United States
Environmental Protection
Agency
Solid Waste
Emergency Response
(5102W)
EPA542-N-95-007
November 7995
Issue No. 22
vvEPA
The Applied Technologies Journal for Superfund Removals & Remedial Actions & RCRA Corrective Actions
CANADIAN BIO-REACTOR
FLARE PIT WASTES - TEST RESULTS
Canada, which has an abundance
of flare pit waste sites, selected flare
pit wastes as the third waste to be
tested in its Bio-Reactor. The Ca-
nadian Bio-Reactor Project tests the
premise that hydrocarbon contami-
nated soils and soil-like wastes with
high levels of salts can be treated ef-
fectively and efficiently by combin-
ing leaching with soil biological pro-
cess by exerting strict controls on all
inputs, the physical-chemical envi-
ronment and the fate of the trans-
formed waste products. TECH
TRENDS has previously reported
on the results of the first two wastes
created in the Bio-Reactor. A major
Bio-Reactor Project axiom has been
that good structure is essential for
bioremediation of solid wastes.
However, with the third waste to be
treated, results suggest that super so-
phisticated controls and procedures
may not be necessary to eliminate
hydrocarbons from wastes as long as
the basic needs of the microorgan-
isms are satisfied in the combined
leaching and bioremediation.
Flare pit wastes are common at
sites in oil and gas producing re-
gions; and most, if not all will re-
quire remediation. Flare pits are lo-
cated at well sites and some pipeline
pump stations where waste gases are
burned off; and, periodically liquid
waste hydrocarbons may be diverted
to pits. Pits may also contain brine,
condensates, lube oils, tank bottom
sludges, pigging waxes and other
wastes that comprise a cornucopia
for microbes. For the Bio-Reactor,
flare pit material in a solid form
contained 8.5% hydrocarbons, a
high level of brine salts (EC > 30
dS m'1) and had a 7.5 pH. The
waste had very heavy clay clods
and balls of tar-like material and
posed handling and wettability
problems. Factors tested in the
Bio-Reactor included the potential
value of aggregation (i.e., does par-
ticle size have an effect); cultiva-
tion; inoculation practices; and
waste depth under uniform condi-
tions of nutrients, water and forced
aeration (i.e., how deep can be
wastes be layered before aeration
becomes a problem —20 cm versus
40 cm).
Treatment in the Bio-Reactor
resulted in a 30% decrease in hy-
drocarbons during the seven-month
period for the "best" (i.e., amended)
treatment. Unexpectedly, there
were also substantial losses in the
"worst" (i.e., no amendment) treat-
ment which was characterized as
having very poor structure and po-
rosity. It did not matter whether or
not the waste was aggregated, culti-
vated, or inoculated or to which
depth it was piled. Differences in
hydrocarbon loss rates among waste
aggregated, cultivated, inoculated
or piled to 20 or 40 cm depth ap-
peared to be small. All of this sug-
gests that the ability of microorgan-
isms to function well under what
appear to be very adverse conditions
was underestimated.
The Bio-Reactor can effectively
treat flare pit wastes by first remov-
ing the salts through leaching and
then reducing the Hydrocarbon con-
tents through bioremediation.
Although the treated material has rela-
tively high residual hydrocarbon levels,
these hydrocarbons have a low bio-
availability so that the material is non-
Hydrocarbons
Bioremediation
Flare Pit Waste
toxic in a battery of tests and w;ll pass
leachate requirements.
As a side note, see the companion
article in this issue of TECH
TRENDS, p. 3, which discusses the
serious analytical problems encoun-
tered and the remedy.
For more information, call the Bio-
Reactor Project's Project Manager,
Lin Callow, of Gulf Canada Re-
sources, Ltd. at 403-233-3924.
For progress reports and more de-
tailed reports, contact Lisa Crichton
at the Canadian Association of Pe-
troleum Producers (CAPP) by
phone at 403-267-1100 or by FAX
at 403-261-4622. There is a charge
for the reports. Information in this
article is from the August 1995 is-
sue of the "BIO-REACTOR
PROJECT Newsletter," published
by CAPP.
The Bio-Reactor Project is co-
funded by the CAPP; by En -:ron-
ment Canada through its contribu-
tions to the Development and Dem-
onstration of Site Remediation
Technology Program (DESRT),
GASReP and Federal Program on
Energy Research and Development;
and by the Alberta Environmental
Research Trust. The research is
conducted by the Alberta Environ-
mental Centre in Vegreville and the
University of Calgary. The Bio-
Reactor is located at the Morrison
Petroleums, Ltd. Nevis Sour Gas
Plant.
For your information, the results
of Bio-Reactor treatment of Waste 1,
agricultural topsoil, and Waste 2,
saline diesel invert mud drill cut-
tings, were reported in the May 1994
issue of TECH TRENDS (Docu-
ment No. EPA 542-N-94-004) and
can be ordered by sending a u-quest
to NCEPI by fax (513-489-8695) or
by mail (P.O. Box 42419, Cincin-
nati, OH 45242-20419).
Recycled/Recyclable
I Printed with Soy/Canota intc on paper
that contains at least SOS recycled fiber
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ALTERNATIVE TREATMENT FOR PAH AND PCP
By Teri Richardson, EPA National Risk Management Research Laboratory
The DARAMEND™ bioremediarion
technology is an effective alternative to soil
washing, incineration or landfilling soils
containing high levels of polynuclear aro-
matic hydrocarbons (PAHs) and chlori-
nated phenols, including pentachlorophe-
nol (PCP). These contaminants are typi-
cally considered too toxic for bioremeoia -
rjon and are found at approximately 400
industrial wood treatment facilities in the
United States and an additional 200 sites
in Canada. The patcnied DARAMEND™
technology, applicable to both in-situ and
ex-situ remediation of soils, was developed
by GRACE Dearborn Inc's Environmen-
tal Consulting Group in Mississauga,
Ontario, Canada. A full-scale demonstra-
tion of the ex-situ application was con-
ducted at the Domtar Wood Preserving
Facility in Trenton, Ontario, by the EPA's
Superfund Innovative Technology
Evaluation (SITE) Program. The SITE
evaluation built upon previous evaluations
of bench and pilot scale testing by the De-
veloper under Canada's Development and
Demonstration of Sice Remediation Tech-
nology (DSERT) Program. The technol-
ogy provides short- and long-term protec-
tion because it provides irreversible treat-
ment of PAHs and total chlorinated
phenols (TCPs) by eliminating these con-
taminants from the soil, dius preventing
further ground water contamination and
pollutant migration.
An important operating parameter of die
technology is an understanding die specific
physical and chemical properties of the
contaminated soil diat could limit die ef-
fectiveness of bioremediation. Once an
evaluation of various soil properties is com-
pleted, die developer selects an organic
amendment formulation widi die specific
particle size distribution and nutrient pro-
file to create ideal soil microbiological con-
ditions. The organic amendments enable
the soil matrix to supply biologically avail-
able water and nutrients to contaminant-de-
grading microorganisms, transiendy bind-
ing pollutants to reduce die acuie tcaticity
ofthe soil's aqueous phase. This, allows me
microorganisms to survive in soils contain-
ingvery nigh concentrations of toxicants.
The technology is a relatively simple soil
remediation system, both in design and
implementation. It consists of diree inte-
grated treatment components (I) addition
of die appropriate specially formulated
solid-phase organic soil amendments to die
target matrix; (2) distribution of me soil
amendments through die target matrix and
the homogenization and aeration ofthe
target matrix using specialized tilling equip-
PAHs, TCPs
Bioremediation
Soil
ment; and (3) soil moisture control using a
specialized system to maintain moisture
content within a specified range, to facili-
tate rapid growdi of an active microbial
population and prevent the generation of
leachate. The process involves a certain
amount of materials handling — the ex-situ
application more so man die in-situ appli-
cation.
For in-situ applications, soil is initially
broken up with excavation equipment to a
depth of 0.6 meters, which is die limit for
the specialized tilling equipment,. For ex-
situ applications, contaminated soil is exca-
vated and screened to 10 cm to remove de-
bris mat might interfere with die incorpo-
ration of organic amendments. Screened
soil is spread uniformly in the constructed
treatment plots to a depth of 0.5 meters.
The plots are lined with a high-density
polyethylene liner (impermeable to die tar-
get compounds), underlain wirh 10 cm of
screened sand to prevent structural damage.
Another 15-cm thick sand layer and a
4mm-thick fiber-pad are spread on top of
the liner to minimize the potential for
direct contact between die liner material
and tillage quipment. The SITE treatment
(continued on page 4)
SONIC PULSE BURNER SYSTEM
By Marta Richards, National Risk Management Research Laboratory
Sonotech, Inc. of Adanta, Georgia has
developed the Cello™ pulse combus-
tion burner that incorporates a combus-
tor that can be tuned to induce large am-
plitude sonic pulsations inside combus-
tion process units such as boilers or in-
cinerators. The pulsations are claimed to
increase heat release, miring and mass
transfer rates in rhe combustion process,
resulting in faster, more complete com-
bustion. Sonotech has targeted waste in-
cineration as a potential application for
die system. The Superfund Innovative
Technology Evaluation (SITE) Program
evaluated the Cello™ system on die pi-
lot-scale rotary kiln incineration system
at die EPA Incineration Research Facil-
ity in Jefferson, Arkansas. In the dem-
onstration, die Cello™ system was ret-
rofit to the primary combustion cham-
ber.
A pulse combustor typically consists of
an air inlet, a combustor section and a
tailpipe. In the Cello™ pulse combus-
tor, fuel oxidation and heat release rates
vary periodically with time, producing
periodic variations or pulsations in pres-
sure, temperature and gas velocity.
Sonotech claims that large amplitude
resonant pulsations excited by its fre-
quency-tunable pulse combustor can sig-
nificantly improve an incinerator's per-
formance, thereby reducing aipttal in-
vestment and operating costs ,for a wide
variety of incineration systems The
Cello™ combustor can be incorporated
into the construction of most new com-
bustion devices or can be retrofit to
many existing systems. It is designed to
be used to treat any material typically
treated in a conventional incinerator;
and, Sonotech believes the technology is
ready to be used for die full-scale incin-
eration of contaminated solids, liquids,
sludges and medical wastes. Contami-
nated soil, sludge and tar samples col-
lected from two manufactured gas plant
Superfund sites were blended for use in
Soils, Sludges,
Liquids
this SITE demonstration.
The primary objective of the demon-
stration was to develop test data to evalu-
ate die treatment efficiency of rhe
Cello™ combustor system compared to
conventional combustion. The Cello™
system increased die incinerator waste
feed rate capacity by 13 to 21%
compared to conventional combustion.
The capacity increase was equivalent to
reducing die auxiliary fuel needed to
treat a unit mass of waste from 27.3
thousand British thermal units per
pound of waste (kBtu/lb) for conven-
tional combustion to 21.5 kBtu/lb for
the Cello™ system; however, die dem-
onstration waste had significant heat
content. Visual observations indicated
improved mixing in die incinerator cav-
ity with the Cello™ system operating.
Benzene Destruction and Removal
Efficiencies (DREs) for all 12 test runs
(continued on page 4)
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"TOTAL HYDROCARBON'^IVIEASUREMENTS
CAUSE CONFUSION I
Canada's Bio-Reactor Project turned
up an unexpected "by-product" when
it set out to assess the rate of remedia-
tion of flare pitwastes. The finding
should provide some sound guidance
for methodology to quantify
bioremediation success.
During bioremediation of the flare
pit waste, a serious analytical problem
was identified. The first results on
hydrocarbon contents in the various
treatments after four and seven
months surprisingly indicated that the
losses of oil were much higher than
predicted by either chemical composi-
tion or the lab treatability study. As a
result a critical evaluation was made of
the standard methodology for extrac-
tion and quantification of hydrocar-
bons in soil-like wastes. This study,
involving two independent methods
for measuring TEH, indicates that the
first losses were overestimated and
that actual losses were much less than
estimated by the original method.
Therefore, selection of analytical
method is crucial; and, remediation
operators may be seriously misled by
results obtained by inappropriate
methods. The analytical method
should be picked based on the knowl-
edge of the specific hydrocarbon ma-
terial to be tested. Carbon number
scans can be used to measure hydro-
carbon fraction that is present.
Currently, all regulatory agencies
and developers of remediation tech-
nologies rely on analytical results gen-
erated by laboratories specialized in
chemical analysis. Precise and accu-
rate methods are required to meet key
criteria for hydrocarbon residuals set
by regulators or to assess the success of
a remediation strategy. Analysts use
numerous methods; and, the results of
comparisons of these methods may be
made under the assumption that all of
them measure the same pool of hydro-
carbons. The determination of TEH
requires two separate steps: (1) ex-
traction from the solid waste and
(2) quantification of the material ex-
tracted. Each of these steps is subject
to errors or shortcomings and extrac-
tion efficiency cannot be assessed
without a "good" detection/quantifi-
cation method — hence the impor-
tance of the Canadian study or TEH
procedures.
Hydrocarbons
Bioremediation
Flaro Pit Waste
/
To quantify TEH, the study chose
two methods routinely used by ana-
lytical service labs, but which are dis-
tinctly different: the gravimetric
method (extractable material dried and
weighed) and the Gas Chromato-
graphic (GC) method (extractables
separated based on mean boiling
point).
The gravimetric quantification mea-
sures heavy hydrocarbons, with light
hydrocarbons lost as volatiles. The
GC method measures light hydrocar-
bons and cannot detect very heavy hy-
drocarbons. Both methods would give
similar results onlywhen there is no
heavy hydrocarbon fraction and when
no volatiles are present in the light hy-
drocarbon fraction. Since gasoline, jet
fuel, diesel fuel, crude oil and oily
sludges never satisfy these conditions,
results using the two detection meth-
ods are guaranteed to be different.
Most importantly, assessing the
biotreatability or a waste using one
method or the other will lead to differ-
ent conclusions, as the light fraction
will be lost and the heavy fraction con-
served.
Since the choice of organic solvent
used to generate the extract may influ-
ence the TEH estimate, the flare pit
waste was extracted with standard sol-
vents and quantified by both methods.
The solvent extractions yielded a com-
plete mixture of heavy and light hy-
drocarbons. Thus, the method of ex-
tracting the flare pit waste had little ef-
fect in this TEH estimate.
However, the quantification method
had a dramatic effect on the TEH esti-
mate. Using dichloromethane (DCM)
extraction solvent, extractable hydro-
carbons were 5.9% with gravimetric
detection method and 4.0% with GC.
.Using the toluene solvent, extractable
hydrocarbons were 5-9% with gravi-
metric and 2.9% with GC. With the
super-critical fluid (CO2) solvent, ex-
tractable hydrocarbons were 5.8%
with gravimetric and 3.0% with GC.
In certain cases, different extractions
will remove different fractions.
The conclusion of the Bio-Reactor
methods study is that exactly the same
method should be used throughout a
remediation sequence. Further, for re-
porting routine analyses, the term
TPH should be reserved exclusively for
methods that truly estimate total hy-
drocarbons. For methods which esti-
mate some unknown fraction, terms
such as "DCM extractable or GC de-
tectable TEH" should be adopted to
reflect more accurately what is being
measured.
For more information, call Lin Callow
of Gulf Canada. Resources, Ltd., who is
the Bio-Reactor Project's Project Man-
ager, at 403-233-3924.
Material for this article is based on in-
formation in the "BIO-REACTOR
PROJECT Newsletter, " Issue 3, August
1995, published by the Canadian Asso-
ciation of Petroleum Producers.
NEW FOR THE BOOKSHELF
EPA has published INNOVATIVE
SITE REMEDIATION TECHNOL-
OGY; BIOREMEDIATION, Volume
1. This monograph on bioremedia-
tion is one of a series of eight on inno-
vative site and waste remediation tech-
nologies that are the culmination of a
multi-organizational effort involving
more than 100 experts. It provides the
experienced, practicing professional
guidance on the application of innova-
tive processes considered ready for full-
scale application. Other monographs
in this series will address chemical
treatment, soil washing/soil flushing,
stabilization solidification, solvent/
chemical extraction, thermal desorp-
tion, thermal destruction and vacuum
vapor extraction.
Volume 1 can be ordered from the
American Academy of Environmental
Engineers by phone (410-266-3311),
by FAX (410-266-7653) or by mail
(130 Holliday Court, Suite 100, An-
napolis, MD21401). Please refer to
the Document No. EPA 542-B-94-
006 when ordering. The cost for Vol-
ume 1 is $59.95. The cost for the se-
ries is $395.00.
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(continuedfrom page 2)
area covered an area, of 2300 aq. meters
and allowed treatment of approximately
1,500 tons of soiL
The treatment plots may abo be con-
tained widiin a temporary waenpcoof
structure to produce a wanner environ-
mencin northern latitudes, and to aid in
the mention of soil moisture. The water-
proof structure consists of an aluminum
fame covered by a shell of polyethylene
sheeting and b left open at each end to al-
low for equipment access.
The SITE evaluation consisted of two
plots, aTreatment Plot and a No-Treat-
ment Plot, both containing excavated con-
taminated soil from die same source en-
sue. The plots were constructed identically,
wtdi the exception diat die No-Treatment
Plot was only 2 meters x 6 meters, while
die Treatment Plot was a 6 meter x 36
meter area. The No-Treatment Plot was
left idle over die course of the demonstra-
tion and was isolated
After 254 days of treatment, die
DARAMEND™ bioremediarion
treatment process achieved an overall ap-
proximate 94% removal of PAHs and an
overall 88% reduction of chlorinated
phenols in die Treatment Plot. Total
PAHs were reduced from an average of
1,710 milligrams per kilogram (makg) to
98 mg/kg and TCPs were reduced (com an
average of352 mg/kg to 43 mg/kg. At die
end of the treatment process, the treatment
plat soil sample was considered non-toxic
The canhworms exhibited a 0% mean
mortality rate compared to a 100% mean
mortality rate prior to treatment. Lettuce
and radish seeds exhibited a 100% to 52%
mean inhibition of germination nite before
treatment and a 33% and 0% ran? respec-
tively post treatment. No significant re-
duction occurred in die No-Treaiment
Plot during die demonstration. Afull-
scafc cleanup of diis site using diis technol-
ogy would cost between $640.00 for an in-
situ plot widi an attendant unit ast of
$133/cubic m ($100/cubicyard), and
$480,000 for an ex-situ plot widi an atten-
dant unit cost of $420/ cubic m. ($320/sq.
yard).
For more information, call Teri Richardson
of EPA's National Risk Management Re-
search Laboratory, Cincinnati, Ohio at 515-
569-7949. To get on the mailing list for a
SITE Capsule Report and Innovative Tech-
nology Evaluation Report, send a FAX'(515-
569-7105) to Teri Richardson
(continuedfrom page 2)
were greater man 99.994%, with a slight
improvement in die third decimal place
for the Cello™ test results. With the
Cello™ system operating, die average
benzene emission rate was reduced from
7.7 to 5.7 milligrams per hour (mg/hr)
at die afterburner exit. This represents a
25% reduction, aldiough changjes of diis
magnitude are widiin the precision of
diis type of measurement. Naphdialene
DREs were greater than or equ;d to
99.998% for all test runs. Widi the
Cello™ system operating, die siverage
naphdialene emission rate was reduced
from 1.2 to 1.1 mg/hr at the afterburner
exit. This represents a reduction, al-
diough again this magnitude of change
is also widiin die precision of die type of
measurement. The average afterburner
carbon monoxide emissions, corrected
to 7% oxygen, decreased from 20 parts
per million (ppm) widi conventional
combustion to 14 ppm widi die
Cello™ system. This represents a 6%
reduction. Average afterburner nitrogen
oxide emissions, corrected to 7% oxy-
gen, decreased from 82 ppm with con-
ventional combustion to 77 ppm widi the
Cello™ system. This represents a 6% re-
duction. Average afterburner soot
emissions, corrected to 7% oxygen,'were
reduced from 1.9 milligrams per dry stan-
dard cubic meter (mg/3scm) For conven-
tional combustion to less dian 1.0 mg/
dson widi die Cello™ system. This rep-
resents a 53% or greater decrease in soot.
However, all soot measurements were
within a factor of 3 of die mediod detec-
tion limit; so, the significance of diis re-
duction is uncertain. Total system com-
bustion air requirements, determined
from stoichiometric calculations, were 5%
lower widi die Cello™ system in opera-
tion.
For more information, callMarta
Richards at EPA's National Risk
Management Research Laboratory at 515-
569-7692. A Technology Capsule (Docu-
ment No. EPA/540/R-95/502a) is avail-
able from CERI by catting 513-569-7562
and referring to the document number.
To get on the mailing list for s.n Innova-
tive Technology Evaluation Report, send a
FAX (515-569-7620) to Marta Richards.
~lST/bjlDfeR INF0/ON-LJNE ACCESS
To *# oa the ptroanent nciting. 1st lot T«dtnb!o» feaownon
ies oFttm; or pBtwoo* Issuer oiT«eh. Ttaocb, sewi a
United StatM
Environmental Prottctton Agency
National C«nt«rYorEnvfctKim«ntai
Publication! and Information
P.O. Box 42419
Cincinnati. OH 45242-2410
Official Business
Penalty for Private Use $300
EPA 542-N-95-007
November 1995
Issue No. 22
BULK RATE
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