United States
Environmental Protection
Agency __^^
Risk Reduction
Engineering Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-91/058' May 1992
Project Summary
Pilot-Scale Incineration of
Contaminated Soil from the
Purity Oil Sales and McColl
Superfund Sites
R. H. Vocque and L. R. Waterland
An incineration test program was con-
ducted at the U.S. Environmental Pro-
tection Agency's (EPA) Incineration Re-
search Facility (IRF) to evaluate the po-
tential of incineration as an option to
treat contaminated soils at the Purity Oil
Sales Superfund site in Fresno, CA, and
the McColl Superfund site in Fullertbn,
CA. The soils at these sites are contami-
nated with up to several percent levels of
sulfur and, to a lesser extent, with haz-
ardous organic constituents. In addi-
tion, the Purity soils are contaminated
with lead. The purpose of these tests
was to evaluate theincinerability of these
soils in terms of the destruction of or-
ganic contaminants and, for the Purity
soils, the fate of lead during the incinera-
tion process. Three Purity soils, with
lead concentrations ranging from 760 to
10,200 mg/kg and two McColl site mate-
rials were tested in a pilot-scale rotary
kiln incineration system with a single-
stage ionizing wet scrubber for particu-
late and acid gas control. Incineration
conditions were nominally the same for
all tests with kiln and afterburner tem-
peratures at approximately 871 °C and
982°C, respectively.
Test results suggest that incineration
would be an acceptable treatment op-
tion for the McColl soils. In these tests,
organic contaminant destruction was
effective, particulate emissions were be-
low the federal hazardous waste incin-
erator performance standard, and BOJ
SO3 emissions were low.
Incineration could be considered ap-
plicable to the treatment of the Purity
soils based on effective organic decon-
tamination, acceptable (in meeting fed-
eral standards) particulate emissions,
and low SO/SO, emissions. These test
results, however, suggest that the re-
sulting kiln ash would be a "characteris-
tic" hazardous waste that would require
further treatment to stabilize or remove
teachable lead levels before redeposition
at the site. Furthermore, if a wet scrub-
ber of the type in place for these tests is
usedfor air pollution control, the accept-
ability of lead air emission levels would
need to be evaluated and the scrubber
blowdown could also be a characteristic
hazardous waste for the highly lead-
contaminated soil areas.
This Project Summary was developed
by EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to announce
key findings of the research project that
is fully documented in a separate report
of the same title (see Project Report
ordering information at back).
Introduction
One of the primary missions of the IRF is
to support EPA's Regional offices in evalu-
ating the potential of incineration as a treat-
ment option for wastes resulting from reme-
dial actions taken at Superfund sites. Sev-
eral types of hazardous wastes exist at two
priority sites in Region 9. EPA Region 9
requested test burns at the IRF of five
contaminated soils from these sites to sup-
port evaluations of the suitability of incinera-
tion as a treatment technology for these
wastes.
The Purity site is an abandoned oil- recy-
cling facility. The results of a soil stratigra-
phy investigation of the site indicated that
four contaminated subsurface layers are
present in the waste pit area at the site. The
top layer is primarily composed of construc-
tion rubble, sand, and gravel. The second
Printed on Recycled Paper
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layer, tar sludge, underlies the construction
debris and is mixed, to some extent, with
soil and rubble. The third layer is composed
of contaminated silty sand. The fourth layer
is uncontaminated-to-slightly- contaminated
silty sand. The materials tested in this pro-
gram werefromthefirst(Alayer), second (B
layer), and third (C layer) subsurface layers.
The materials are contaminated to varying
degrees with organiccontaminants and lead.
Concentrations of both are highest in the B
layer.
The McColl site is an abandoned refinery
waste disposal area. The major soil con-
taminants here areprganicconst'rtuents and
sulfur. The soil borings excavated from the
site during the remedial investigation/feasi-
bility study efforts were stored in drums at
the site. The physical characteristics of the
materials do not vary significantly from drum
to drum. Two drums, one containing a high-
sulfur-content material and a second con-
taining a low-sulfur-content material, were
selected for testing in this test program.
The overall objective of the test program
was to determine whether treatment by
incineration would result In a treated soil
residue suitable for redepositing at each
site during full-scale remediation. Specific
technical objectives were as follows:
• to determine the distribution of lead
present in the Purity soils among the
incinerator discharges,
• to determine the concentrations of
semivolatile organic hazardous con-
stituent contaminants in the flue gas
emission and incineration residuals to
verify the suitability of incineration for
treating the materials,
• to evaluate the effectiveness of the
ionizing wet scrubber air pollution con-
trol system (ARCS) for removing lead
(Purity site), SOa and SO3, and
• to demonstrate compliance with the
federal hazardous waste incinerator
performance standards for particulate
emissions.
Thetests were completed during January
and February 1990. An outline of the test
program and test results are given in the
following sections.
Test Program
The test program consisted of five tests,
one each with the three Purity soils and the
two McColl soils. All tests were performed in
the rotary kiln system (RKS) at the IRF with
a single-stage ionizing wet scrubber APCS.
A schematic of the RKS is given in Figure 1,
andthe design characteristics of the system
are given in Table 1.
Soil was shipped to the IRF in 55-gal
drums, 200 kg (440 Ib) of each material was
nominally shipped. Before testing, each
drum of soil was packaged into 1.5-gal
fiberpack containers at the IRF for feeding
to the RKS via the ram feeder system. The
fiberpack drums were nominally filled with
4.1 kg (9 Ib) of test material. During the
tests, the material was fed to the kiln at a
rate of 12 fiberpack drums per hr (1 drum
every 5 min). Thus, test material feedrate
was about 49 kg/hr (108 Ib/hr). All tests
lasted about 4 hr, and each set of incinera-
tor operating conditions was similar. These
conditions are listed in Table 2. The kiln
rotation speed, noted in Table 2, corre-
sponds to a solids residence time in the kiln
of about 1 hr.
Figure 2 identifies the sampling location
for the tests and summarizes the sampling
protocols employed.
Test Results
Throughout the test program, CO levels
at the scrubber exit and the stack were, at
most, af ew parts per million. Total unburned
hydrocarbon levels were similarly low at the
afterburner and scrubber exits and in the
stack. Average NOX concentrations at the
stack ranged from 20 to 38 ppm, levels
typical for the RKS. Average SO2 levels,
measured with the use of a continuous SO2
emission monitor, atthe stack, were <1 ppm
for the Purity site soil tests, and 4 to 7 ppm
for the McColl site sulfur-contaminated soil
tests.
Flue gas particulate levels at the scrub-
ber exit (corrected to 7% O2) ranged from 6
mg/dscmforthe Purity C layer material test
to 126 mg/dscmforthe McColl high-sulfur-
material test. In the stack, after the flue gas
passed through with a secondary APCS
consisting of a carbon bed absorber and a
high-efficiency particulate air (HEPA) filter,
particulate levels ranged from 7 mg/dscrh
for the Purity C layer material test to about
70 mg/dscmfor both the Purity B layer and
McColl high-sulfur-material tests. All levels
fell well below the federal hazardous-waste
incinerator performance standard of 180
mg/dscm.
Table 3 summarizes the ultimate analy-
sis data for the soil samples from each test
drum. Table 3 also shows the carbon con-
tent of the kiln ash resulting from the incin-
eration of each test soil. The data suggest
that incineration was quite effective in de-
stroying the overall organic content (as indi-
cated by total carbon content) of the Purity
site A and C layer soils. The kiln ash result-
ingfrom the incineration of the Purity Slayer
soil and the McColl site soils, however, still
had significant carbon content.
Table 4 summarizes the results of the
semivolatile organic hazardous constituent
analysis for each soil. As shown, of the
semivolatile organic hazardous constituents,
naphthalene was found in four of the five
soils, and bis-(2-ethylhexyl)-phthalate was
found in three of the five. Kiln ash from all
tests contained no detectable semivolatile
constituents at detection limits of 1 to 2 mg/
kg, and the scrubber blowdown contained
no detectable semivolatile constituents at
detection limits of 0.02 to 0.04 mg/L.
Semivolatiles were specifically not detected
in the McColl soil kiln ashes despite their
significant residual carbon content. Evidently
the kiln ash carbon content consisted of
fixed carbon or organic compounds not
classified as semivolatile hazardous con-
stituents. Kiln ash and scrubber blowdown
leachate samples from the toxicity charac-
teristic leaching procedure (TCLP) contained
no detectable semivolatiles at detection lim-
its of 0.02 to 0.04 mg/L.
Scrubber exit and stack flue gas concen-
trations of semivolatile organic constituents
were at less-than-detectable limits of 4to 12
Hg/dscm except bis-(2-ethylhexyl)-phtha-
late. The phthalate concentrations of 8 to 80
(xg/dscm for these tests are ascribed to
commonly encountered laboratory contami-
nation by this compound.
Test results with respect to lead distribu-
tions for the Purity soil are summarized in
Table 5. The table shows lead concentra-
tions measured in each sample of soil feed
analyzed: kiln ash, scrubber blowdown, flue
gas, and the extraction procedure (EP) tox-
icity and TCLP leachate for soil feed, kiln
ash and scrubber blowdown. Table 5 also
shows the corresponding lead feedrates
and residual stream discharge rates for
each test.
As shown in Table 5, lead concentrations
in resulting kiln ash from the incineration
treatment of all soils were all roughly twice
the parent soil concentrations. This results
in part from the volume reduction of the
material during incineration and in part from
mass balances achieved.
The toxicity characteristic (TC) threshold
concentration for lead is 5 mg/L Thus, no
Purity soil would be considered a character-
istic hazardous waste for lead based on the
EP toxicity test, but all three would be con-
sidered so based on the TCLP test. (The EP
toxicity test has been replaced by TCLP).
Despite the fact that the kiln ash resulting
from the incineration treatment of the Purity
soils contained roughly twice the lead con-
centrations of the parent soil, their EP toxic-
ity leachate concentrations : were lower.
TCLP leachate lead concentrations for the
kiln ash of all three soils were significantly
greater than corresponding EP toxicity
leachate concentrations and greater than
the parent soil TCLP leachate concentra-
tionsfortwoofthe three Purity soils. As was
the case with the soils, these tests suggest
that the kiln ash resulting from incineration
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Single-stage Ionizing
Wet Scrubber
Quench
Afterburner
Ail-
Natural
Gas,
Liquid
Feed
Solids
Feeder I
'air)
Burrier
Demister
Venturi
Scrubber
Columr
Scrubber
\Carbon Bed
Adsorber H£PA
Filter
Rotary Kiln
Incinerator
Scrubber Liquor
Recirculation
Modular Primary Air
Pollution Control Devices
Redundant Air
Pollution Control
System
Atmosphere
Stack
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Table 1. Design Characteristics of the IRF Rotary Kiln System
Characteristics of the Kiln Main Chamber
Length
Diameter, outside
Diameter, inside
Chamber volume
Construction
Refractory
Rotation
Solids retention time
Burner
Primary fuel
Feed system:
Liquids
Sludges
Solids
Temperature (max)
2.49 m (8 ft-2 in)
1.37m(4ft-6in)
Nominal 1.00 m (3 ft-3.5 in)
1.90m3 (67.3 fP)
0.95 cm (0.375 in) thick cold-rolled steel
18.7cm (7.375 in) thick high alumina castable refractory, variable depth to produce a frustroconical effect for moving solids
Clockwise or counterclockwise, 0.2 to 1.5 rpm
1 hr (at 0.2 rpm)
North American burner rated at 800 kW (2.7 MMBtu/hr) with liquid feed capability
Natural gas
Positive displacement pump via water-cooled lance
Moynopump via front face, water-cooled lance
Metered twin-auger screw feeder or fiberpack ram feeder
101CPC (185CPF)
Characteristics of the Afterburner Chamber
Length
Diameter, outside
Diameter, inside
Chamber volume
Construction
Refractory
Gas residence time
Burner
Primary fuel
Temperature (max)
3.05m (10 ft)
1£2m(4ft)
0.91m (3 ft)
1.80m3 (63.6 fP)
0.63 cm (0.25 in) thick cold-rolled steel
15.2 cm (6 in) thick high alumina castable refractory
0.8 to 2.5 s depending on temperature and excess air
North American Burner rated at 800 kW (2.7 MMBtu/hr) with liquid feed capability
Natural gas
120CfC (220CPF)
Characteristics of the Ionizing Wet Scrubber APCS
System capacity,
inlet gas glow
Pressure drop
Liquid flow
pH control
SStrf/min (3000 acfm) at 7fl°C (172°F) and 101 kPa (14.7psia)
1.5kPa(6inW.C.)
230 Umin (60 gpm) at 345 kPa (50 psig)
Feedback control by NaOH solution addition
Characteristics of the Venturi/Packed Column Scrubber APCS
System capacity,
Mat gas now
Pressure Drop
Venturi scrubber
Packed column
Liquid flow
Venturi scrubber
Packed column
pH control
•\07rcPMn (3773 acfm) at 120CPC (220CPF) and 101 kPa (14.7 psia)
7.5 kPa (30 in W.C.)
1.0kPa(4inW.C.)
772 L/min (20.4 gpm) at 60 KPa (10 psig)
116 L/min (30.6 gpm) at 69 kPa (10 psig)
Feedback control by NaOH solution addition
kg lead), scrubber blowdown and exit
flue gas concentrations were increased
to 45 mg/L and 24 mg/dscm, respec-
tively. Lead concentrations in the scrub-
ber blowdown, TCLP leachates of
scrubber blowdown, and EP toxic'rty
leachates of the soil feed, kiln ash, and
scrubber blowdown were less than the
TCthreshold, which defines a "charac-
teristic" hazardous waste for the two
low-lead-concentration Purity soils.
Leadconcentrations in TCLP leachates
of the soil feed and kiln ash, however,
exceeded the TC threshold for these
soils.
These test results suggest that incinera-
tion would be an acceptable treatment op-
tion for the McColl site materials. Based on
these results, organic contaminant destruc-
tion is effective, particulate emissions com-
ply with the federal hazardous-waste incin-
erator performance standards, and SO2
emissions are low.
Incineration could be considered appli-
cable to the treatment of the Purity soils
based on effective organic decontamina-
tion acceptable particulate emissions and
low SOZ emissions. These test results do,
however, suggest that the resulting kiln ash
would require further treatment to stabilize
or remove teachable lead levels andthat the
scrubber blowdown from the incineration of
the high-lead-concentration soil could be-
come a characteristically hazardous waste
if an ionizing wet scrubber were used for air
pollution control. Furthermore, the accept-
ability of lead emission levels from
a wet scrubber control device would require
further evaluation.
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Thefull report was submitted in fulfillment
of Contract 68-C9-0038 by Acurex Corpo-
ration under the sponsorship of the U.S.
Environmental Protection Agency.
Kiln
O
After-
burner
i_ ».
Quench
Section
Ionizing
Scrul
jWet
iber
Demister
Carbon
Bed
HEPA
Filter
Sampling
point Waste feed
1 X
2
3
4
5
6
7
Figure 2. Sampling matrix.
Kiln ash
X
Ionizing wet
scrubber
blowdown
Continuous flue
gas monitoring
X
X
X
X
MethodOOlO
(semivolatile
organics)
Method 12
(lead)
Method 5/8
(paniculate
90,30,)
X
X
X
X
X
X
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r
Table 2'. Incinerator System Operating Conditions for Purity Oil Sales and
McColl Site Soil Incineration Tests
Total waste/so// feedrate
Kiln temperature
Kiln exit flue gas Oz
Afterburner
Afterburner exit Hue gas O2
Kiln rotation speed
Scrubber btowdovm fJowrate
Scrubber liquor flowrate
Scrubber pressure drop
49kg/hr(108lb/hr)
871°C (160CPF)
11% to 13%
982°C (1800PF)
9% to 11%
0.2 rpm
1.9L/min(0.5gpm)
150 L/min (40 gpm)
1.5kPa(6inW.C.)
Tablo 3. Ultimate Analysis of the Test Soils and Resulting Kiln Ashes
Soil
Parameter
(wt%)
C
H
o
N
S
Cl
Ash
Total organic carbon
Purity A
layer
(Test 1)
2.14
0.99
527
<0.5
0.58
<0.18
S6.09
1.74
Purity C
layer
(Test2)
1.63
<0.5
2.75
<0.5
0.43
<0.21
86.15
1.61
Purity B
layer
(Tests)
24.83
4.64
17.50
<0.5
2.43
<0.27
58.39
24.83
McColl low
sulfur
(Test 4)
15.64
3.36
17.13
<0.5
3.58
<0.58
57.29
15.60
McColl high
sulfur
(Tests)
19.88
3.65
20.83
<0.5
8.13
<0.28
41.40
19.88
Kiln ash
C
0.19
0.12
3.39
4.18
6.65
Table 4. Semivolatite Organic Hazardous Constituents in Test Soils
Concentration (mg/kg)
Constituent
Naphthalene
Bis(2-ethylhexyl)-phthalate
All other semivolatiles analyzed
Purity A
layer
(Test 1)
ND1
ND
<25
Purity C
layer
(Test2)
35
77
<25
Purity B
layer
(Tests)
90
41
<25
McColl low
sulfur
(Test 4)
96
ND
<25
McColl high
sulfur
(Tests)
340
43
<25
•ND - not detected at detection limits of 25 mg/kg for base-neutrals and 50 mg/kg for acids.
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Table 5. Lead Distributions for the Purity Oil Sales Site Soil Tests
Parameter
Testl
(1/19/90)
Purity A layer
Tests
(1/23/90) •
Purity C layer
Tests
(1/31/90)
Purity B layer
Lead concentration
Soil feed, mg/kg
Kiln ash, mg/kg
Scrubber blowdown, mg/L
Scrubber exit flue gas, mg/dscm
Stack gas, mg/dscm
Lead flowrate, g/hr
Soil feed
Kiln ash
Scrubber exit flue gas
Stack gas
Soil feed leachate
EP toxicity concentration, mg/L
Fraction teachable, %
TCLP concentration, mg/L
Fraction teachable, %
Kiln ash leachate
EP toxicity concentration, mg/L
Fraction teachable, %
TCLP concentration, mg/L
Fraction teachable, %
Scrubber blowdown leachate
EP toxicity concentration, mg/L
TCLP concentration, mg/L
860
1,620
2.8
1.6
1.2
42
61
3.3
2.8
2.1
4.9
5.7
13
<0.07
<0.1
10
12
1.4
1.4
780
1,830
3.2
_ 1-0
0.47
39
64
1.9
1.0
2.6
2.8
18
46
0.23
0.25
15
16
1.2
1.2
10,200
23,800
45
24
21
510
588
46
45
2.6
0.5
21
4.1
0.33
0.03
110
9.2
19
17
Table 6. Lead Discharge Distributions for the Purity Oil Sales Site Soil Tests
Parameter
Testl
Purity A Layer
Test2
Purity C layer
Tests
Purity B layer
Total kiln ash discharge 77
(% of soil weight fed)
Lead distribution (% of
leadfed)
Kiln ash 146
Scrubber liquor 1
Scrubber exit flue gas 8
Total 155
69
163
1
5
169
49
115
2
9
126
•&U.S. GOVERNMENT PRINTING OFFICE: 1992 - £48-080/40252
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R. H. Vocque andL. R. Water/and are with Acurex Corp., Jefferson, AR 72079.
Howard Wall is the EPA Technical Task Manager and R. C. Thurnauis the EPA
Project Officer (see below).
The complete report, entitled "Pilot-Scale Incineration of Contaminated Soil from the
Purity Oil Sales and McColl Superfund Sites," (Order No. PB92-105 857/AS; Cost
$19.00, subject to change) wilt be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Technical Task 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 PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/600/S2-91/058
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