: The IWT stabilization
demonstration took place at a PCB-contaminated
site in Hialeah, Florida. The preliminary results of the
SITE demonstration showed that the processes
produced a solidified mass with good physical
A
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ir
ontrolled
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