SEPA
United States
Environmental Protection
Agency
EPA/540/M5-89/005
August 1989
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin
Solidification/Stabilization Process
Soliditech, Inc.
TECHNOLOGY DESCRIPTION: The Soliditech
solidification/stabilization technology mixes hazardous
waste materials in soils or sludges with pozzolanic
material (cement, fly ash, or kiln dust), a proprietary
additive called Urrichem, other proprietary additives,
and water. The process is designed to aid in the
physical and chemical immobilization of the hazardous
waste constituents by binding them in a leach-
resistant matrix.
After the contaminated waste material is collected and
screened to remove oversized material, it is
introduced to a batch mixer. Each waste material is
mixed with proprietary chemical reagents and
additives, water, and cement. Figure 1 is a schematic
of the process.
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C
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Once thoroughly mixed, the treated waste is
discharged from the mixer and allowed to harden. The
treated waste is a solidified mass with significant
unconfined compressive strength, high stability, and a
rigid texture similar to concrete. Batch mixers of
various capacities are available to treat different
volumes of waste.
WASTE APPLICABILITY: This technology is intended
for the treatment of soils and sludges contaminated
with organic compounds, metals, inorganic
compounds, and oil and grease.
DEMONSTRATION RESULTS: The Soliditech
process was demonstrated December 5-8, 1988, at
the Imperial Oil Company/Champion Chemicals
Superfund site in Morganville, New Jersey. In the
past, this location contained both chemical processing
and oil reclamation facilities.
Physical test results of the solidified waste samples
were very good. Unconfined compressive strengths
ranged from 390 to 860 psi. Wet/dry and freeze/thaw
durability test results were excellent, showing no or
very little weight loss after 12 cycles. Permeability of
the treated waste was very low.
TCLP extraction tests indicated reduced leaching of all
metals except those contributed by the cement or
other additives (aluminum, calcium, chromium, and
sodium). No volatile organic compounds were
detected in the TCLP leachates of the treated wastes.
Several semivolatile organic compounds (phenols)
were detected in the treated wastes that were either
not present or present at lower concentrations in the
untreated waste. The presence of these compounds
has not been explained but may be due to a chemical
reaction. Oil and grease was found to leach from the
treated waste at the same or at slightly higher
concentrations than from the untreated waste. Raw

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waste contained from 2,000 to 50,000 times more oil
and grease than leachates from the treated waste.
Key findings from the Soliditech demonstration are
summarized below.
•	Chemical analyses of TCLP, EP, BET, and ANS
16.1 leachates showed that heavy metals
present in the untreated waste were immobilized
by treatment.
•	The process solidified solid and liquid wastes
with high organic content (up to 17%) containing
oil and grease.
•	Volatile organic compounds were not detected in
the treated waste and were assumed to be lost
during waste collection, screening, and
treatment.
•	Excellent physical properties were measured in
the treated waste including low permeability, high
unconfined compressive strength, and resistance
to weathering.
•	Semivolatile organic compounds (phenols) were
detected in the treated waste and the TCLP
leachate from the treated waste; but not in the
untreated waste or its TCLP leachate.
•	Oil and grease content of the untreated waste
ranged from 2.8 to 17.3 percent. Oil and grease
content of the solidified waste ranged from 4.6 to
7.7 percent. Oil and grease content of the TCLP
leachate of both the untreated and treated
wastes was in the 1.4 to 12 ppm range.
•	The solidified wastes increased in volume an
average of 22 percent. The bulk density of the
waste material increased by approximately 35
percent due to solidification.
•	The pH of the solidified waste ranged from 11.7
to 12.0. The pH of the untreated waste ranged
from 3.4 to 7.9.
•	PCBs were not detected in any TCLP leachates,
whether the waste was treated or not.
•	Visual observation of the broken pieces of the
solidified waste showed the presence of dark
inclusions approximately 1 mm in diameter,
which may be untreated waste. Microstructural
studies are ongoing.
A technology Evaluation Report and an Applications
Analysis Report describing the complete
demonstration will be available in the Winter of
1989/1990.
FOR FURTHER INFORMATION:
EPA Project Manager:
Walter E. Grube, Jr.
U.S. EPA
Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
513-569-7798 (FTS: 684-7798)
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
United States-	Center for Environmental Research
Environmental Protection	Information
Agency	Cincinnati OH 45268
EPA/540/M5-89/005

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