\ I/
United States
Environmental Protection
Robert S. Kerr Environmental
Research Laboratory
Ada OK 74820
Research and Development
EPA/600/S6-86/003 Feb. 1987
Project  Summary
Waste-Soil  Treatability  Studies
for  Four   Complex   Industrial
Wastes:   Methodologies  and
Results,  Volumes  1   and   2

R. C. Sims, J. L. Sims, D. L. Sorensen, W. J. Doucette, and L. L. Hastings
  The full two-volume report presents In-
formation pertaining to quantitative evalu-
ation of the soil treatment potential re-
sulting from waste-soil interaction studies
for four specific wastes listed under Sec-
tion 3001 of the Resource Conservation
and Recovery Act (RCRA). Volume 1 con-
tains information from literature assess-
ment, waste-soil characterization, and
treatability screening studies  for each
selected waste. Volume 2 contains results
from bench-scale waste-soil interaction
studies; degradation, transformation, and
immobilization data are presented for four
specific wastes: API separator sludge, slop
oil emulsion solids,  pentachlorophenol
wood preserving waste, and creosote
wood preserving waste. The scope of the
study involved assessment of the poten-
tial  for treatment of these hazardous
wastes using  soil  as the treatment
  The experimental approach used in this
study was designed to characterize de-
gradation, transformation, and immobiliza-
tion potentials for hazardous constituents
contained in each candidate waste. For
each waste and soil type, treatment was
evaluated as a function of waste loading
rate, soil moisture, and time. Combinations
of selected chemical analyses and bio-
assays were used as endpoints to char-
acterize treatment.
  Methodologies were developed for the
measurement of specific soil treatment
parameters  including  "volatilization-
corrected"  degradation  rates  and  for
measurement of partition  coefficients
among waste, water, and air phases of a
waste-soil matrix. Partitioning between the
water soluble extract of the waste-water-
air mixture and soil was evaluated by con-
ducting soil isotherm studies using the
water soluble extract. These parameters
provide input to the proposed  U.S. En-
vironmental Protection Agency (EPA) Reg-
ulatory and Investigative Treatment Zone
(RITZ) model developed to assess treat-
ment potential for potentially hazardous
organic constituents in soil.
  This Project Summary was developed
by EPA's Robert S. Kerr Environmental
Research Laboratory (RSKERL), Ada, OK,
to announce key findings of the  research
project that is fully  documented in a
separate two-volume report of the same
title (see Project Report ordering  informa-
tion at back).

  Land treatment (LT) is defined  in RCRA
as the hazardous waste management
technology pertaining to application/incor-
poration of waste into upper layers of the
soil for the purpose of degrading, trans-
forming, and/or immobilizing hazardous
constituents contained  in the applied
waste (40 CFR Part 264). Soil systems for
treatment of a variety of industrial wastes
have been utilized for many years; al-
though, application of hazardous industrial
waste to soil utilizing a controlled engine-
ering design and management approach
has not been widely practiced. This is due,
in part, to the lack of a comprehensive
technical information base concerning the
behavior of hazardous constituents in the
soil treatment zone as specifically related

to current  regulatory requirements (40
CFR Part 264) concerning treatability, i.e.,
degradation, transformation, and immobil-
ization of such constituents. Soil treat-
ment  systems  that are designed  and
managed based on knowledge of waste-
soil interactions may represent  a signifi-
cant technology for simultaneous treat-
ment  and ultimate  disposal of  selected
hazardous wastes in an environmentally
acceptable manner. This treatment con-
cept also may be useful during  remedial
activities  at  certain contaminated soil
  In this research project, representative
hazardous  wastes  from two industrial
categories, wood preserving and petro-
leum  refining, were evaluated as to the
potential for treatment in soil systems. A
literature assessment for each waste cat-
egory was conducted as an aid in the pre-
diction  of soil treatment potential. The
literature review also was used as a guide
for design of an experimental approach for
obtaining specific information pertaining
to degradation, transformation, and  im-
mobilization of hazardous waste constit-
uents in soil.
  Standards were promulgated in 40 CFR
Part 264.272 for demonstrating treatment
of hazardous wastes in soil. These stand-
ards require demonstration of degradation,
transformation, and/or immobilization of a
candidate waste in the treatment zone
soil. For the  purposes of this  research,
demonstration of degradation  of waste
constituents  was based on the loss of
parent  hazardous  organic  compounds
within the waste-soil matrix as opposed
to "complete" degradation, which is the
term used to describe the process where-
by  waste  constituents are  mineralized
completely to inorganic end products, i.e.,
carbon dioxide,  water, and  inorganic
species of nitrogen,  phosphorus, and
sulfur. Rates  of degradation were estab-
lished by measuring the loss of parent
compounds from the  waste-soil matrix
with time. Transformation refers to partial
alteration of hazardous compounds in the
soil, thereby converting a problem waste
or substances into innocuous or environ-
mentally safe forms. In this context, trans-
formation  refers to formation  of inter-
mediate products during waste-soil inter-
actions (i.e.,  physical, chemical, and/or
biological mechanisms); some intermedi-
ate products may become refractory com-
pounds in the soil matrix. Immobilization
refers to the  extent of retardation of the
downward transport (leaching  potential)
and upward transport (volatilization poten-
tial) of waste constituents. The  transport
potential for waste constituents from the
waste to water, air, and soil phases is af-
fected by the relative affinity of the waste
constituents for each phase, and in this
project was characterized in column and
batch reactors. Therefore, an acceptable
demonstration of soil treatment involves
an evaluation/quantification of degrada-
tion, transformation, and immobilization
processes, in order to obtain an integrated
assessment of design and  management
requirements for successful assimilation
of a waste in a soil system.
  Demonstration of the potential for treat-
ment of a particular hazardous waste in
soil can be  addressed using several ap-
proaches. Information can be obtained
from several sources, including literature
data, field tests, laboratory  analyses and
studies, theoretical parameter estimation
methods, or, in the case of existing land
treatment units, operating data. In this pro-
ject, specific information obtained from
literature sources  included quantitative
degradation, transformation, and immobi-
lization data for identified waste-specific
hazardous constituents in soil systems.
Due to the current lack of a comprehen-
sive technical  information base, the U.S.
EPA considers the use of literature infor-
mation  only as insufficient to  support
demonstration of treatment of hazardous
wastes  in soil  at the present time.

  Specific objectives of this research pro-
ject were to:

  (1) Conduct a literature assessment for
     each  candidate  hazardous waste
     (API separator sludge,  slop oil emul-
     sion solids, creosote wood preserv-
     ing waste, and pentachlorophenol
     (PCP)  wood preserving waste) to
     obtain specific information  pertain-
     ing to degradation, transformation,
     and immobilization in  soil of hazar-
     dous constituents identified in each
  (2) Characterize candidate wastes for
     identification of specific constitu-
     ents of concern; and characterize
     experimental soils for assessment of
     specific parameters that influence
     soil treatability potential.
  (3) Conduct  laboratory screening ex-
     periments using a  battery of bio-
     assays to determine waste loading
     rates (mg waste/kg soil) to  be used
     in subsequent longer term experi-
     ments designed to assess potential
     for treatment of  each selected
     waste in soil.
  (4) Develop  degradation, transforma-
     tion, and immobilization information
     for each candidate hazardous waste^
     in the two soils selected for study. 1
  (5) Develop  methodologies for  mea-
     surement of "volatilization-correct-
     ed" degradation rates and partition
     coefficients; use the methodologies
     developed to generate degradation
     kinetics/partition coefficients for a
     subset of waste-soil combinations
     and for those constituents common
     to all wastes.

  Objectives 1, 2, and 3 are addressed in
Volume 1 of this report; objectives 4 and
5 are addressed in Volume 2.

Research Approach
  Four  listed  hazardous wastes  were
selected for study (Table 1). The wastes
chosen are produced in high volume, con-
tain numerous organic and inorganic con-
stituents, and represent a broad spectrum
of physical, chemical, and toxicological

API separator sludge—(K051)
  This waste  is generated from primary
settling of wastewaters that enter the oily
water  sewer  and typically consists  of
water, oil, and solids.  Solids are largely
sand and coarse silt, but also may contain
significant quantities of hazardous metals,
i.e., chromium and lead.  Heavy oils that
settle  and become part of the bottom
sludge in an API separator are largely com-
posed  of  heavy tars,   large  mutiple
branched aliphatic compounds (paraffins),
polyaromatic  hydrocarbons, and coke
fines. Proportions of oily material which
are tar-like, paraffinic or polyaromatic are
largely dependent on the crude source.

Slop oil emulsion solids—(K049)
  This waste is generated from skimming
the API separator and typically consists of
approximately 40 percent water, 43 per-
cent oil, and 12 percent solids. Chromium
and lead typically are present in significant
concentrations in the solid phase.
 Table 1.    Hazardous Wastes Selected for
    Waste                       No.

 Petroleum Refinery Wastes
  API Separator Sludge          K051
  Slop Oil Emulsion Solids       K049
 Wood Preserving Wastes
  Creosote                     K001
  Pentachlorophenol            K001

i Creosote wood preserving waste
   Creosote is a  distillate from coal tar
 made by high temperature carbonization
 of bituminous coal. Creosote alone or in
 combination with coal tar or petroleum is
 a major preservative used in wood treat-
 ment. The principal classes of organic con-
 stituents present in creosote wastes are
 polyaromatic hydrocarbons and phenolics.

 Pentachlorophenol (PCP) wood
 preserving waste—(K001)
   Pentachlorophenol is widely used as a
 wood preservative and also has been used
 for slime and algae control. The combined
 PCP-creosote sludge used in this experi-
 mental investigation  contained polyaro-
 matic hydrocarbons, phenolics, and PCP.
   An experimental approach was designed
 to test  the hypothesis  that treatment
 would be achieved for each of four listed
 hazardous wastes in two soil types and to
 evaluate the effect of selected design and
 management factors, i.e., waste loading,
 on treatment. Therefore, the scope of the
 study involved addressing the demonstra-
 tion of treatment of hazardous waste us-
 ing soil as the treatment medium. The soil
 treatment  potential  for each candidate
 waste was evaluated as a function  of
 waste loading rate, soil moisture, and time.
 A combination of chemical analyses and
 bioassays was used to characterize end-
 points for degradation, transformation,
 and immobilization of waste constituents.
   Treatment of a  hazardous waste refers
 specifically to treatment of hazardous con-
stituents contained in the waste.  Stand-
 ards identified in 40 CFR Part 264.272(c)
 (i)  refer to Appendix VIM constituents
listed in part 261. Where waste(s) are from
an identified industry with well  defined
processes, i.e., petroleum refining, it may
be acceptable to perform analyses  for a
subset of Appendix VIII constituents. The
subset of organic constituents selected for
evaluation  in these waste-soil interaction
studies included  semivolatile polycyclic
aromatic hydrocarbon (PAH) compounds
and the  volatile  organic  constituents
(VOC) benzene, toluene, xylene, ethylben-
zene,  and  naphthalene for each  waste,
with the addition of pentachlorophenol for
the  PCP wood preserving sludge.
   Two soil types  were selected as treat-
 ment media to allow evaluation of the ef-
fect of varying soil characteristics on the
 extent and rate of treatment. Soil types
were chosen that (1) represented  soils
typical of operating land treatment facili-
ties and (2) provided  a range of specific
characteristics for evaluating treatment as
 a function of soil type. Each soil selected
 was characterized for specific properties
 considered to be important in influencing
 soil treatment processes.
   The  experimental  waste loading  rate
 (mass/area/application, or mg waste/kg so-
 il) was the first design parameter deter-
 mined. In order to evaluate the extent and
 rate of treatment, sustained soil microbial
 activity must be maintained. Therefore,
 the impact of an applied waste on indige-
 nous soil microbial populations must be
 evaluated, especially for any waste con-
 taining hazardous constituents specifically
 designed to inhibit biological activity, i.e.,
 wood preserving wastes.  In this study, a
 battery of microbial toxicity screening
 assays was used to estimate acceptable
 initial  waste application rates for use in
 subsequent bench-scale waste-soil inter-
 action  studies.
   A comparative study of the sensitivity
 of five microbial assays: Microtox,  soil
 respiration, soil dehydrogenase, soil nitrifi-
 cation, and viable soil microorganism plate
 counts, to pentachlorophenol (PCP)  and
 slop oil wastes in Kidman sandy loam soil
 was performed to evaluate response of
 these commonly used assays to identical
 waste-soil mixtures.
   The degradation potential of hazardous
 organic constituents in any waste applied
 to soil is critical since  biodegradation
 usually represents  the primary removal
 mechanism for such constituents. Degra-
 dation coefficient measurements involve
 determination of soil concentrations of
 specific organic constituents as a function
 of time. Degradation was characterized as
 a first order kinetic rate process for all con-
 stituents evaluated; the first order reaction
 rate constant was then  used to calculate
 half-lives for each  constituent. These
 calculated half-lives provided quantitative
 information for evaluating the extent and
 rate of treatment, and for comparing treat-
 ment effectiveness  for each waste-soil
 combination  as a function of design and
 management factors.
   Conversion of hazardous constituents to
 less toxic intermediates within  the  soil
 treatment medium also was evaluated. In-
 formation concerning the toxicity reduc-
 tion of the waste-soil mixture over time
 was evaluated using an  acute  toxicity
 assay (Microtox test), and a mutagenicity
 assay   (Ames Salmonella typhimurium
  Evaluation of treatment also involved in-
vestigation of the extent of migration of
hazardous constituents contained in each
hazardous waste. A loading rate based on
degradation potential was selected  for
 each waste-soil  combination;  leaching
 potential was subsequently characterized
 for  these  loading rates in laboratory
 column  studies.  Partition  coefficients
 among  waste (oil), water, and air for a
 subset of organic constituents also were
 determined for use as input parameters to
 the proposed Regulatory and  Investigative
 Treatment Zone (RITZ) model  that has
 been developed by the U.S. EPA Robert S.
 Kerr Environmental Research Laboratory

 Results and Discussion

 Characterization and Loading Rate

  Each waste was characterized for poly-
 cyclic aromatic hydrocarbons (PAH), vola-
 tile organic constituents (VOC), and poly-
 chlorinated dibenzo-p-dioxins (PCDD) and
 polychlorinated  dibenzofurans  (PCDF)
 using GC/MS, HPLC, and GC instrumenta-
 tion.  Concentrations of individual PAH
 compounds in the waste as determined by
 HPLC are presented in Table 2. Results
 from VOC analyses for all wastes identi-
 fied  naphthalene as the prominent peak.
 No TCDD was detected (detection limit 10
 ppb) in the  PCP waste, although other
 PCDDs as well as PCDFs were identified.
  The highest loading rate for each waste-
 soil combination was evaluated for muta-
 genic potential using the Ames test with
 and  without microsomal (S9) activation.
 With activation all four wastes exhibited
 a positive mutagenic potential in  Durant
 clay loam soil. Slop oil emulsion solids and
 creosote wood preserving waste exhibited
 a positive mutagenic potential in Kidman
 sandy loam soil; API separator sludge and
 PCP wood preserving waste did not exhibit
 a mutagenic potential in Kidman soil.
  None of the wastes exhibited a muta-
 genic potential as measured by the Ames
test  without microsomal (S9) activation.
 All  wastes exhibited  a high degree  of
 water soluble fraction (WSF) toxicity as
 measured by the Microtox toxicity test.
  Important differences in soil properties
 between the two  experimental soils in-
cluded organic carbon  content (2.88%,
0.5%), pH (6.6, 7.9), and moisture at -1/3
 bar (41.6%, 20%) for the Durant clay loam
and  Kidman sandy loam, respectively.
  Waste loading rates in soil as selected
based  on results  of Microtox  and soil
respiration assays are presented in Table
3. The wood preserving  wastes used  in
this project exhibited greater levels of tox-
icity than the petroleum refining wastes
used. Loading  rates selected were gen-
erally higher for the Durant clay loam than

Table 2.    Concentration of Individual PAH Compounds in Wastes Determined by HPLC
                                                           Concentration in Waste (mg/kg) *
Benzo (k) fluoran thene
Benzo (ghi)pyrene
Indenod, 2, 3-cd)pyrene
Separator Sludge
580 ± 87 (15%)
480 ± 100 (21%)
29 ± 33 (1 14%)
810 ± 140 (17%)
110 ± 27 (25%)
5,500 ± 230 (5%)
6,000 ± 440 (7%)
1,400 ± 58 (4%)
570 ± 310 (54%)
310 ± 62 (20%)
170 ± 73(43%)
40 ± 11 (28%)
61 ± 25 (41%)
Slop Oil
2,500 ± 700 (28%)
440 ± 300 (68%)
3,600 ± 2,100(58%)
480 ± 93 (19%)
18,000 ± 5,000 (28%)
23,000 ± 6,700(29%)
2,000 ± 1, 100 (55%)
1,100 ± 150(14%)
340 ± 140 (41%)
160 ± 42 (26%)
260 ± 200 (77%)
59 ± 18 (31%)
15 ± 1 (7%)
88 ± 19 (22%)
28,000 ± 1,200 (4%)
3,600 ± 1,000 (28%)
180,000 ± 40,000 (22%)
23,000 ± 5,900 (26%)
76,000 ± 15,000 (20%)
15,000 ± 6,800 (45%)
72,OOO ± 17,000(24%)
64,000 ± 12,000 (19%)
7,400 ± 1,600 (22%)
8,300 ± 2, 100 (25%)
3,OOO ± 700 (23%)
2,400 ± 460 (19%)
2,700 ± 380 (14%)
1,100 ± 280(25%)
820 ± 76 (9%)
Pen tachlorophenol
42,000 ± 28,OOO (67%)
< 13,000
52,000 ± 6,200 (12%)
1 1,000 ± 6.800 (62%)
46,000 ± 6,200 (13%)
56,000 ± 13,000 (23%)
16,000 ± 2,400 (15%)
6,900 ± 2,200 (32%)
10,100 ± 5,100 (51%)
^Average concentration of three replicate analyses ± one standard deviation (coefficient of variation %).
Table 3.
V. jste-Soil Loading Rates Selected Based on Microtox
and Soil Respiration Test Results
                                    Loading Rates
                   Kidman Sandy Loam
Durant Clay Loam
                         Low    Medium    High       Low     Medium     High
                                     (% waste wet weight/soil dry weight)
API Separator Sludge
Slop Oil
the Kidman sandy loam, thus indicating a
difference with respect to the effect of soil
type on waste-soil interactions.
  Results from a battery of microbial as-
says conducted using PCP and slop oil
wastes indicated a good correlation be-
tween the Microtox, soil nitrification, and
soil dehydrogenase assays. Highly variable
results were obtained with soil respiration
(carbon dioxide evolution) and viable plate
count  assays. The latter two assays ap-
peared to be much less sensitive to the
waste loadings used.
  A series of experiments were conducted
to evaluate the PAH extraction procedure
using the Tekmar Tissumizer. Results for
spiked recoveries of 16 PAH compounds
from Durant clay loam and Kidman sandy
loam soils are presented in Table 4. Four
concentration levels were used to bracket
the range of PAH concentrations in waste-
soil mixtures from the beginning  (high
concentration)  to the termination (low
concentration)  of  the  degradation
  Information presented in Table 4 indi-
cates  consistent and  generally high re-
                               coveries for all 16 PAH compounds from
                               both soil types. Also, recoveries did not
                               vary greatly  and  were  relatively high
                               through a three-log change in  soil PAH
                               concentrations. Thus, the soil extraction
                               procedure used in this project appeared to
                               provide consistent and relatively high ex-
                               traction efficiencies for both soils over the
                               range of concentrations of concern.

                               Treatment Results
                                 Results of degradation studies for  all
                               four wastes in both  soils generally indi-
                               cated an increase in PAH  half-life with  in-
                               creasing  molecular weight or compound
                               size. This observation is generally consis-
                               tent with results obtained in other studies
                               for the PAH class of compounds in soil
                               systems. However, soil  half-lives for some
                               higher molecular weight PAH compounds
                               in these complex wastes were  observed
                               to be lower than half-lives reported in the
                               literature for PAH compounds  only,  i.e.,
                               without the waste matrix. The  observed
                               variation in degradation rates and half-lives
                               obtained for PAH constituents in these
                               studies may be due,  in part, to the diffi-
culty in  accurately analyzing individual
constituents in soil mixed with complex
environmental mixtures. These degrada-
tion rates and half-lives observed in these
studies may be lower, however, as a result
of cooxidation/cometabolism  or  other
matrix-induced phenomena.
  An increase in  soil  moisture content
from -2 to -4 bars to -1/3 to -1 bars gen-
erally was associated with a decrease in
PAH compound half-life  for  waste-soil
  Results also indicate that half-life values
for constituents in each petroleum waste
were similar for some compounds even
though waste loading rates were different.
These results would be expected if de-
gradation followed first order kinetics.
  Half-life values for waste constituents
in each wood preserving waste also were
similar even though loading rates were dif-
ferent. These results are similar to those
observed for the petroleum wastes, and
are  expected if  degradation processes
follow first  order kinetics.
  After the first experimental period of ap-
proximately 280 days, wastes were reap-
plied to the soil according to the follow-
ing schedule: 1) waste originally loaded at
the medium rate was reloaded at the medi-
um rate (M/M); 2) waste originally loaded
at the low  rate was reloaded at the high
rate  (L/H);  3) nonacclimated soil was
loaded at the high rate of waste applica-
tion  (N/H);  and 4) waste-soil mixtures
originally loaded at the high loading rate,
but  not reloaded (H/NR). Results from
reapplication experiments were converted
to first order reaction rate constants and
half-life values. A subset of waste-soil mix-
tures for each soil and waste type was

  Table 4.    Tissumizer Extraction Recovery Results for PAH Compounds in Kidman and Durant Soils'
                                      Kidman Sandy Loam
                                   Soil concentration in mg/kg
                                                   Durant Clay Loam
                                               Soil concentration in mg/kg
92.3 13.8)
89.7 14.7)
82.3 13.2)
98.0 11.01
98.7 (1.5)
98.7 1 1.5)
95.0 12.7)
106.3 13. 1)
97.0 (2.0)
95.6 (1.5)

96.0 (0.0)
82.0 (4.4)
96.7 (0.6)
99.3 (0.6)
89.3 (1.5)
99.3 (1.2)
107.7 (0.6)
97.3 (1.2)
97.0 (1.0)
61.0 (0.0)
75.3 (2.5)
101.7 (2.1)
97.0 (1.0)
86.3 (14.6)
103.5 (5.0)
110.0 (0.0)
57.7 (2.5)
85.3 (2. 1)
73.7 (4.0)
96.3 15. 1)
94. 7 (3. 1)
87.7 (1.5)
61.7 (3.1)
78.0 (8.5)
100.0 (2.0)

158.3 (8. 1)
78.5 (5.0)
77.5 (5.0)
94.3 (4.0)
98.7 (2.5)
86.7 (3.5)
98.7 (1.5)
105.0 (5.3)
98.0 (1.0)
63.3 (1.2)
105.0 (2.0)
61.7 (2.1)
101.3 (4.0)
90.3 (2.5)
98.3 (1.2)
94.5 (7.8)
115.3 (7.2)
65.0 (5.3)
88.0 (16.5)
80.0 (24.3)
100.0 (1.4)
97.0 (1.7)
86.7 (2.1)
99.7 (2.5)
68.3 (10.0)
86.3 (2.3)
111.0 (4.6)
108.0 (0.0)
  * Table values represent average recoveries of triplicate extractions at each loading level with standard deviations in parentheses.
 selected for detailed characterization of
 degradation. The subset was evaluated for
 approximately an additional 100 days.
   For the petroleum wastes, reapplication
 did not appear to alter the half-life values
 for PAH constituents. Neither an inhibiting
 nor stimulating effect was observed. For
 the wood preserving wastes, there is no
 trend that would suggest a change in half-
 life with one reapplication.
   PAH degradation results for wastes in-
 cubated in Kidman sandy loam soil gener-
 ally followed the trend observed for waste
 treatment  in Durant clay loam soil. PAH
 degradation generally appeared to be in-
 fluenced by molecular weight or com-
 pound ring size. Variation in the data ob-
 tained for degradation increased  when
 waste was reloaded.
   Pentachlorophenol degradation also was
 evaluated for the PCP wood preserving
 waste. Kinetic information is presented in
 Tables 5 and 6 for PCP waste in Durant
 clay loam soil and Kidman sandy loam soil,
 respectively. Half-life values  are  similar
 (257 days and  204 days)  for PCP initially
 loaded at the high rate in both soils and
 not  reapplied.   Acclimation of Kidman
 sandy loam soil to PCP may have occur-
 red as indicated by comparing results in
Table 6 for experiments N/H and H/NR in
 Kidman soils. Both sets of experiments
 received PCP waste at the high loading
 rate (0.3%). However, PCP in mixtures in-
cubated for 400 days (H/NR)  had  a half-
life of 204 days, while PCP in mixtures in-
cubated for 164 days (N/H) had a half-life
of 330 days. Evidence for acclimation is
also indicated in the experimental set (L/H)
initially  receiving  the low  loading  rate
(0.075%)  and  reloaded at the high rate
 Table 5.    Degradation Kinetic Information
           for Pentachlorophenol in Pen-
           tachlorophenol Wood Preserving
           Waste Reapplied to Durant Clay
           Loam Soil at -1 Bar Soil
r *
(day- 1)
       after waste incorporation into soil.
 + M/M = originally loaded at medium rate
         (0.5%), reloaded at medium rate.
 *H/NR = originally loaded at high rate
         (0.7%), not reloaded.
Table 6.    Degradation Kinetic Information
           for Pentachlorophenol in Pen-
           tachlorophenol Wood Preserving
           Waste Reapplied to Kidman
           Sandy Loam Soil at -1/3 Bar
           Soil Moisture
r *
_ + +
k .
(day~ 1)
      after waste incorporation into soil.
+M/M =  originally loaded at medium rate
         (0.15%), reloaded at medium rate.
*L/H - originally loaded at low rate
       (0.075%), reloaded at high rate
* *N/H =  nonacclimated soil loaded at high
         rate (0.3%).
+ +  = not analyzed.
**H/NR = originally loaded at high rate
         (0.3%), not reloaded.
 (0.3%).  The half-life for PCP in this soil
 was 151 days. Acclimation of soil micro-
 organisms to PCP would be expected to
 result in lower half-life values when waste
 is reapplied.
   Transformation of hazardous wastes in
 all waste-soil combinations was evaluated
 by measuring changes in the toxicity of
 the water soluble fraction (WSF) of waste-
 soil mixtures as indicated by the Microtox
 test.  An  increase  in WSF toxicity was
 observed for all waste-soil mixtures evalu-
 ated during the first experimental  period,
 and a decrease in WSF toxicity was gen-
 erally observed during the second  experi-
 mental period. These results were consid-
 ered to be indicative of the formation and
 subsequent degradation of toxic interme-
 diate constituents.
   The Microtox assay proved to be an ex-
 tremely sensitive assay that did not corre-
 late with  gross degradation indicators
 such as soil respiration studies, and there-
 fore could not be used to positively iden-
 tify the level at which soil biodegradation
 was inhibited. The WSF toxicity results did
 indicate, however, that transformation of
 the waste occurred for all waste-soil com-
 binations. Since the WSF may contain haz-
 ardous intermediates, it may be concluded
 that lower loading rates will be required if
the treatment evaluation criterion is com-
 plete  detoxification  of the  waste-soil
   Results of mutagenicity evaluations for
 soil detoxification of petroleum refinery
wastes indicated a  reduction from muta-
genic to nonmutagenic activity with treat-
 ment  time for API  separator sludge in
 Durant clay loam soil and for slop oil emul-
sion solids incubated in Durant clay loam

and  in Kidman sandy loam soils. Wood
preserving wastes, however, were not ren-
dered nonmutagenic after 400 days of soil
incubation  in  Durant clay loam  soil  at
waste loading rates of 1.3 percent and 0.7
percent for creosote and PCP wastes, re-
spectively. However, no mutagenicity was
detected at a loading rate  of 0.3 percent
PCP waste in Kidman sandy loam soil, and
the initial positive mutagenic potential for
a loading rate of 1.0  percent  creosote
waste was reduced to  a  nonmutagenic
level with a treatment time of 400 days.
  Immobilization of hazardous waste was
measured using one bioassay, the Micro-
tox test, of laboratory column leachates.
Microtox  test  results  indicated the
presence of little toxicity in  leachates from
petroleum wastes incubated  at the high
loading rates in both Durant clay loam and
in Kidman sandy loam soils. Leachates pro-
duced from creosote and PCP loaded col-
umns exhibited definite toxicity to Micro-
tox,  thus  indicating  the  potential  for
leaching of water soluble  toxicants that
should be considered when defining waste
loading rates for these experimental soils.
The absence of Microtox test toxicity of
some leachates did not conclusively dem-
onstrate that leachates were free of toxic
  Partition  coefficients that were deter-
mined for PAH and volatile constituents of
all four wastes indicated highest partition-
ing  of constituents into the oil (waste)
phase. Relative concentrations between
water  and  oil  (waste)  phases for  PAH
constituents  were  generally 1:1000  to
1:100,000, with the higher ratios observed
for the petroleum wastes. Relative  con-
centrations among  air:water:oil (waste)
phases for volatile constituents were
generally 1:100:100,000.
  Specific  conclusions  based on objec-
tives and results of this research  project
  (1)  Literature assessment  of specific
      hazardous constituents experimen-
      tally  identified in each candidate
      waste indicated a potential for treat-
      ment in soil systems.
  (2) Characterization of  all candidate
      wastes by  GC/MS,  GC, and HPLC
      identified the PAH  class of semi-
      volatile constituents as common to
      each waste.  In addition, the PCP
      wood preserving  waste contained
      pentachlorophenol  and  some
      dibenzo-p-dioxins and  dibenzofur-
      ans; however, no tetrachlorodiben-
      zodioxins were detected at a detec-
      tion limit of 10 ppb.
(3) A comparative study of the sen-
   sitivity of five microbial assays for
   selection  of initial waste  loading
   rates indicated that Microtox, soil
   dehydrogenase, and soil nitrification
   assays were the most sensitive to
   the presence of hazardous wastes,
   and would result in selecting lower
   loading rates. Soil  respiration and
   viable soil microorganism  plate
   counts were much less sensitive to
   hazardous waste application, and
   would result  in  selecting higher
   loading rates.
(4) Based on screening assay  results,
   initial loading rates for petroleum
   refinery wastes were indicated to be
   an order of magnitude higher than
   for wood preserving wastes.
(5) A methodology was developed for
   measurement  of   "volatilization-
   corrected" degradation rates in soils
   in order to more accurately evaluate
   degradation as a treatment  mecha-
   nism. For the semivolatile PAH com-
   pounds studied, volatilization was
   important only for naphthalene.
(6) A methodology was developed for
   measurement  of  partition coeffi-
   cients for hazardous constituents
   among waste  (oil), water,  and air
   phases.  It  was  not possible to
   measure the partitioning between
   the water soluble  extract and  soil
   because the very low water solubil-
   ities of the aromatic hydrocarbons
   and the very high  affinity of these
   constituents for  soil  resulted  in
   reduction of constituent concentra-
   tions in the water soluble extract to
   below detection limits. The method-
   ology proved useful for obtaining
   partition  coefficients  for  waste
   (oil)/water (K0), air/water (Kh), and
   air/waste (oil) Koa), for volatile con-
   stituents  and for waste (oil)/water
   for semivolatile constituents.

(7)  PAH constituents contained in each
    of  the four wastes investigated
    were degraded under conditions of
    initial waste application to nonac-
    climated soils as well as when
    wastes were reapplied  to soils. In
    general, PAH degradation  did  not
    appear to be influenced by varia-
    tions in soil type  or loading rates
    used in this study; however, PAH
    degradation in petroleum  refinery
    wastes generally  exhibited higher
    rates than in wood  preserving
(8)  All waste-soil  mixtures tested ex-
    hibited an initial increase  in WSF
      toxicity followed by a decrease in *
      toxicity with incubation time. The I
      pattern of WSF toxicity with time
      was considered to be an indication
      of formation and  degradation  of
      toxic intermediates.
  (9) Partition coefficients determined for
      PAH and volatile constituents con-
      tained  in each of the wastes eval-
      uated demonstrated highest parti-
      tioning of constituents into the  oil
      (waste) phase. Relative concentra-
      tions between water and oil (waste)
      phases for PAH constituents were
      generally 1:1000 to 1:100,000, with
      the higher ratios observed for the
      petroleum wastes. Relative concen-
      trations among air:water:oil (waste)
      phases for VOCs  were generally
  The  following  recommendations  are
made in regards to conducting future soil
treatability studies for hazardous wastes:
  (1)  The use of chemical analyses alone
      appears to be insufficient to charac-
      terize treatability  potential of  a
      hazardous  waste in soil. Use of
      chemical analyses alone fails to ac-
      count for  interactions of compo-
      nents in a waste and the production
      of toxic/mutagenic  metabolites.
      Use of bioassays to characterize the
      degradation, transformation and im-
      mobilization processes should be
      used  to  complement chemical
      analyses information.
  (2)  Careful  attention  in  future  soil
      treatability studies should be given
      to potential fate, transport and ef-
      fects of  intermediate  products
      formed  during  waste-soil interac-
      tions. Information obtained  con-
      cerning degradation, transforma-
      tion, and immobilization of hazard-
      ous constituents should be used to
      aid in selecting waste loading rates
      to be used in field evaluation study.

  (3)  When determining partition coeffi-
      cients (K0, Kh, KD, Kao) for evalua-
      tion of immobilization processes in
      waste-soil mixtures,  several differ-
      ent ratios  of waste:water volumes
      and several water soluble fraction
      volumes:soil weights  should  be
      used  to  generate   partition  iso-
      therms  with several points in order
      to evaluate the ranges of linearity
      for the isotherm and  partition coef-
      ficient values. Determination of par-
      tition coefficients between soil and

      water soluble extract of the waste
      (KD) will require larger amounts of
      waste and water than used in this
      investigation to  generate larger
      amounts of water soluble fractions.
  The full report was  submitted in fulfill-
ment of Cooperative  Agreement  No.
CR-810979 to Utah State University under
sponsorship of the U.S. Environmental Pro-
tection Agency.
   R. C.  Sims,  J. L.  Sims, D.  L. Sorensen, W.  J. Doucette, and L. L Hastings
     are with Utah State University, Logan, UT 84322.
   John £. Matthews /s the EPA Project Officer (see below).
   The complete report consists of two volumes, entitled "Waste/Soil Treatability
     Studies for Four Complex Industrial Wastes: Methodologies and Results,"
     "Volume 1.  Literature Assessment, Waste/Soil Characterization,  Loading
     Rate Selection," (Order No. PB87-111 738/A S; Cost: $ 18.95)
     "Volume 2. Waste Loading Impacts on Soil Degradation, Transformation, and
     Immobilization,"(Order No. PB 87-111 746/AS; Cost: $24.95)
   The above reports  will be available only from: (costs subject to change)
           National Technical Information Service
           5285 Port Royal Road
           Springfield, VA 22161
           Telephone: 703-487-4650
   The EPA Project Officer can be contacted at:
           Robert S.  Kerr Environmental Research Laboratory
           U.S. Environmental Protection Agency
           P.O. Boz1198
           Ada, OK 74820

United States
Environmental Protection
Center for Environmental Research
Cincinnati OH 45268
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