United States
Environmental Protection
Agency
EPA/540/S5-89/001
March 1989
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Technology Demonstration
Summary
Technology Evaluation Report,
SITE Program Demonstration
Test, HAZCON Solidification,
Douglassville, Pennsylvania
The major objective of the HAZCON
Solidification SITE Program
Demonstration Test was to develop
reliable performance and cost
information. The demonstration
occurred at a 50-acre site of a
former oil reprocessing plant at
Douglassville, PA containing a wide
range of organic and heavy metal
contaminants. The HAZCON process
mixes the hazardous waste material
with cement, a proprietary additive
called Chloranan, and water. The
Chloranan is claimed to neutralize
the inhibiting effect that organics
normally have on the hydration of
cement
The technical criteria used to
develop the effectiveness of the
HAZCON process were contaminant
mobility, based on leaching and
permeability tests; and potential
integrity of solidified soils, based on
measurements of physical and
microstructural properties.
Extensive sampling and analyses
were performed showing (1) the
concentration of the organics were
the same in the TCLP leachates of
the untreated and treated soils, (2)
heavy metals reduction was
achieved, and (3) structural
properties of the solidified cores
were found to indicate good long-
term stability.
This Summary was developed by
EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to
announce key findings of the SITE
Program demonstration that is fully
documented in two separate reports
(see ordering information at back).
Introduction
In response to the Superfund
Amendments and Reauthorization Act of
1986 (SARA), the Environmental
Protection Agency's Offices of Research
and Development (ORD) and Solid Waste
and Emergency Response (OSWER)
have established a formal program to
accelerate the development,
demonstration, and use of new or
innovative technologies as alternatives to
current containment systems for
hazardous wastes. This new program is
called Superfund Innovative technology
Evaluation or SITE.
The major objective of a Demonstration
Test Program is to develop reliable cost
and performance information. One
technology, which was demonstrated at
the Douglassville, PA Superfund Site, is
the HAZCON proprietary solidification
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process. The process involves the mixing
of hazardous waste material and cement
with a patented nontoxic chemical called
Chloranan. The Chloranan is claimed to
neutralize the inhibiting effects that
organic contaminants normally have on
the hydration of cement-based
materials. For this treatment, the wastes
are immobilized and bound by
encapsulation into a hardened, leach-
resistant concrete-like mass.
The Douglassville, PA Superfund Site,
No. 102 on the National Priority List, was
selected as the location for the
Demonstration Test. This is a 50-acre
rural site of an oil recovery facility that
includes: two large lagoons once filled
with oily sludge, an oily filter cake
disposal area, an oil drum storage area,
an area where generated sludge was
landfarmed into the soil and the plant
processing area. More than 250,000 cu
yd of soil is contaminated.
The major objectives of this SITE
Project were to determine the following:
1.Ability of the stabilization/
solidification technology to
immobilize the site contaminants,
which included volatile organics,
base neutral/acid extractables
(BNAs), oil and grease,
polychlorinated biphenyls (PCBs),
and heavy metals.
2. Effectiveness of the technology for
treating soils with contaminant
concentrations varying over the
range 1%-25% by wt. oil and
grease.
3. Performance and reliability of the
process system.
4.Probable long-term stability and
integrity of the solidified soil
5. Costs for commercial-scale appli-
cations
Project documentation will consist of
two reports. This Technology Evaluation
Report describes the field activities and
laboratory results. An Applications
Analysis will follow and provide an
interpretation of the data and conclusions
on the results and potential applicability
of the technology
The following technical criteria were
used to evaluate the effectiveness of the
HAZCON process:
1. Mobility of the contaminants:
a. Leachability of the contaminants
and oil and grease before and
after treatment.
b. Relative permeability of the
treated and untreated soil.
2. Integrity of the solidified soil mass:
a. Physical properties - unconfined
compressive strength, bulk
density, etc.
b Microstructure of the hydrated
matrix.
The above criteria were used to develop
the sampling program.
Procedure
The Demonstration Test utilized
contaminated soil from six plant areas,
referred to as Lagoon North (LAN),
Lagoon South (LAS), Filter Cake Storage
Area (FSA), Drum Storage Area (DSA),
Plant Facility Area (PFA), and Landfarm
Area (LFA). The intent was to process 5
cu yd from each of five areas and then
perform an extended duration run for the
sixth area The purpose of the extended
run was to confirm the reliability of the
operating equipment. The extended run,
which was intended to process
approximately 25 cu yd from FSA, was
performed on LAS feed, due to very
difficult access to FSA and convenience
of access and high contaminants level at
LAS. The runs used less feedstock than
anticipated, and produced approximately
5 cu yd from the short runs and 25 cu yd
from the extended run of treated soil.
The contaminated soil was excavated
and screened to remove aggregate and
debris greater than 3 inches in diameter.
It then was fed to the HAZCON Mobile
Field Blending Unit (MFU) along with
cement, water, and Chloranan. Cement
was used on an approximately 1:1 ratio
with soil, and the soil-to-Chloranan
ratio was 10:1. The four feed
components were blended in a mixing
screw and fed into five 1-cu-yd
wooden molds for the short tests and
three 1-cu-yd molds plus two 12-
cu-yd pits for the LAS run.
While the contaminated soil was
processed and cured, the excavation
holes were enlarged, lined with an
impervious plastic liner, and partially
filled with clean soil. After the 1-cu-yd
blocks cured sufficiently to be moved
(48-96 hours), they were removed from
their molds and placed into the pits. The
blocks then were covered with clean soil.
The blocks were sampled 28 days later
and will be sampled at 6 or 12 month
increments for 5 years, along with the
surrounding clean soil, which is to be
checked for contaminant leaching from
the blocks.
Soil samples were taken in tr
phases before treatment, as a si
exiting the MFU for analysis after 7 c
of curing, and from the buried blc
after 28 days of curing. For the first
runs, two untreated soil compo
samples, three sets of slurry samf
and three solidified cores were taken
the extended run on LAS feed, additi
samples were taken.
Physical property measurerm
performed were:
• bulk density
• moisture content
• permeability
• unconfined compressive strength c
solidified cores
• weathering tests-freeze/thaw
wet/dry
Chemical analyses were perform*
identify the organic and m
contaminants in the soil. In addition,
different leaching tests were run:
• Toxicity Characteristic Leac
Procedures (TCLP)-standard lea<
procedure used for measu
teachability of the contaminants.
• ANS 16.1 - simulates leaching
the intact solidified core with re
flowing groundwater
• MCC-1P - simulates leaching
the intact solidified core in rela
stagnant groundwater regimes.
These latter two tests were drawn
the nuclear industry and modified t
hazardous waste analysis.
In order to obtain informatio
potential long-term integ
microstructural studies were perfc
on the untreated soil and solidified i
Theses analyses included:
• X-ray diffractometry-identi
crystalline structures in the solid
• Microscopy-scanning ele<
microscope and optical rr
scope-characterizing porosity, r
tion products, fractures, anc
presence of unreacted soil/'
material in the treated soil.
Results and Discussion
The following observations were
and summarized in Tables 1 and 2:
• The six plant areas offered a
diversity of feedstock. The o
grease ranged from 1% by wt. £
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Table 1. Physical Properties
Untreated Soil
Location
DSA
LAN
FSA
LFA
PFA
LAS
Bulk Density,
9/ml
1.23
1.40
1.60
1.68
1.73
1 59
Permeability,
cm/sec
0.57
1.8 x 10-3
Impermeable
20 x TO'2
7 7 x 10-2
1 5 X 10-5
Bulk Density,
glm
1.95
1 61
1 51
1 84
2.07
1.70
28-Day Cores
Permeability
cm/sec
1.8 x ro-s
4.0 x 10-9
8.4 x 70-9
45 x 1Q-9
5.0 x 70-'0
2.2 x W-9
UCS, psi
1113
523
219
945
1574
889
Table 2. Chemical Properties
Leachate Concentrations, mg/l
Untreated Soil
28-Day Cores
Location
DSA
LAN
FSA
LFA
PFA
LAS
'VOC -
BNA -
Pb
VOC"
0.92
002
1 03
5.10
1 10
0.06
BNA'
NO
1.02
2.31
0.010
0.010
0.010
Pb'
1 5
31.8
17.9
27.7
22.4
52.6
VOC
0.38
0.06
0.72
037
0.84
0.77
BNA
ND
1.45
2.79
0.10
0.11
073
Pb
0.007
0.005
0.400
0.050
0.011
0.051
Volatile Organic Carbon
Base Neutral/Acid Extractable
Lead
to 25% at FSA. Polychlorinated
biphenyls (PCBs) were detected up to
52 pprn by wt., with the maximum
value detected at LAS. Lead
contamination concentrations ranged
from 03% to 2.3% by wt. at FSA.
Volatiles and base neutral acid
extractables (BNAs - semivolatiles)
organics reached levels in excess of
100 ppm by wt. at FSA.
The volume of the solidified soil was
more than double that of the
undisturbed feedstock Optimization by
HAZCON could reduce this volume
increase, but other physical and
chemical properties may change.
Permeabilities of the treated soil, after
curing for more than 28 days, were
very low, in the range of 1Q-8 to 10~9
cm/sec.
The unconfined compressive strengths
(UCS) of the solidified sods ranged
from about 220 psi for FSA to 1570 psi
for PFA, and the values were inversely
related to the oil and grease level.
The wet/dry and freeze/thaw
weathering tests showed small weight
losses (0.5%-1.5%) at the end of the
12 cycle test for the test specimens
and their controls. Unconfined
compressive strengths, performed
after the final weathering cycle,
showed no loss in strength compared
to the unweathered samples. No other
analyses were performed on the
weathered samples.
The TCLP leaching tests compared
leachate concentrations in the treated
soil with that from untreated soil. Due
to the addition of cement, Chloranan,
and water, the treated soil contaminant
concentration levels, on average, was
40% of the untreated soil
concentrations. The results were as
follows:
-Metals-The leachate from the
solidified soils showed metal levels
at or near the detection limits. The
results for lead, the predominant
metal, were lower by a factor of
about 500, from 20 to 50 mg/l in the
leachates from the untreated soils to
less than 0.1 mg/l in the treated soil
leachates. The other five metals
were at or near the detection limits
for both untreated and treated soils.
-Volatile Orgamcs-The primary
compounds detected were tri-
chloroethene, tetrachloroethene,
toluene, ethyl benzene, and xylenes.
The leachate concentrations of the
contaminants appear to be
approximately the same in both the
untreated and treated soils at levels
of less than one milligram per liter
(mg/l).
- BNAs-The compounds detected in
the leachates were phthalates,
phenols, and naphthalene. The
phthalates were reduced to near their
detection limits of 10 pg/l in both the
treated and untreated soil leachates.
The total phenols in the leachates
reach 3-4 mg/l for FSA where the
feedstock had phenol concentrations
as high as 400 mg/l with similar
concentration levels seen in both the
untreated and treated soil leachates.
The values for naphthalene were less
than 100 u,g/l for both the treated
and untreated soil leachates.
-Oil and Grease-Leachate concen-
trations for treated soils were slightly
greater than for untreated soils in
each case. The values for the
untreated soil were 0.2 to 2.0 mg/l
and for the treated soil 2 to 4 mg/l.
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- PCB analyses of all leachates, both
for untreated and treated soil, were
all below the detection limits of 1.0
jug/I.
The special leaching tests, ANS 16.1
and MCC-1P, which simulate
leaching of the solidified soil cores,
were performed on the treated soil
samples from each plant area except
DSA and LFA. Experience with these
tests on hazardous waste is limited.
Results are compared to the TCLP
results for treated soils, but this may
not be relevant as a performance
measure. The results are as follows-
Metals-For ANS 16.1 the values in
the leachate increased with leaching
time. They were of the same order of
magnitude as for TCLP leachates. The
MCC-1P leachates also increased
with time; for the largest time interval
(28 days) they were greater by a factor
of about 10 than the TCLP leachates.
Volatile Organics-For ANS 161, the
total concentrations of all the volatiles
in the leachates were lower than the
TCLP leachates by a factor of about 2.
For MCC-1P the leachate concen-
trations were approximately the same
as for the TCLP leachates. In both
tests, no discernible trend between
leachate concentration and time
interval was noted.
BNAs-The leachate concentrations
for ANS 16.1 were less than for TCLP
leachates, while the MCC-1P leachate
concentrations were approximately
equal Leachate concentrations for the
dominant components, phenols,
appeared to increase with leaching
time interval for MCC-1P, but no
trends for ANS 16.1 were observed.
Oil and Grease-MCC-1P leachate
concentrations were about the same as
for TCLP and ANS 16.1
PCBs-For both leaching tests, all
leachate concentrations were below
detection limits.
> Microstructural analysis are proven
methods for understanding the
mechanism of structural degradation of
soils, cement, and soil-cement
mixtures. However, there have been
relatively few studies of complex
waste/soil mixtures for stabiliza-
tion/solidification processes. Conse-
quently, in some cases, interpretation
of the observations may be difficult.
The microstructural studies provided
the following information:
- Mixing did not appear to be highly
efficient.
-There were many pores; some
including air bubbles.
-Soil components survived the
solidification/stabilization process
unchanged and appeared in the
cores. The factors that suggest this
were the presence in the cores of
unaltered brownish aggregates, and
observations of x-ray diffraction
peaks, which cannot be identified
with minerals constituents of the soil
and are also present in the core,
suggest that contaminant materials
are being carried through the
solidification process in an unaltered
form. Since the two features being
referred to are apparently major
components of the contaminated
soil, it appears that encapsulation is
a major part of the mechanism of
solidification/stabilization.
• The operations for the first five runs (5
cu yd) required many startups due to
unscheduled shutdowns caused
primarily by plugging in the soil feed
screw.
In addition, the consistency of the
slurry mix was quite variable, running
the gamut from powdery to a very thin
slurry However, physical property
changes due to this variation were not
observed For the extended time run
(25 cu yd) at LAS, operation was more
uniform, with only a few short-term
outages.
• The economic analysis was based on
the 70% on-stream factor and a 300
Ib/min operating capacity observed for
the HAZCON equipment. A cost of
$205/ton was calculated for the Mobile
Field Blending Unit during the
Douglassville, PA demonstration The
process is very intensive in labor and
chemical additives, with these items
amounting to approximately 90% of
the total costs. Substantial cost
reductions are expected with process
and chemical optimization.
Summary
A Demonstration Test on the HAZCON
solidification technology was performed
on a wide range of hazardous waste
feedstocks. Test runs producing 5 cu yd
of treated soil were performed in five
plant areas, and an extended run
producing about 25 cu yds of treated soil
in a sixth area. Many samples were taken
and a wide range of laboratory analyses
were performed to obtain a comparison
of physical properties and contaminant
mobilities before and after soil treatn
Highlights of the results are as follow:
• The volume of the solidified :
compared to the untreated s
increased by approximately 12
HAZCON could reduce the vol
increase by optimizing the quantr
cement and Chloranan, but c
physical and chemical properties
change.
• The unconfined compressive stre
ranged from 220-1570 psi an
inversely related to the oil and gr
concentration.
• Permeabilities of 10~8 to 10'9 en
were obtained which surpass
generally accepted permeabilit
10-7 cm/sec for soil barrier liners.
• The TCLP leach test showed
heavy metals were immobilized
the range of oil and gr<
encountered.
• TCLP leach tests performec
untreated and treated soils sh
equivalent concentrations of vol
organics and BNAs in their resp<
leachates.
• The leachates from MC(
contained greater concentratioi
metals and organics than ANS 16
an equivalent time interval. Ther
no protocols for these test
unsolidified waste and no attemp
made to run the ANS and
procedures on untreated waste.
• PCBs were not detected in
leachates, whether the soil was ti
or untreated.
• The microstructural study o
solidified soil showed the followini
- high porosity
- brownish aggregates passed ti-
the process unaltered
- mixing was not highly efficient
- encapsulation is a major part
mechanism of solidific;
stabilization
• Startup operating difficulties
encountered by HAZCON durir
Demonstration Test.
• A cost of $205/ton was calculai
the Mobile Field Blending Unit
the Douglassville, PA demonstra)
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The EPA Project Manager, Paul de Percin, is with the Risk Reduction
Engineering Laboratory, Cincinnati, OH 45268 (see below).
The complete report consists of two volumes, entitled "Technology Evaluation
Report, SITE Program Demonstration Test, HAZCON Solidification,
Douglassville, Pennsylvania:''
"Volume I" (Order No. PB 89-158 810/AS; Cost: $27.95, subject to
change) discusses the results of the SITE demonstration
"Volume II" (Order No. PB 89-158 828/AS; Cost: $36.95, subject to
change) contains the technical operating data logs, the sampling and
analytical report, and the quality assurance project plan/test plan
Both volumes of this report will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
A related report, entitled "Applications Analysis Report: HAZCON
Solidification," which discusses application and costs, is under development.
The EPA Project Manager can be contacted at:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
BULK RATE
POSTAGE & FEES PI
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EPA/540/S5-89/001
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