"EPA Forum on Innovative Hazardous Waste Technologies",
Dallas, Texas, 11-13 June 1991 5401 991 7
Enhanced Composting for Cold-Climate Biodegradation of
Organic Contamination in Soil
by
James D. Berg1, Ph.D. and Trine Eggen2, M.Sc.
1. Aquateam - Norwegian Water Technology Centre A/S
P.O. Box 6326 Etterstad, 0604 Oslo 6, Norway
2. Terrateam - Norwegian Environmental Technology Centre A/S
P.O. Box 344, 8601 Mo i Rana, Norway
ABSTRACT
Bioremediation of soils contaminated with hazardous wastes is becoming a preferred
technology because of its simplicity, lack of residuals requiring special handling, and
relatively low cost when compared with traditional alternatives. Bioremediation was
evaluated as an alternative for a coke works site in northern Norway near the Arctic circle,
which was characterized in 1989 as having significant contamination by polycyclic aromatic
hydrocarbons (PAH). About 20,000 tons of soil containing PAH's (ca. 500 mg/kg) were
excavated. Groundwater at the site contained ca. 2-3 mg/1 and 0.4-1.6 mg/1 naphthalene and
benzol. A pilot study was conducted in 1990, in which 1,000 m3 of soil were treated in an
enhanced composting system. Composting was chosen over landfarming or slurry reactors
because of: low capital and operating costs, on-site capability (low ^a requirement), minimal
developmental requirements, capability for cold-climate, year-round operation.
The variables tested were: N & P, bark matrix and dispersant addition, temperature (4°-16°C),
moisture (10-35 %), and aeration by blowers, HjOj addition or pile turning. Composite soil
samples from five sampling points from each pile were takenctwice weekly for PAH analyses
(GC-MS) and soil moisture. Soil gas CO2 and O2, temperature, pH, and odor were measured
onsite twice weekly. The treatment objective was £ 10 mg/kg Total PAH. Results showed
that the PAH-content was reduced to below the objective within 8 weeks at 12-16°C. The
"lag phase" for biodegradation was ca. 1 week under optimal conditions versus 8 weeks for
unamended compost piles. Thereafter, degradation kinetics were biphasic with approximately
90 % PAH removal within 4 weeks under optimal conditions. Treatment efficiency ranged
from 96-99 % dependent on test variables. Optimal results were obtained by 1) addition of
tree bark as a matrix, 2) supplemental forced aeration, 3) soil moisture maintained at 25-30
% for this soil type, 4) N additives, and 5) dispersant additives. Provision for pile warming
during winter operation by heating cables in the pads is desirable, although cultures were
developed which performed satisfactorily at 4°C. The process includes soil sorting, mixing
with tree bark and amendments (nutrients and dispersant). The soil is placed in rows ca. 2
m wide x 1.5 m high on geomembranes. Forced aeration is not initiated for 2-4 weeks until
the more volatile aromatics (e.g. naphthalene) have been degraded. Treatment costs are
estimated to be NOK 1350/ton or approx. $ 200/L (Lower labor and material costs will likely
015
-------
prevail outside of Scandinavia). The costs include pile-to-pile material handling, materials,
operations, and analytical control.
INTRODUCTION
The remediation of a contaminated coke works site (Norsk Koksverk) i Northern Norway was
initiated in 1989. It was unique in that it was Norway's first major cleanup in which several
technologies had to be considered for the contaminants, including polycyclic aromatic
hydrocarbons (PAH), arsenic, cyanide, and copper. The subject of this paper concerns the
treatment of the PAH-comaminated soil, in which a biological process was chosen for the
pilot study. The treatment of the other contamintants in both soil and groundwater have been
described in reports in Norwegian and will be made available in English publications in the
near future.
Biological treatment of soils contaminated with organics is a preferred technology in many
cases because of its simplicity, lack of residuals (e.g. sludges) requiring further treatment, and
relatively low cost The technology for excavated soils is generally applied in three process
types: land farming, composting or slurry reactors. In situ biorestoration is also applicable,
circumstances permitting. All of these processes are in use internationally and have recently
been reported by others (Sims, et al, 1989; Steps, 1989; Borow and Kinsella, 1989;
Christiansen, etal, 1989).
Coke or gas works sites are typically contaminated by PAH's (Turney and Goerlitz, 1990),
which are also components of many hydrocarbon products. Since these compounds are
relatively refractory, carcenogenic, and bioaccumulate, there is considerable interest to
effectively treat contaminated sites. PAH's can be biologically degraded by naturally
occuring bacteria and fungi (Park, et .al, 1990; Pothuluri, 1990) and adapted cultures (Portier,
1989). Bioremediation processes especially designed for aromatics have also recently been
described (Mahaffy and Compeau, 1990; Bewley and Theile, 1988; Compeau, et al, 1990;
Tan, et al, 1990; and Stroo, et al, 1989).
Composting technology was chosen for further investigation at pilot scale after having
determined at bench scale that the contaminants were biodegradable. Composting was chosen
over landfarming because of the better opportunity for temperature control in a rather cold
climate, and because of smaller area requirements. Composting was chosen over slurry
reactors because of simplicity and the lack of a substantial investment requirement in reactors
and process controls. A description of the pilot study and the proposal for full scale
remediation follows.
NORSK KOKSVERK SITE - NORWAY
History
The Norwegian Parliament (Stortinget) decided in 1961 to build a coke plant located in Mo
i Rana in the northern part of Norway. The state owned steel mill (Norsk Jernverk A/S) who
hwoc c*or*iw*oaot*piScramf*p. O-W11, J.6J991
-------
would be the major user of the coke, was also located in Mo i Rana. The plant processed
approximately 440 000 tons of coal per year. The coal was primarily shipped in from
Spitsbergen.
The plant began operations in 1964. The ammonia production was started 6 months later.
The plant annually produced 55-60 000 tons NH^, approx. 15000 tons tar and 5000 tons
benzene. These products were sold without further processing at the plant.
The area of the industrial site is 250 ha (101 acres). The various activities are shown in
Figure 1. The plant was closed down in the fall of 1988 for economic reasons. Site
characterization and clean-up was required by the pollution control authorities (SFT) before
any further development of the area would be permitted.
Contamination at the site is the result of both routine operations over the 27 year plant
lifetime plus a recent accident The primary contaminant associated with operations involved
intermittent leakage of benzene and other aromatic solvents to the site, resulting in a ca. 10-15
cm floating layer of aromatics on the groundwater, the second was a spill of an alkaline
arsenic solution (ca. 200 m3). Both involved surface tanks in two separate areas of the site.
Preliminary analyses also revealed contamination by copper, cyanide, PAH, and other
aromatics than benzene.
Site Characterization/Contamination Survey
To the north a rocky ridge extends to the west The rockface can be seen in the open terrain.
The natural sediments in the area consist of silt and clay. The clay content increases with
depth. The site itself is sedimentary material or sandy fill from 2 to 3 m thick on a clay layer
which is the original fjord bottom.
The railroad track divides the area in two. The lower portion of the area, outside the clean-up
area, is filled in with bottom sediments from the fjord and slag from the steel mill. The slag
has the same particle size as coarse sand.
The groundwater consists primarily of surface runoff that infiltrates the area. , All
groundwater movement is shallow and directed toward the fjord, which is the final recipient
Tidal changes influence the groundwater movement (variation - 1.7 m to + 1.3 m).
To identify the contamination in the area 45 test wells were eventually installed. Soil camples
and groundwater samples were collected at each well. In addition to the test wells, georadar
(SIR-3) was used to point out areas with concentrated deposits of waste, e.g. buried drums.
, SJS.1991
-------
1 Administration
2 Laboratory
3 Coke oven
4 Benzen production |
5 Benzen storage
6 Ammonia production
7 Ammonia storage
8 Sulphur treatment plant
M
Figure 1. Norsk Koksverk Plant in Mo i Rana, Norway
hwcr.
-------
Figure 2 shows the location of the sampling wells and seven areas requiring remediation.
Owing to the acute contamination of two areas, approx. 20,000 tons of soil from area "1" was
excavated and placed in lined and covered depositories on the site (Dep. 1-4). This was
designated as the 'TAH-SoiT for the composting study. An equally large amount of arsenic-
cyanide contaminated soil was also excavated and securely deposited. The major
contaminants of these two soils are shown in Table 1, the result of a U.S. EPA Priority
Pollutant Scan.
Figure 2. Site characterization during 1988-1990 revealed seven areas requiring
remediation. Excavated soil was placed in secure deposits (Dep. 1-4) and
comes mostly from two locations in Area No. 1, which still has significantly
groundwater contamination.
hwtr c^oixr\iintaoui>cT>*fonxm.Dip, O-8911. 5.6.1991
-------
Table 1. Major contaminants of the two excavated soil types and groundwater
associated with the areas.
Compound
Arsenic
Cyanide
Naphthalene
3-methylnaphthalene
2-methylnaphthalene
1 -methylnaphthalene
Biphenyl
Sum bicyclic aromatics
Acenaphthylene
Acenaphthene
Fluorene
Phenathrene
Anthracene
Fluoranthene
Pyrene
Benzo (J,K) Fluoranthene
Benzo (E) Pyrene
Benzo (A) Pyrene
Perylene
Dibenzofuran
Sum PAH w/bicyclics
Sum PAH wo/bicyclics
Benzene
Toluene
water 1
mg/l
0.047
0.136
11.1
1.35
12.45
0.023
0.875
0.125
0.021
0.528
14.022
1.572
0.006
soil 1
mg/kg
19.1
2.3
381
38.676
419.676
17.906
6.489
2.288
0.211
0.283
0.187
13.806
460.846
41.17
water 2
mg/l
8.23
2.45
0.004
0.004
0.002
0.075
0.021
0.002
0.028
0.132
0.128
0.03
0.008
soil 2
mg/kg
9970
1090
0.667
0.17
0.837
0.365
1.778
0.524
1.986
0.441
1.77
1.748
0.583
11.701
9.1951)
More comprehensive testing of the PAH soil revealed that there were predominantly 17 PAH
compounds and most of these were 2 and 3 ring structures (Table 2). The more complex
PAH's were generally at concentrations which were below the proposed target treatment level,
which was the Dutch "B" level of 20 mg/kg for total PAH's.
>, O4911. 3AI991
-------
Table 2.
Common PAH's at the Norsk Koksverk site.
Structure
.CO
or
c6.
oo
&
&
. . ceo
0?
•ceo
oS
fi?
9A
C0$>
C$>
oS? '
<#
C£O
Name
Naphthalene
2-Methylnaphthalene
1 -Methylnaphthalene
Biphenyl
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
BenzoG)fluoranthene
Benzo(k)fluoranthene
Benzo(e)pyrene
Benzo(a)pyrene
Perylene
Dibenzofuran
M.W.
128.19
142.20
142.20
154.21
152.21
154.21
166.23
178.24
178.24
202.26
202.26
252.32
252.32
252.32
252.32
252.32
168.2
Sol. (ug/1)
30000
—
—
7500
3930
3420
800
435
59
260
133
2.4
2.4
2.4
3.8
2.4
10000
KOW
3.37
—
—
3.95
4.07
3.92
—
4.46
4.5
5.03
4.98
6.21
6.21
6.21
6.04
6.21
4.12
Source: Afghan and Chau. Analysis of Trace Organics in the Aquatic
Environment, CRC Press 1989.
PILOT STUDY REMEDIATION PLAN
General
As stated above, there were several types of contamination, requiring different remediation
processes. Three separate pilot treatability studies were conducted:
(1) Composting of excavated PAH-soiL
(2) Stabilization of excavated As-soil.
. 3.6.1991
-------
8
(3) Physical-Biological Pump-and-Treat of As-PAH groundwater.
The first study is reported herein.
Soil Composting Study
PAH-contaminated soil (Avg. concentration = 500 mg/kg total PAH) from "Dep. 4" was
sorted, crushed, and mixed to form as homogenous a material as possible (Fig. 3).
The soil was then placed in 9 separate piles of ca. 10 m3, 2 m x 3 m x 1.5 m (W x L x H),
on geomembranes. Seven piles were placed in an unused industrial building, while two were
placed in an abandoned local mine. The latter was chosen since the mine is a candidate full-
scale treatment facility with excellent capacity for final, secure deposition of treated soil
(Volume of storage space is 1 million m3 with excellent ventilation and controlled drainage).
Table 3 shows the variables tested in the study, which are described below.
Table 3. Experimental variables in the pilot study. FA = Forced aeration, T = pile
turning, N & P = Nitrogen and phosphorous.
Pile
1.
2.
3.
4.
5.
6.
7.
8.
9.
Treatment
Bark
-
+
+
+
+
+
+
+
+
N&P
-
-
+
++
-
+
+
+
+
Aeration
T
T
T
T
FA
HA
T
-
T
Temp(°C)
10-16
10-16
10-16
10-16
10-16
10-16
25-35
4
4
Other
-
-
-
-
-
Recirc H2O +
dispersant
-
-
-
hwoc
. O-*911. 54.1991
-------
Figure 3. PAH-soilfrom "Dep. 4" (top panel) was sorted, crushed, and homogenized
at the site (bottom).
bwo: ctortfyinteoufeptforamjap. O-S911,
-------
10
Bark Addition
Pine park was addtd to all piles except No. 1 (control with no amendments) in a ratio of
bark: soil equal to 1:1 on a volume basis. The soil was sandy and had very little capacity to
retain moisture.
Nutrients
Nitrogen and phosphorous were added to six of the piles in two different doses at the start
of the study and after 8 weeks.
Oxygen
The piles were oxygenated by either turning the piles every three weeks, by forced aeration,
or by peroxide addition via a water recirculation system. Peroxide was replenished three
times per week.
Temperature
Ambient temperature ranged from 4-16°C for six of the piles in the industrial building. One
pile was artificially heated by electric cables under the geomembrane base. The 2 remaining
placed piles in the mine remained at a constant 4°C throughout the study.
Moisture
The piles were watered initially, and after weeks 6 and 8. Pile 6 also had regular periodic
recirculation of water throughout the study. Dispersant, peroxide, and nutrients were added
to the water.
Sampling and Analytical Methods
The piles were sampled twice weekly from 3 random locations at ca. 80 cm depth.
Composite samples were prepared and placed in acid-washed brown glass jars and either
analyzed immediately or frozen at -18°C. Temperature and soil gas measurements were taken
at five locations at ca. 80 cm depth twice weekly also.
Analyses were conducted on site if possible. However, contract laboratories performed all
PAH analyses. Analyses consisted of:
Moisture
pH
boot c*x*i
-------
11
TotN
TotP
Total PAH (+ all components by GC/MS)
Soil gas (O2 and COj)
RESULTS
PAH Treatment
The results of the study for the most predominant PAH's are shown in Figures 4-6. The
group parameters, "Bicyclic aromatics", and "Total PAH" are shown in Figures 4 and 5. In
all cases, biphasic reduction in PAH's occurs over the 14 week study period. It is largely the
duration of the lag phase or initial reduction rate that is influenced by the various
amendments. Notably, the control pile shows the slowest rate of PAH reduction in all cases.
The proposed treatment goal, the Dutch "B" level of 20 mg/kg PAH is achieved in 6-8 weeks
under optimal conditions. The individual PAH's, as typified by Figure 6 for fluorene and
acepnapthene, also follow the same behaviour. Forced aeration and nutrient additions both
contributed to a much more effective process. Other lab experiments (data not shown)
indicate that increased volatilization of the 2-5 ring PAH's by forced aeration was not
significant, suggesting that it was primarily more effective biological activity that explains the
reduction in PAH's.
Also, it is interesting to note that even at 4°G, there was effective removal of PAH's (See Fig.
6, Piles 8 and 9 for fluorene and acenapthene) suggesting that the naturally occuring
populations had been well adapted to the low temperature environment. Owing to problems
with regulating the temperature in the pile with heating cables, no reliable data were obtained
for greater than ambient temperature which ranged from 4°-16°C during most of the study.
Lastly, the PAH removal results of the water recirculation experiment were unexpectedly low.
Therefore, other dispersants were subsequently evaluated in bench scale batch and flow-
through column studies. Results showed that another type of dispersant, ECO/+ (R.L. King
Assoc. - Dutch Pride Products, 500 Airport Blvd., # 238, Burlingame, CA 94010) greatly
enhanced the mobilizaton and removal of PAH's. In batch mixing studies, low concentrations
of ECO/+ at ca. 10°C removed > 62 % of Total PAH's. The product is reported to be
biodegradable so that the composting process should not be inhibited. Column studies are
underway to test washing and biodegradation effects simultaneously.
The results of the PAH reduction aspects of the study are compared with available published
literature values in Table 4. Generally, the results from the Koksverk pilot study are
comparable with the published studies. Where it is possible to directly compare individual
compounds, for example with phenanthrene, the half life (t V4) in this study was ca. 14 days
under optimal conditions versus 16-200 days under a range of other comparable conditions
of temperature (10-20°C) and amendments (added nutrients). The same is true for
fluoranthrene, with this study reporting t V4 = 48.5 days versus 29 to 440 days. (Sims, et al,
1988; Sims, 1986; and Coover and Sims, 1987).
ten c*a*Ha*aaat*i*laim*w. O-WH. 5.6. Wl
-------
12
9 10 11 12 13 14
Figure 4. Reduction in bicyclic aromatics.
Inrac
OW11.
-------
13
-o
Nr. 1
Nr.2
Nr. 4
Nr.5
Nr.6
Figure 5. Reduction of Total PAH's.
. 5A1991
-------
14
Dryweight
(HO/0)
tOOti
Nr.1
&—-O Nr. 3
Mr. 5
— Nr. 6
»Nr.9
Week
Figure 6. Reduction offluorene and acenaphthene.
hw
-------
15
Where total PAH data were available, this study reports t V4 = 22 days under optimal field
conditions versus 43 days in a laboratory study (McGinnis, et al, 1991).
o
Table 4. Results of this study (Norsk koksverk, 1990) are compared with literature
values for half-lives (t %) from similar laboratory experiments or field
studies.
Half-lives of Selected PAH's.
Group/Compound
Naphthalene
1-Methylnaphlhalene
I Bicyclics
Phenanthrene
Flouranthene
I PAH
Conditions
20°C Resp. Test
20°O Resp. Test
4-1 6°C Pilot scale +
amendments
4-1 6°C Pilot scale
No amendments
20°C Resp. Test
Field Soil - No amend.
Field Soil + amend.
10°C Resp. Test
20°C Resp. Test
4-1 6°C Pilot scale + amend.
4-1 6°C Pilot scale - No amend.
20°C Resp. Test
Field Soil - No amend.
Field Soil + amend.
20°C Resp. Test
4-1 6°C Pilot scale + amend.
22° EPA Lab. procedure
4-1 6°C Pilot scale + amend.
4-1 6°C Pilot scale - No amend.
c,
(mo/kg)
101
102
18
24
902
40
54
883
4
1095
260
290
tn
(days)
2.1
1.7
19.2
87.7
16
69
23
200
60
13.9
90.1
377
104
29
440
48.5
43
22.2
98.4
Source
Sims et al., 1988
Sims et al., 1988
Norsk koksverk, 1990
Norsk koksverk, 1990
Sims et al., 1988
Sims, 1986
Sims, 1986
Coover and Sims, 1987
Norsk koksverk, 1990
Norsk koksverk, 1990
Sims et al., 1988
Sims, 1986
Sims, 1986
Coover and Sims, 1987
Norsk koksverk, 1990
McGinnes et al., 1991
Norsk koksverk, 1990
Norsk koksverk, 1990
OPERATING PARAMETERS
1. Temperature
The development of pile temperatures in the building is shown in Figure 7. Pile 1
temperatures reflect the ambient air temperature which ranged from 0°C to 16°C at the end
of the study. All piles showed greater than ambient temperatures due to biological activity,
the highest being Pile No. 4 which had a very high dose of N & P. The temperature of the
piles in the mine remained at 4°C throughout the study.
, 04911. 3.6J991
-------
16
Temperature
T«mp.
26*
24
22-
20
18-
16-
14
•\2-
10
8>
6'
4-
2
0
jr//
Iff " o~oNr.4
f-/ o oNr.2 -—Mr. 6
If If »—4 Nr 3 ^_ Nr 7
01 2345 6789 10 11
Time (week)
Figure 7. Temperature development in the compost piles.
2. Moisture
The percent moisture reported as an average of all samples are shown in Figure 8. Pile No.
1, the control, was ca. 7 % throughout the study. The other piles which had the added bark
matrix ranged from 25 to 35 %. Pile No. 6 which received regular sprinkling with
recirculated water retained ca. 32 % moisture after the watering program was started, which
is considered the maximum attainable for this soil/matrix combination.
3.
Soil gas O, and CO,
The average soil gas values are also shown in Figure 8. The relationship between the O2 and
COj values indicates the biological activity, as evidenced by PAH reduction, quite welL The
control pile No. 1, for example, which exhibited the least biodegradation of PAH's shows the
highest ratio of O2: CO2, whereas in the other piles the ratio is either close to one (Pile No.
2), or the relationship is reversed. The only exception is for Pile No. 5 receiving forced
aeration, in which gas phase COj is rapidly exchanged with O2, hence yielding a low value.
l, O4911. S44991
-------
17
30
9
» 20-
1
10-
n n
Nr.1 Nr.2 Nr.3 Nr.4 Nr.5 Nr.6 Nr.7 Nr.8 Nr.9
30-
20
£
I
n
m
Nr.1 Nr.2 Nr.3 Nr.4 Nr.5 Nr.6 Nr.7 Nr.8 Nr.9
21
20*
19*
18
* 17-
16*
15*
14
I
Nr.1 Nr.2 Nr.3 Nr.4 Nr.5 Nr.6 Nr.7
o
o
u
#
Figure «. Average temperature (*C), moisture (%), and soU gas O2 and COa (%).
4. Toxicitv
Limited plant toxicity tests were conducted with rye grass which quantitatively showed that
treated soil under optimal conditions was ca. 80% less inhibitory to plant growth relative to
the untreated soil. This study was conducted since one alternative for ultimate disposal of
the soil was as cover material at a local landfill.
Toxicity of groundwater from the same area from which the soil originated was also treated
biologically in a parallel study. Toxicity was measured by standard "Microtox™" procedures
O-WU, &6J991
-------
18
and showed a 93 % reduction in toxicity of the treated water as compared to the raw
groundwater (data not reported here). It is assumed that leachate from the soil composting
studies will behave similarly, thus some form of toxicity testing is recommended as a routine
quality control parameter during full-scale operations.
SUMMARY
Pilot Study Results
1. Among the amendments evaluated in the study, and addition of bark and nutrients,
primarily nitrogen and forced aeration, essential for optimal biological activity.
2. The surfactants chosen for the pilot study did not improve PAH removal. However,
subsequent column and batch studies with another commercially available product
(ECO/+) were very promising.
3. Cultures adapted to low temperatures showed significant degradation at 4°C, however,
better results were obtained at temperatures ranging from 6-16°C, as one would
expect
4. The proposed treatment objective of 20 mg/kg Total PAH was attained within 6-7
weeks, while a more stringent goal of 10 mg/kg was reached within 8-9 weeks.
Considerations for Full-scale Remediation
1. Location. The site is large enough to accomodate composting remediation on site for
the 20,000 tons of excavated soil. However, if development of the site is to proceed
quickly an attractive alternative is an abandoned mine. It is scheduled to be a full-
scale treatment facility with a 1 million m3 capacity for secure deposition of wastes.
2. Facilities. On site composting will require tents placed over geomembrane liners.
Operations in the mine will require only the impervious liner.
3. Operations. After sorting and crushing, samples will be taken to ensure that the
arsenic contamination is below acceptable limits. High .As-containing soil will be
separately treated by stabilization. Then the soil will be mixed with bark and nutrients
and dispersant, and placed in windrows at the treatment facility.
Forced aeration will be used if site development plans require a 30-40 % shorter
treatment program. Capacity for air heating will be designed in the system. Aeration
will not commence until the third or fourth week of operation, when most of the
semivolatile bicyclic aromatics have been degraded.
bwtt c.\»»SJrf«oBN^faron4»p, O-ttll.
-------
ACKNOWLEDGEMENTS
The pilot study was .conducted for the municipality of Mo i Rana with additional support from
the Royal Norwegian Council for Scientific and Industrial Research (NTNF) and Norwegian
Applied Technology A/S, Stavanger, Norway. Technical support from Dr. Royal Nadeau,
U.S. EPA, New Jersey is gratefully acknowledged.
REFERENCES
Afghan, B.K. and Chau, A.S.Y. (1989): Analysis of Trace Organics in the Aquatic
Environment, CRC Press.
Bewley, RJJF. and Theile, P. (1988): Decontamination of a coal gasification site through
application of vanguard microorganisms. In: K. Wolf, WJ. van den Brink, FJ. Colon (eds.),
Contaminated Soil '88, pp. 739-743, Kluwer Academic Publishers.
Borow, H.S. and Kinsella, J.V. (1989): Bioremediation of Pesticides and Chlorinated Phenolic
Herbicides - Above Ground and In Situ - Case Studies. In: Proceedings from the HMRCTs
10th National Conference and Exhibition, Washington, DC, November 27-29, pp. 325-331.
Christiansen, J.A.; Koenig, T.; Laborde, S. and Fruge, D. (1989): TOPIC 2: Land Treatment
Case Study Biological Detoxification of a RCRA Surface Impoundment Sludge Using Land
Treatment Methods. In: Proceedings from the HMRCTs 10th National Conference and
Exhibition, Washington, DC, November 27-29, pp. 362-367.
Compeau, G.C.; Borow, H. and Cioffi, J.C (1990): Solid Phase Remediation of Petroleum
Contaminated Soil. In: Proceedings from the HMCRI's llth Annual Conference &
Exhibition, Superfund '90, Washington, DC, November 26-28, pp. 814-819.
Coover, MJ*. and Sims, R.C (1987): The effect of temperature on polycyclic aromatic
hydrocarbon persistence in an unacclimated agricultural soil. Hazardous Waste & Hazardous
Materials, 4: 69-82.
Mahaffey, W.R. and Compeau, G. (1990): Biodegradation of Aromatic Compounds. In:
Proceedings from the HMCRI's llth Annual Conference & Exhibition, Superfund '90,
Washington, DC, November 26-28, pp. 780-787.
McGinnis, G.D., et al. (1991): Bioremediation studies at a northern California Superfund site.
In Proceedings of Bioremediation - Fundamentals and Effective Applications Gulf Coast
Hazardous Substance Research Center.
Park, K.S.; Sims, R.C.; Dupont, R.R.; Doucette, WJ. and Matthews, I.E. (1990): Fate of PAH
compounds in two soil types: Influence of volatilization, abiotic loss and biological activity.
Environmental Toxicology and Chemistry, Vol, 9, pp. 187-195.
bwoc <*ar*ia*xaf
-------
20
Portier, R.J. (1989): Bioremediation Using Adapted Bacterial Cultures. Topic 1: Examination
of Site Data and Discussion of Microbial Physiology With Regard to Site Remediation. In:
Proceedings from the HMRCTs 10th National Conference and Exhibition, Washington, DC,
November 27-29, pp. 351-361.
Pothuluri, J.V.; Freeman, JJV, Evans, F.E. and Cemiglia, C.E. (1990): Fungal transformation
of fluoranthene. Applied and Environmental Microbiology, Vol. 56, No. 10, pp. 2974-2983.
Sims, R.C, et al. (1988): Treatment potential for 56 EPA listed hazardous chemicals in soil.
U.S. EPA/600/6-88/001.
Sims, R.C. (1986): Loading rates and frequencies for land treatment systems. In: R.C. Loehr
and J.F. Mallna, Jr. (eds.) Land Treatment: A Hazardous Waste Management Alternative.
Water Resources Symposium No. 13, Center for Research in Water Resources, The University
of Texas at Austin, Austin, TX.
Sims, J.L.; Sims, R.C. and Matthews, JJE. (1989): Bioremediation of contaminated surface
soils. U.S. EPA/600/9-89/073.
Steps, JMJvL (1990): International evaluation of in-situ biorestoration of contaminated soil
and groundwater. In Proceedings of NATO/CCMS Third International Conference
Demonstration of Remediation Action Technologies for Contaminated Land and Groundwater,
Montreal, Canada, November 6-9.
Stroo, HJ:; Smith, J.R.; Torpy, MJF.; Coover, MJP. and Kabrick, RM. (1989):
Bioremediation of Hydrocarbon-Contaminated Solids Using Liquid/Solids Contact Reactors.
In: Proceedings from the HMRCTs 10th National Conference and Exhibition, Washington,
DC, November 27-29, pp. 332-337.
\
Tan, C-K.; Gomez, G.; Rios, Y.; Guentzel, M.N. and Hudson, J. (1990): Case study:
Degradation of Diesel Fuel With In Situ Microorganisms. In: Proceedings from the HMCRI's
llth Annual Conference & Exhibition, Superfund '90, Washington, DC, November 26-28, pp.
776-779.
Tumey, G.L. and Goerlitz, D JF. (1990): Organic contamination of groundwater at Gas Works
Park, Seattle, Washington. Ground Water Monitoring Review, Vol. 10, No. 3, pp. 187-198.
. O-W11, S4J991
------- |