EPA/600/A-92/188
Removal of Creosote from Soil by
Bioslurry Reactors
by
Richard P.Lauch and Jonathan G. Herrmann
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
William R. Mahaffey and Alan B. Jones
ECOVA Corporation
Redmond, Washington 98052
Majid Dosani and Judy Hessling
International Technology Corporation
Cincinnati, Ohio 45246
Presented at the AIChE
Spring National Meeting
New Orleans, Louisiana
March 29 - April 2, 1992
Risk Reduction Engineering Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
-------
Removal of Creosote from Soil by
Bioslurry Reactors
by
Richard P.Lauch and Jonathan G. Herrmann
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
William R. Mahaffey and Alan B. Jones
ECOVA Corporation
Redmond, Washington 98052
Majid Dosani and Judy Hessling
International Technology Corporation
Cincinnati, Ohio 45246
ABSTRACT
Biological slurry reactors were tested for removal of polynuclear
aromatic hydrocarbons (PAHs) from creosote contaminated soil. Five bioslurry
reactors, operated in parallel, kept the soil aerated, partially suspended and
well mixed. The reactors were inoculated with indigenous microbes of the
Genus Pseudomonas. Nutrients were added to maintain the optimum ratio of
carbon, nitrogen, and phosphorus. Temperature within the reactors was
approximately 25°C. The slurry consisted of approximately 30% contaminated
soil.
Results of pilot studies showed that approximately 90% of the total PAHs
were removed in the first two weeks. Total PAH concentration in the soil was
reduced from approximately 10973 mg/kg to 1097 mg/kg. Two and three ring
PAHs, such as naphthalene, fluorene, and phenanthrene were approximately 96%
removed in the first two weeks and higher ring compounds such as chrysene,
benzo-a-pyrene, and benzo(b) fluoranthene were approximately 83% removed in
the first two weeks,
1
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INTRODUCTION
This study was performed for the U.S. EPA to supply information as part
of the data base on Best Demonstrated Available Technologies (BOAT) for soil
remediation. The data base will be used to develop soil standards for Land
Disposal Restrictions (LDRs). IT Environmental Programs (ITEP) and ECOVA
Corporation, in conjunction with the U.S. EPA's Risk Reduction Engineering
Laboratory (RREL), evaluated the performance of pilot-scale bioslurry
treatment on creosote contaminated soil. ECOVA performed testing, monitoring,
and analysis at the U.S. EPA Test and Evaluation (T&E) facility in Cincinnati,
Ohio. IT Analytical Services (ITAS) performed analyses for the critical
parameters that will be used in the development of the LDRs.
Biodegradation involves the oxidation of organic compounds by
microorganisms. The ultimate goal of biodegradation is to convert organic
wastes into biomass and relatively harmless byproducts of microbial metabolism
such as carbon dioxide (C02), methane (CH4), water, and inorganic salts.
Several biodegradation technologies are available for the remediation of soils
and sludges contaminated with organic compounds. These technologies include
composting, in situ biodegradation, solid-phase treatment, and slurry-phase
treatment. In slurry-phase bioremediation (bioslurry), contaminated soil is
excavated and treated in a bioreactor in which the soil is mixed with water to
form a slurry. If necessary, nutrients, microorganisms, and surfactants are
added to the slurry to enhance the biodegradation process. The pretreatment
soil was analyzed for the Contaminated Soil and Debris (CS&D) List of
Contaminants. The organic contaminants that were found were identified as the
critical contaminants of interest for this study. These contaminants are
listed in Table 1. The contaminants are all aromatic compounds. The
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volatlles are single ring compounds. The semivolatiles are two to six ring
compounds and they are listed in order of increasing rings and increasing
molecular weight.
This paper is a summary of the full Onsite Engineering Report (OER)1
that completely describes the operation, sampling, analyses, and results of
the pilot-scale study.
PILOT SCALE TREATMENT SYSTEM & PROCEDURES
Reactors--
Five EIMCO Biolift™ Reactors each with 64 liters capacity, were used
for this study (Figure 1), These reactors are made of stainless steel
and equipped with agitation, aeration, and temperature controls. Agitation is
provided by three mechanical methods. First, a rake mechanism moves the
settled material from the bottom of the reactor to the second agitation
mechanism, an airlift circulation system that circulates the material to the
top of the reactor. The third agitation mechanism is a low-sheer impeller
located on the central shaft of the reactor. Aeration is supplied by a set of
air diffusers that are attached to the rake arm shaft near the bottom of the
reactor. Temperature is controlled by a heat tape system with a digital
readout.
The EIMCO Biolift™ Reactor can be sampled in two ways. An opening at
the front top of the reactor allows access at the top surface of the liquid.
This permits visual inspection of the mechanical actions within the reactor as
well as data collection with hand-held instruments that can be inserted into
the slurry from the top. Samples are collected from the three sampling ports
located along the side of the reactor at three vertical penetrations through
the reactor wall. Samples collected from each of the three ports represent
-------
three distinct zones of the slurry. The bottom sampling port provides sample
material from within the rake mixing zone where the heaviest particles are
likely to be present. The middle sampling port provides sample material from
within the most well-mixed zone of optimal grain size. Finally, the top
sampling port provides sample material from the finest mixing distribution.
Samples of the contaminated material, collected by means of these three ports,
are crucial in the evaluation of the mechanical efficiency of the reactor.
Samp!ing--
The five bioslurry reactors were operated in parallel and composite
samples were collected from each reactor at approximately the same time for
pre- and post treatment analysis and throughout the study to monitor system
operation. Sampling volumes, taken from each port, were proportioned so the
composited sample contained 30% solids which was representative of the total
slurry. Composite sampling ensured that analyses were performed with a
representative sample of the entire slurry column. These composite samples
were centrifuged to separate the liquid and solid layers and both layers were
analyzed for PAHs. Some analyses (e.g., particle size distribution, plate
counts) were performed on samples collected from individual ports to determine
potential differences among the three slurry zones.
All parameters in this study were monitored in accordance with the
sampling schedule presented in Table 2. Week T0 corresponds to May 8, 1991,
and Week T12 corresponds to July 31, 1991. The values in Table 2 refer to the
volumes of slurry, soil, or water taken for each analysis at each point in
time.
Air sampling was also conducted to characterize the off-gases emitted
from the bioreactors during the operations and to determine organic
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constituent loss through volatilization. These samples were collected for
information only and were not used to evaluate the technology's performance.
All five reactors were vented through stainless steel piping into a manifold
system before carbon filtration and eventual exhausting to the outside air.
The air monitoring was conducted at a point prior to the collection manifold
to obtain emissions from two individual reactors.
Two sampling trains were constructed to collect samples of volatile and
semivolatile organics. Volatile organics were collected in a SUMHA passivated
canister, and semivolatiles were collected in XAD-2 resin tubes. The XAD-2
resin tubes and canisters were installed in the venting systems for the tested
reactors. The XAD-2 resin tubes were analyzed for semivolatile organic
compounds, and the SUMMA passivated canisters were analyzed for volatile
organic compounds.
Soil Particle Size--
A major factor of concern from the initiation of the pilot-scale phase
was the particle size of the slurried soil. It was important to decrease the
settling velocity of the soil by increasing the viscosity so as to maintain a
manageable slurry suspension that could be recirculated within the bioreactors
Also, bioavailability of the soil-bound PAH residues as a function of the path
length from the particle surface to the innermost recesses was crucial for
maintaining a timely and efficient biodegradation rate. The soil was
therefore wet-milled by passing it through a ball mill three times before
using it to charge the reactors. Particle-sizing samples were taken before
and after milling and at Week T8. These samples were analyzed in accordance
with ASTM 0422-62. The resulting comminution of the soil particles is shown
in Figure 2. As a percentage of the total solids, soil directly from the site
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(premilled) had a diameter that was approximately 32% greater then 0.3 mm.
After milling (postmilling), the fraction of this soil particle size greater
than 0,3 mm was about 8%. Examination of the particle size data (Figure Z)
for Week T8 soil reveals a further phenomenon that must have occurred within
the reactors themselves. The percentage of the soil with smaller "particle"
size at Week T8 appears to be greater than that for the pre- or postmilled
soil. This indicates a further comminution of the soil particles to a greater
fraction of smaller particles within the reactors over time. Comminution
increases the viscosity of the slurry and as the number of particles
increases, the path length that the PAHs within the soil particles must
diffuse to the surface decreases (hence, the mass transfer limitations
decrease). This creates greater surface area to which bacteria can attach and
adsorb PAHs for metabolism, and probably increases the extraction efficiency
of soil-bound PAHs.
RESULTS OF BENCH-SCALE TESTS
Bench-scale tests were performed to determine optimum conditions for the
pilot-scale studies. One objective was to determine which combination of
nutrients, inoculum, and surfactant would yield the best biodegradation
results. These results are shown in Figures 3 and 4. These Figures show that
nutrients plus inoculum gave results that were slightly better than nutrients
alone and just as good as nutrients, inoculum, and Tween™ (surfactant).
Therefore, nutrients plus inoculum were used for the pilot-scale tests.
Surfactant was not added because it did not enhance degradation and it would
cause additional foaming within the reactors.
A microbial evaluation of the contaminated soil was conducted.to
determine the size and diversity of bacterial populations and the ability of
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these organisms to degrade polycyclic aromatic hydrocarbons. Enrichment
culture techniques and selective plating procedures were used to isolate and
characterize PAH degrading organisms. Seventeen distinct isolates were
identified as having the ability to degrade PAHs. The most prevalent species
identified were Pseudomonas fluorescens and Pseudomonas stutzeri. Three of
the isolates were chosen for use in an inoculum on the basis of their broad
substrate oxidation range: Alcallgenes sp. (CFL-1), P. stutzeri (CPH-1), and
PA fluorescens (CP-3). The pilot scale reactors were inoculated with these
PAH degrading organisms at a concentration of 9.3 x 107 per gram of soil.
Inorganic nutrient data were collected (table below) to determine whether,
based upon TOC, the levels and ratio of N and P were sufficient to support
optimal microbial activity.
Baseline Inorganic Chemical Analyses
Analysis
Calcium
Magnesium
Potassium
Sodium
Ammonia (NH,-N)
Nitrate (NO,-N)
Ortho-Phosphorous (P04-N)
Total Kjeldahl Nitrogen
Total Orqanic Carbon
Reel
43.3
8.33
2.72
5.28
37.5
0.559*
0.559*
874.
34000.
icates
44.1
8.40
3.15
5.12
36.1
0.565*
0.565*
882.
37000.
Means
43.7
8.37
5.90
5.20
36.8
n/a
n/a
878.
35000.
* Detectable but below the limit of quantitation
The pilot scale reactors were supplemented initially with ammonia-nitrogen and
phosphorus at a TOC:N:P ratio of 100:10:1.
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RESULTS OF PILOT SCALE TESTS
Soil Sampling--
Table 3 summarizes the results of the baseline (Week T0) characteri-
zation of the soil used in the pilot-scale phase of this study. Fluoranthene,
naphthalene, and acenaphthene are the constituents present at the highest
concentrations followed by fluorene and benzo(a)anthracene. Total PAH
concentration in these soils averaged 10973 mg/kg. The 2- and 3-ring PAHs
constitute 5892 mg/kg of the total, and the 4-ring and higher PAHs account for
5081 mg/kg.
Total PAH degradation averaged 93.4 ± 3.2 percent over all five
operating reactors during the 12-week study (Tables 4 and 5). After only 2
weeks of slurry-phase treatment, total PAH degradation averaged 89.3 ± 3.9
percent for the five reactors. Average degradation rates (mg/kg/wk) for 2-
and 3-ring PAHs were appreciably higher at two weeks (95.9 ± 1.8%) than they
were for 4 and higher ring PAHs (81.6 ± 3.9%). The more rapid degradation of
the lower molecular-weight PAHs reflects the preference of the bacterial
populations for these PAHs over the higher molecular-weight PAHs. The final
concentrations at week T12 averaged 653.5 ± 178.9 mg/kg for total PAHs, 152.1
± 81.9 m/1 for 2- and 3-ring PAHs, and 501.4 ± 103.5 mg/kg for 4- and higher
ring PAHs.
As shown in Figures 5, 6, and 7, the degradation of the different PAHs
varied appreciably during the course of the study, reflecting changes in the
reactor environments. Figure 5 shows that a very large amount of the total
PAH was degraded after only 2 weeks; however, the apparent level of soil-bound
PAH residues began to rise slightly for some reactors through Week T6, to
decrease through Week T9 to rise again through Week T11? and finally, to
8
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decrease through Week T12.. It is important to note that these data
necessarily reflect not only the nominal concentrations of soil-bound PAHs,
but also the extraction efficiency of the analytical method. Apparent
increases in the levels of soil-bound PAHs probably reflect an increased PAH
extraction efficiency rather than the unlikely production of soil-bound PAHs
during the study.
A comparison of Figures 6 and 7 shows almost complete degradation of the
2- and 3-ring PAHs, whereas, degradation of 4- through 6-ring PAHs was less
complete. Also, there was less variation between reactors for concentrations
of 2- and 3-ring PAHs (Figure 6) and more variation between reactors for
concentrations of 4- to 6-ring PAHs (Figure 7).
Immediately after sampling at Week T9, Reactors 2 and 4 were
reinoculated with fresh bacterial populations, and Reactors 5 and 6 were both
reinoculated and amended with the surfactant Tween 80. Reactor 1 was not
amended in any way. At Week T11$ levels of total PAHs in unamended Reactor 1
and Reactors 2 and 4 increased dramatically; whereas total levels in
reinoculated and surfactant-amended Reactors 5 and 6 essentially did not
change (Figures 5, 6, and 7). By Week T12 the total levels in Reactors 1, 2,
and 4 had again declined, but total levels in Reactors 5 and 6 increased.
Anomalies in the PAH degradation rates occurred in reactor 4 for 4 and
higher ring PAHs at Weeks T, and T6 (Figure 7). For these times, the total
PAH level was appreciably higher than for the other reactors. Among the
individual PAHs, levels of acenaphthene were clearly higher than
those of other 2- and 3-ring PAHs at Weeks T4 and T,, (Figure 8). The anomaly
may be related to widely varying levels of acenaphthene among the five
reactors which was observed from the standard deviation data for acenaphthene.
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A final anomaly was the surge in both the mean levels and standard deviations
for the 4 and higher ring PAHs at Week T1 (Figure 9). This was not exhibited
by the 2- and 3-ring PAHs for that time point.
These anomalies are indicative of several problems and events. Clearly,
further comminution of the soil particles accounted for a portion of the rise
in soil-bound PAH residues by reducing the resistance to mass transfer. This,
in turn, allowed a higher extraction efficiency in the analytical method and,
therefore, higher apparent concentrations. Although acenaphthene is an
identifiable compound in an analytical method, it is difficult to quantitate
accurately. It has the lowest molar extinction coefficient of all the PAHs in
ECOVA's analytical method and is therefore the PAH most subject to errors in
quantitation. After Week T2, PAH residue levels were low enough that a small
error in the area assessed for acenaphthene could have an enormous effect on
the total levels of PAH residues.
Air Sampling--
Air sampling for semivolatile, volatile, and total organics was
conducted during the first 9 weeks of treatment. Total hydrocarbon (THC) was
determined as methane. This sampling was conducted continuously at the main
exhaust line for the first 5 days of operation. Figure 10 is a graph of the
THC data during the 5 days of continuous monitor operation. The THC data
compare well with the other organic data, showing high emissions the first 2
days of process operation, followed by a steady decline and close to baseline
recordings by the fifth day of operation.
Semivolatile organic emissions were sampled on Reactors 1 and 2 for the
first 4 days of operation. The main exhaust line was sampled for the
remainder of the operation. Table 6 lists the results of semivolatile organic
10
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emissions that were detected during the study. Semivolatile organic emissions
(naphthalene, 2-methylnaphthalene, acenaphthylene, acenaphthene, dibenzofuran,
fluorene, phenanthrene, and anthracene) were detectable during the first 4
days of sampling. Beginning the fifth day of operation, very small quantities
(at or below detection) of semivolatilies were found. Note that the semi-
volatiles were all lower molecular weight 2-and-3 ring compounds. These lower
ring compounds were more readily diffused into solution and volatilized. The
highest concentrations was for naphthalene. These lower ring compounds are
easily degraded and Table 6 shows that insignificant concentrations of
napthhalene remained after the second day. All of the semivolatiles were
below the detection limit after 6 days of operation.
Volatile organic sampling was conducted simultaneously with semi-
volatile organic sampling on Reactors 1 and 2 for the first 4 days of
operation. The main exhaust line was sampled for the remainder of the
program. Table 7 lists the volatile organic concentrations. The table shows
that relatively low concentrations of volatiles (mostly benzene, toluene,
ethyl benzene, xylenes, and styrene) were detected during the first few days of
operation and then dropped off to concentrations that were near or below the
detection limits. This is expected because the volatiles are all lower
molecule weight single ring compounds that are very easy to degrade.
Very low to zero concentrations of volatiles were detected in the
pretreatment soil and the reason they were detected in the off-gas is probably
because they were products of degradation of the higher ring compounds.
11
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CONCLUSIONS
Bench tests were performed first to determine the optimum conditions for
the pilot scale tests. Results of the bench tests showed that inoculum plus
nutrients should be added for the pilot tests. Surfactant addition did not
enhance degradation and it would cause additional foaming. During the bench
tests isolates of Pseudomonas (£.. fluorescens, £.. stutzeri and Alcaligenes
sp.) were distinguished as having the best ability to degrade creosote and
high concentrations of these indigenous organisms were inoculated into the
pilot reactors. During the bench test a TOC:N:P ratio of 100:10:1 was
determined. Other minerals,including potassium, magnesium, calcium and iron
were added to the pilot reactors.
After two weeks of pilot test treatment, total PAH degradation averaged
89.3%. Degradation of 2- and 3-ring PAHs averaged 95.9% and degradation of 4-
and higher-ring PAHs averaged 81.6%. After two weeks of pilot operation,
total 2- and 3-ring PAHs were reduced from an average concentration of 5892
mg/kg to 227 mg/kg and total 4- and higher-ring PAHs were reduced from an
average concentration of 5081 mg/kg to 870 mg/kg.
There was considerable variation between reactors for individual and
total PAH concentrations. This variation was higher for higher ring
compounds.
Some PAH concentrations (especially for higher ring compounds) appeared
to increase from one week to the following week. This is probably do to
.increased extraction efficiency with time because of additional soil comminu-
tion and the longer time required for the heavier higher ring compounds to be
worked out of the soil. Very low concentrations of PAHs were detected in the
water phase because the organisms are able to degrade PAHs very quickly in
12
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this phase.
During the air sampling, low concentrations of volatiles (toluene,
benzene, xylene) and low concentrations of lower 2-and 3- ring semivolatiles
(napthalene, fluorene, phenanthrene) were detected for the first few days of
operation. All of these contaminants diminished to concentrations that were
below the detection limit after 5 days of operation. The lower molecular
weight volatile compounds were probably products of degradation of the higher
molecular weight compounds because the pretreatment data showed that most of
the volatiles were below the detection limit.
ACKNOWLEDGMENT
The authors acknowledge Mr. Michael Smith from IT Corp., Mr. Ernie
Grossman, Mr. Leo Fichter, and Mr. Charles Euth all from the U.S. EPA, and Ms,
Madonna Brinkmann and Mr. Christopher Krauskopf from ECOVA Corp. for their
technical contributions to the project.
DISCLAIMER
This paper has been reviewed in accordance with the U.S. Environmental
Progection Agency's peer and administrative review policies and approved for
presentation and publication. Mention of trade names or commerical products
does not constitute endorsement or recommendation for use.
REFERENCES
1. IT Environmental Programs, Inc., Onsite Engineering Report of the
Slurry-Phase Biological Reactor for Pilot-Scale Testing on Contaminated
Soil. Volumes I and II. EPA Contract No. 68-C9-0036, WA No. 69, U.S.
EPA Cincinnati, Ohio, In Preparation.
13
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ROTARY VAlVf
RAKE DRIVE SHAFT
SUPPORT
SUPPORT BEARWQS
IttPELLER DRIVE
G£AflnOTO«
A«IFT A« SUPPLY
8.0CK VAUVE
WATER PLUSH
CONNECTION
ARLFT CHECK VALVE
DfUN VALVf $
SHAFT
Figure l, EIMCO BIOLIFT1" REACTOR,
14
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D)
CD
JD
CD
Q
O
CD
CL
Gravel
Fine
Sand
Coarse
Medium
Fine
Fines
Silt
1
0
10 1 0.1 0.01
Figure 2. GRAIN DIAMETER (millimeters)
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BOAT BENCH-SCAUE DATA
2-3 Ring Pdycycilc Aromatic Hydrocarbons
Stern*
NuUienl
Nutrfenl/Inoculum
Nu!n«nt/Tween
* Nut/ient/Tnoculum/Tween
Figure 3.
BOAT BENCH-SCALE DATA
4-6 Ring PolycycJic Aromatic Hydrocarbons
c.
NuUient/Twe*n
~* Nui/Ient/lnocufum/Tween
Figure 4.
16
-------
16000
PPM 8000
TOTAL PAHs [Solid Phase]
Reactor #1
Reactor *2
Reactor
Reactor #5
Reactor #6
Figure 5. Total PAH soil residue levels.
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2 & 3 RING PAHs
[Solid Phase]
Reactor »2 » Reactor »4 O Reactor *5 * Reactor «6
Figure 6. Two- to three-ring individual mean PAH levels.
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4-6 RING PAHs
[Solid phase]
12000 T
10000 --
8000 -•
PAH
ppm
6000
4000 •-
2000 -
6
WEEK
8
10
12
Reactor #1
Reactor #2 • Reactor #4 o Reactor #5
Reactor #6
Figure 7. Four- to six-ring PAH soil residue levels.
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2 & 3-RING PAHs (SoiWs, all 5 reactors)
2500 T
2000
1500 -
ro
O
PPM
1000
500
o O
•NAPHTHALENE
PHENAMTMRCNE
6
WEEK
8
ACEMAPHTHCNC
• ANTHRACENE
10
12
Figure 8. Two- to three-ring individual mean PAH levels.
-------
4-TO 6-RING PAHs (Solids, all 5 reactors)
2500
2000 f
1500 --
PPM
1000
500
-a
-*
-A
fLUOftANTHENE
PYHENE
BENZCX*>ANTHAACENE
CHRYSENE
BENZOmFLOURANTHENE
BENZO(K)FLUORANT>4ENC
• OlBENZOu.h)ANTHRACCNE
WOENCX U.>CO)PVBENE
Figure 9. Four- to six-ring individual mean PAH levels
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r\>
rv>
400
350
300
I 250
200
o
I
150
100
50
n
May 7.91 May 8.91 May 9.91 May 10. 91 May 11. 91 May 12. 91 May 13. 91 May 14. 91 Mav 15.91
Time
Figure 10. THC emission data.
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Table 1. Critical Contaminants of Interest
Semivolatile Organics Volatile Orqarn'cs
Naphthalene 2-Butanone
Acenaphthylene Benzene
Acenaphthene Toluene
Fluorene Ethyl benzene
Phenanthrene Styrene
Anthracene Total Xylenes
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a) pyrene
Dibenzo(a,h)anthracene
Ideno(l,2,3-cd)pyrene
23
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TABLE 2. REACTOR MONITORING SCHEDULE
Sample Volume Per Reactor,
Slurry-Phase Pilot Test
Analyst
S*mivo!ati!e organic* (mL)
PAH/HPLC-Wat*r/SoiI (ml)
O&G/TPH (mL)
TOC (mL)
Nutri*nts (ml)
Ammonia (mil)
Total htterotrophs (ml)
PAH degradert (ml)
Microtox (mL)
TS (mL)
TSS & TVSS (mL)
Dissolved oxygen
Temperature
PH
Total volume (ml)
IT vol. p«r we»k (mL)
Ecova vol. per w«*k (mL)
Eoova (T&E facility) (mL)
Total volume (L)
Sample % solids
Slurry wt. removed (mL)
Soil wl removed (g)
Slurry % solids remaining
0
2000
60
100
100
40
10
10
10
20
60
250
DR*
OR
CR
2860
2160
250
250
64
30
296
228
29.73
1
60
10
60
OR
DR
CR
130
70
60
64
30
51
39
29.88
2
60
100
100
40
10
10
10
20
60
150
CR
DR
DR
S80
100
250
210
64
30
218
168
29.48
3
60
100
10
60
70
CR
OR
OR
300
100
70
130
64
30
78
60
29.41
4
60
100
100
40
10
10
10
20
60
100
OR
CR
DR
510
100
250
160
64
30
199
153
29.22
5
DR
OR
DR
0
64
30
0
0
29.22
Week
6
60
100
100
40
10
20
20
60
100
CR
OR
DR
510
100
250
160
64
30
199
153
29.04
• 7
CR
OR
.OR
0
64
30
0
0
29.04
8
CR
OR
OR
0
64
30
0
0
29.04
9
2000
60
100
100
40
10
10
10
20
60
100
OR
DR
DR
2510
2100
250
160
64
30
199
153
28.85
10
60
100
100
40
10
10
10
20
60
100
OR
DR
CR
510
100
250
160
64
30
199
153
28.67
11
240
100
10
60
100
.CR
Cfl
DR
510
100
250
160
64
30
199
153
28.49
12
2000
60
100
100
40
10
10
10
20
60
100
OR
CR
DR
2510
2100
250
160
64
30.0
199
153
28.30
aOR • Measured using « direct-reading instrument.
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TABLE 3. BASELINE SOIL PAH CONCENTRATIONS
AVERAGE OF 5 REACTORS (WEEK T0)
PAH
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
TOTAL 2-& 3-ring PAHs
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a,)pyrene
DiBenzo (a, h) anthracene
Indeno(l,2,3-cd)pyrene
TOTAL 4-6 ring PAHs
TOTAL PAHs
MEAN (5)
rag/kg
2143.3
17.4
1937.1
967.8
518.9
307.0
5891.5
2428.7
161.1
957.2
468.1
389.4
279.6
260.2
119.9
17.2
5081.4
10972.9
Std. Dev.
mg/kg
710
7.6
1016.8
288.4
12.1
34.7
732.6
51.2
284.8
129.6
112.7
83.1
75.4
94.1
4.8
25
-------
TABLE 4. TOTAL, 2-3 RING AND 4-6 RING PAH LEVELS (SOLID PHASES)
BOAT Pilot-Seal* Polyaromatic Hydrocarbon Levels
Weak
0
1
2
3
4
6
9
10
11
12
2-3 RinaPAHs
Reactor 1
Reactor 2
Reactor 4
Reactor 5
Reactor 6
Reactor 1
Reactor 2
Reactor 4
Reactors
Reactor 6
Reactor 1
Reactor 2
Reactor 4
Reactor 5
Reactor 6
4380.59
6158.29
6699.04
3758.81
8460.94
3526.33
5696.53
6603.17
3360.94
6220.41
7906.62
11854.8
13302.21
7119.75
14681.4
64.26
970.17
2904.45
683.53
948.59
2273.11
3754.18
11827.2
2397.9
3259.33
3015.94
4724.35
14731.62
3081.43
4207.92
312.25
160.72
189.59
168.53
'304.9
1043.28
942.26
840.23
644.33
877.3
1355.53
1102.98
1029.82
812.86
1182.2
37.55
55.66
41.48
85.05
144.92
4
445.29
480.62
409.88
559.17
1035.39
482.84
536.28
451.36
644.22
1180.31
682.82
247.76
150.26
359.75
241.23
- 6 Ring
1734.92
1278.03
645.52
1318.67
1035.92
Tola!
2417.74
1525.79
795.78
1678.42
1277.15
31.66
212.93
333.88
69.2
51.62
PAH»
417.93
1132.16
1830.56
1178.01
402.25
PAHs
449.59
1345.09
2164.44
1247.21
453.87
63.09
116.37
124.09
85.04
183.71
238.82
463.94
449.57
549.64
274.42
301.91
580.31
573.66
634.68
458.13
56.66
72.96
307.52
317.95
66.04
470.94
552.36
503.68
449.14
498.19
527.6
625.32
811.2
767.09
564.23
600.95
492.38
551.41
80.12
42.44
524.9
503.44
481
654.13
715.29
1125.85
995.82
1032.41
734.2S
757.73
78.42
95.29
104.97
249.72
232.32
488.13
432.39
375.2
593.56
617.6
566.55
527.68
480.17
843.28
849.92
-------
TABLE 5. TOTAL, 2-3 RING AND 4-6 RING PAH DEGRADATION RATES (SOLID PHASES)
BOAT Pilot-Scale
Reactor 1
Reactor 2
Reactor 4
Reactor 5
Reactor 6
Reactor 1
Reactor 2
Reactor 4
Reactor 5
Reactor 6
1
98.53
84.25
56.64
81.82
88.79
4
35.54
34.10
-79.11
28.65
47,60
2
92.
97.
97.
95.
96,
- 6
2-3
87
39
17
52
40
Ring
70.41
83.46
87.28
80,83
85.90
Polyaromatic Hydrocarbon Levels
3
4
Week
6
Ring PAH Degradation Rate
99.14
99.10
99.38
97.74
98.29
84.41
95.98
97,76
90.43
97.15
99.28
96.54
95,02
98.16
99,39
9
10
11
12
, % Degradation
98.S6
98.11
98.15
97.74
97.83
98.71
98.82
95.41
91.54
99.22
86.
92.
91.
97.
99.
28
00
77
87
50
98.21
98.45
98.43
93.36
97.25
^KAH Degradation Rale, % Degradation
87.37
91.56
93.79
83.36
83.35
Total PAH
Reactor 1
Reactor 2
Reactor 4
Reactor 5
Reactor 6
81.86
60.15
•10.75
66.72
71.34
82
90
92
68
91
.86
.70
.26
.58
.95
93.89
95.48
96.61
90.95
91.96
50.80
77.56
90.22
60.76
83.35
Degradation
69.42
87.13
94.02
76.43
91.30
88.15
80.13
72.28
64.95
93.53
Rate. %
S4.31
88.65
83.73
82.48
96,91
93.23
91.86
93.19
83.65
95.59
Degradation
96.18
95.10
95.69
91.09
96.88
86.65
90.30
92.37
86.64
91.99
93.33
94.73
93.90
89.23
96.16
91
92
80
88
85
91
92
89
94
.11
.16
.72
.54
.50
.60
,24
,69
.84
86.16
92.41
94.32
82.34
90.07
.
92.83
95.55
96.39
88.16
94.21
-------
TABLE 6. SEMIVOLATILE ORGANIC EMISSIONS DATA
(pig/sample)
Compound
Naphth*l«n*
2-m*thy!naphth«1«n*
Ac*naphthyl*n*
Ac*n»phth«n«
Dib*nzofuran
Fluor»n«
Phananthr*n«
Anthr«c«n«
SAMPLE NO. - DAY
XA01-1
6650
1500
78
330
170
120
31
8
XAD2-1
8600
1559
70
390
180
110
33
7
XAD1-2
h '98
200
55
360
160
110
41
8
XA02-2
247
376
69
420
160
120
54
10
XA01-3
10
10
35
390
140
140
41
8
XA02-3
20
10
64
500
200
170
69
13
XA02-4
9
. 10
62
703
230
220
69
23
XA01-5
10
10
10
15
10
10
10
10
XA02-5
10
10
10
15
10
2
10
10
XA01-6
10
10
10
^ 10
10
10
10
10
XAO2-6
10
10
10
13
10
10
10
10
r\>
CO
-------
TABLE 7. VOLATILE ORGANIC EMISSIONS DATA (ppb)
SAMPLE NO.
Compound
Benzene
Toluene
Ethyl benzene
m- and/or p-Xyl
o-Xylene
Styrene
1-1
55
240
150
ene 720
300
44
2-1
45
230
160
800
320
81
1-2
1.5
3.2
2.2
12.0
7.7
1.8
2-2
2.
4.
3.
17.
14.
3.
3
6
4
0
0
6
- DAY
1-3
1.8
5.6
0.86
0.32
1.4
2-3
2.4
8.0
1.5
7.3
3.5
0.85
1-4
1.2
3.2
0.91
3.0
1.4
0.45
1-5
0.79
2.6
0.63
1.9
0.7
0.42
2-5
0.82
2.2
0.5
1.4
0.53
DL
0.4
0.4
0.4
0.4
0.4
0.4
DL = Detection Limit
29
-------
TECHNICAL REPORT DATA
(Pleat read Instructions on the reverse before comptt
1. REPORT NO.
EPA/600/A-92/188
2.
4. TITLE AND SUBTITLE
Removal of Creosote from Soil by Bioslurry Reactors
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R. P. Lauch, J. G. Herrmann, W. R. Mahaffey,
A. B. Jones, M. Dossani, and J. Hessling
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
IT Environmental Programs, Inc.
Cincinnati, OH 45246
ECOVA Corporation
Redmond, Washington 98052
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-C9-0036
12. SPONSORING AGENCY NAME AND ADDRESS
Risk Reduction Engineering Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13. TYPE OF REPORT AND PERIOD COVERED
Published Paper_,
14. SPONSORING AGENCY CODE
EPA/600/14
15.SUPPLEMENTARY NOTES
Project Officer = Richard P. Lauch (513) 569-7237
Presented at AICHE Spring National Meeting, New Orleans, LA, 3/29-4/2/92
16. ABSTRACT
• Biological slurry reactors were tested for removal of polynuclear aromatic
hydrocarbons (PAHs) from creosote contaminated soil. Five bioslurry reactors,
operated in parallel, kept the soil aerated, partially suspended and well mixed.
The reactors were inoculated with indigenous microbes of the Genus Pseudomonas.
Nutrients were added to maintain the optimum ratio of carbon, nitrogen, and
phosphorus. Temperature within the reactors was approximately 25°C. The slurry
consisted of approximately 30% contaminated soil.
Results of pilot studies showed that approximately 90% of the total PAHs were
removed in the first two weeks. Total PAH concentration in the soil was reduced
from approximately 10973 mg/kg to 1097 mg/kg. Two and three ring PAHs, such as
naphthalene, fluorene, and phenanthrene were approximately 96Z removed in the first
two weeks and higher ring compounds such as chrysene, benzo-a-pyrene, and benzo(b)
fluoranthene were approximately 83% removed in the first two weeks.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Croup
Soils, contaminants, aromatic polycyclic
hydrocarbons, treatment, biological,
degradation
Soil remediation,
bioslurry reactors,
creosote contamination,
polynuclear aromatic
hydrocarbons
B. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (This Rtport)
Unclassified . ,.
21. NO. OF PAGES
20. SECURITY CLASS (This pSfel
Unclassified
.21
22. PRICE
EPA Form 2220-1 (R«v. 4-77) PREVIOUS EDITIC
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