Vast areas of abandoned mine tailings in southeast Kansas are to be reclaimed by covering them with topsoil and revegetating. Although this procedure will reduce wind erosion and runoff of heavy metal contamination, the impact on leaching of metals is not known. A greenhouse experiment was initiated to measure the changes in metal mobility resulting from covering mine tailings with up to 60 cm of soil and establishing vegetation. Columns with different depths of topsoil over tailings were planted with a cool- season grass (tall fescue, Festuca arundinacea Schreb), and a warm-season grass (big bluestem Andropogon gerardii Vitm.). Duplicate columns for each treatment were prepared for unsaturated flow and leached with 0.001 M CaCl2 at a flow rate of 3.8 L/s. A vacuum (0.03 MPa) was applied to the bottom of the column, and effluents were collected every 24 h. The concentrations of cadmium, lead and zinc in the leachate were measured. After six months, plants were harvested and analyzed for heavy metals. Sequential extractions of column subsoil will be conducted to evaluate different metal forms labile for leaching.
Keyword(s): heavy metals, leaching, unsaturated flow.
Oral presentation in research track.
The U.S. Bureau of Mines, Salt Lake City
Research Center (SLRC), is investigating the
biological reduction of selenate and selenite to
develop a bioreactor for selenium removal from
various processes and wastewaters. Indigenous
selenium-reducing microorganisms vary
somewhat from site to site and overgrowth of an
established indigenous selenium-reducing
microbial population by other indigenous
nonselenium-reducing bacteria can pose a major
bioreactor problem. In attempts to overcome this
problem, the SLRC has used a consortium of
selenium-reducing bacterial isolates as biofilms
and immobilized in alginate beads to treat
wastewaters containing 0.6 to 30.0 mg/L
selenium. Reduction of both selenate and selenite
to elemental selenium was obtained. Selenium
reduction has been observed in a variety of
bacteria under both aerobic and microaerophilic
conditions. The SLRC has also used immobilized
crude enzyme preparations to remove selenium
from mining process solutions. The enzyme
preparations reduced selenium in process
solutions containing 100 mg/L cyanide; selenium-
reducing bacteria are not cyanide tolerant. In
laboratory tests, over 98% selenium removal has
been attained using mining wastewaters.
Keyword(s): selenium reduction, bacteria, enzyme, immobilization.
Poster presentation.
Predictions of bacterial transport/attenuation
during passage through porous media are widely
based on filtration theory. Cell-collector affinity,
in this context the fraction of collisions between
the biocolloid and collector material that result in
bacterial sorption, is generally represented by a
single value, a, that must be empirically
determined. This is often accomplished through
bench-scale simulations of field-scale situations.
Using radiolabeled bacteria to measure biocolloid
retention within a uniform bed of spherical
borosilicate beads in a bench-scale reactor, we
have shown that there is a wide range of affinities,
or a values, within even monoclonal bacterial
populations. A probability density function (PDF)
representing the distribution of a values in a
population of deep subsurface bacteria was
mathematically deduced. That PDF was then used
to test the importance of such variation in scaling
from laboratory results for prediction of bacterial
transport in large reactors or in the field.
Prediction of far-field concentrations of residual
microorganisms proved extremely sensitive to the
representation of a values in the bacterial
population.
Keyword(s): biocolloid transport, porous media, heterogeneities, modeling.
Poster presentation.
Hard rock mining has been an important factor
in the development of Montana as well as many
western states for over one hundred years. As a
result of these past mining operations that
occurred prior to the passage of the mined land
reclamation and other environmental statutes,
mining was not regulated. Therefore many
environmental degradation and reclamation
problems exist at these "pre-law" mining sites that
are abandoned or inactive today.
In an effort to eliminate the environmental
degradation problems at these sites, the State of
Montana, through the Montana Abandoned Mine
Reclamation Bureau completed an inventory that
identified some 6,000 sites, many of which require
some form of reclamation/cleanup. It soon
became apparent that the number of the
abandoned and inactive mines needing cleanup far
exceeded the Abandoned Mine Reclamation
Bureau's ability to address this number of sites.
Additionally, it was determined that many of these
sites had multiple surface and mineral owners,
including private, federal and state lands, as well
as hazardous substances. These factors further
complicate the issues of Responsible Party
determination, responsibility for cleanup, and the
cleanup standards that need to be met.
This presentation addresses the actual hands-
on problems that need to be resolved when trying
to coordinate and implement environmental
cleanup and reclamation at these kinds of sites.
Keyword(s): hard rock mining, reclamation, inventory, hazardous substances, responsible parties.
Oral presentation in research track.
The National Institute of Environmental Health
Sciences (NIEHS) Superfund Basic Research and
Training Program (SBRP) was established in 1986
by the Superfund Amendments and
Reauthorization Act (SARA). This is a unique
program of basic research and training grants
directed towards understanding, assessing and
attenuating the adverse effects on human health
resulting from exposure to hazardous substances.
Grants made under the SBRP are for coordinated,
multicomponent, interdisciplinary studies. The
program's primary goal is to provide an
opportunity for researchers from the biomedical
sciences, engineering, ecology, and the
geosciences to explore the scope of the problems
of uncontrolled hazardous waste and seek
solutions. The program, now in its eighth year, is
designed to provide a broader and more detailed
body of scientific information to the field of
environmental management. The research findings
from this program are being used by state, local,
and federal agencies, private organizations and
industry in making decisions related to the
management of hazardous substances.
Many innovative technologies for detecting,
assessing and reducing toxic materials in the
environment have been developed as a result of
funding by the SBRP. To assist grantees, the
SBRP has developed a technology transfer
strategy designed to handle the unique problems
associated with transferring multidisciplinary
technology from basic research to applied
research. By 1995 this will result in the validation
of many of the research products being generated
by this program as driven by technology
demonstrations and commercialization. A number
of these novel technologies are presented. The
SBRP has actively pursued increasing the
availability of these findings to the scientific
community. Currently, the database detailing each
program is available through the NIEHS Gopher
server on the Internet. A description of how to
access this system is given. To encourage the
interdisciplinary nature of the program, the SBRP
has strongly encouraged grantees’ participation in
scientific conferences and workshops. A listing of
conferences and workshops sponsored by the
SBRP for the years of 1993-1994 will be
presented.
Keyword(s): superfund, technology transfer, database.
Poster presentation.
Biohydrometallurgy is the science and
engineering concerned with the extraction of
chemical elements from ores, concentrates and
rocks through the solubilizing action of
microorganisms. Acidophilic bacteria, especially
Thiobacillus, are associated with this process and
are used commercially in bioleaching (heap
leaching.) These naturally occurring
microorganisms also increase the rate at which
acid mine (rock) drainage occurs. Traditional
studies do not easily allow visualization of
bioleaching. Flowthrough cell techniques adapted
from biocorrosion/biofilm research used at
Montana State University's Center for Biofilm
Engineering will be presented and discussed.
Comparisons between these new methods will be
made with the more traditional batch/column
studies, usually associated with
biohydrometallurgical research.
Keyword(s): biohydrometallurgy, bioleaching, biofilm, Thiobacillus, techniques.
Oral presentation in research track.
The differential soil bioreactor is a continuous-
flow, laboratory treatability-study device in which
groundwater, supplemented with nutrients, is
recirculated through a disc of aquifer material at a
rate that simulates actual groundwater flow. A
high recycle ratio ensures that all bacteria in the
disc are exposed to the same physiochemical
environment, so rate and yield parameters needed
for modeling in-situ bioremediation can, in
principle, be derived directly from measurements
of inlet and outlet concentrations of contaminants,
nutrients and cells. Results are shown for the
biodegradation of trichloroethylene by
methanotrophic bacteria in sediments from the
Savannah River site. The limitations of the
technique for slow-flowing aquifers are discussed.
Keyword(s): in-situ, bioremediation, trichloroethylene, methanotrophs.
Oral presentation in research track.
The transport of bacteriophages MS-2 and
PRD-1 through three different saturated porous
media formations were investigated in a two-
dimensional pilot-scale flume (10m L, 0.05m W
and 1.2 H), located in the Hydraulics Laboratory
of the University of Colorado at Boulder. The
migration of the virus-sized biocolloids co-
injected with a bromide tracer were monitored in
both space and time using up to fifteen sampling
ports along the length of the flume. The three
different simulated aquifer formations—a cross
section of #30 sand (U.S. sieve size)
homogeneously packed; a cross section of #30
sand, #8 sand (10 cm layer) and #30 sand; and a
cross section of #30 sand, #30 sand coated with
iron oxides (10 cm layer) and #30 sand—highlight
the influences of physical and chemical aquifer
media heterogeneities on the migration of virus-
sized biocolloids. Included in this discussion is a
description of the pilot-scale design and
associated boundary conditions, methods for
positioning injection and sampling points,
techniques for packing and pre-experimental
monitoring, approaches for analyzing and
extrapolating information from breakthrough
curves, and results from the experiments.
Keyword(s): biocolloid, transport, heterogeneities.
Oral presentation in research track.
Processes have been developed for the
restoration of environments contaminated with
hydrocarbons and heavy organics. The intended
product is a field deployable materials handling
system and phase separation process ranging in
size from 1 yd3/hr to 50 yd3/hr for commercial
application to environmental problems associated
with the exploration, production, refining and
transport of petroleum, petroleum products and
organic chemicals. Effluents from contaminated
sites will be clean solids (classified by size if
appropriate), and the concentrated contaminant.
The technology is based on biochemical solvation,
liquid/liquid and liquid/solid extractions, materials
classification, mechanical and hydraulic
scrubbing, and phase separation of organic and
aqueous phases. Fluid use is minimized through
utilization of closed-loop (recycle) systems.
Contaminants that are removed from the solid
material may be destroyed, disposed of using
existing technologies, or used on-site for
cogeneration of power for plant operations.
Additionally, if the contaminant is a valued
product, the material may be recovered for
application or sale. Clean solid material is not
sterilized and may be returned to normal
agricultural, commercial, residential or
recreational use in most instances.
Keyword(s): hydrocarbon removal, restoration, petroleum contaminants.
Oral presentation in technology transfer track.
A common environmental problem associated
with the pumping and refining of crude oil is the
disposal of petroleum sludge. This sludge is often
treated by incorporation into the soil. If the soil is
frequently tilled and fertilized, soil
microorganisms will be stimulated and organic
contaminants biodegraded. Unfortunately, the
biodegradation rate of more recalcitrant and
potentially toxic contaminants, such as the
polynuclear aromatic hydrocarbons (PNAs), is
rapid at first but declines quickly. Biodegradation
of these compounds is limited by their strong
adsorption potential and low solubility.
Recent research has suggested that vegetation
may play an important role in the biodegradation
of toxic organic chemicals, such as PNAs, in soil.
The establishment of vegetation on hazardous
waste sites may be an economic, effective, low
maintenance approach to waste remediation and
stabilization. The use of plants for remediation
may be especially well-suited for soils
contaminated by organic chemicals to depths of
less than 2 meters. The beneficial effects of
vegetation on the biodegradation of hazardous
organics are two-fold: organic contaminants may
be taken up by the plant and accumulated,
metabolized, or volatilized, and the rhizosphere
microflora may accelerate biodegradation of the
contaminants.
Completed greenhouse studies have indicated
that vegetative remediation is a feasible method
for clean-up of surface soil contaminated with
petroleum products. However, a field
demonstration is needed to exhibit this new
technology to the industrial community. In this
project, several petroleum contaminated field sites
will be chosen in collaboration with three
industrial partners. These sites will be thoroughly
characterized for chemical properties, physical
properties, and initial PNA concentrations. A
variety of plant species will be established on the
sites, including warm and cool season grasses and
alfalfa Soil analyses for the target compounds
over time will allow us to assess the efficiency
and applicability of this remediation method.
Keyword(s): bioremediation, vegetation, petroleum, biodegradation, rhizosphere.
Poster presentation.
Nitrogen oxides (NOx) are primary air
pollutants and, as such, there is considerable
interest in the development of efficient, cost
effective technologies to remediate NOx
containing emissions. Biofiltration involves the
venting of contaminated gas streams through
biologically active material such as soil or
compost. This technology has been used
successfully to control odors as well as volatile
organic compounds from a variety of industrial
and public sources. The purpose of this study was
to evaluate the feasibility of using biofiltration to
convert NOx to nitrogen gas.
Bioreactor studies measuring nitric oxide (NO)
removal by bacteria indigenous to coniferous
wood compost were conducted. Vertical
bioreactors (2 l volume) were constructed using
glass process pipe (12 in. x 3 in.). Compaction of
the compost in the bioreactors was minimized by
the addition of wood chips (17% w/w) measuring
approximately 1.2-1.5 cm in diameter. The
compost/bark mixture was ten loaded (1.4 l) into
the columns. A nitrogen gas stream containing
various concentrations of NO (100-500 µl l-1) was
purged (1 l min-1) through the compost under
single pass continuous flow conditions. The
effects of moisture, pH, temperature and
exogenous carbon sources on nitric oxide removal
in the biofilters were investigated.
Moisture measurements during nitric oxide
removal experiments indicated that biological
activity was optimum when the compost was
moist but not saturated (9-12 centibars of soil
suction). Studies demonstrated that pH control in
the biofilter was a critical variable for maximum
nitric oxide removal. Optimum denitrifying
activity occurred at pH levels ranging between 6-
7. Nitric oxide removal rates were found to
increase in biofilters treated with an external
carbon and energy source. Biofilters maintained at
37şC and treated with lactate were shown capable
of removing ł90% of the nitric oxide from an
influent gas stream containing 500 ml/l NO.
Keyword(s): nitrogen oxides, biofiltration, denitrification.
Oral presentation in research track.
Elemental iron and zinc have been used to
reductively convert part-per-thousand levels of
aqueous-phase tetrachloromethane to
trichloromethane in a few hours. Products include
free metal irons, chloride ion and hydrogen gas.
Hydrogen ions are consumed. Process kinetics are
dependent on solution pH, surface area of the
elemental metal, tetrachloromethane
concentration, and buffer selection. In mixed
solvent experiments, conversion kinetics and
process stoichiometry were dependent on the
alcohol that was added to water. When
isopropanol was added, acetone was among the
suite of products. Dehalogenation reactions using
elemental metals as reductants offer promise as a
means for initiating the destruction of heavily
halogenated aliphatic compounds. However,
models of process mechanism, and therefore
factors that will influence remediation designs, are
incomplete. The results of recent experiments will
be described.
Keyword(s): reductive dehalogenation, elemental metals, groundwater remediation, tetrachloromethane.
Poster presentation.
In 1990, the Department of Energy approved a
cooperative agreement for a Waste-management
Education and Research Consortium (WERC)
program. This consortium includes as its members
the New Mexico State University (NMSU), the
University of New Mexico (UNM), the New
Mexico Institute of Mining and Technology
(NMIMT), the Navajo Community College, the
Los Alamos National Laboratory, and the Sandia
National Laboratories working with industrial
affiliates.
The formative years have conclusively
demonstrated that the partnership of universities,
national laboratories and industry developed by
WERC is an effective tool for education,
technology development and technology transfer,
with the education process also playing a critical
role in technology transfer.
The university/national laboratory/industry
partnership of WERC has resulted in unique
solutions to technology issues. These have
attained the demonstration stage at DOE and
industry sites within the short period of three
years after the start of the program. Further, the
program has resulted in students with
conventional course type education as well as
experience on practical development projects at
the leading edge of technology, thus forming a
base for technology transfer as these students flow
into government and industry jobs. Several of our
past students occupy responsible positions and are
already technology transfer agents.
Several of the unique technologies developed
via WERC are successfully demonstrated via
application at national laboratories and industrial
sites. Examples are listed below.
Remediation of soil contaminated with
plutonium using a polymer capture
process has been applied at a DOE waste
site.
Subsurface mapping of buried waste has
been applied at a DOE integrated
demonstration (ID) site.
A pipeline detection system has been
applied to leak detection from storage
tanks and pipelines in the oil industry.
This paper will present how the WERC
partnership has been successful because of its
unique structure and method of operation.
Keyword(s): technology transfer, partnerships, education.
Oral presentation in technology transfer track.
The kinetics of the transformation of volatile
chlorocarbons in water solution in the presence of
the zero-valence metal particles was studied using
Gas Chromatography and Gas
Chromatography/Mass spectroscopy. Metals
including magnesium, zinc, tin were exposed to a
low concentration (100 to 1000 ul L-l) of carbon
tetrachloride in water. Tin caused the degradation
of carbon tetrachloride and appearance of carbon
dioxide, chloroform and tin oxide. The
transformation of chlorocarbons was found to
depend on the surface properties of the metal
particles.
Keyword(s): metal particles, chlorocarbons, water, degradation.
Oral presentation in research track.
2,4-D is a widely used systemic herbicide for
the control of broadleaf weeds in grain crops, field
corn, pastures, and other crop and non-crop land.
This herbicide also has a large market in home
and garden use. Under aerobic conditions, 2,4-D is
rapidly degraded by microbes in soil.
Groundwater contamination is limited due to the
pesticide’s high rate of microbial degradation and
uptake by plants. Groundwater is susceptible to
contamination at point sources where 2,4-D is
formulated, loaded onto application equipment,
and at clean-up areas where large amounts of
rinseates can be produced. We have developed an
aerobic biological process to degrade 2,4-D found
in these rinseates and other water which may have
contamination. This process involves establishing
an environment in which a known 2,4-D
degrading bacterium can utilize the herbicide as a
carbon source and achieve mineralization to
carbon dioxide and water. The environment
conducive to 2,4-D degradation is produced by
using an inexpensive nitrogen and phosphate
source such as agricultural grade
diammoniumphosphate and
monoammoniumphosphate producing a buffer.
Oxygen is provided by vigorous aeration of the
water with compressed air. The bacterium used is
Alcaligenes eutrophus JMP134 (pJP4). The
organism is produced in large amounts at
relatively low cost by fermentation. The organism
is air dried on peat and has exhibited good
survival and degradation capabilities when stored
at room temperature in a desiccated form for at
least 60 days. This process has been successfully
tested on rinseates produced by the cleaning of
commercial spray rigs applying the herbicide
Curtail®. Optimum physical parameters for the
process such as pH, temperature, inoculam
amounts, and buffer concentrations have been
determined.
Keyword(s): 2,4-D, degradation, rinseates.
Poster presentation.
The field site was manipulated with injection
of air (control experiment), 1% methane (in air),
pulsing of air only and 4% methane, and pulsing
of 4% methane supplemented with gaseous forms
of nitrogen and phosphorous. Gases were injected
through a horizontal well into the aquifer and a
vacuum was established in a second horizontal
well in the vadose zone. Following each injection
regime, sediment samples from the contaminated
region (100-140 feet below ground surface) were
analyzed. Analyses included most-probable-
number enrichments for physiological groups
known or suspected to degrade trichloroethylene
(TCE) and per-chloroethylene (PCE), TCE and
PCE removal from enrichments, and DNA
extraction and hybridization with various gene
probes corresponding to enzymes known to
degrade TCE or TCE metabolites.
Culturable populations in sediments following
methane pulsing plus nitrogen and phosphorous (+
N + P) compared to pre-methane sediments
showed methanotrophs increased 0 to >3 orders of
magnitude (to >2400/g), propane-oxidizers
increased 2 to >3 orders of mag (to >2400/g), and
ammonia-oxidizers increased 2 to >4 orders of
magnitude (to >24000/g). These three microbial
trophic groups are known to degrade TCE.
Culturable methylotroph populations increased 1
to >2 orders of magnitude (to >2400/g) and
culturable anaerobes showed little to no increase.
Following methane pulsing + N + P, TCE and
PCE removal occurred in methanotrophic
enrichments for most sediments with 1 mg of
inoculum and 100 mg of inoculum, respectively.
In contrast, TCE and PCE removal in
methanotrophic enrichments from pre-methane
sediments rarely occurred with 1 g of inoculum. A
messenger RNA probe corresponding to the
soluble methane monooxygenase gene showed
that the cultural methods underestimated the
density of the gene in sediments by several orders
of magnitude. The underestimation occurred
during all injection regimes but was most severe
following the 1% methane injection. Populations
of TCE-degrading microorganisms corresponded
with increases in contaminant removal in vadose
zone piezometers and groundwater, strongly
suggesting that microorganisms were responsible
for much of the TCE and PCE removal.
Keyword(s): bioremediation, trichloroethylene, nucleic acid probes, methanotrophs.
Oral presentation in research track.
This work was supported by the U.S. Department of
Energy as part of Pacific Northwest Laboratory’s Laboratory
Directed Research and Development. Pacific Northwest
Laboratory is operated for the U.S. Department of Energy by
Battelle Memorial Institute under contract DE-AC06-76RLO
1830.
Plants have profound effects on physical,
chemical and biological processes in soils and can
potentially accelerate the rate of degradation of
hazardous organic chemicals. Quantitative
information describing the effects of vegetation on
the fate of organic chemicals in soils is needed to
increase our general understanding of the fate
process and evaluate the potential use of plants in
enhancing the remediation of contaminated soils.
This study was designed to examine rates and
extent of degradation by the plant/soil system, as
well as plant uptake, accumulation and
metabolism, for several representative organic
chemicals. A flow-through system, consisting of
six modules, was designed to accommodate rapid
flow rates through the plant growth chamber.
Rapid flow rates prevent condensation in the
chamber and also prevent the unnatural
accumulation of volatile compounds in the
chamber air. Each system module consisted of
planted or unplanted soil covered with a glass bell
jar, through which passed a continuous stream of
air. Bell jars stood in a growth chamber, and
plants (or soil controls) were kept at 23 ± 1 C,
with a 16 hr photoperiod. Pre- and post-chamber
flow rates were carefully balanced to minimize
pressure gradients and thus minimize air leaks.
Six such modules ran simultaneously, three each
for the planted and unplanted systems.
Radiolabeled (14C) and non-radiolabeled aromatic
hydrocarbons, dissolved in ethanol, were added to
the soil to yield a concentration of approximately
100 mg/g dry weight of soil. Plants were started
from seed at the beginning of a trial.
Concentrations of the 14C labeled test compounds
in the vapor, plant and soil phases were
determined, after appropriate extraction and/or
concentration techniques, by liquid scintillation
counting. Preliminary results, using the system
and procedures described above, show that
mineralization of the test aromatic hydrocarbons
is significantly greater in the rhizosphere soil than
in the unplanted soil after two weeks.
Keyword(s): plants, biodegradation, organic contaminants.
Oral presentation in research track.
The wood rotting Basidiomycete
Phanerochaete chrysosporium is able to degrade a
wide variety of environmentally persistent organic
pollutants to carbon dioxide. The unique
biodegradative abilities of this fungus are due, in
part, to lignin peroxidases, oxidative enzymes that
are secreted in response to nutrient deprivation.
Lignin peroxidases catalyze the initial oxidation
of many of the organic pollutants that are
degraded by this fungus. Lignin peroxidases
mediate the initial oxidation of N,N,N',N',N",N"-
hexamethylpararosaniline, several azo dyes and
certain polycyclic aromatic hydrocarbons. Lignin
peroxidases also mediate oxidative dechlorination.
For example, lignin peroxidases oxidize
pentachlorophenol to 2,3,5,6-tetrachloro-
2,5cyclohexadiene-1,4-dione. Similarly these
enzymes mediate oxidative oligomerization of 4-
chloroaniline resulting in production of several
dimers, trimers and tetramers and net
dechlorination of the aromatic ring. Interestingly,
many, but not all, of the reactions mediated by
lignin peroxidases are also mediated by other
plant, fungal and mammalian peroxidases. In
some instances the major role of lignin
peroxidases is the oxidation an intermediate. In
the case of phenanthrene degradation lignin
peroxidases do not mediate the initial oxidation.
However, these enzymes do mediate the oxidation
of 9-Phenanthrol, forming Phenanthrene-9,10-
dione. This is of interest because 9-Phenanthrol is
a major metabolite formed under nonligninolytic
conditions while Phenanthrene-9,10-dione is a
major metabolite formed in ligninolytic cultures.
Thus, in this case, lignin peroxidases appear to
link the pathway occurring under nonligninolytic
conditions with the pathway that predominates in
ligninolytic cultures. (Supported by NIEHS grant
ESO 4492.)
Keyword(s): Phanerochaete chrysosporium, lignin peroxidase, biodegradation.
Poster presentation.
A laboratory study was conducted to determine
whether the concentration of heavy metals, zinc
(Zn), lead (Pb), and cadmium (Cd), in leachate
from mine tailings could be affected by the
presence of organic acids exuded by plant roots
and microbes in the rhizosphere. Geochemical
modeling predicted that some organic ligands
found in the rhizosphere have the capability to
complex and increase the solubility of Zn. The
leachate was analyzed for Zn, Pb and Cd content
and for organic acid concentration. These results
were confirmed by batch and column studies in
which mine tailings were exposed to 0 to 10,000
mM organic acids.
Keyword(s): heavy metals, organic acids, rhizosphere, plants.
Oral presentation in research track.
The Mine Waste Technology Pilot Program
(per published material) is involved with testing
technologies to clean up mine and mineral waste
and with the education and training of people who
are or will be involved with mine waste issues.
The education component is a part of the larger
MWTPP, sponsored by The Environmental
Protection Agency through The Department of
Energy, and administered by MSE, Inc., in Butte,
Montana. Montana Tech's education role is to
implement the following four point program:
Master of Science degree with a mine and mineral
waste emphasis, providing students with enhanced
exposure to the interdisciplinary field of mine
waste processing under existing
engineering/science graduate programs; awards
fellowships, graduate research assistantships, and
graduate teaching assistantships; educational and
training opportunities for industry professionals
through specialized workshops; and educational
opportunities for students and teachers, from
kindergarten through high school.
In 1990, the Department of Energy approved a
cooperative agreement for a Waste-Management
Education and Research Consortium.. This
consortium includes as its members the New
Mexico State University, the University of
Mexico, the New Mexico Institute of Mining and
Technology, the Navajo Community College, the
Los Alamos National Laboratory, and the Sandia
National Laboratories. The model five year
program was assigned the mission of
demonstrating that a university/national laboratory
partnership can effectively expand the nation’s
capability to address the issues related to
management of all types of waste via education
and technology development. This partnership of
universities, national laboratories, and industry
developed by WERC is an effective tool for
education, technology development, and
technology transfer, with the education process
playing a critical role in technology transfer. The
WERC program is available to over 3000 students
in academic institutions with a minority
population of 25-95%.
Keyword(s): mine, hazardous, waste, education, university.
Oral presentation in research track.
The study reported here investigated the
overall effect poplar trees exert on the fate and
transport of atrazine in a variety of soil types. The
research was conducted in batch reactors.
Reactors utilizing small poplar cuttings, reactors
quantifying sorption/desorbtion phenomenon, and
reactors dosed with surrogate and actual poplar
root exudate were prepared containing a silica
sand or a silt-loam soil. The atrazine fate was
monitored by the use of atrazine labeled with
carbon-14 isotopes. The extent of uptake in the
poplars was then quantified through oxidation of
the poplar biomass followed by liquid scintillation
techniques. Experimental results indicate that
virtually all of the atrazine in sand can be taken up
by the poplars in a reasonably short amount of
time, with little adverse effects on the trees. In
organic soils, the poplars can take up only mobil
atrazine which is not bound to the soil. Results
also indicate that the poplars have either a positive
effect or no detrimental effect on all fate and
transport mechanisms studied. This would
indicate that poplar trees may have a promising
future in the role of remediation of pesticide
contaminated waters.
Keyword(s): atrazine, pesticides, poplars, remediation.
Oral presentation in research track.
A field application using sulfate-reducing
bacteria (SRB) to treat acidic mine water
discharging from the Lilly/Orphan Boy Mine near
Elliston, Montana, is described. The field
application is a project under the MWTPP
implemented by MSE, Inc., funded by the U.S.
Environmental Protection Agency (EPA), and
jointly administered by the EPA and the
Department of Energy. The design of the field
application involves using a flooded mine shaft as
an in-situ biological reactor to which organic
substrate and SRB will be added. Technical
parameters required for the field application are
presently being developed from laboratory testing
of SRB in packed-bed reactors.
Keyword(s): sulfate-reducing bacteria, acid rock drainage.
Oral presentation in research track.
Creosote contaminated sites are of
environmental significance due to the high
concentrations of toxic and/or mutagenic PAH
usually found at these sites. Microbial degradation
of PAH can be seen as a novel form of
contaminant detoxification. This paper describes
the microbial degradation of PAH in creosote
contaminated soils using (9-14C) phenanthrene as
a model PAH. Microbial metabolism was assessed
with a mass balance approach as well as
identification of PAH metabolites by
GC/MS/FTIR. The mass balance accounted for
the amount portion of the added phenanthrene. To
confirm the effectiveness of microbial degradation
to decrease soil toxicity, the Microtox® and
Mutatox® assays were used to monitor toxicity of
the creosote soils throughout the experiments.
Mass balance results indicated that phenanthrene
was readily mineralized in the contaminated soils,
while metabolite production accounted for only a
minor portion of the added phenanthrene. Toxicity
of contaminated soils increased slightly early in
the incubation and then decreased over longer
time periods. Mutagenicity of soils, however, did
not decrease appreciably over a 3-month time
period. The identity of metabolic products found
in the soils will be discussed.z
Keyword(s): polycyclic aromatic hydrocarbons, biodegradation, metabolite production, Microtox®/Mutatox®.
Poster presentation.
Complex mixtures of polynuclear aromatic
hydrocarbons (PAHs) are organic combustion
products and are components of creosote and oily
wastes which have been identified in a large
number of hazardous chemical waste sites. Risk
assessment of PAH mixtures must take into
account the toxicity or carcinogenicity of the
individual compounds and their possible additive
or nonadditive interactive effects. A reconstituted
PAH mixture which resembled manufactured gas
plant PAH residues was prepared using 16
different compounds and the immunotoxicity and
monooxygenase induction activity of the 2-ring,
3-ring and ł 4-ring PAHs were compared to that
observed for the reconstituted mixtures in
B6C3F1 mice. The results showed that the
reconstituted mixture inhibited the splenic plaque-
forming cell response to T-cell dependent and
independent antigens and induced hepatic
microsomal ethoxyresorufin O-deethylase activity
and Cyp1a-1 mRNA levels. The relative potencies
of the reconstituted mixture and its components
indicated that most of the activity was associated
with ł 4-ring PAHs and the interactive effects of
the individual PAHs in the reconstituted PAH
mixture were essentially additive. This research
was supported by the Electric Power Research
Institute and the National Institute for
Environmental Health Sciences (P42 ES04917).
Keyword(s): polynuclear aromatic hydrocarbons, interactive effects.
Poster presentation.
Contamination of soils with polychlorinated
biphenyls at industrial and military sites is a
significant problem. A process based on
supercritical carbon dioxide extraction of
polychlorinated biphenyls from the soil followed
by supercritical water oxidation of the extract
appears to be economically attractive with the
benefit of returning clean soils/sediments to the
environment. Our research objective is to assess
the technical feasibility of this process and
provide data for economic evaluation.
Results of desorption rate studies of Aroclor
1248 from soils and sediments will be presented.
Data were acquired on a continuous flow fixed-
bed laboratory-scale supercritical extraction unit.
The experimental range of variables include: 30
to 50 C, 75 to 400 atmospheres, soil/sediment
sample size of 8 grams, carbon dioxide flow rate
of 0.02 to 0.54 grams/second, modifier flows 0.0 -
5 mole %, moisture content 0.0 to 20 weight %,
and initial polychlorinated biphenyl concentration
of 500 to 10,000 parts per million. The soils (sand,
clay, till and surfacial soil) and sediment samples
are representative of a specific Superfund
Hazardous Waste Site in New York State. Contact
time needed for sub 5 parts per million residual
polychlorinated biphenyl concentrations range
from 30 to 90 minutes depending on soil type,
level of contamination, and conditions of
contacting. A desorption rate model is presented
to model the data. Also, solubility data of specific
polychlorinated biphenyl congeners were obtained
and modeled using the Peng-Robinson equation of
state. These results will also be presented. Future
work involving bench-scale studies with a 1.0 liter
system will be described.
Keyword(s): supercritical extraction, carbon dioxide, polychlorinated biphenyls.
Oral presentation in research track.
Biodegradation of pentachlorophenol by
Phanerochaete chrysosporium was examined in
nonsterile soil. The rate of mineralization of
pentachlorophenol was essentially linear for at
least 27 days and increased almost linearly with
increasing concentration of pentachlorophenol
(from 50 to 1600 parts per million). With an initial
concentration of 100 parts per million, no
pentachlorophenol was found at 18 days while
40% of the added pentachlorophenol was present
as pentachloroanisole, and mineralization
continued linearly. Both pentachlorophenol and
pentachloroanisole were found after 18 days when
the initial concentration of pentachlorophenol was
800 parts per million. The rate of mineralization
of pentachloroanisole also increased with
increasing concentration of pentachloroanisole,
however the increase was not linear. Essentially
no radioactivity was found in either the aqueous
or volatile organic fraction during the
mineralization of either pentachlorophenol or
pentachloroanisole.
Keyword(s): pentachlorophenol, pentachloroanisole, Phanerochaete chrysosporium, white rot fungi.
Oral presentation in research track.
A method for enumerating subsurface soil
bacteria by direct epifluorescent microscopy was
developed. The dyes DAPI (4, 6-diamidino-2
phenylindole) and CTC (5-cyano-2,3 ditolyl
tetrazolium chloride) were used to assess total and
viable cells, respectively. The DAPI-CTC method
was compared in the laboratory to an INT-AO [(2-
(p-iodopheny)-3-(p-nitropheny)-5-phenyl
tetrazolium chloride]-[acridine orange] method
and viable plate counts. The DAPI-CTC method
was found to adequately evaluate microbial
numbers.
Keyword(s): epifluorescent microscopy, subsurface, microbes, soil microflora.
Poster presentation.
Soil cores were obtained from the vadose zone
of the Konza Prairie. Tempe cells and rigid-wall
permeameters were used to determine water
characteristic curves and saturated hydraulic
conductivity. Runoff plots, neutron access tubes,
and automated rain gauges were installed at the
two sites to determine runoff, soil moisture, and
rainfall amounts. A mathematical model was
developed to predict the movement of water
through the vadose zone using the soil hydraulic
properties and surface water balance.
Keyword(s): vadose zone, soil hydraulic properties.
Poster presentation.
Missouri has a long history of lead mining
activities. One of the most productive areas was in
the southwest part of the state in what was called
the "Tri-State District." It received this name
because the ore deposits were in Kansas and
Oklahoma, as well as Missouri. About 40% of all
the ore came from Missouri. Mining in this region
began in 1848, with production ending in 1957.
The tailings or mining wastes were stored on the
surface, where an estimated 8 million cubic yards
remains today.
Because of the high levels of lead in the area,
several superfund sites have now been designated
in the "District." A cooperative study was done by
Region VII EPA, Missouri Department of Health,
and the Centers for Disease Control (CDC). Blood
samples, dust, soil, water and paint samples were
collected from 150 houses where young children
lived in the Joplin, Missouri, area. The dust and
soil samples were split and part was sent to the
University of Missouri for analysis by sequential
extraction in order to determine the environmental
availability and possible bioavailability of lead.
The dust samples were determined to be
significantly more available than the soil. Other
relationships including correlation with blood lead
results will be presented.
Keyword(s): bioavailability, lead, soil, dust.
Oral presentation in research track.
Manufacturing and handling of conventional
munitions have produced explosives-contaminated
soil at numerous military installations. These soils
pose both a reactivity and toxicity hazard. Waste
streams at manufacturing facilities further add to
the problem. To prevent contamination of
groundwater, facilitate clean up of contaminated
sites, and bring current manufacturing plants into
line with environmental regulations, practical
remediation methods are being sought.
Ideally, biological treatment would eliminate
anthropogenic substances by aerobic
mineralization to carbon dioxide and water or
anaerobic decomposition to carbon dioxide and
methane, hydrogen sulfide or nitrogen. However,
accumulation of toxic intermediates rather than
complete degradation, has hindered widespread
application of the biological approach. Also,
biodegradation that performs well in the
laboratory is not always as efficient when tested in
the field.
Microorganisms from extreme environments
are a rich source of unique metabolic pathways
and unusually stable enzymes. Anaerobic
enrichment cultures were started a year ago with
TNT, nitrobenzene or nitrotoluene and samples of
thermal water. Of the five cultures now running,
one has developed a thriving consortium.
Recently, samples were analyzed under the
direction of Dr. Donald Crawford. A total of 1200
ppm TNT was added to the culture. Now only
41.4 ppm TNT and 2.5 ppm 4-amino-2,6
dinitrotoluene remains in the liquid, while the soil
extract contains 50.0 ppm TNT and 1.1 ppm 4-
amino-2,6 dinitrotoluene.
Keyword(s): TNT, biodegradation, nitro-substituted.
Poster presentation.
Biodegradation research has focused primarily
on the metabolism of single pollutants by pure
strains of microorganisms despite the fact that
contamination of soil and water is caused more
often by chemical mixtures. When available,
biodegradation data for mixtures is usually cast in
terms of bulk measurements like total organic
carbon, which are inadequate for many
applications.
In this presentation, two aspects of our
research into the biodegradation of organic
chemical mixtures will be discussed. First, results
of biodegradation experiments with Pseudomonas
putida F1 and benzene, toluene, phenol and
trichloroethylene will be presented.
Biodegradation rate data were obtained for the
aromatic compounds individually and in mixtures,
and cometabolism of trichloroethylene with these
compounds has also been studied. Mathematical
models have been proposed to describe these
results.
The second part of the presentation will cover
the application of these results to the development
of an immobilized-cell bioreactor for the
cometabolic degradation of trichloroethylene.
Phenomena such as competitive inhibition,
induction and energy supply have been
incorporated into a mathematical model. Results
from bioreactor experiments will be discussed.
Keyword(s): biodegradation, kinetics, mixture, aromatics, trichloroethylene.
Oral presentation in research track.
Abiotic interactions of pentachlorophenol
(PCP) on manganese oxide surfaces were
investigated to determine the extent of
transformation. The optimal pH and ratio of
manganese oxide to PCP were determined.
Sorption of PCP on manganese oxide surfaces was
quantified at optimal conditions. The effectiveness
of utilizing manganese oxide to remediate
contaminated subsurface environments was
investigated.
Keyword(s): groundwater quality, geochemistry, remediation, aquifers.
Oral presentation in research track.
Microbial bioassays have been used to assess
the genotoxic hazard at more than 30 different
hazardous waste sites. Environmental samples
were extracted with dichloromethane and
methanol, and the resulting residue tested using
GC/MS analysis as well as the Salmonella
Microsomal and E. coli Prophage Induction
assays. At a munitions wastewater contaminated
site, there was no correlation between
mutagenicity in bacteria, and the risk as estimated
from chemical analysis data. Samples 202 and 204
from a coal gasification site contained 72 mg/kg
and 9 mg/kg benzo(a)pyrene, whereas the
mutagenic responses of these samples were 231
net revertants/mg and 902 revertants/mg,
respectively. The data suggest that microbial
bioassays provide a valuable tool for monitoring
the interactions of the components of a complex
mixture.
Keyword(s): bioassay, hazardous waste, benzo(a)pyrene, trinitrotoluene.
Oral presentation in research track.
This research was supported by NIH grant P42 ES04917.
Information regarding biodegradability is
critical for assessing the environmental fate and
impact of organic chemicals in soil/plant systems.
However, quantitative information describing the
biodegradation of organic chemicals in soils and
the effect of vegetation is lacking, primarily due
to the difficulty and expense associated with
experimentally measuring biodegradation rates.
Typically, biodegradation rates in soils are
determined directly by measuring the
disappearance of the chemical of interest over
time or indirectly by measuring evolved CO2 or
O2 consumption. Indirect methods are generally
simpler, less expensive and less time consuming
than direct methods. The focus of this study was
to develop a simple microcosm approach, utilizing
measurements of O2 consumption, to investigate
the biodegradability of selected organic
compounds in rhizosphere soil. The microcosms
consisted of 100 mL glass vials fitted with
Mininert® valves and typically contained 40
grams of either rhizosphere or control soil. The
rhizosphere soil was obtained from a vegetated
plot, while the control soil from a unvegetated
plot. All compounds were added directly to the
soil, without a carrier solvent, resulting in a soil
concentration of approximately 200 ppm.
Headspace concentrations of O2, converted to
percent of theoretical oxygen demand (%ThOD),
were analyzed over time using a gas
chromatograph equipped with a thermal
conductivity detector. The indirect microcosm
technique provided a simple, inexpensive method
for comparing the aerobic biodegradation of
several aromatic hydrocarbons in rhizosphere
versus soil.
Keyword(s): microcosm, biodegradation rates, plants, soil, oxygen, carbon dioxide, gas chromatography.
Oral presentation in research track.
Our nation faces a daunting challenge to clean
up and protect our environment. Before launching
any cleanup, one must characterize the type,
concentration and extent of the contamination.
During cleanup, one must monitor the progress,
and after cleanup, one must often monitor the site
to ensure that the cleanup was successful.
Chemical characterization and monitoring
techniques and methods are at the heart of
executing these efforts. R&D efforts to improve
capabilities can translate into major savings and
improvement in environmental cleanup by
reducing the unit cost of measurements (e.g.,
fewer steps in an analysis), reducing the time
required to provide the information to the user
(e.g., field analytical), or improving the quality of
information (e.g., chemical speciation).
Radiochemical analysis is of particular concern to
DOE, where over $300 million is expended
annually on this activity. Unlike organic and
inorganic analytes, which are widely found as
contaminants, there has been comparatively little
effort expended on improvements of
radiochemical analyses. Desirable characteristics
of any new methods for characterization of DOE's
radiochemical contamination are
faster, to reduce horrendous turnaround
times
cheaper, to reduce the burden on the
taxpayers
better performance, to achieve desired
data quality objectives
reduced scale and fewer steps, to
minimize secondary mixed waste
Methods for chemical characterization of the
environment are being developed under a
multitask project for DOE's Office of Technology
Development within the Office of Environmental
Restoration and Waste Management. The project
focuses on improvement of radioanalytical
methods with an emphasis on faster and cheaper
routine methods. We have developed improved
methods for separation of environmental levels of
technetium-99, radium and actinides from soil
and water; separation of actinides from soil and
water matrix interferences; and isolation of
strontium. We are also developing methods for
simultaneous detection of multiple isotopes
(including nonradionuclides) using the new
instrumental technique inductively coupled
plasma/mass spectrometry (ICP/MS). These
ICP/MS methods would more efficiently replace
alpha and beta counting techniques. Integration
and automation of the separation methods with the
ICP/MS methology using flow injection analysis
is underway with the objectives of achieving more
reproducible results, reducing labor costs, cutting
analysis time, and reducing secondary waste
generation through miniaturization of the process.
The final product of all activities will be methods
which are available (published in DOE's analytical
methods compendium) and acceptable for use in
regulatory situations.
Keyword(s): analytical chemistry, flow injection analysis, inductively coupled plasma/mass spectrometry, radioanalytical, separations
Poster presentation.
This work is supported by the U.S. Department of
Energy, Assistant Secretary for Environmental Remediation
and Waste Management, Office of Technology Development,
under contract W-310109-Eng-38.
Subsurface stratigraphy plays an important role
in the migration and distribution of chemical and
waste products that are in the form of nonaqueous
phase liquids (NAPL). In the saturated zone,
coarse layers act as preferential flow channels and
as pockets for fluid entrapment. The entrapment
saturations resulting from these macro-scale soil
heterogeneities are much larger than the residual
saturations controlled by the micro-scale pore
characteristics of the soil. The phenomena of
preferential flow and macro-scale entrapment
have been observed in our laboratory spill
simulations and in the field. It is our hypothesis
that they are caused by the capillary barrier effects
existing at the interfaces of the coarse and fine
sand formations. Precision flow experiments were
conducted in soil cells to obtain quantitative data
to understand the nature of these capillary barrier
effects. A complete testing program was
implemented with five sands using both air and a
light NAPL as the non-wetting phase. The
experimental design and the results are presented.
The experimental results are used to identify the
characteristics of the soils in layered aquifers that
produce barrier effects. The results of this study
will help in developing field characterization
techniques to determine soil parameters needed in
modeling nonaqueous phase fluid flow and
entrapment in heterogeneous aquifers. This
knowledge will also be useful in the design of fine
soil barriers for the containment of plumes and
coarse soil traps for the recovery of waste fluids.
Keyword(s): groundwater contamination, organic wastes, nonaqueous phase fluids.
Oral presentation in research track.
The Environmental Restoration Project at
Sandia National Laboratories/New Mexico
(SNL/NM) is tasked with performing assessments
and remediation of waste sites resulting from over
40 years of weapons development and testing.
Operable Unit 1295, Septic Tanks and Drainfields,
includes 23 different sites at SNL/NM where
hazardous and radioactive wastes may have been
released into the environment. A RCRA Facility
Investigation (RFI) Work Plan for the sites has
been submitted to the U.S. EPA for approval. This
presentation will outline the proposed technical
approach for the characterization of these sites for
the RFI Report and the Corrective Measures
Study. The phased assessment of the sites is
designed to quickly eliminate sites where
contamination levels are at or below background
levels and fully determine the nature and extent of
contamination at the other sites. Field
investigation methods and sample field-screening
techniques will also be presented.
Keyword(s): septic systems, site characterization, drainfields, field screening methods.
Poster presentation.
Subsurface contaminants are frequently
encountered as mixtures of nonaqueous phase
liquids (NAPLs) at sites contaminated by gasoline
or coal tar comprising organic mixtures. The
leaching of these organic mixtures from the
aquifer has been examined with and without
biodegradation. The results obtained have been
compared with the limiting case of a single
component NAPL.
Various physical processes involved have been
quantified based on the assumptions that liquid-
liquid and sorption equilibria are established at the
beginning of each flushing; oxygen required for
biochemical oxidation is completely consumed by
the end of each flushing; and the rate of
biochemical oxidation obeys the Monod kinetics
for a multi-substrate system, characterized by an
oxygen utilization factor. This has given rise to an
equilibrium model expressing the mass fraction of
any component remaining in the aquifer, its
aqueous concentration, and the composition of the
NAPL as functions of the number of flushings.
The results of the simulation with the model
demonstrate that bioremediation can significantly
reduce the time necessary for removing the
components of intermediate solubility such as
xylene. Highly soluble components of the NAPL
are mainly removed by the pump-and-treat
mechanism while the components of extremely
low solubility are unavailable to the microbes as
substrates in a multi-component system. The
results also demonstrate that relatively soluble
contaminants tend to persist for a longer duration
in the mixture than when they exist as pure
components and that this effect is magnified by
the inclusion of a non-soluble component in the
mixture. The proposed mass balance approach
yields a useful bound of the effectiveness of
biodegradation aided dissolution of a multi-
component NAPL; the approach is relatively
simple and computationally efficient.
Keyword(s): dissolution, biodegradation, NAPL, mixture, equilibrium.
Oral presentation in research track.
In the development and application of
groundwater models, it has been recognized that
the process understanding at a small scale does
not necessarily lead in a straightforward manner
to appropriate models at a large scale. The
upscaling of models of water flow and solute
transport in saturated porous media has been the
topic of significant theoretical investigation. Data
from a few field sites have been used to validate
some of these theories. However, the field data
will have limitations with respect to accuracy and
the inability to fully characterize the soil
conditions which define the field-scale
heterogeneities. Laboratory investigations in soil
columns and tanks can provide much accurate
data compared to the field. Also, soils which are
used to create heterogeneities can be well
characterized in the laboratory. The purpose of the
study reported in this paper is to develop an
experimental facility to generate accurate data on
water flow and solute transport in heterogeneous
aquifers. The data is used to study the scale effects
in solute transport (scale-dependent dispersivity).
The experimental facility consists of a horizontal
soil tank of dimensions 2.44 m x 1.22 m. Soil
samples of approximately 5 cm thickness can be
packed into the tank. Two constant head end tanks
are used to create various groundwater flow
velocities. Pressure measurements and solute
sampling will be done over the horizontal plane
using 45 sampling ports drilled through the top
wall. These same ports can be used for tracer
injection. The experiments will involve injection
of a tracer into the flow field and measurement of
water pressure and solute concentrations at
prescribed locations in the flow field. Pressure
measurements are done using an automated
pressure scanning system. The measured values of
flow, pressure and solute concentrations are used
to estimate hydraulic conductivity and dispersivity
using inverse problem solution techniques. Both
homogeneous and heterogeneous soil packing
configurations could be investigated. Results from
simulations with homogeneous packing are
presented.
Keyword(s): upscaling, dispersivity.
Poster presentation.
A source removal action plan was developed
by Midwest Gas and the Iowa Department of
Natural Resources to address the source coal tar
contamination within the underground gas holder
basin at Former Manufactured Gas Plant (MGP)
sites. The procedure utilizes a mixture of coal,
contaminated soil, and coal tar sludge to provide a
material that had suitable material handling
characteristic for shipment and burning in high
efficiency utility boilers. Screening of the mixture
was required to remove oversized debris and
ferrous metal. The resulting mixture did not
exhibit toxic characteristics when tested under the
Toxicity Characteristics Leaching Procedure
(TCLP). Test results on the coal tar sludges have
indicated that the more pure coal tar materials
may fail the TCLP test and be classified as a
RCRA hazardous waste. The processing
procedure was designed to stabilize the coal tar
sludges and render those sludges less hazardous
and as a result pass the TCLP test. This procedure
was adopted by the Edison Electric Institute to
develop a national guidance document for
remediation of MGP sites. EPA Office of Solid
Waste and Emergency Response recommended
this strategy to the Regional Waste Management
Directors as a practical tool for handling wastes
that may exhibit the RCRA characteristics.
Keyword(s): stabilization, coal tar, RCRA, TCLP.
Oral presentation in technology transfer track.
PAHs are a class of widespread pollutants,
some of which have been shown to be genotoxic,
hence the fate of these compounds in the
environment is of considerable interest. Research
on the biodegradation of 4 and 5 ring PAHs has
been limited by the general lack of microbial
isolates or consortia which can completely
degrade these toxicants. Heitkamp and Cerniglia
have described an oxidative soil Mycobacterium-
strain PYR-1 that metabolizes pyrene and
fluoranthene more rapidly than the 2 and 3 ring
naphthalene and phenanthrene; although some
metabolites of benzo-(a)-pyrene (BaP)were
detected, no mineralization of BaP was observed.
In 1991 Grosser et al. reported the isolation of a
Mycobacterium sp. which mineralizes pyrene and
also causing some mineralization of BaP. Our
study describes a comparative analysis of these
two strains, which show very similar colony
morphology, growth rate and yellow-orange
pigmentation. Genetic differences were shown by
DNA amplification fingerprinting (DAF) using
two arbitrary GC-rich octanucleotide primers, and
by sequence comparison of PCR amplified 16S
rDNA, although both strains show similarity
closest to that of the genus Mycobacteria. These
16S rDNA sequences are in use for the
construction of strain-specific DNA probes to
monitor the presence, survival and growth of these
isolates in PAH-contaminated soils in studies of
biodegradation.
Keyword(s): polycyclic aromatic hydrcarbons, mycobacteria, pollution.
Poster presentation.
Supported by NIEHS Grant ES04908.
Ions derived from tributyl phosphate (TBP) are
observed in the static secondary ion mass
spectrum of minerals exposed to TBP; these ions
are very dependent on the nature of the mineral
surface. When TBP is adsorbed onto a reducing
site, specifically Fe(ll), the compound will be
reduced upon SIMS bombardment, and ions
corresponding to tributyl phosphite will be
observed. This observation can be made for TBP
that is adsorbed to basalt samples having
substantial reducing phases, and FeO. The tributyl
phosphite that is formed from the reduction of
TBP concurrently undergoes a hydride abstraction
during the SIMS process, and proceeds to
eliminate one and/or two C4H8 and/or one H20
molecules to form ions at m/z 193+, 137+, and
119+. These same ions can be observed in the SIM
spectrum of tributyl phosphite adsorbed onto the
same mineral surfaces, although ions
corresponding to the protonation of tributyl
phosphite are also observed. The m/z 193+ and
137+ ions are also observed in the methane
chemical ionization (CI) mass spectrum of tributyl
phosphite, which demonstrates that hydride
abstraction is also occurring in the gas-phase
(although this is a minor ion series in the CI mass
spectrum).
When TBP is adsorbed onto surfaces that are
not reducing, then protonation or hydride
abstraction occur. Ions resulting from protonation
derive from the sequential elimination of up to
three C4H8 molecules (m/z 211+, 155+, 99+) from
[M + H]+, and are observed from "oxidized" basalt
samples. These ions are also observed from Fe2O3
although in this case substantial hydride
abstraction is also observed. This latter ionization
mode is followed by the elimination of one and/or
two C4H8 molecules to produce ions at m/z 209+
and 153+. Both ion series (protonation and hydride
abstraction) can be observed in the CI mass
spectrum of TBP. Significantly, none of the ions
attributed to tributyl phosphite are observed in the
CI mass spectrum of TBP, which supports the idea
that their formation is the result of a surface
process, and not the result of gas-phase ion
chemistry.
A significant ion is observed at m/z 99+ in the
SIM spectrum of tributyl phosphite on oxidized
surfaces: Fe2O3 and basalt This ion is interpreted
in terms of tributyl phosphite being oxidized
during the SIMS analysis.
Keyword(s): mass spectrometry, surface analysis, reduction.
Oral presentation in research track.
Degradation of many hazardous compounds in
the soil environment can be affected by the
different components of the soil matrix as well as
the degrading microbial population present. Fulvic
acids were extracted from various soils (both
impacted and non-impacted) and then used to
determine their effect on pyrene mineralization by
an isolated pyrene-degrading Mycobacterium sp.
A comparison of non-impacted to impacted soil
fulvic acids was done to determine whether these
fulvic acids have different binding affinities for
the pyrene. To determine the effects of fulvic acid
addition on mineralization, samples were prepared
using sterile sand and different concentrations of
fulvic acids (1, 4 and 10%) lyophilized onto the
sand. Slurries were made using sterile water and
added Mycobacterium cells. Serum bottle
radiorespirometry was used to measure
mineralization of added 14C-pyrene over a 32 day
period. Results show that the addition of fulvic
acid up to 5% had little overall effect on pyrene
extent of mineralization by the bacteria, but the
5% fulvic acid addition resulted in a lag before
mineralization began. The 10% fulvic acid
addition decreased mineralization with an
extended lag period. Because the addition of
fulvic acids to the slurries decreases the pH,
survival studies were conducted at unadjusted pH
and at pH adjusted to 7, and with varying fulvic
acid concentrations up to 2.5%. Activity of the
Mycobacterium cells was measured as 14C-acetate
incorporation into lipids and indicates that the
activity in both unadjusted and pH 7 slurries was
similar with up to 1% fulvic acid added. Fulvic
acid addition of 2.5% resulted in six times greater
activity in pH 7 slurry than in the unadjusted
slurry. The decreasing mineralization of pyrene
with increasing levels of fulvic acid addition
appears to be due to toxicity to the microbes and
possible sorption of the compound making it less
bioavailable.
Keyword(s): Mycobacterium, mineralization, fulvic acid, sorption, bioavailability.
Poster presentation.
Ion exchange, surface adsorption/desorption,
complexation by organic materials, and
precipitation/dissolution of discreet solid phases
are typical mechanisms that control heavy metals
in solution. Understanding the mechanism that is
responsible for a given metal is critical to
prediction of leaching behavior. Plants can affect
mobility of heavy metals by releasing organic
compounds into the rhizosphere. Some of the
organics released by plant roots (and
microorganisms) are strong complexing agents for
metals and can potentially increase metal
mobility. Sorption and desorption reactions
(kinetics and isotherms) of a variety of heavy
metals will be determined for diffusion controlled
and ion exchange reactions. Organic compounds
that could impact metal transport, mine tailings,
and soil will be equilibrated for approximately 18
hours in batch studies. The solution phase will be
separated and concentrations of target metals
measured. This research will quantify heavy metal
adsorption/desorption characteristics of soil
influenced by plant roots.
Keyword(s): heavy metals, rhizosphere, leaching, adsorption.
Poster presentation.
We are investigating the abiotic reductive
dechlorination of carbon tetrachloride using
elemental iron as an electron donor. Equation 1
shows the thermodynamic favorability of the
reduction of carbon tetrachloride with the
oxidation of iron metal at neutral pH.
Fe0 + CCl4 + H+ ® Fe2+ + CHCl3 + Cl- Eo’ = +0.99 Volts (1)
Reduction of mono-, di-, and trichloromethane
is also thermodynamically favorable to a lesser
degree. Our work has provided preliminary
feasibility data for the development of novel and
inexpensive remediation techniques for carbon
tetrachloride in groundwater, including an in-situ
process, which may be applicable to other
halogenated priority pollutants. Batch experiments
were conducted in aqueous solution to determine
stoichiometric and pseudo first order reaction rate
coefficients for the sequential reduction of carbon
tetrachloride to chloroform, methylene chloride,
chloromethane and methane using powdered iron
metal as the sole reductant. Aerobic reduction
rates were slower than anaerobic rates,
presumably due to dissolved oxygen from the
ambient atmosphere competing with carbon
tetrachloride as the terminal electron acceptor.
Reduction rates were accelerated at higher
temperatures in agreement with the Ahrennius
equation. Soil column experiments which
simulated reductive dechlorination of carbon
tetrachloride in subsurface environments were
conducted under anaerobic conditions. These
experiments showed the beneficial effect of
treatment with iron powder. Potential field
applications include in-situ chlorinated solvent
remediation and containment and treatment of off
gasses.
Keyword(s): carbon tetrachloride, in-situ, iron, reductive dechlorination.
Poster presentation.
Recent surveys of mixed wastes in interim
storage throughout the 30-site Department of
Energy complex indicate that only 12 of those
sites account for 98% of such wastes by volume.
Current inventories at the Idaho National
Engineering Laboratory (INEL) account for 38%
of total DOE wastes in interim storage, the largest
of any single site. For a large percentage of these
waste volumes, as well as the substantial amounts
of buried and currently generated wastes, thermal
treatment processes have been designated as the
technologies of choice.
Current facilities and a number of proposed
strategies exist for thermal treatment of wastes of
this nature at the INEL. High level radioactive
waste is solidified in the Waste Calciner Facility
at the Idaho Central Processing plant. Low level
solid wastes until recently have been processed at
the Waste Experimental Reduction Facility
(WERF), a compaction, size reduction, and
controlled air incineration facility. WERF is
currently undergoing process upgrading and
RCRA Part B permitting.
Recent systems studies have defined effective
strategies, in the form of thermal process
sequences, for treatment of wastes of the complex
and heterogeneous nature in the INEL inventory.
These recommendations have resulted in the
proposal of combinations of treatment, storage
and disposal facilities to most effectively fill these
needs.
A number of research, development and
demonstration projects are also currently active in
both the low temperature incineration and high
temperature melting regimes, to provide the
fundamental scientific understanding necessary to
support design, construction and operation of the
proposed facilities. These studies address the
partitioning of the toxic metals and radionuclides
to the treatment process products and strategies
for minimizing release of such residuals to the
environment.
This presentation reviews the current status of
operating facilities, active studies in this area, and
proposed strategies for thermal treatment of INEL
wastes.
Keyword(s): thermal treatment, incineration, melting, mixed waste, heavy metals.
Oral presentation in technology transfer track.
This study addresses a viable and natural
solution to the elimination of volatile organic
compounds (VOCs), pollutants, through the
bioremediation process. Plants and associated
rhizosphere bacteria have the ability for
bioremediation of both volatile and non-volatile
organic compounds. For volatile compounds,
intersystem transfer by transpiration may be a
matter for concern when plants interact with such
materials. We have monitored, using FT-IR, the
potential transfer of toluene from subsurface water
in the presence of toluene-adapted alfalfa plants.
These experiments show that the plants and/or
their associated micro-organisms effectively
degrade toluene so that potential intersystem
transfer of VOCs by transpiration may be quite
manageable with adapted-plants. Presently, we are
monitoring l,l,l-trichloroethane (TCA) and
trichloroethylene (TCE) from subsurface water
and gas phase above plants. TCA does not show
an indication of degradation whereas TCE does.
Methane is produced in the groundwater but not
transferred to the atmosphere, indicating the
presence of a consortium of methanogens and
methanotrophs in this soil. The TCE presumably
is the substrate for methane production based on
chloride ion accumulation. The majority of TCE
must be degraded aerobically to yield CO2 in the
vadose zone. The FT-IR spectrometer can quickly
determine and analyze contaminants in the gas
phase, groundwater and plant tissue successfully.
Keyword(s): FT-IR, bioremediation, volatile organic compounds.
Oral presentation in research track.
Heavy metal contamination of soil is a
common problem encountered at many hazardous
waste sites. Lead, chromium, cadmium, copper,
zinc and mercury are among the most frequently
observed metal contaminants. They are present at
elevated concentrations at many National Priority
List sites. Heavy metals are toxic to people and
pose a great risk for safe groundwater supply.
Once released into the soil matrix, most heavy
metals are strongly retained and their adverse
effects can last for a long time.
Chelating extraction of heavy metals from
contaminated soils has recently been seen as a
treatment method. However, only a few chelates,
familiar ones such as EDTA and NTA, have been
tried for this application, and the choice of
chelates for decontamination purpose appears to
be haphazard. There exists a need to assess the
full potential of this technology in removing
and/or recovering heavy metals from
contaminated media, e.g., soils and mine tailings
ponds. This paper will:
present a methodology to examine a large
number of chelates and to identify those
chelates suitable for the selective removal
or recovery of various heavy metals.
Chemical equilibrium modeling has been
used to examine over 100 chelates for
their extraction potential;
present the experimental results of heavy
metal extraction from soil using a few
selected chelates. The extraction of metals
including cadmium, copper, lead and zinc
has been studied under different pH, soil
suspension, total chelate concentration,
total carbonate concentration, and age
conditions;
demonstrate that, through a proper choice
of chelate, the extraction can be made
more selective toward heavy metals;
demonstrate that, with the chosen
chelates, the extracted metals can be
readily recovered as solid precipitates and
the soluble chelates reclaimed and reused.
Keyword(s): metal, soil, chelate, contamination, remediation.
Poster presentation.
Detoxification of pentachlorophenol-
containing wood preserving waste was monitored
under ambient, enhanced and chemical
pretreatment conditions for genotoxicity and
parent compound removal. Samples were
collected throughout the treatment periods and
sequentially extracted with dichloromethane and
methanol with the Tecator Soxtec apparatus. The
organic extracts were analyzed on GC/ECD and
GC/MS. The extract mutagenic and genotoxic
potentials were evaluated with and without
metabolic activation with the Salmonella
Microsomal and E. coli Prophage Induction
assays. The Salmonella mutagenic responses of
extracts from Weswood soil amended with wood
preserving waste and treated under ambient
conditions were 2.0, 34.6 and 2.4 times greater
than the solvent control on days 0, 540 and 1,200
respectively. Organic extracts of soil amended
with wood preserving waste and treated under
enhanced conditions in a solid-phase rotating
drum bioreactor had mutagenic potentials of 3.4,
4.9 and 3.5 on days 0, 14 and 30, respectively.
Extracts from wood preserving waste sludge
treated with potassium polyethylene glycol were
shown to have mutagenic potentials of 2.8, 6.1
and 3.8 at 0, 10 and 30 minutes. The results
indicate that the initial products of the wood
preserving waste detoxification under all
treatment conditions appear to have greater
genotoxic potentials than the starting material.
The results also suggest that a more rapid
detoxification occurs under enhanced and
chemical pretreatment conditions.
Keyword(s): detoxification, chemical pretreatment, hazardous waste, pentachlorophenol, bioremediation.
Oral presentation in research track.
This research was supported by NIH grant P42 ES04917.
Organic solute mobility may be better
understood by simulating field conditions in the
greenhouse. Turf/soil columns from a Kentucky
bluegrass (Poa pratensis L.) area near Mead, NE,
and Ames, IA, were excavated, concrete encased,
and transported to a greenhouse. Organic solutes
applied at recommended rates included the
herbicides 2,4-D, dicamba, mecoprop, and
pendimethalin, the insecticides isazofos and
chlorpyrifos, and metalaxyl fungicide. Nitrogen
(15N urea) was applied at 49 kg ha-1. Potassium
bromide was applied at 100 kg ha-1 as a
conservative tracer. Two irrigation water regimes
(2.5 and 5.0 cm) with drainage suction (500 cm
water) were imposed. Daily column and leachate
weights were used to determine water balance and
schedule irrigations. The distribution of organic
solute residues among leachate, verdure, thatch,
and soil depth to 50 cm, were determined and
related to nitrogen and water tracer movement.
Residual analysis pesticide in the turf/soil profile
was metalaxyl > chlorpyrifos = pendimethalin >
isazofos. The amount of metalaxyl residue was
mainly influenced by differences in soil types.
The amount of isazofos residue was affected by
irrigation level in the Nebraska soil. Chlorpyrifos
and pendimethalin residues were similar in both
soils and were not affected by irrigation level.
Keyword(s): pesticides, irrigation, chemical properties, soil properties.
Poster presentation.
The objective of this study was to evaluate the
efficiencies of the automatic Soxtec and U. S.
EPA SW846 Soxhlet soil extraction methods. In
phases one and two of the experiment, extractions
were performed on silicon dioxide matrices and
silt-loam soils spiked with benz(a)pyrene,
pentachlorophenol, and naphthalene at three
concentration levels. Each test sample contained
either an individual chemical or a 1:1:1 mixture of
all three chemicals. Phase three consisted of
extractions performed on a silt-loam soil spiked
with a coal tar complex mixture. Soxtec samples
were sequentially extracted with dichloromethane
and methanol while Soxhlet samples were
extracted with dichloromethane.
Gas chromatographic results obtained from
sample extract analysis were used to calculate
percent recoveries of the chemicals. The
recoveries of benz(a)pyrene and
pentachlorophenol in the Soxtec procedure ranged
from 55-88% and 49-88%, respectively. For the
Soxhlet method, the recoveries ranged from 46-
73% and 52-87%, respectively. Complex mixture
recoveries ranged from 50-60% for both
procedures. The mutagenic potentials of the
solvent extracts were evaluated using Salmonella
typhimurium strain TA98 with and without
metabolic activation. Assay results indicated a
positive correlation between mutagenic response,
assay controls, and the chemical concentrations
derived from GC analysis. The data indicate that
the Soxtec method, which requires 2 hours, is as
effective as the traditional 16 hour Soxhlet
extraction procedure for recovering organic
chemicals from contaminated matrices. The
Soxtec method, thus, offered substantial time and
cost savings.
Keyword(s): pentachlorophenol, benz(a)pyrene, extraction, bioassay, soil.
Poster presentation.
This research was supported by NIH grant P42 ES04917.
Numerical models of water flow and solute
transport have been extensively used in problems
in groundwater quantity and quality management.
The fundamental processes which govern the flow
and transport behavior are fairly well understood,
and the models have been adequately validated
using both laboratory and field data. Field and
laboratory techniques for the determination of
parameters needed in these models are generally
available. However, the same cannot be said about
the models which have been developed to
simulate multiphase flow in aquifers. The need to
model multiphase flow arises in dealing with
contamination problems involving organic
chemicals and waste products which are in the
form of nonaqueous phase liquids. Existing
models use the basic equations, mathematical
formulations, and numerical schemes which have
been used in reservoir simulators in petroleum
engineering applications. The field application of
these models as prediction tools for the design of
remediation schemes in hazardous waste problems
have been limited for a variety of reasons. These
models have not been adequately validated in the
laboratory or in the field due to the scarcity of
data. The models sometimes fail in attempting to
simulate flow and entrapment behavior under
heterogeneous soil conditions that are commonly
encountered in the field. Accurate field calibration
and prediction become difficult due to the
limitations of the field and laboratory techniques
which are used to obtain the model parameters.
The assumptions which are made in modeling the
mass transfer from the nonaqueous phase to
aqueous phase become questionable under some
conditions of ganglia formation and macro-scale
entrapment. Results from laboratory spill
simulations conducted in large soils tanks, soil
columns, soil cells and field investigations, and
model analysis are used to discuss some of these
limitations. Conclusions on possible
improvements to models and issues related to
laboratory and field characterization are
presented.
Keyword(s): remediation design, multiphase flow, numerical models, groundwater models.
Oral presentation in research track.
An understanding of degradation rates of
organic chemicals under transport conditions is
critical for enhancing biodegradation rates in-situ.
Currently, most solute transport models assume
first-order degradation kinetics, and users
generally rely on rate constants determined under
batch conditions. However, the rates of solute
diffusion and sorption-desorption reactions, which
influence contaminant bioavailability, are
dependent on pore water velocities. Consequently,
batch degradation rates are probably not adequate
for describing actual degradation rates occurring
during transport. To test this hypothesis, we
conducted transport experiments using l4C-labeled
2,4-D in disturbed soil columns at three different
pore water velocities under unsaturated flow
conditions. The amount of 2,4-D in effluent
fractions was determined using scintillation
analysis, and plotted as a function of pore volume
(i.e. 2,4-D breakthrough curves, BTCs). The
percent of applied 2,4-D degraded during
transport was directly related to the residence time
of 2,4-D in the column. For example, higher pore
water velocities corresponding to lower residence
times resulted in lower total amounts of 2,4-D
degraded. These results can generally be predicted
using the convection-dispersion equation for
solute transport with a first-order model for 2,4-D
degradation using batch-determined degradation
rate constants. However, batch-determined
degradation rates significantly underpredicted the
amount of 2,4-D degraded during transport
conditions. Optimized rate constants determined
for the transport experiments were greater than
batch-determined degradation rate constants, and
increased with increasing pore water velocity. It is
hypothesized that higher pore water velocities
yield greater contaminant diffusion rates through
interstitial pores and increase contaminant
desorption rates, both resulting in enhanced
bioavailability.
Keyword(s): biodegradation, transport, 2,4-D.
Poster presentation.
Research was undertaken to assist the Bureau
of Land Management and Forest Service in
determining the best rehabilitation techniques for
mine waste streamside deposits in the Elkhorn
Mountains of Montana. These wastes have a high
sulfur content, a low pH, and are contaminated
with elevated levels of arsenic, lead and other
trace metals.
Utilizing a randomized block experimental
design, these mine wastes were amended with
calcium carbonate, calcium hydroxide, manure
and fertilizer. Three grass species, Agrostis alba,
Deschampsia caespitosa and Elymus cinereus,
were grown under greenhouse conditions to
determine their performance.
Keyword(s): revegetation, trace metals, acid mine waste.
Oral presentation in research track.
The oxidation of sulfide minerals in mine
waste is a widespread source of resource
degradation, often resulting in the generation of
acidic water and mobilization of heavy metals.
The quantity of acid-forming minerals present in
mine waste, dominantly as pyrite (FeS2) is
routinely determined by acid-base account (ABA)
analytical methods. The acid-base account method
specifies the use of extraction techniques to
determine the total quantity of acid-forming sulfur
compounds in a sample relative to the neutralizing
potential. However, when common sulfide and
sulfate minerals were subjected to ABA extraction
methods, the ABA method failed to accurately
distinguish the acid-forming from nonacid-
forming minerals, resulting in errors in the
determination of potential acidity. These
analytical errors are subsequently reflected in
inaccurate liming of acid producing waste
materials resulting in either excessive cost when
potential acidity is overestimated, or potential
reclamation failure when potential acidity is
underestimated.
Keyword(s): acid-base account, heavy metals, pyrite oxidation, acid mine drainage.
Oral presentation in research track.
In-situ soil vapor extraction, commonly known
as soil gas venting, has become an effective
remediation technique to remove volatile organic
contaminants from the subsurface. The major
drawback of this scheme is that the efficiency
tends to decrease with the presence of less-volatile
organics. Since fluid properties are highly
sensitive to ambient subsurface temperature, it is
potentially feasible to perform vapor extraction
under induced thermal gradients, also called
thermal venting, to enhance the recovery of less-
volatile fraction of the contaminant mass. The
objective of this work is to demonstrate the
applicability of the thermal venting technique to
enhance the recovery of organics from the liquid
unsaturated zone.
To investigate the applicability of the thermal
venting scheme, a multicomponent, non-
isothermal theoretical model was developed to
predict the coupled gas flow, heat transport and
mass transport in the unsaturated zone. Heat input
to the system was through the incoming gas flow.
As the inlet heated air passes through the
contaminated zone, enhanced volatilization of
liquid contaminant occurs at the air-liquid
interface. Heat energy transport was considered
under thermodynamic equilibrium condition
between different fluid phases. Also the latent
heat transfer due to moisture condensation and
evaporation of the organic phase was considered.
Mass transport analysis used local phase
equilibrium approximation to partition component
mass between the air, oil, water and adsorbed
phases within the residual oil plume. Phase
partitioning between the aqueous, air and solid
phases were considered outside the organic plume.
A number of hypothetical simulations were
performed to demonstrate the applicability of the
proposed technique. The results were used to
demonstrate the propagation of heat through the
soil due to the effects of conductive and
convective heat fluxes, the latent heat absorbed
during contaminant volatilization, and the latent
heat released during condensation of water vapor
of the incoming air. The results also showed the
rate of mass recovery and oil saturation in the
contaminated zone during venting. The results of
the model will also demonstrate the effectiveness
of various forms of heat energy input, energy
balance within the system, and the efficiency of
the technique with different organic compounds.
Keyword(s): thermal venting, vapor extraction, less-volatile, remediation, hydrocarbons.
Oral presentation in research track.
Reduced radicals of highly oxidized and
electron deficient halocarbons (carbon
tetrachloride, chloroform, dichloromethane,
trichloroethylene, 1,1,1-trichloroethane) were
detected by electron paramagnetic resonance spin
trapping spectroscopy in a reductive reaction
system consisting of lignin peroxidase, hydrogen
peroxide, veratryl alcohol,
ethylenediaminetetraacetic acid or oxalate,
hydrogen peroxide, phenyl-N-t-butylnitrone (as
the spin trap) and 1% of the halocarbon. This is a
free radical mediated process which uses the
organic acid as the electron donor. To correlate
the involvement of this mechanism in vivo,
mineralization of trichloroethylene and carbon
tetrachloride was studied by ligninolytic cultures
of Phanerochaete chrysosporium. Both
trichloroethylene (20.3% of 10 parts per million)
and carbon tetrachloride (18.8% of 10 parts per
million) were mineralized by the fungus over a
period of 9 days. Mineralization of these
chemicals did not take place in formaldehyde-
killed control cultures or nonligninolytic cultures
of the fungus, indicating that lignin peroxidases
play an important role in the process. Since all the
components of the reductive system are excreted
entracellularly, we propose that this fungus can be
used for bioremediation of these halocarbons.
Keyword(s): Phanerochaete chrysosporium, white rot fungi, aliphatic halocarbons, trichloroethylene.
Oral presentation in research track.
Polycyclic aromatic hydrocarbons (PAHs) are
a class of potentially hazardous chemicals that
exhibit toxic, mutagenic or carcinogenic
properties. Microbial degradation is the major
route through which PAHs are removed from
contaminated environments although other
mechanisms such as volatilization, leaching and
photodegradation may also be effective.
The rhizosphere contains a diversity of
microorganisms that contribute to plant health and
soil homeostasis. Recent studies indicate that
microorganisms in the rhizosphere can degrade
toxicants of concern to human health and the
environment. The increased density and diversity
of rhizosphere microflora may be an important
factor for enhanced microbial degradation of
PAHs.
The objective of this study is to evaluate
degradation of a number of different PAHs in
rhizosphere and non-rhizosphere soil. It has been
shown that the biodegradation rates of PAHs
increase as the number of PAH rings decrease, but
there is little information about the biodegradation
in rhizosphere soil. This study will provide results
from a microcosm experiment designed to
evaluate degradation of PAHs in rhizosphere and
non-rhizosphere. Also, kinetic models will be
developed to represent data collected.
Keyword(s): polycyclic aromatic hydrocarbons, rhizosphere, biodegradation.
Poster presentation.
Methane is the main component of natural gas
and has been connected with global warming. The
oxidative coupling of methane has been studied to
enhance the C2 hydrocarbons selectivity and to
reduce the formation of carbon oxides. The acid
sites of supported catalysts play an important role
in the formation of carbon oxides. The supported
Zn-Oxide catalyst with a-Al203 shows no acidity
in temperature programmed desorption by using
NH3 and exhibits good C2 hydrocarbons
selectivity. The optimum loading of Zn-Oxide on
a-Al203 is 60wt%. The specific surface area of
the catalyst appears not to influence activity.
Using alkali metal salts as a promoter in the Zn-
Oxide (60wt%)/a-Al203 catalyst, the activity
performance for C2 hydrocarbons is
LiCl>NaCl>KCl, and that performance is well
correlated with the apparent molal enthalpy of
formation in alkali halides. The activity
performance for reducing carbon oxides is
LiCl>KCl>NaCl, which is well correlated with the
melting point in alkali halides.
Keyword(s): methane, oxidative coupling, C2 hydrocarbons, carbon oxides, promoter.
Poster presentation.
Conventionally prepared and autoclave
prepared calcium oxides were studied to
understand the decomposition of the carbon
tetrachloride and trichloroethylene processes. To
explain the increased ability of autoclave prepared
calcium oxide for decomposition of
chlorocarbons, different methods were employed.
The infra-red technique for observing adsorbed
species on calcium oxide after adsorbing carbon
tetrachloride and spring balance studies to
understand the importance of the basic and acidic
sites on the oxide were done. To enlighten some
other differences between these two oxides,
transmission electron microscopy,
thermogravimeric analysis, and instrumental
analysis were used.
Keyword(s): chlorocarbon, calcium oxide, decomposition.
Oral presentation in research track.
Eleven polyelectrolytes were tried separately
to treat the wastewater from a paint manufacturing
industry. Amongst these, Zetag 66, a cationic
polyelectrolyte was found to be most effective. A
dosage of 5 mg/L of this polyelectrolyte was
found to be adequate to achieve 65% COD
removal, 97% suspended solids removal and 90%
heavy metals removal. The use of this
polyelectrolyte assumes significant importance as
it eliminates the use of alum completely. This
elimination of alum consumption results in
considerable reduction of effluent treatment plant
sludge which is a hazardous waste. The savings
that results in the primary treatment is an added
advantage.
Keyword(s): polyelectrolyte, heavy metals, alum consumption, hazardous waste.
Oral presentation in research track.
A near-infrared spectrophotometer has been
interfaced with a high-pressure apparatus,
utilizing a fiber optic probe. The system was
designed to re-circulate carbon dioxide for studies
of supercritical extraction. Near-infrared spectra,
over the range of 400 to 2400 nm, have been
obtained for dense carbon dioxide, at pressures to
8 MPa. Spectra for chlorinated biphenyls in
supercritical carbon dioxide have been recorded
also. Data is stored directly; a software package
correlates solubility in dense carbon dioxide for
long-term information management. New
opportunities for non-invasive sampling in high-
pressure environments are being explored.
Solubilities in dense carbon dioxide are modeled
utilizing the fugacity coefficient approach with
appropriate equations of state.
Keyword(s): supercritical, sampling, solubility, extraction, fugacity.
Oral presentation in research track.
This study investigated the feasibility of using
iron rich mine tailings in a metals removal process
for leachate based on the natural iron cycle. The
natural iron cycle involves the photoreductive
dissolution of iron(III) (hydr)oxides resulting in
soluble iron(II) during the day, and subsequent
oxidation and reprecipitation to iron(III) during
the night. Photolysis experiments conducted in the
laboratory using mine tailings produced
significant concentrations of soluble iron(II) in
aqueous solution at low pH. Oxidation of soluble
iron(II) to iron(III) removed soluble arsenic and
cadmium from solution to concentrations less
toxic, with the solid phase precipitate more
concentrated for a possible metals recovery
system. Factors influencing the photoproduction
of iron(II) from the mine tailings included the
concentration of organic matter, the presence of
amorphous iron oxides, and the chemical forms of
iron in the mine tailings. Solution pH and the
addition of ligands also affected iron(II)
photoproduction. Factors influencing the removal
of arsenic and cadmium from aqueous solution
included the pH of the solution, as well as the
presence of organic matter and amorphous iron
oxides in the mine tailings.
Keyword(s): iron, photoreduction, oxidation, adsorption, coprecipitation.
Oral presentation in research track.
Throughout the United States, petroleum
hydrocarbon contamination of soil is a severe
problem. Storage tanks are quite often the source,
whereby hydrocarbons are released on or near the
ground surface and are free to migrate through the
soil to the groundwater. Sometimes, such
chemicals accumulate at interface of different soil
types.
Hexadecane transport and degradation in soil
reactors were studied in a series of experiments.
Three reactors, consisting of soil in sand-clay-
sand layers, were contaminated at single points in
the center of the top sand layer just below the
surface. One reactor was used as a control while
the other two were equipped with influent and
effluent water ports located above the sand/clay
interface. The ports were utilized to add water to
the soil. One reactor was supplied with water only
and the other was injected with a
phosphorus/nitrogen solution to enhance
degradation.
The project focused on two aspects: (1) the
transport of the NAPLs at an abrupt sand/clay
interface and (2) the ability of the soil microbes to
degrade the hexadecane under aerobic conditions.
Gas chromatography analysis of the effluent water
samples indicate no significant removal of the
NAPL from the soil by pumping, while mass
balances indicate NAPL degradation due to
microbial action. In addition, gas chromatography
data of soil samples trace the movement of the
chemical throughout the three reactors.
Keyword(s): NAPLs, bioremediation, soil interface, transport.
Oral presentation in research track.
The objective of this research is to investigate
the impact of vegetation on the fate of toxic and
recalcitrant pyrene in soil as well as the influence
of different plant species (alfalfa (Meticago
sativa) and fescue (Festuca arundinacea)). The
effect of vegetation will be evaluated by
determining the distribution of 14C among soil,
plant tissue, leachate, and CO2 evolved in planted
and unplanted soils using highly controlled plant
growth chambers during a 6-month experiment.
The influence of plant species on the fate of
pyrene will be estimated by comparing the
dissipation rate of the 14C-target compound
between alfalfa and fescue. These data will be
analyzed to ascertain if there are differences
between vegetated and non-vegetated soils, also
between plant species with regard to leaching,
degradation, plant uptake, mineralization of the
14C-labelled pyrene. The beneficial effects of
vegetation planted in soil contaminated by pyrene
is anticipated.
Keyword(s): vegetation, pyrene, soil, plant, rhizosphere.
Poster presentation.
Low concentrations of toxic heavy metals
generally encountered in wastewater treatment
exclude, for economical reasons, the use of
traditional removal methods such as chemical
precipitation, ion exchange, filtration, membrane
technology, etc. The economical feasibility of
recovering heavy metals can be extended by using
relatively inexpensive yet efficient natural
biopolymers.
Pursuant to our goal of using these
biopolymers in decontaminating natural waters,
we have measured thermodynamic and kinetic
parameters for combinations of metals over a
series of temperatures. Copper, lead and zinc
divalent metal ions were investigated, as were
three different types of calcium alginate
biopolymer gel beads. Water-jacketed batch
reactors were used in these studies.
Keyword(s): heavy metals, toxic waste, biopolymers, water.
Oral presentation in research track.
Past production practices at munitions
ordnance plants have resulted in contamination of
terrestrial and aquatic ecosystems. Efforts to date
have documented the nature of contamination and
attempted to estimate potential migration routes.
To predict the fate of munitions in contaminated
soils, an accurate prediction of the adsorption-
desorption process is critical. Soils from drainage
ditches at the abandoned Nebraska Ordnance Plant
were found to be highly contaminated with TNT.
Equilibrium soil solution concentrations were
approximately 70 mg L-1 and relatively
independent of soil to solution ratios, indicating
the presence of solid phase TNT. Transport
experiments were conducted using solute pulses
of 70 mg TNT L-1 with uncontaminated soil and
with soil columns containing contaminated and
uncontaminated layers. Experiments were
performed by displacing 27 or 53 pore volumes of
TNT-3H20 pulse through disturbed soil columns
(5.1 cm diam, 7.5 cm length) at a pore water
velocity of 11 cm d-1. Results using
uncontaminated soils indicated that breakthrough
curves of TNT effluent concentrations never
reached initial solute pulse concentrations (C/Co »
0.8) . The equilibrium adsorption isotherm for
TNT sorption on the uncontaminated soil was
characterized as a nonlinear Freundlich type.
Assuming local equilibrium and using a batch-
determined distribution coefficient (Kd) in the
convection-dispersion equation resulted in an over
estimation of elution times. These results indicate
that errors can result by assuming a linear
adsorption isotherm when predicting TNT
transport in highly contaminated soils.
Keyword(s): TNT, fate, transport.
Poster presentation.
A sticking coefficient (a) is defined as a ratio
of the rate particles stick to a surface to the rate
they strike a surface. A relatively non-attaching
bacterium (~ 1 µm) may undergo 350 collisions
while only being transported 10 m in soils (0.5
mm diameter). Bacteria do not instantaneously
and completely desorb from surfaces producing
two major effects. First, sticking coefficients
measured from breakthrough concentrations in
continuous injection tests can be overestimated
since the slowly desorbing cells are incorrectly
included in the "steady state" breakthrough
concentration. Second, varying times to
desorption and large numbers of collisions
enhance longitudinal dispersion. We developed a
computer program to model desorption rate as a
function of time by tracking the desorption of
bacteria striking soil surfaces. Model results were
compared to bacterial injection experiments
conducted in soil columns. We found slow
desorption resulted in two factors commonly
observed in bacterial breakthrough curves: a slow
rise to steady state, and continuous elution of cells
at 2-log concentration reductions after a pulse
injection.
<
b>Keyword(s): biocolloids, filtration, groundwater, particles, subsurface.
Oral presentation in research track.
Polycyclic aromatic hydrocarbons (PAH) are a
hazardous group of compounds which are highly
toxic, recalcitrant and persistent, and belong to the
class of hazardous organic compounds. Petroleum
refining, coal conversion and chemical
manufacturing sites are most often contaminated
with PAHs. The propensity for bioaccumulation
and possible adverse health effects of PAH parent
compounds as well as intermediates pose special
problems in designing a soil treatment system that
will effectively reduce the concentration of these
compounds. Once incorporated into the soil,
biodegradation seems to be the most significant
means of PAH decomposition.
The role of vegetation to stimulate the
degradation and detoxification of toxic and
recalcitrant organic chemicals at low soil
concentrations is brought about by several
mechanisms of plant-soil interactions, including
improvement of physical and chemical properties
of contaminated soils, increase in soil microbial
activity and increase in contact between microbes
associated with the roots and toxic compounds in
a contaminated soil. This represents a potential
cost effective and low maintenance alternative for
waste management. However, there is not enough
information concerning specific application of
plants, chemicals and soils either in the form of
laboratory or field results.
In the research to be presented, different and
diverse perennial plant species [grasses
(monocot), legumes, and dicots] were collected
from the native prairie grasslands and tested for
their efficiency in mineralization of the target
PAH contaminant—phenanthrene.
The mineralization of phenanthrene was
evaluated by the measurement of 14CO2 from the
radiolabeled target compound incubated in a
rhizosphere soil microcosm. Results from this
study will indicate the potential of using different
types of plants to enhance degradation of PAHs in
contaminated soils.
Keyword(s): bioremediation, phenanthrene, rhizosphere, mineralization.
Poster presentation.
Many acres of soil at the former Nebraska
Ordnance Plant (NOP) are contaminated with
TNT and other munitions residues. In some areas,
solid phase TNT is present and controls the
concentration of the soil solution. Native
microbial populations in uncontaminated soils
similar to those at the NOP site were severely
reduced when solid phase TNT was allowed to
control the soil solution TNT concentration.
However, examination of NOP soil revealed an
active population of Pseudomonas sp. A single
species that could utilize TNT as a sole C source
was isolated from the contaminated soil and
tentatively identified as Pseudomonas corrugata
through the BIOLOG system. Subsequent growth
and characterization experiments indicate that the
Pseudomonad metabolizes TNT while in the
exponential phase of growth in medium
containing glucose as a C source. In addition, a
consortium of organisms was found that could
utilize TNT as a sole N source. Low TNT
mineralization rates (measured by CO2 evolution)
in soil and media using the various isolates
suggest reduced availability due to sorption and
incorporation of transformation intermediates into
the organic matrix and microbial biomass.
Pretreatment of TNT by acid-metal catalyzed
reduction resulted in an initially higher rate of
mineralization following addition to TNT-
contaminated soil. Observations indicate more
rapid microbial utilization of the 2,4,6-
triaminotoluene (TAT) reduction product and its
spontaneous decay product, methylphloroglucinol
(2,4,6-trihydroxytoluene), than TNT. Abiotic
pretreatment may be useful in enhancing
microbial transformation and detoxification of
TNT in highly contaminated soils.
Keyword(s): TNT, degradation, acid-metal catalyzed reduction.
Poster presentation.
Scanning electron microscopy, confocal
scanning laser microscopy, fatty acid methyl ester
profiles and restriction fragment length
polymorphism pattern analysis of total community
amplified 16S ribosomal RNA genes were used to
study the development, organization and structure
of natural aerobic multispecies biofilm
communities in laboratory and field field-scale
granular activated carbon fluidized bed reactors
(GAC-FBR) treating petroleum contaminated
groundwater. The processes of biofilm formation
were studied in a laboratory reactor, which was
fed toluene-amended groundwater. The GAC was
allowed to become colonized by the indigenous
aquifer populations. Subsequent cell binary fission
of attached cells embedded in their own polymeric
matrix led to the formation of microcolonies.
During the early stages of colonization,
microcolonies were primarily observed in crevices
and other regions sheltered from hydraulic stream
stresses. Eventually, these microcolonies grew
over the entire surface of the GAC. This lead to
the development of highly complex multilayer
biofilm structures. During this phase, spatial cell
organization appeared to play key structural roles.
Channel-like structures of variable sizes were
observed to interconnect the surface film with the
deep inner layers. Ultimately, this resulted in an
increase in the overall biological surface
area/volume ratio, and may facilitate transport of
substrates in and waste products out of deep
regions of the biofilm at rates greater than
possible due to diffusion only. Common
architectural features were observed among
biofilms from field GAC systems that were
examined. This suggests that channel formation
may be a general microbial strategy to deal with
diffusion limitation problems in these type of
reactor systems.
Keyword(s): biofilm, bioremediation, microbial ecology.
Poster presentation.
An overview of the on-going demonstration of
an Ukrainian Integrated Clay-based Grouting
technology will be presented. The field
application is a project under the MWTPP which
is being implemented by MSE Inc., funded by the
U.S. Environmental Protection Agency (EPA) and
jointly administrated by the EPA and the
Department of Energy. Surface water
measurements taken in Mike Horse Creek indicate
a “loosing reach” in an area of the creek which
corresponds with a portion of underground
workings of the mine and with faulting in the local
geology. Tests are being conducted to determine
the subsurface water courses and to characterize
the project area. Results from the initial phase of
the project, the Characterization Phase, being
conducted at the inactive Mike Horse Mine near
Lincoln, Montana, will be reported. The
preliminary plans for grout placement and
evaluation of the project will be included in the
presentation.
Keyword(s): grouting, hydrological control, acid rock drainage.
Oral presentation in research track.
Biodegradation of volatile organic compounds
such as petroleum hydrocarbons and xenobiotic
agents in the vapor phase is a promising new
concept in well-head and end-of-pipe treatment
which may have wide application where in-situ
approaches are not feasible . The microbial
degradation of the volatile organics can be carried
out in vapor phase bioreactors which contain inert
packing materials. Scale-up of these reactors from
a bench scale to a pilot plant can best be achieved
by the use of a predictive model, the success of
which depends on accurate estimates of
parameters defined in the model such as
biodegradation kinetic and stoichiometric
coefficients. The phenomena of hydrocarbon
stress and injury may also affect performance of a
vapor phase bioreactor. Batch kinetic studies on
the biodegradation of toluene by P. putida 54G
will be compared to those obtained from
continuous culture studies for both suspended and
biofilm cultures of the same microorganism.
These results will be compared to the activity of
the P. putida 54G biofilm in a vapor phase
bioreactor to evaluate the impact of hydrocarbon
stress and injury on biodegradative processes.
Keyword(s): biodegradation, vapor phase bioreactor, toluene.
Oral presentation in research track.
Photocatalytic oxidation of organic compounds
in aqueous solution has gained interest as a
possibility for purifying waste water and drinking
water. Aqueous suspensions of titanium dioxide
when irradiated with ultraviolet light are capable
of decomposing some organic water
contaminants. In this regard, different size
titanium dioxide particles were prepared by an
aerogel technique to investigate the effect of
particle size on the photocatalytic activity of
titanium dioxide. Different sized titanium dioxide
particles were made, characterized and compared
with a common industrial source of titanium
dioxide, Degussa P-25, in the photocatalytic
oxidation of chloroform.
Keyword(s): photocatalytic oxidation, aerogel, chloroform, titanium dioxide.
Oral presentation in research track.
The Anaconda Revegetation Treatability Study
(ARTS) is being conducted to demonstrate in-
place treatments of mill tailings, smelter wastes,
and soils contaminated by smelter emissions at the
Anaconda Smelter National Priorities List Site in
Anaconda, Montana. A study area of
approximately 11,000 acres has been divided into
designated subareas: Opportunity Tailings Ponds,
Anaconda Tailings Ponds, Smelter Hill, Old
Works, and Adjacent Areas. Acidic mill tailings
which contain elevated metal levels are contained
in the Opportunity and Anaconda Tailings Ponds
systems. The other three areas have been affected
by smelting processes and stack emissions. The
materials also contain elevated metal
concentrations and have pH values ranging from
acidic to neutral.
ARTS is being conducted in four phases. The
first, completed in 1993, included reviews of
reclamation literature and data searches to
determine factors controlling the revegetation of
acid metalliferous materials at the Anaconda site
and at other locations with problems similar to
Anaconda. Other Phase I activities included
physical and chemical data collection and the
selection of demonstration sites within the
designated subareas. The second Phase (currently
ongoing) includes laboratory and greenhouse tests
which are being used to develop effective
amendment/vegetation treatments. Large
demonstrations have been implemented in three of
the subareas as Part of Phase III. On Smelter Hill,
a 5 acre site was treated with selected
amendments using specialized equipment and
seeded with selected vegetation in the fall of 1993.
A one acre demonstration site in the Old Works
area was treated with various combinations of
amendments and two different pieces of heavy
equipment were used to mix the amendments into
these wastes. This site is to be seeded with
selected plant species in the spring of 1994.
Another one acre site located on contaminated
soils will test the effectiveness of different sources
of organic matter (wood wastes, commercial
compost, and composted manure) in combination
with different lime materials in providing a
suitable rootzone. Field demonstration on the
tailings ponds will begin in the summer of 1994.
In Phase IV the effectiveness of the treatments at
each site will be monitored in terms of reducing
contaminant movement in the different pathways.
Changes in waste chemistry, rootzone hydrology,
and vegetation response will be measured.
Keyword(s): revegetation, smelter, tailings, soils.
Oral presentation in research track.
ARTS is funded by Atlantic Richfield Company (ARCO)
and is under the direction of a Technical Committee
comprised of representatives of the Environmental Protection
Agency, the Montana Department of Health & Environmental
Sciences, and ARCO. The ARTS study is being conducted by
the Reclamation Research Unit at Montana State University.
Current methods of detecting sorbed soil
pollutants require that the contaminant be
extracted from the soil. In an effort to make
detection simpler and safer, standard fluorescent
immunoassay techniques are being modified to
allow fluorescent tags on the pollutant to be
viewed and photographed with epifluorescent
microscopy. Initial research focuses on detecting
chlorinated benzenes on various soil types and
developing a technique for tagging these
pollutants with appropriate antibodies. This
should lead to detection in actual soil cores and a
better understanding of how contaminants
progress through different soils.
The following flowchart illustrates the
antibody linkage mechanism used. The
compounds listed were used for the initial
feasibility tests of this method.
dinitrobenzene (DNB) (pollutant)
ß
rabbit anti-DNB (primary antibody)
ß
goat anti-rabbit (secondary
gamma globulin/ antibody/
fluorescein fluorescent tag)
The figures following are fluorescent
microscopy photos acquired using this method.
The light areas indicate brick chips that were
contaminated with DNB, while the
uncontaminated chips remain dark.
DNB-contaminated brick
Uncontaminated brick
Keyword(s): fluorescence microscopy, immunoassay, sediments, soils.
Oral presentation in research track.
Revegetation is normally proposed as the
ultimate fate of ash disposal ponds to alleviate the
potential for contamination of water systems and
to improve the appearance of the landscapes that
contain these structures. This ash is usually
phytotoxic due to large quantities of salts.
Revegetation is most often accomplished by
capping followed by seeding. The question
becomes one of the depth of soil necessary to
support adequate vegetation, to protect the surface
from erosion by surface water flows, and to
protect groundwater from salts leaching from the
ash pond. Western fly ash ponds are especially
sensitive to these problems because of the scarcity
of water in this region and the presence of high
salt loads in most groundwater systems.
A coarse textured diffusion barrier and variable
soil depths were evaluated for their ability to
stimulate vegetation development, prohibit salt
movement into surface soil horizons, and permit
plant roots to harvest water that infiltrates into the
soil. After three growing seasons the vegetation
appears to be flourishing. It has stabilized the
surface of the test plots and plant roots appear to
be harvesting water before it can penetrate below
the root zone.
Keyword(s): revegetation, coal ash, salinity.
Oral presentation in technology transfer track.
Experimental investigations were carried out in
the laboratory to study the impact of vegetation in
bioremediating soil and groundwater
contaminated with hazardous organic substances.
A 90 cm long chamber with 2 U-shaped channels,
each 10 cm in width and 35 cm in depth, was set
up. Alfalfa plants were chosen and they have been
growing in the channels under laboratory
conditions for nearly 2 years. The channels were
packed with fine sandy soil collected from near a
landfill. The "groundwater" fed to one channel
was water contaminated with toluene solution at
saturated concentrations @ 25 C, whereas, the
other channel was fed with water contaminated
with phenol solution @ 500 ppm (v/v). The
contaminant concentrations in the groundwater of
the channels were monitored at the sampling wells
located along each of the channels. The influent
and effluent flow rates from each channel were
measured every day and recorded.
"Evapotranspiration" significantly influenced the
fate of the pollutants. Dispersion and adsorption
processes in the channel were studied by
introducing bromide tracer, as a broad pulse, into
the toluene fed channel and by observing toluene
and phenol concentrations, following a feed step
change to pure water. Tracer studies indicated that
short-circuiting in the end of the channel was
quite significant. Models which were previously
developed to describe the fate of the contaminants
in variably-saturated soils in the presence of
vegetation are being employed to simulate the fate
of these hazardous organic substances in the
laboratory chamber.
Keyword(s): bioremediation, evapotranspiration, adsorption, rhizosphere.
Oral presentation in research track.
Evaluation of processes according to their
environmental compatibility is necessary at a
relatively early stage of planing, since this
becomes a more and more decisive feature of
competitiveness.
However, at an early stage in the development,
data are scarce and the effort to investigate
various process alternatives using full blown
ecobalances or comparable methods is prohibitive.
The SPI offers a chance to evaluate the
ecologic compatibility of a process (or process
revamping) in a quick and reliable way. It is based
on the concept of sustainable development and
uses only information about mass flows, energy
flows and investment needs besides readily
available environmental data. It allows clear
distinction between environmentally compatible
and problematic processes and indicates those
steps within the process which pose the largest
obstacles on a way to environmental
compatibility.
Keyword(s): environmental compatibility, process evaluation.
Oral presentation in research track.
Spatial variability exhibited by many field
soils necessitates the use of stochastic methods for
prediction of average solute movement. Data from
a field experiment were analyzed to characterize
the random nature of the velocity and dispersion
of solute (Potassium Bromide) in field scale
vertical transport experiments. Solute
concentrations were measured at over fifty spatial
locations and at six depths within the soil. The
analysis indicates that solute velocities at deeper
soil layers exhibit a statistically homogeneous
behavior. Dispersion was determined from
breakthrough curves using a standard nonlinear
regression model. These results will be presented,
and the implications of modeling average solute
behavior will be discussed.
Keyword(s): spatial variability, stochastic methods, transport.
Oral presentation in research track.
Assessment of in-place chemical
immobilization of metal contaminants in mine
wastes/soils followed by revegetation as a
potential remedial alternative for cleanup of a
Superfund site is described. This six year
treatability study evaluated the use of different
amendments, various incorporation techniques,
and selected plant species in both
laboratory/greenhouse tests and at five
waste/contaminated soil locations along Silver
Bow Creek between Butte and Opportunity,
Montana.
Amendments (mainly calcium hydroxide and
calcium carbonate) found in the laboratory to be
most effective in controlling pH of these acid
producing metalliferous wastes and reducing their
soluble metal levels were mixed with the
wastes/soils in replicated greenhouse trials.
Amendments and greenhouse selected plant
species were combined into replicated field trials
using different amendment incorporation
techniques. Vegetation response and components
of the soil chemistry and soil hydrology were
measured, and differences among treatments were
assessed.
Data support coversoil as most effective, but
coversoils are not available in quantities adequate
for the rehabilitation of all the disturbances along
Silver Bow Creek. Pressure injection of lime
slurry into the wastes did not provide an adequate
rootzone for long term plant growth. Agricultural
tilling of amendments provided only 15
centimeters of adequate rootzone materials. A
plow capable of mixing waste to a depth of 122
centimeters provided an ameliorated rootzone that
varied from 30 to 60 centimeters deep. Plant cover
and production were greater on deep plowed plots
than on plots prepared by the two other
incorporation techniques. Deeper root penetration
was also found in the deep plowed plots than in
plots treated by agricultural tillage or the injection
technique. Surface runoff was markedly reduced
and surface water quality improved by all
treatments.
Keyword(s): revegetation, tailings, metal, immobilization.
Oral presentation in research track.
On Minnesota’s Mesabi Iron Range, coarse
taconite iron ore tailing is often used as the
principal material in the construction of dams for
large tailing impoundments. Mineland
reclamation rules in Minnesota require that tailing
dams be vegetated to control erosion for dam
stability and safety. Vegetation helps to maintain
the structural integrity of the dam by resisting
erosion resulting from the forces of wind and
water. Coarse taconite iron ore tailing is
characterized chemically by its alkaline reaction,
low water-holding capacity, and dark color; and
biologically by its lack of microorganisms. To
ameliorate these conditions and make the material
more amenable to plant establishment and growth,
the U.S. Bureau of Mines implemented a series of
factorial experiments at two active taconite mine
sites in northeastern Minnesota. At each
experimental site vegetative cover has improved
depending on the type of municipal solid waste
compost used and rate of application. At site I,
overall plant cover across all treatments had
improved from 0% prior to experimental
manipulation to 72% after 4 years, with 7
treatment combinations exceeding 90% cover. At
site II, overall plant cover has improved from 0%
prior to experimental manipulation to 83% after 4
years, with 23 treatment combinations exceeding
90% cover. At both sites, total cover has
progressively increased over 4 years and has not
reached steady state conditions. These results
suggest a possible new strategy for reclaiming
difficult sites through the use of municipal solid
waste compost.
Keyword(s): taconite, tailing, revegetation, compost, cover.
Oral presentation in research track.
Studies have been conducted assessing the
influence of competitive substrate interactions on
the rate/extent of trichloroethene degradation by
Nitrifying mixed cultures. Specifically, the effect
of ammonia, hydroxylamine, tetrachloroethene
and cis-dichloroethene have been examined.
Results demonstrate that rates of degradation and
finite transformation capacity are significantly
influenced by these interactions. Adding
hydroxylamine as an exogenous source of energy
in the absence of the primary substrate produced
an increase in the degradation capacity of these
cultures up to threefold. Models are being tested
to predict these phenomena.
Keyword(s): biodegradation, nitrifiers, trichloroethene, substrate interactions.
Oral presentation in research track.
Molecular oxygen is one of the strongest
naturally occurring redox species. In subsurface
environments, oxygen is quickly consumed by
microorganisms and is slow to recharge. When
oxygen becomes limiting, microorganisms must
utilize alternative terminal electron acceptors to
mediate growth. Iron and Manganese have high
redox potentials and are commonly found in the
subsurface. Abiotic and microbially mediated
reactions are potentially energetically favored by
electron transport systems that utilize these metal
species.
Calculated free energy changes are used to
show the potential use of iron and manganese as
terminal electron acceptors in the transformation
of pentachlorophenol in anaerobic environments.
Microbial yields based on free energy liberated
from pentachlorophenol transformation are
estimated under iron and manganese reducing
conditions using a simple bioenergetic growth
model.
Iron and manganese was extracted from
aquifer solids obtained at a superfund site and
mixed with pentachlorophenol under anaerobic
conditions. The rate of appearance of reduced
metal species was correlated with the
disappearance of pentachlorophenol. Sequential
utilization of iron and manganese based on
calculated free energy changes was investigated.
Keyword(s): redox, electron acceptors, remediation, aquifers.
Oral presentation in research track.
Nutrient cycling has been shown to enhance
the degradation rate of carbon tetrachloride in
anaerobic batch cultures. In addition, nutrient
pulsing has been suggested as a method for
controlling near-bore biofouling in application of
in-situ bioremediation. To determine the effects of
nutrient pulsing on biomass accumulation, soil
columns were fed with nitrate and acetate to
develop a denitrifying biofilm within a porous
sand matrix to compare two nutrient delivery
strategies. The strategies that were compared were
continuous nutrient feeding and pulsed nutrient
feeding.
Acetate, as the sole carbon and energy source,
was fed to the columns continuously at 83 mg/L
or pulsed at 2222 mg/L for 30 minutes every 12
hours. This resulted in the same time-averaged
substrate loading to the soil columns. Final
biomass profiles indicate a much more uniform
biomass accumulation profile using a pulsed
nutrient strategy. Also, notable differences in the
effluent suspended cell concentrations were
measured. This data was used to help calibrate a
detailed model for bacterial transport in porous
media, which will be used to aid in the design and
implementation of in-situ bioremediation at the
Hanford site.
Keyword(s): in-situ bioremediation, biofilm, biofouling, denitrification, nutrient delivery.
Oral presentation in research track.
This work was supported by the U.S. Department of
Energy as part of Pacific Northwest Laboratory’s Laboratory
Directed Research and Development. Pacific Northwest
Laboratory is operated for the U.S. Department of Energy by
Battelle Memorial Institute under contract DE-AC06-76RLO
1830.
Surface and subsurface sources of groundwater
contamination is a major problem at Department
of Energy (DOE) facilities and is found at more
than seventy percent of the sites currently on the
Environmental Protection Agency (EPA) National
Priority List (NPL). These water supplies are vital
national resources to be utilized as sources for
drinking, industrial, commercial, municipal,
governmental, recreational and agricultural water
uses. Once contaminated, these resources are very
expensive to recover due to the large volumes and
relatively low contaminant concentrations.
This paper discusses a systematic approach to
recover contaminated waters and to produce
marketable products that is amenable to market
drivers and optimization. This systems
configuration is utilized to identify potential
treatment processes, define process constraints,
assemble treatment technologies for insertion into
a logical and feasible order, and define technology
deficiencies. The systems configuration displays
conventional and novel technologies to be
considered in combinations as well as
individually, with respect to their technical
feasibility, effectiveness, applicability to DOE
needs, implementability, cost, regulatory
acceptability, and readiness for demonstration.
The strategy addresses the innovative technologies
being developed by DOE and integrating novel
DOE technologies with the conventional and
innovative technologies of industries to develop
the Berkeley Pit resource recovery plan. To offset
the cost of resource recovery, the scope of this
research includes the vision toward the recovery
and marketability of the valuable mineral and
water resources contained in the Berkeley Pit.
Keyword(s): heavy metals, systems configuration, flowchart, resource recovery, contaminated water.
Oral presentation in research track.
In addition to advective and diffusive transport
of contaminants in the subsurface, clay colloid-
associated transport in the shallow subsurface
regions was recently found to provide a significant
component. This study dealt with an assessment
of clay colloid migration and the associated
transport of contaminants from surface run-off
into the subsurface. The study consisted of two
phases of experimental investigations. In the first
phase, a series of tests were conducted in
permeameters on sandy soils of various densities.
Suspensions of montmorillonite particles were
introduced into the samples to obtain deposition
profiles of montmorillonite particles. In the
second phase, zinc was used as the sorptive
contaminant in the influent. Breakthrough curves
and zinc profiles in the soil sample were obtained.
Results from these experiments were used to
assess the impact of clay colloid-associated
transport of contaminants on soil and groundwater
quality under a range of in-situ conditions.
Finally, an approach was outlined to model this
transport mechanism. A sensitivity analysis was
conducted to identify the effects of key
parameters such as soil density, soil-contaminant
interactive properties such as the distribution
coefficient, and residence time of influent.
Keyword(s): clay colloids, colloid-associated transport.
Oral presentation in research track.
The metals iron, stainless steel, copper,
nichrome, titanium, aluminum and aluminum
alloys were exposed to different cultures of
bacteria. The microorganisms included pure
strains of sulfate-reducing bacteria, cocultures and
mixed cultures. The results of the biological
activity such as biocorrosion, scaling and
precipitation of metals was studied by using
Environmental Scanning Electron Microscopy,
gravimetric analysis, and by Energy Dispersive X-
ray analysis. The effect of different nutrients,
cultures, and the presence of oxygen were studied.
The observation of bacteria, colloids and plaque
of iron sulfide, crystals and tubercules in their
natural and wet state was facilitated by the
environmental microscopy.
Keyword(s): environmental microscopy, biocorrosion, sulfate-reducing bacteria.
Oral and/or poster presentation in research track.
The effects of vibrations on soils containing
immiscible liquids were described in the context
of soil remediation. Vibrations when augmented
with flow gradients have the beneficial effect of
dislodging immiscible liquid blobs and mobilizing
them toward the point of intended collection.
Several bench-scale experiments were conducted
using a laboratory vibrator on sandy soils
contaminated with Soltrol. The experiments were
conducted under controlled conditions using a 4-ft
diameter tank. The effect of vibrations on the soil-
contaminant medium was measured via pore
pressure transducers installed at various radial
distances from the vibrator. Soil samples from the
tank were analyzed for contaminant
concentrations before and after inducing
vibrations. The effectiveness of vibrations was
assessed in terms of reduction of residual
saturation of the liquids. The results were
analyzed to assess the effects of various test
parameters on the process such as frequency of
vibrations, flow velocities in the tank, duration of
vibrations, and density of soil. The lateral zone of
influence of vibratory mobilization was also
assessed. In order to predict the in-situ
effectiveness of the process, mobilization criteria
were developed as functions of soil, contaminant
and vibration parameters. The zone of influence
obtained using these mobilization criteria agreed
well with the observed values for bench-scale
experiments. Finally, a prototype design
integrating vibrator and pumping mechanism was
recommended for in-situ use at hazardous waste
sites.
Keyword(s): immiscible (nonaqueous phase) liquids, vibrations, in-situ remediation.
Oral presentation in research track.
A strain of Clostridium bifermentans isolated
from a munitions-supplemented enrichment was
able to remove both TNT (2,4,6-trinitrotoluene)
and RDX (1,3,5-triaza 1,3,5-trinitrocyclohexane)
from its growth media. Biotransformations of
TNT and RDX by cometabolism in a nutrient rich
medium reduced the removal time from several
days to a few hours, as compared to a nutrient
limited medium. Redox potential (Eh) of the
media had important effects on the biological and
abiological transformations of the munition
compounds.
Keyword(s): biotransformation, cometabolism, 2,4,6-trinitrotoluene, 1,3,5-triaza 1,3,5-trinitrocyclohexane, clostridium.
Poster presentation.
A survey of industrial waste generated in the
state of Kansas revealed that foundry sand is
produced in significant quantities and that its
disposal costs are high. A new research project
was initiated in 1993 to identify ways to utilize
the foundry sand such that the waste components
in the sand are stabilized and rendered harmless.
Chemical analyses of the waste material showed
significant quantities of phenolic compounds. A
series of experiments were conducted on mixtures
of foundry sand and cementitious materials to
identify useful mechanical properties and to assess
leachability of chemicals. Three types of
cementitious materials were used as binders: i)
naturally available clay minerals such as kaolinite
and montmorillonite, ii) waste by-products such
as fly ash which are known to possess
cementitious nature, and iii) portland cement. The
mechanical properties (primarily compressive
strength) and the leachability of the mixes were
analyzed as functions of various test parameters
such as mix proportions and setting time. The
results show that waste materials from foundries
can adequately be stabilized using cementitious
binders such that the leachates do not contain
detectable levels of harmful chemicals. Finally,
some engineering uses of the stabilized mixes
were identified.
Keyword(s): waste stabilization, waste utilization, leachability.
Oral presentation in research track.
Recently, contamination levels of vegetated
soil in polluted areas were found to be lower than
contamination levels of non-vegetated soil in the
same area. The greater mineralization of
pollutants observed in vegetated soils may be a
result of the higher microbial and metabolic
activities observed in the plant's rhizosphere
environment which may lead to enhanced
biodegradation of xenobiotics in contaminated
vegetated soils.
After determining the different factors
affecting the fate and the metabolic activity of
microorganisms in the rhizosphere, we plan to
study the possibility of introducing specialized
organisms in the rhizosphere in order to enhance
the biodegradation of target compounds.
Our purpose is to develop a soil
bioremediation technology based on stimulating
synergistic interactions existing between the
rhizosphere environment and selected
microorganisms to enhance the biodegradation of
organic pollutants in contaminated soil. If
effective, this technology could be used
worldwide over large areas to effectively and
inexpensively treat contaminated soil.
Keyword(s): soil bioremediation, rhizosphere, metabolic activity, synergistic interactions, enhanced biodegradation of xenobiotics.
Oral presentation in research track.
As a result of 100 years of mining, the largest
lead-contaminated Superfund site, located in
Silver Valley, Idaho, is highly contaminated with
lead, mercury, and arsenic, among other metals.
Despite attempts to lessen the impact of these
metals upon the environment, the problem of
heavy metal contamination still exists. Microbial
communities are known to possess resistance to a
variety of metals raising the possibility of using
such microbes to detoxify heavy metal
contaminated soils and waters. However, little is
known about the microbial communities in these
soils. Microbial soil communities from soils
collected from the Silver Valley region were
analyzed for total and viable numbers, metabolic
activity, and resistance to lead. Different
microbial communities were found to respond
differently to varying lead concentrations
resulting in the isolation of members of a variety
of genera, including Bacillus spp., Pseudomonas
spp., and Corynebacterium spp. representing
common lead-resistant isolates from these soils.
An Enterobacter spp., isolated from a pristine
soil, also exhibited lead resistance. The basis of
lead resistance was explored using plasmid
analyses, microscopy, and scanning electron
microscopy equipped with electron diffraction X-
ray analysis. Early results indicate that lead was
excluded rather than sequestered intracellularly.
Keyword(s): lead, bacteria, resistance.
Oral presentation in research track.
Polynuclear aromatic hydrocarbons (PAHs) are
a major source of contaminants at coal gas
manufacturing sites, wood treating operations, and
petroleum land farms. They are potentially
carcinogenic and mutagenic. It has been known
that vegetation can enhance the rate and extent of
degradation of PAHs in contaminated soil. Plant
roots release root exudates capable of supplying
carbon and energy to microflora for degrading
PAHs. It is a well established fact that the
population of microorganisms in the rhizosphere
is significantly greater than that in non-vegetated
soil. The microbial population in the rhizosphere
appears to be responsible for the enhanced
biodegradation of PAHs. Since their solubility in
water is low, significant quantities of PAHs often
form a hydrocarbon phase; moreover, some
quantities of them are adsorbed on soil. A model
has been derived for describing the rates of
disappearance of anthracene and pyrene in the
rhizosphere. This model takes into account
dissolution, adsorption, desorption and
biodegradation of these compounds, without
neglecting the size distribution of the organic
phase droplets; the rate of biodegradation is
expressed in terms of the Monod kinetics. The
model is in good accord with the available
experimental data
Keyword(s): polynuclear aromatic hydrocarbons, rhizosphere, soil, biodegradation, model.
Poster presentation.
Utilization of microbial processes for
bioremediation requires measuring compound
degradability as well as characterization of the
intermediates formed. A Mycobacterium sp. and
Xanthomonas sp. were isolated from coal
gasification site soils using standard enrichment
techniques. The Mycobacterium sp. was isolated
for its ability to mineralize pyrene, but was also
found to be capable of degrading other polycyclic
aromatic compounds. The Xanthomonas sp. was
isolated for its ability to mineralize carbazole and
showed very high substrate specificity. Through
analysis, metabolites formed during pyrene
degradation were found to include 4,5-pyrene-
dihydrodiol, 4-phenanthroic acid, and 4,5-
diphenanthroic acid. This Mycobacterium sp. was
also found to biodegrade benz(a)anthracene and
benzo(a)pyrene producing ring cleavage products.
For benz(a)anthracene, analyses of organic
extracts of the growth medium show a dihydrodiol
intermediate formed as well as a ring cleavage
product. A dihydrodiol intermediate and ring
cleavage product were also found with
benzo(a)pyrene. Fluorescence spectra of the
benzo(a)pyrene dihydrodiol intermediate was
characteristic of that for benz(a)anthracene. The
Xanthomonas sp. was incubated with carbazole as
sole added carbon source for approximately two
weeks. Analyses of organic extracts show the
presence of at least three cleavage products of
carbazole. These have been tentatively identified
as indoleacetic acid, cis-indoleacrylic acid, and
indolepropionaldehyde. A pathway for carbazole
degradation by this species is proposed in which
the indole moiety is maintained. These results
show that microbes isolated for their ability to
degrade a specific compound can show some
diversity in their substrate specificity.
Keyword(s): Mycobacterium, Xanthomonas, biodegradation, metabolites, polycyclic aromatic hydrocarbons.
Poster presentation.
Supercritical Water Oxidation is being
developed by the Department of Energy as a
promising technology for treatment of mixed
waste—that is waste that contains hazardous and
radioactive constituents. The aim of this program
has been to identify and resolve key technical
challenges that have been barriers to
commercialization of supercritical water
oxidation. Initial testing with benchscale systems
indicated that the overriding technical challenge
for this technology was prevention of corrosion
and deposition inside the reactor. A number of
approaches are being pursued to resolve the issue
of corrosion and deposition including alternate
reactor designs, advanced material development
and testing, salt separation processes, and
analytical modeling of supercritical water
oxidation systems. Ongoing projects in these areas
are discussed along with plans for pilot plant
testing with promising configurations.
Keyword(s): oxidation, mixed waste.
Oral presentation in research and technology
transfer tracks.
The pTOM31C plasmid was derived from the
large plasmid of Pseudomonas cepacia G4. Strain
G4 is an environmental isolate that is capable of
cometabolic mineralization of trichloroethylene
(TCE). The degradation of TCE by strain G4 is a
result of the induction of enzymes in a non-
constitutive aromatic degradative pathway that is
present on the large plasmid of G4. A Tn5
insertion into the large plasmid of G4 resulted in a
TCE constitutive plasmid designated as pTOM31C.
A number of laboratory and field studies have
been performed to determine the feasibility of
applying pTOM31C, via a host microbe designated
Ps. cepacia PR1-(pTOM31C), into vapor phase
TCE bioreactors. Results from degradation studies
show a linear degradation rate of TCE by PR1-
(pTOM31C). The growth kinetics of PR1-
(pTOM31C) on phthalate followed the Monod
kinetics model. However, bench scale studies
showed that PR1-(pTOM31C) growing on
phthalate was incapable of developing a
substantial biofilm. The results from a number of
bench scale and field scale reactor studies showed
that PR1-(pTOM31C) could not compete with
invading microorganisms, even when selective
pressures for PR1 were applied to the systems. In
the field scale reactors, PR1-(pTOM31C) was able
to colonize only the top fraction of the oyster shell
support media. During the progression of the field
study, the activity in the top of-the column also
diminished due to the washout of PR1-
(pTOM31C). Field studies showed that the
combination of the crushed oyster shell support
media and the physiology of PR1-(pTOM31C) is
an inadequate system for developing an effective
TCE degrading biofilm. Additional studies are
focused on conjugal transfer of pTOM31C into
superattaching and competitive microorganisms.
We have had successful transfers of pTOM31C to
various Pseudomonad strains. Currently we are
determining the stability and TCE degradation
activity of pTOM31C in its new host strains. It is
the longterm goal of this research to exploit the
capability of pTOM31C to cometabolically and
constitutively mineralize TCE in TCE biofilm
reactors.
Keyword(s): trichloroethylene (TCE), bioreactor, pTOM31C, constitutive, conjugal transfer.
Oral presentation in research track.
Reductive dechlorination of polychlorinated
biphenyls primarily removes chlorines (Cls) from
the meta and para positions although ortho
dechlorination has also been reported. This
preferential removal is determined by the pattern
of Cl substitution. Thus, the final products may
not only be orth-substituted congeners. In fact,
certain congeners such as 2,4'-, 2,5,2', 2,4,4'-,
2,4,2',5'- and 2,4,2',4'-chlorobiphenyls
accumulated at high concentrations in both the
laboratory and natural sediments in the Hudson
and St. Lawrence Rivers. Many of these
accumulating congeners are known to be
neurotoxic by reducing cellular dopamine content.
Therefore, although in-situ dechlorination may
reduce the overall degree of chlorination, it is
important to consider the health implications of
accumulating products.
Dechlorination competence varies with
sediment microorganisms from different sites,
resulting in the accumulation of dissimilar
products. Microorganisms from the General
Motors site in the St. Lawrence River removed a
higher proportion of para Cls relative to meta
whereas those organisms at the Reynolds and
ALCOA sites removed a higher proportion of
meta Cls. Sediment amendments with H2 or
biphenyl also resulted in the accumulation of
different products. These results suggest that it
may be possible to alter the final products through
artificial manipulations.
We have identified several conditions which
are critical for dechlorination. Dechlorination is
most effective under methanogenic conditions;
sulfidogenic or nitrate-reducing conditions
inhibited it partly or completely. H2 promoted
dechlorination, probably acting as an electron
donor to the sediment microorganisms. Heat-
killed cyanobacterial cells could serve as a carbon
and energy source. A periodic addition of a
nonionic surfactant at a level below the critical
micelle concentration also accelerated
dechlorination. Therefore, it appears possible to
remediate contaminated sediments and soils with
further optimization of dechlorinating activities.
Keyword(s): polychlorinated biphenyls (PCBs), reductive dechlorination, bioremediation, electron acceptors, surfactant.
Poster presentation.
Biodegradation of trinitrotoluene by the white
rot fungus Phanerochaete chrysosporium was
studied in both liquid reactors and soil
microcosms. It has been previously shown that
trinitrotoluene mineralization by P.
chrysosporium only occurs under lignin-degrading
conditions. In this study trinitrotoluene
biotransformation rates were dependent on initial
trinitrotoluene concentration and fungal mycelia
present. Nonligninolytic reactors containing 50
g/L mycelia were able to degrade up to 100 parts
per million trinitrotoluene within four hours but
the reduced aminonitrotoluenes were not
degraded, even after 70 days incubation. On the
other hand, ligninolytic reactors containing 8 g/L
mycelia required 6 days to degrade 100 parts per
million trinitrotoluene, and aminonitrotoluenes
were completely degraded within 10 days.
Ligninolytic conditions could be maintained for
18 days by addition of 3.0 g/L glucose and 0.25
mM ammonia to the reactors every three days. In
soil, P. chrysosporium was able to metabolize 200
mg/kg trinitrotoluene to less than 5 mg/kg within
21 days. The trinitrotoluene metabolites,
aminonitrotoluenes reached a maximum
concentration of 35 mg/kg on day 14 and 10
mg/kg on day 28. During the same time,
trinitrotoluene was decreased to 150 mg/kg and
aminonitrotoluenes increased to 40 mg/kg in
uninoculated soil.
Keyword(s): Phanerochaete chrysosporium, white rot fungi, trinitrotoluene, bioremediation.
Oral presentation in research track.
A sandy aquifer contaminated with dissolved
phase BTEX compounds is currently being
remediated through a combination of physical
processes (pump and treat) and enhanced in-situ
biodegradation. Extensive data collected from site
monitoring and pump-back wells, along with
knowledge of site sorptive and hydrodynamic
properties, allowed the calculation of a
contaminant mass balance, from which in-situ
biotransformation was estimated. Data indicates
that pump and treat removals of dissolved BTEX
accounts for approximately half of the total
reduction in BTEX mass on the site. Oxygen
utilization data implicates biodegradation as
responsible for the majority of remaining
contaminant mass removal. Contaminant
reductions in-situ appear to be associated with
zones of increased contaminant-oxygen mixing
located immediately downgradient from site
injection wells.
Keyword(s): BTEX, in-situ, biodegradation, pump and treat.
Oral presentation in research track.
The solubility enhancement of nonionic
organic compounds (NOCs) by surfactants may
represent an important tool in chemical and
biological remediation of contaminated soils. In
aqueous systems, the presence of dissolved
surfactant emulsions or micelles may enhance the
solubility of NOCs by acting as a hydrophobic
partitioning phase for the NOCs. However, most
environmental remediation efforts involve soil-
water or sediment-water systems, where surfactant
molecules may also interact with the solid phase.
An understanding of the effect of surfactants on
the sorption and distribution of NOCs in soil or
sediment environments will provide an essential
basis for utilizing surfactants in environmental
remediation. In this study, we examined the effect
of a micelle-forming surfactant (Triton X-100) on
the sorption of 2,2',4,4',5,5'-PCB, 1,1-bis(p-
chlorophenyl)-2,2,2-trichloroethane (p,p'-DDT)
and 1,2,4-trichlorobenzene (1,2,4-TCB). Our
results show that the apparent distribution
coefficient (K*) describing the partitioning of the
NOC by the soil solid phase exhibited a similar
pattern as a function of aqueous phase Triton X-
100 concentrations for all three solutes studied. At
aqueous concentrations of Triton X-100 below
200 mg L-1, K* values actually increased with
increasing surfactant concentration. At Triton X-
100 concentrations above 200 mg L-l
(approximately the critical micelle concentration,
CMC, for Triton X-100), K* values decreased
with increasing surfactant concentration. At
surfactant concentrations below the CMC,
surfactant monomers in the aqueous phase are
relatively ineffective as a partitioning phase for
the NOCs. However, bound surfactant molecules
increase the sorptive capacity of the solid phase.
At surfactant concentrations above the CMC,
surfactant micelles in the aqueous phase begin to
compete with the solid phase as an effective
partitioning phase. A conceptual model, which
accurately describes the functional dependence of
K* on Triton X-100 concentration, was developed
based on the partition coefficients of these NOCs
by soil, soil-surfactant, surfactant monomer and
surfactant micelle phases. This model can be
further modified to provide quantitative prediction
of K* of a given NOC at different surfactant
concentrations.
Keyword(s): nonionic organic compounds, surfactant, sorption, remediation.
Poster presentation.
A Savannah River Laboratory nuclear waste
glass (SRL) and a plasma furnace nuclear waste
slag were subjected to vapor hydration as small
suspended rectangular samples within a sealed
reaction bomb at 200 C for time periods of up to
26 days. The samples were then removed from the
reaction bomb and the residual water analyzed by
ICP and ICP-MS for trace elements and bulk glass
constituents. The sample hydration rind thickness
was measured and photographed with an optical
microscope and the data plotted as thickness vs.
time profiles which are presented as an indicator
of the relative durability of the waste medium.
The chemical transport of various dissolved
glass constituents from the bulk medium to the
sample surface developed residual diffusion
textures within the hydration rind which have
been investigated relative to the residual bomb
water chemistry and SEM-EDX analysis of the
hydration rind. These textures reveal that the
water vapor diffuses into the surface of the
nuclear waste slag along the path of least
resistance and selectively dissolves the more
soluble constituents within the slag. The
development of secondary silicate phases and
selective dissolution of soluble elements
contribute to extensive fracturing of the hydrated
region. This enhances material transport as
insoluble crystals are entrained within a surface
debris flow composed of gelatinous silica, which
slowly flows down the sample surface. In contrast,
a nuclear waste glass hydrates more uniformly
and, initially, the solvation appears to be evenly
distributed within the hydration layer. Eventually
diffusion gradients are established within the
hydration layer. These diffusion gradients
eventually result in the formation of double to
triple layers within the hydration rind which have
differing chemical composition. The development
of these variable composition layers can impede
further vapor hydration of the glass.
Keyword(s): slag, glass, vapor hydration.
Oral presentation in research track.
Spills of nonaqueous phase liquids (NAPLs) in
the environment pose a serious long-term threat to
groundwater resources through slow dissolution of
entrapped NAPL in the groundwater saturated
zone. Based on various spill simulation
experiments conducted in large soil flumes, we
conclude that the NAPL can exist as a “residual”
saturation held by capillary forces, or at higher
saturations through macroscopic entrapment. The
“micro-scale” residual entrapment is controlled by
the pore characteristics of the soil, whereas the
macroscopic entrapment is caused by much larger
scale macroscopic soil heterogeneities in the
aquifer. A study to evaluate mass transfer under
both residual and macro-scale entrapment is
currently underway. This paper focuses on
dissolution of NAPLs entrapped at residual
saturation. Current practice usually assumes local
equilibrium at the NAPL source. We have found
that this approximation may underestimate the
length of time needed for clean-up in some cases.
An existing flow model was modified to account
for the reduced relative permeability in the NAPL
source zone. This model was in turn coupled to a
method of characteristics (MOC) based advection-
dispersion model that accounted for rate limited
mass transport between the NAPL and aqueous
phases. Using this hybrid model, we have
estimated overall mass transfer rate coefficients
(time-1) for NAPL sources over a range of
saturations and groundwater velocities. This
information will be useful in remediation design
in aquifers contaminated with organic waste
chemicals.
Keyword(s): groundwater contamination, NAPL, dissolution.
Oral presentation in research track.
Sulfate-reducing bacteria, nitrate-reducing
bacteria and bacteria present in sewage sludge
were examined for their ability to reduce the level
of soluble U(VI) in enriched media. Cultures of
Desulfovibrio desulfuricans, D. gigas, and D.
vulgaris were grown in sulfate-containing media
while Pseudomonas putida and P. denitrificans
were cultivated in nitrate media. The amount of
U(VI) removed from solution was dependent on
metabolism because greater levels of uranium
were removed when U(VI) was added to a
growing culture than when added to a culture in
stationary phase. The presence of vanadate,
arsenate, selenate or molybdate at 0.1 and 0.01 M
levels in sulfate-reducing cultures, nitrate-
respiring cultures or in sludge cultures did not
have an effect on the amount of uranium removed.
In all cultures the amount of uranium in solution
was markedly reduced after 10 to 20 days and
reduced uranium, as U(IV), was detected in
several cultures. Present in the cultures of D.
desulfuricans were crystals of uranium.
Examination of these cultures by electron
microscopy indicates that the uranium (IV) is
deposited outside of the cell and these needle-like
crystals are associated with cellular material. X-
ray probe analysis with the electron microscope
gave an image that was in close agreement with
U(IV). With D. desulfuricans in a continuous
stirred tank reactor, kinetic parameters have been
calculated for uranium reduction. Over a period of
20 to 60 hours, the amount of soluble uranium
removed from the bioreactor was proportional to
residence time over a period of 20 to 60 hours.
Keyword(s): uranium, denitrification, sulfate reduction, anaerobisis.
Poster presentation.
Recent attention has focused on the
neurotoxicity of polychlorinated biphenyls,
dibenzofurans, and quaterphenyls and related
compounds. The hippocampus may be an
important target for neurotoxic compounds
because of its role in short-term memory and
learning. We report preliminary experiments on
the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin
(TCDD) as a model for the neurotoxicity of
halogenated aromatic hydrocarbons. Exposure of
cultured rat hippocampal neurons and glia to
TCDD (10-100 nM) invoked a rapid (within 3
min), concentration dependent increase in
intracellular calcium ion concentration as
determined by microscopic image analysis of cells
noninvasively labeled with fluo-3. This rapid
increase was blocked by the addition of EDTA (2
mM) or nifedipine (100 µM) to the external
medium. In contrast, the nontoxic congener
1,2,3,4-TCDD was inactive at concentrations up
to 10 µM. Other effects of TCDD on cultured
neurons and astroglia were measured, including
cell-cell communication via gap junctions, which
was down-regulated, and cytosolic glutathione
content, which was depressed in astroglia.
Astroglial cells serve vital roles in regulating the
neuronal environment. We have also conducted
pilot experiments on TCDD effects on synaptic
function in hippocampal slices. In these
experiments, the excitatory postsynaptic potential
was decreased. A cytosolic aryl hydrocarbon
receptor was identified in the astroglia, but the
neuronal cultures have not been studied. However,
nuclear extracts from the astroglia treated with
TCDD did not bind to a dioxin responsive element
in a gel shift assay. These findings suggest that
TCDD has effects on neural cells that are not due
to the classical aryl hydrocarbon receptor-
mediated signal transduction pathway. Calcium
ions may play a role in TCDD-induced cell
dysfunction and death, as has been previously
shown for thymocytes.
Keyword(s): dioxin, neurotoxicity, hippocampus, neuron, astroglia.
Oral presentation in research track.
Recently, much work has been performed on
the use of vegetative systems for remediating soil
and groundwater contaminated with hazardous
organic substances. A model to describe the
performance of these vegetative systems under
varying hydrogeochmeical conditions has been
previously developed by several of the authors.
Studies of the variability of difference plant
characteristics on the performance of vegetative
remediation systems have been reported.
However, a greater factor in the variability of
vegetative remediation system performance could
be caused by yearly changes in climatological
conditions at a site. This paper will present the
results of model analyses that use historical
climatological data on the performance of
vegetative remediation systems at a site. The
results of these analyses will produce an estimate
of the performance of the vegetative remediation
system as well as a measure of the anticipated
variability of the system for a particular site. The
results could then be used to provide guidelines
for design of a vegetative remediation system at a
site.
Keyword(s): groundwater, phytoremediation, hazardous organic contaminants.
Oral presentation in research track.
Some bacteria can destabilize the soluble
uranyl carbonate complex prevalent in mine
drainage by enzymatically reducing U(VI) to
U(IV). Reduced uranium is highly insoluble and
precipitates from solution as the U(IV) oxide,
uraninite. The advantage of this technology is that
the uranium is easily separated from the aqueous
phase resulting in a small volume of relatively
pure uraninite waste. Although a wide range of
bacteria can reduce U(VI) to U(IV), many of the
bacteria exhibit undesirable characteristics for
large-scale treatment of contaminant waste
streams. In this technology, dissimilatory iron
reducers are used to reduce uranium under
anaerobic conditions. The process is also
applicable to other metal species such as chrome
and technecium.
In initial experiments, cells from a 100-ml
culture were introduced into a 1.5-L bioreactor
containing 10-mM uranyl carbonate and reduced
100% of the U(VI) to U(IV). Pure uraninite
precipitated from solution and was recovered from
the vessel in a concentrated 20-ml suspension
resulting in a 75-fold reduction in uranium waste
volume. Additional experiments were conducted
to describe the process kinetics using Monod
expressions. These process kinetics and the pre-
and post-treatment requirements of this
technology will be presented.
Keyword(s): uranium, bioprecipitation, heavy metals, mine drainage.
Oral presentation in research track.
This work was supported by the U.S. Department of
Energy as part of Pacific Northwest Laboratory’s Laboratory
Directed Research and Development. Pacific Northwest
Laboratory is operated for the U.S. Department of Energy by
Battelle Memorial Institute under contract DE-AC06-76RLO
1830.
The timing of onset of mineralization of
pyrene by P. chrysosporium correlates with the
production of ligninase activity. Ligninase activity
is monitored by the decolorization of the
polymeric dye Poly R-478. A layer of native soil
decreased the growth of P. chrysosporium by
visual assessment of hyphal mass and
measurement of ergosterol, a fungal membrane
sterol. The native soil layer slowed the production
of ligninase as determined by Poly R-478
decolorization. The rate of mineralization of
pyrene also was decreased. Mineralization, fungal
growth, and rate of decolorization of the dye was
improved when soil sterilized by autoclaving was
used. Extracts from the native soil contained a
consortium of bacteria and fungi. Several of the
fungi and the bacteria were antagonistic to the
growth of P. chrysosporium on solid medium. The
bacteria caused antagonism as well as hyphal
lysis. The onset of dye decolorization by P.
chrysosporium on a nitrogen-limited medium was
delayed by certain of the bacteria. These findings
suggest that in certain soils, bioremediation by P.
chrysosporium could be suppressed by indigenous
soil microbes.
Keyword(s): P. chrysosporium, soil microbes, suppression.
Oral presentation in research track.
A simplistic approach to designing a waste
minimizing chemical process is to synthesize the
structure of the process first, followed by the
design of the treatment system for the waste
generated. In general, such an approach does not
lead to a truly optimal process with integrated in-
plant waste treatment because of the unavoidable
interaction between the product generation and
waste treatment. Thus, the waste generation and
treatment should be taken into account from the
outset in designing or synthesizing the process.
This, however, will inevitably overburden the
already complex task of process synthesis or
design. Avoiding this difficulty requires a
drastically improved algorithmic approach. The
often adopted mixed-integer nonlinear
programming (MINLP) model of a total flowsheet
synthesis problem usually contains a large number
of discrete or binary variables. This makes the
model difficult to solve by methods that do not
exploit the unique combinatorial feature of
feasible process structures. The combinatorially
accelerated branch and bound algorithm
developed by us previously for the general total
flowsheet synthesis minimizes the complexity
involved in applying the conventional branch and
bound algorithm by reducing the number of
subproblems generated and by decreasing the size
of each subproblem. This accelerated branch and
bound algorithm has been extended to the optimal
integrated synthesis of a total process flowsheet
without neglecting waste treatment from the
outset of design. The efficiency of the algorithm is
demonstrated by synthesizing a relatively simple,
commercial-scale process together with its waste
treatment system; the stepwise procedure is given
in detail.
Keyword(s): process design, waste minimization, algorithm.
Oral presentation in research track.
Spills of organic chemicals and waste products
in the form of nonaqueous phase fluids (NAPL)
has the potential to contaminate groundwater.
Accidental spills at the soil surface or chemicals
applied to the soil from leaking underground tanks
result in the chemical to first travel through the
unsaturated zone before reaching the groundwater
in the saturated zone. During the migration
through the vadose zone, a significant fraction of
the contaminant, however, stays behind in the
unsaturated soil as an entrapped phase. These
entrapped chemicals act as a continuous source of
contamination, as small amounts of the NAPL
will continue to move within the soil or dissolve
into the aqueous phase. The rising water table
which results from the transient behavior of the
regional groundwater system may also mobilize
large amounts of the contaminant entrapped in the
vadose zone. Thus, for cleanup measures it is very
important to evaluate the process of entrapment
and quantify the entrapped saturations based on
the characteristics of the fluids and soils. In spill
simulations which have been conducted in large
tanks with various soil packing configurations, we
have observed that entrapment is especially large
in heterogeneous and layered soils. As only
qualitative and semi-quantitative data can be
obtained in large two-dimensional tanks, an
experimental program was developed to
investigate and obtain accurate data on entrapment
in layered sand in vertical soil columns.
In the descriptions of entrapment of
nonaqueous phase contaminants in layered soils, it
is assumed that the residual saturation can be
determined using static pressure. The results from
the column experiments are used to test this
assumption. A test NAPL was spilled on top of a
sand-filled layered column. The saturation and
pressure distribution are monitored over a longer
period of time. A dual-gamma system is used to
determine the phase saturations. Specially
designed ring-tensiometers are used to measure
the average pressures at selected sections along
the column. The transient pressure values are used
to determine whether the entrapment is controlled
by the static pressure distribution or is a steady
state flow process which is reflected as a
permanent entrapment. A simple steady state
model will be evaluated to determine whether it
can accurately predict this entrapment behavior.
Then a non-steady state finite difference model
developed by us will be used to see whether it can
predict the steady state behavior.
Keyword(s): nonaqueous phase liquids, entrapment.
Oral presentation in research track.
A mixed, suspended-growth, methanotrophic
bioreactor was operated with continuous aqueous
feed and increasing trichloroethylene loading until
failure due to toxicity. Biomass and TCE
degradation were continuously maintained as TCE
loading increased from 4 to 10 µg TCE/mg
protein/day. The maximum sustainable ratio of
TCE degraded to methane consumed was 6 µg
TCE/mg methane. Biomass, methane
consumption, and TCE degradation fell
precipitously when TCE loading exceeded 10 µg
TCE/mg protein/day. Reactor failure was
preceded by a fall in soluble methane
monooxygenase activity.
Keyword(s): trichloroethylene, methanotrophic, bioreactor, toxicity, monooxygenase.
Poster presentation.
Water-solvated chlorophenols (CPs) are
environmental toxins associated with wood
preservation and pesticide synthesis and usage.
Their toxicity and association with dioxin-
contaminated wastes are well-documented, as is
their stability in most environmental settings.
Several analytical procedures, mainly HPLC and
GC/MS, are currently used to detect and quantify
CPs, but these procedures are based on expensive
equipment and technical expertise in a laboratory
setting. We have developed an inexpensive, field-
practical method for CPs, utilizing a small, packed
glass minicolumn and derivatization of target CP
molecules with dansyl chloride (5-
dimethylaminonaphthalene-1sulfonyl chloride), or
DsCl. A nonfluorescent borosilicate glass tube
was used to house an array of inorganic sorbent
materials, including preparative layers and a
reactive neutral alumina interface separated by
sand. DsCl is a substituted naphthalene with a
conjugated X system that is responsible for its
fluorescent complexation. Amines that reacted
with DsCl were removed with a small amount of
phyllosilicate clay to avoid interference. A neutral
alumina/sand interface was used to strongly bind
and immobilize the dansylated CPs. Activities
greater than 3.0 for the alumina were avoided to
prevent loss of selectivity, intensity and color of
the fluorescence at the reactive interface. Our
results indicated that this assay was capable of
rapidly screening potable water samples and
detecting CP contamination at very low
concentrations (i.e., 1.0 ppb of pentachlorophenol
in drinking water).
Keyword(s): detoxification, chlorophenols, rapid analysis.
Poster presentation.
Vapor-phase bioreactors (VPBRs) have been
considered for treating gas streams contaminated
by volatile organic compounds (VOCs). A VPBR
is a gas absorption column that employs a biofilm
as a heterogeneous catalyst growing on an
artificial porous medium.
To aid in the design, scale-up and operation of
a VPBR, a phenomenologically-based
mathematical model has been developed to
describe the steady-state operation of a VPBR.
The present version tracks the electron-donor
(VOC) and the electron-acceptor (oxygen) in the
gas/liquid/biofilm phases within the bioreactor.
The model uses a single species in the biofilm
with reaction rates modeled by Monod kinetics for
the electron acceptor and Haldane kinetics for the
electron donor. Bench-scale VPBRs and the
model show evidence of electron-acceptor
limitation under certain operating conditions.
Due to the effects of the inorganic salts and
biomass on the apparent Henry's law coefficients,
these coefficients were experimentally determined
using reactor effluent. The coefficients were found
to be approximately 50% of the published values
for the VOCs.
Mass-transfer coefficients for the gas-liquid
interface are predicted by Onda correlations.
Literature shows these correlations to be within
20% of actual coefficients for abiotic systems.
Bench-scale experiments using a non-reactive
tracer showed that the Onda correlations can
overestimate mass-transfer coefficients by as
much as three times.
Keyword(s): modeling, mass-transfer coefficients, Onda, biofilm, Henry's law.
Poster presentation.
Contamination of soil by petroleum
hydrocarbons is a significant problem in the
United States. Release of nonaqueous phase
liquids (NAPLs) petroleum contaminants at or
near the ground surface can migrate through the
vadose zone to the groundwater. In contaminated
coarse-textured soils containing abrupt interfaces
with clay layers, petroleum hydrocarbons can
accumulate at the clay interface due to restricted
water flow through the clay layer. In addition, the
soil matrix can act as a sink to which the
petroleum contaminant becomes adsorbed,
resulting in a difficult remediation scenario. Soil
columns were erected using six inch PVC pipe.
Three types of columns were constructed: one
comprised only of sand, one of only clay, and one
with both clay and sand layers. Each column was
24 inches long and duplicate columns were
prepared, as well. Dodecane was introduced into
the columns at a single mid-point at the top of
each column as a one-time event. Four sets of
each type of column were constructed to permit
sampling of the column soil at four subsequent
time intervals. Each column was disassembled at
specified times and the contaminant concentration
levels were quantified as a function of distance
into the column. Results of this study contribute to
a more comprehensive understanding of the
behavior of NAPLs in contaminated
heterogeneous soils with high clay content.
Keyword(s): petroleum hydrocarbons, NAPLs, vadose zone, heterogeneous soil.
Poster presentation.
In 1993 Congress appropriated funds to the
Environmental Protection Agency for the five
national Hazardous Substance Research Centers to
begin programs to serve minority educational
institutions. The Great Plains-Rocky Mountain
Hazardous Substance Research Center (GP-RM
HSRC) serves EPA Regions VII and VIII. The
states that the GP-RM HSRC serves contain 17
predominantly Native American colleges and
universities, two predominantly black universities,
and two predominantly Hispanic colleges. Due to
the prominence of Native American educational
institutions in its regions, the GP-RM HSRC has
decided to make the emphasis of its program
toward American Indian and Alaska Native
institutions, but the program will also serve other
minority institutions in EPA Regions VII and
VIII. The GP-RM HSRC has joined with Haskell
Indian Nations University to begin the Native
American and Other Minority Institutions
(NAOMI) Program. The NAOMI Program will
involve minority educational institutions in
research, training and technology transfer. This
will be accomplished primarily through the
establishment of an outreach office of the GP-RM
HSRC on the campus of Haskell Indian Nations
University. This office will be called the Haskell
Environmental Research Studies Center (HERS).
The NAOMI Program will include a seminar
program, a summer research participation
program at GP-RM HSRC consortium
universities, and projects at NAOMI consortium
schools.
Keyword(s): Native American, minority, research, technology transfer, hazardous substances.
Poster presentation.
Characterization and delineation of the source
of volatile organic compounds (VOCs) detected in
a groundwater plume was performed using a cone
penetrometer testing (CPT) rig equipped with a
drive point groundwater sampling system.
Attempts to delineate the source area using a soil
gas survey, borings and soil analyses were not
successful. The VOCs were apparently released at
the surface of a 45-foot-thick interlayered sand
and clay alluvium overlying a limestone aquifer.
Depth to groundwater was approximately 25 feet
below ground surface. Lithologic data and
groundwater samples were collected with the CPT
rig along four sampling lines located
perpendicular to the direction of groundwater
flow. The high resolution lithologic data obtained
at each sampling point delineated transition zones
from coarse-grained sand to clay soils.
Groundwater samples were collected from the
saturated transition zones. Expedited analyses of
groundwater samples and on-site development of
geologic cross sections determined the locations
of the additional sampling lines. A total of 24 CPT
soundings and 31 groundwater samples were
required to delineate the lithology and distribution
of VOCs in four distinct source areas.
The CPT sounding and sampling technique
produced high resolution hydrogeologic and
groundwater chemical data of the source area for
approximately one-third of the cost of a traditional
boring and monitoring well program. In addition,
soil cuttings, well development water, or well
purge water were not produced.
Keyword(s): site characterization, volatile organic compounds, cone penetrometer testing.
Oral presentation in technology transfer track.
Pollution prevention is considered as the
principal means for true waste reduction in rural
areas since traditional waste minimization
activities such as reuse, recycling and recovery are
not easily implemented in such areas. This
presentation will focus on the final products
resulting from the development of a pollution
prevention educational program for small quantity
hazardous waste generators within the EPA
Regions VII and VIII. The principal goal of the
educational program is to provide additional
incentives for true hazardous waste prevention
through source reduction in commercial
businesses (small quantity generators) such as
vehicle maintenance, dry cleaning operations,
agricultural cooperatives, pesticide applicators,
and others. The presentation will center on results
of development of waste prevention "tool kits"
which will be targeted for use by small quantity
generators. These "tool kits" will be made
available to small quantity generators which in
turn can be used in the implementation of waste
prevention programs within their facilities. The
"tool kits" consist of self assessment and self help
"how to" documents and checklists that can be
used by individual small quantity generators. Five
different types of "tool kits" will be presented,
each for a different type of hazardous waste small
quantity generator.
Keyword(s): pollution, prevention, hazardous, waste, reduction.
Oral presentation in technology transfer track.
The potential of biological processing of mixed
hazardous waste has not been determined.
However, the use of selected microorganisms for
the degradation and/or detoxification of hazardous
organic compounds is gaining wide acceptance as
an alternative waste treatment technology. The
isolation of a unique strain of Pseudomonas
Putida Idaho seems well adapted to withstand the
demands of the input stream comprised of liquid
scintillation waste. This paper describes the
results from the continuous processing of a
mixture comprised of p-xylene and surfactant as
well as commercial liquid scintillation
formulations. The two formulations tested
contained xylene and pseudocumene as the
solvent base. The process is now at the
demonstration phase at one of DOE’s facilities
which has a substantial amount of stored waste of
this type. The system at the DOE facility is
comprised of two CSTR units in series.
Keyword(s): bioremediation, mixed waste, organic solvents.
Oral presentation.
Since many petroleum components are barely
soluble in water, they are frequently present as
nonaqueous phase liquids (NAPLs) in subsurface
soils. Bioremediation of soils contaminated by
such residual hydrocarbons appears to be cost-
effective under various situations. More often than
not, however, bioremediation can be rate-limited
by dissolution, solute transport or
biotransformation in a four-phase system
comprising the NAPL, aqueous, solid and
microbial phases. This paper proposes a model
elucidating the microbial assimilation of
hydrocarbon contaminants on the solid surface
and in the aqueous phase. It focuses on those
situations in which dissolution is the main rate-
limiting factor. An investigation has been carried
out on the rates of biodegradation of some
common petroleum components such as benzene,
ethyl-benzene, toluene and xylene in the four-
phase system. The effects considered are those of
the mass-transfer area, specific growth rate of
biomass, and velocity of pore-water flow.
Keyword(s): NAPL, bioremediation, soil, BETX, batch reactor.
Poster presentation in research track.
The number and activity of microorganisms in
the unsaturated zone of both pristine and
agricultural soils have been examined in depth
profiles. Numbers of total and actively respiring
microbes were enumerated by DAPI ( 4’,6-
diamidino-2-phenylindole ) and CTC (5-cyano-
2,3-ditolyl tetrazolium chloride) epifluorescent
microscopic direct count methods, respectively.
Viable aerobes were also assessed by plate counts.
Denitrifiers were enumerated by most probable
number (MPN) method. Results show that there is
little variability in total numbers of microbes
among the depths for both sites and between the
two sites. The numbers of actively respiring
bacteria in the pristine site decreased with depth
above groundwater table and increased thereafter.
The numbers of actively respiring bacteria in
agricultural site, however, showed little variability
with depth. The results of plate counts show a
similar pattern throughout the depth profile to the
CTC counts. Numbers of denitrifiers in the
agricultural site increased with depth up to two
meters from the surface, but stayed constant
between a depth of two meters and water table.
The numbers of denitrifiers in pristine site were
lowest at water table and became consistently high
in the saturated zone. The results suggest that
there was low microbial activity around the
groundwater table at pristine soils. The results
also show the numbers of microbes and
denitrifiers are higher in the agricultural site than
in the pristine soils. The number and activity of
microbes in the unsaturated soil appear to vary
with the land use and methods of assessment.
Keyword(s): unsaturated, soil, microorganism, direct count.
Oral presentation in research track.BIOREDUCTION OF SELENIUM
D.J.Adams, K.R. Gardner and B.E. Dinsdale, U.S.
Bureau of Mines, Salt Lake City Research Center,
729 Arapeen Drive, Salt Lake City, UT 84108THE INFLUENCE OF INTRA-STRAIN
HETEROGENEITY IN MONO-CLONAL
POPULATIONS OF BACTERIA ON
BIOCOLLOID TRANSPORT THROUGH
POROUS MEDIA
O. Albinger, B.E. Logan, B.
Biesemeyer and R.G. Arnold, Department of
Chemical and Environmental Engineering,
Arizona University, Tucson, AZ 85721RECLAMATION OF ABANDONED AND
INACTIVE HARD ROCK MINES IN
MONTANA
G. Amestoy, Montana Department
of State Lands, Helena, MT 59620THE NIEHS SUPERFUND BASIC RESEARCH
AND TRAINING PROGRAM
B. Anderson1 and B. Blackard2,1Superfund Basic Research
and Training Program, National Institute of
Environmental Health Sciences, P.O. Box 12233,
Research Triangle Park, NC 27709; and
2Technology Planning and Management
Corporation, Headquarters Park, Beta Building,
Suite 220, 2222 Highway 54, Durham, NC 27713BIOFILM TECHNIQUES ADAPTED FOR
BIOHYDROMETALLURGICAL RESEARCH
D. Anderson1, L. Twidwell2 and G. Geesey3,
1Department of Biological Sciences, Montana
Tech, Butte, MT 59701; 2Metallurgy Department,
Montana Tech, Butte, MT 59701; and 3Center for
Biofilm Engineering, Montana State University,
Bozeman, MT 59717APPLICATION OF THE DIFFERENTIAL SOIL
BIOREACTOR TO IN-SITU
BIODEGRADATION OF
TRICHLOROETHYLENE AT THE
SAVANNAH RIVER SITE
G.F. Andrews and S.G. Hansen, Idaho National Engineering
Laboratory/EG&G Idaho, Inc., Office of
Industrial Biotechnology and Process
Engineering, P.O. Box 1625, Idaho Falls, ID
83415-2203BOICOLLOID TRANSPORT THROUGH
SATURATED POROUS MEDIA: A TWO-
DIMENSIONAL PILOT-SCALE STUDY
J.S. Aronheim, T.H. Illangasekare, J.N. Ryan, G.L.
Amy, R.W. Harvey, J.P. Loveland and A. Pieper,
Department of Civil, Environmental and
Architectural Engineering, University of Colorado
at Boulder, Boulder, CO 80309; 303-492-6754;
email: aronheim@uscu.colorado.eduPROCESS FOR THE RESTORATION OF
SOLIDS CONTAMINATED WITH
HYDROCARBONS AND HEAVY ORGANIC
COMPOUNDS
G.A. Bala, C.P. Thomas, J.D.
Jackson and R.A. McMillin, Idaho National
Engineering Laboratory, EG&G Idaho Inc.,
Center for Industrial Bioprocess Engineering,
Idaho Falls, ID 83415-2203BIOREMEDIATION OF PETROLEUM
CONTAMINATED SOIL USING
VEGETATION A TECHNOLOGY
TRANSFER PROJECT
M.K. Banks1, A.P. Schwab2, R.S. Govindaraju1 and Zhi Chen1,
1Department of Civil Engineering, and
2Department of Agronomy, Kansas State
University, Manhattan, KS 66506REMOVAL OF NITROGEN OXIDES FROM
GAS STREAMS BY BIOFILTRATION
K.B. Barrett, J.M. Barnes and W.A. Apel, Industrial
Biotechnology and Process Engineering, Idaho
National Engineering Laboratory, PO Box 1625,
Idaho Falls, ID 83415-2203KINETICS AND MECHANISM OF
REDUCTIVE DECHLORINATION OF
TETRACHLOROMETHANE USING
ELEMENTAL METALS
E.A. Betterton1, K.D. Warren2 and R.G. Arnold2,
1Department of Physics and Atmospheric Chemistry and
2Department of Chemical and Environmental
Engineering, Arizona University, Tucson, AZ
85721WERC—A CASE STUDY OF A SUCCESSFUL
TECHNOLOGY TRANSFER PARTNERSHIP
Ron K. Bhada1, Abbas Ghassemi1, Ricardo
Jacquez1 and Dave Kauffman2, 1New Mexico State
University, Box 30001, Dept. WERC, Las Cruces,
NM 88003-8001; 2College of Engineering,
University of New Mexico, Farris Engineering
Center, Albuquerque, NM 87131CHLOROCARBON TRANSFORMATION IN
WATER CAUSED BY METAL PARTICLES
T. Boronina and K.J. Klabunde, Department of
Chemistry, Kansas State University, Manhattan,
KS 66506BIOLOGICAL PROCESS FOR THE
TREATMENT OF WATER CONTAMINATED
WITH 2,4-DICHLOROPHENOXYACETIC
ACID (2,4-D)
S. Bradley, M. Roberts and R.
Crawford, Center for Hazardous Waste
Remediation Research, FRC 105, University of
Idaho, Moscow, ID 83843USE OF ENRICHMENTS AND NUCLEIC
ACID PROBES IN MONITORING
BIOREMEDIATION OF A DEEP
TRICHLOROETHYLENE PLUME
F. Brockman, W. Payne, D. Workman, A. Soong, S.
Manley, W. Sun and A. Ogram, Pacific Northwest
Laboratory, Richland, WA 99352; and
Department of Crop and Soil Sciences,
Washington State University, Pullman, WA 99164EFFECT OF PLANTS ON THE
BIODEGRADATION OF PYRENE IN SOIL
B. Bugbee1 and W.J. Doucette2, 1Utah
Agricultural Experiment Station and 2Utah Water
Research Laboratory, Utah State University,
Logan, UT 84322MULTIPLE ROLES FOR LIGNIN
PEROXIDASES IN THE BIODEGRADATION
OF ORGANIC POLLUTANTS
John A. Bumpus, C.W. Chang and Matthew Tatarko,
Department of Chemistry and Biochemistry,
Department of Biological Sciences and the Center
for Bioengineering and Pollution Control,
University of Notre Dame, Notre Dame, IN 46556THE EFFECT OF ORGANIC ACIDS ON THE
LEACHING OF HEAVY METALS FROM
MINE TAILINGS
S.R. Burckhard1, A.P.Schwab2 and M.K. Banks1,
1Department of Civil Engineering, and 2Department of Agronomy,
Kansas State University, Manhattan, KS 66506MINE, MINERAL AND HAZARDOUS WASTE
EDUCATION—MINE WASTE TECHNOLOGY
PILOT PROGRAM (MWTPP) AND THE
WASTE-MANAGEMENT EDUCATION &
RESEARCH CONSORTIUM (WERC)
Karl E. Burgher1 and Abbas Ghassemi2, 1Director,
MWTPP Training and Education, Montana Tech
of the University of Montana, Butte, MT; and
2Director, WERC Special Programs, New Mexico
State University, Las Cruces, NMTHE EFFECT OF POPLAR TREES ON THE
FATE AND TRANSPORT OF ATRAZINE IN
VARIABLE SOIL TYPES
J.G. Burken and J.L. Schnoor, Department of Civil and
Environmental Engineering, University of Iowa,
Iowa City, IA 52242PRACTICAL APPLICATION OF SULFATE-
REDUCING BACTERIA TO CONTROL ACID
ROCK DRAINAGE AT THE LILLY/ORPHAN
BOY MINE NEAR ELLISTON, MONTANA
M.C. Canty and T.F. McIntyre, Mine Waste
Technology Pilot Program (MWTPP), MSE, Inc.,
Butte, MT 59701MICROBIAL METABOLISM OF
POLYCYCLIC AROMATIC HYDROCARBONS
(PAH) IN CREOSOTE CONTAMINATED
SOILS
L.M. Carmichael and F.K. Pfaender,
Department of Environmental Sciences and
Engineering, CB #7400, University of North
Carolina at Chapel Hill, Chapel Hill, NC 27599-
7400RISK ASSESSMENT OF COMPLEX
MIXTURES: POLYNUCLEAR AROMATIC
HYDROCARBONS
K. Chaloupka1, N. Harper1, M. Steinberg1, S. Safe1,
L.V. Rodriguez2 and L.S. Goldstein3, 1Department of Veterinary
Physiology and Pharmacology, Texas A&M
University, College Station, TX 77843-4466;
2Department of Molecular Pathology, The
University of Texas, M.D. Anderson Cancer
Center, Houston, TX 77030; 3Electric Power
Research Institute, P.O. Box 10412, Palo Alto, CA
94303SUPERCRITICAL CARBON DIOXIDE
EXTRACTION OF POLYCHLORINATED
BIPHENYLS FROM SOILS
P. Chen, E. Yu, W.S. Amato, Z. Zhang and L.L. Tavlarides,
Department of Chemical Engineering and
Materials Science, Syracuse University, 320
Hinds Hall, Syracuse, NY 13244-1190DEGRADATION OF PENTACHLOROPHENOL
IN SOIL BY PHANEROCHAETE
CHRYSOSPORIUM
Namhyun Chung and Steven D. Aust, Biotechnology Center,
Utah State University, Logan, UT 84322-4705ENUMERATION OF TOTAL AND VIABLE
MICROORGANISMS IN THE UNSATURATED
ZONE
C.S. Clennan, W. Yu and M.K. Banks,
Department of Civil Engineering, Kansas State
University, Manhattan, KS 66506HYDRAULIC CHARACTERIZATION OF THE
VADOSE ZONE
B.J. Clennan, J.K. Koelliker
and G.J. Kluitenberg, Kansas State University,
Manhattan, KS 66506BIOAVAILABILITY OF LEAD IN SOILS AND
DUST SAMPLES
T.E. Clevenger1, Daryl
Roberts2 and Pat Phillips2,1Water Resources
Research Center, University of Missouri-
Columbia, Columbia, MO 65211; 2Missouri
Department of Health, Jefferson City, MO 65101TNT DEGRADATION BY ANAEROBIC
THERMOPHILES
Joan Combie and Kenneth
Runnion, J. K. Research, 210 South Wallace,
Bozeman, MT 59715BIODEGRADATION KINETICS OF
AROMATIC HYDROCARBON AND
TRICHLOROETHYLENE MIXTURES
Jeffrey R. Conuel, Douglas C. Mosteller and Kenneth F.
Reardon, Department of Agricultural and
Chemical Engineering, Colorado State University,
Fort Collins, CO 80523INTERACTIONS OF PENTACHLOROPHENOL
WITH MANGANESE OXIDE
A. Cramer, J.E. McLean and R.C. Sims, Utah Water Research
Laboratory, Utah State University, Logan, UT
84322-8200BIOASSAY-BASED RISK ASSESSMENT OF
HAZARDOUS WASTE
K.C. Donnelly, K.W. Brown and L.Y. He, Departments of Veterinary
Anatomy & Public Health and Soil & Crop
Sciences, Texas A&M University, College Station,
TX 77843MICROCOSM METHOD FOR
INVESTIGATING THE BIODEGRADATION
OF ORGANIC COMPOUNDS IN
RHIZOSPHERE SOILS
W.J. Doucette1 and B. Bugbee2, 1Utah Water Research Laboratory and
2Utah Agricultural Experiment Station, Utah State
University, Logan, UT 84322RADIOCHEMICAL METHOD
DEVELOPMENT
Mitchell D. Erickson1,
Joseph H. Aldstadt1, Jorge S. Alvarado1, Jeffrey S.
Crain2, Kent A. Orlandini1 and Lesa L. Smith2,
1Environmental Research Division and 2Chemical
Technology Division, Argonne National
Laboratory, 9700 S. Cass Ave., Argonne, IL
60439-4837, 708-252-7772, FAX 70X-252-9594PREFERENTIAL FLOW AND ENTRAPMENT
OF NONAQUEOUS PHASE FLUIDS IN
WATER SATURATED HETEROGENEOUS
POROUS MEDIA
Terence M. Fairbanks, Tissa Illangasekare
and Dobroslav Znidarcic,
Department of Civil, Environmental and
Architectural Engineering, University of
Colorado, Boulder, CO 80309-0428PROPOSED CHARACTERIZATION OF
CONTAMINATED SEPTIC SYSTEMS
R.B. Galloway, B.S. Langkopf and J.T. McCord,
Environmental Restoration Department, Sandia
National Laboratories, P.O. Box 5800,
Albuquerque, NM 87185-0727DISSOLUTION AND BIODEGRADATION OF
A MIXTURE OF IMMISCIBLE LIQUIDS
P. Gandhi, L.E. Erickson and L.T. Fan, Department
of Chemical Engineering, Durland Hall, Kansas
State University, Manhattan, Kansas 66506-5102AN EXPERIMENTAL INVESTIGATION OF
UPSCALING OF WATERFLOW AND SOLUTE
TRANSPORT IN SATURATED POROUS
MEDIA
Julio Garcia1, Ranjith B. Mapa1, Tissa
Illangasekare1 and Thomas Russell2, 1Department
of Civil, Environmental and Architectural
Engineering, University of Colorado, Boulder, CO
80309-0428; 2Department of Mathematics,
University of Colorado, Denver, CO 80309SOURCE REMOVAL STRATEGY
DEVELOPMENT FOR MANUFACTURED GAS
PLANT SITES
J. Golchin1 and S. Nelson2,
1Iowa Department of Natural Resources, Des
Moines, IA 50319; 2Midwest Gas, Sioux City, IA16S rDNA-BASED PROBES FOR TWO
POLYCYCLIC AROMATIC HYDROCARBON
(PAH)-DEGRADING SOIL MYCOBACTERIA
M. Govindaswami, D.J. Feldhake and J.C.
Loper, University of Cincinnati Medical Center,
Cincinnati, OH 45262-0524STATIC SIMS DESORPTION OF TRIBUTYL
PHOSPHATE FROM MINERAL SURFACES:
EFFECT OF Fe(II)
G.S. Groenewold, J.C Ingram, A.D. Appelhans, J.E. Delmore
and D.A. Dahl, Idaho National Engineering Laboratory,
P.O. Box 1625, Idaho Falls, ID 83415-2208THE EFFECTS OF FULVIC ACIDS
EXTRACTED FROM SOILS ON THE
MINERALIZATION OF PYRENE BY AN
ISOLATED MYCOBACTERIUM SP.
R.J. Grosser, D. Warshawsky and B. Kinkle,
Department of Biological Sciences, University of
Cincinnati, Cincinnati, OH 45221-0006ADSORPTION OF HEAVY METALS ON
RHIZOSPHERE SOIL
Yinghong He1, Suzette Burckhard1, A.P. Schwab2, and M.K. Banks1,
1Department of Civil Engineering, and
2Department of Agronomy, Kansas State
University, Manhattan, KS 66506REDUCTIVE DECHLORINATION OF
CARBON TETRACHLORIDE IN WATER
USING ELEMENTAL IRON
B.R. Helland, J.L. Schnoor and P.J. Alvarez, Department of
Civil and Environmental Engineering, University
of Iowa, Iowa City, IA 52242THERMAL TREATMENT TECHNOLOGY AT
THE IDAHO NATIONAL ENGINEERING
LABORATORY
J.M. Hillary, Industrial
Process Engineering Research, EG&G Idaho Inc.,
PO Box 1625, Idaho Falls, ID 83415-2203MONITORING OF PLANT BIOREMEDIATION
OF VOLATILE ORGANIC COMPOUNDS
(VOCs) USING OPEN PATH FOURIER
TRANSFORM INFRARED (FT-IR)
SPECTROMETRY
R.M. Hoffman1, V.P. Visser1, L.C. Davis2, L.E. Erickson3, N.
Muralidharan3, R.M. Hammaker1 and W.G.
Fateley1, Departments of Chemistry1,
Biochemistry2, and Chemical Engineering3,
Kansas State University, Manhattan KS, 66506REMOVAL OF HEAVY METALS FROM SOIL
USING CHELATES
Andy Hong, Department of Civil Engineering,
University of Utah, Salt Lake City, UT 84112DETOXIFICATION OF WOOD PRESERVING
WASTE UNDER AMBIENT, ENHANCED,
AND CHEMICAL PRETREATMENT
CONDITIONS
M.S. Hong, K.W. Brown, B.E.
Dale, K.C. Donnelly, L.Y. He and K.V.
Markiewicz, Depts. of Chemical Engineering, Soil
& Crop Sciences, and Veterinary Anatomy &
Public Health, Texas A & M University, College
Station, TX 77843ORGANIC SOLUTE MOBILITY IN INTACT
TURF/SOIL COLUMNS
G.L. Horst1, W.L. Powers2, P.J. Shea2, D.R. Miller1 and C.L.
Stuefer-Powell2, 1377 Plant Science, and 2279
Plant Science, University of Nebraska, Lincoln,
NE 68583EVALUATION OF TWO EXTRACTION
PROCEDURES FOR THE RECOVERY OF
ORGANIC CHEMICALS FROM SPIKED SOILS
H.J. Huebner, K.W. Brown, K.C. Donnelly and
L.Y. He, Department of Veterinary Anatomy &
Public Health, Texas A & M University, College
Station, TX 77843EVALUATION OF TWO EXTRACTION
PROCEDURES FOR THE RECOVERY OF
ORGANIC CHEMICALS FROM SPIKED SOILS
H.J. Huebner, K.W. Brown, K.C. Donnelly and
L.Y. He, Department of Veterinary Anatomy &
Public Health, Texas A & M University, College
Station, TX 77843DEGRADATION OF 2,4-D IN SOILS UNDER
BATCH AND TRANSPORT CONDITIONS
W.P. Inskeep, S. Sun, H. Gaber, J.M. Wraith and
R. Doughten, Department of Plant, Soil and
Environmental Sciences, Montana State
University, Bozeman, MT 59717REVEGETATION OF CONTAMINATED
STREAMSIDE MINE WASTES
D.B. Jackson and D.J. Dollhopf, Reclamation Research Unit,
Montana State University, Bozeman, MT 59717ACID-BASE ACCOUNT EFFECTIVENESS
FOR DETERMINATION OF MINE WASTE
POTENTIAL ACIDITY
S. Jennings and D.J. Dollhopf, Reclamation Research Unit, Montana
State University, Bozeman, MT 59717APPLICABILITY OF THERMAL VENTING IN
REMEDIATING LESS-VOLATILE
HYDROCARBON CONTAMINATED SITES
Jagath J. Kaluarachchi and K.M. Mesbah-ul
Islam, Utah Water Research Laboratory, Utah
State University, Logan, UT 84322-8200BIOREMEDIATION OF ALIPHATIC
HALOCARBONS BY PHANEROCHAETE
CHRYSOSPORIUM
Aditya Khindaria, Thomas A. Grover and Steven D. Aust,
Biotechnology Center, Utah State University, Logan,
UT 84322-4705ENHANCEMENT OF POLYCYCLIC
AROMATIC HYDROCARBON
BIODEGRADATION IN THE RHIZOSPHERE
S.C. Kim1, M.K. Banks2 and A.P. Schwab3,
1Department of Chemical Engineering,
2Department of Civil Engineering, and
3Department of Agronomy, Kansas State
University, Manhattan, KS 66506REDUCING THE FORMATION OF CARBON
OXIDES IN THE PRODUCTION OF C2
HYDROCARBONS FROM METHANE
S.C. Kim1, L.E. Erickson1 and E.Y. Yu2, 1Center for
Hazardous Substance Research, Kansas State
University, Manhattan KS 66506; 2Department of
Chemical Engineering, Chonnam National
University, Kwangju 500-757, Korea,PROPERTIES OF NANOSCALE AND
COMMERCIAL CALCIUM OXIDE—THE
DESTRUCTIVE ADSORBENT OF
CHLOROCARBONS
Olga Koper and Kenneth J. Klabunde, Department of Chemistry,
Kansas State University, Manhattan, KS 66506TREATMENT OF WASTEWATER FROM A
PAINT INDUSTRY USING
POLYELECTROLYTES
M.M. Kori and S.K. Gupta, Centre for Environmental Science
and Engineering, Indian Institute of Technology,
Powai, Bombay 400 076, INDIAON-LINE SPECTROSCOPY IN
SUPERCRITICAL CARBON DIOXIDE
SYSTEMS
Srinivas Kothandaraman, Robert C.
Ahlert and E.S. Venkataramani, Chemical and
Biochemical Engineering, Rutgers University, PO
Box 909, Piscataway, NJ 08855-0909, 908-932-
3399, FAX 908-932-4963PHYSIOCHEMICAL FACTORS OF IRON
PHOTOPRODUCTION FROM MINE
TAILINGS WASTES
L.J. Kurimski, M.A. St. Clair, K. Kai Fan and J.L. Schnoor,
Department of Civil and Environmental Engineering,
University of Iowa, Iowa City, IA 52242TRANSPORT AND BIODEGRADATION OF
NAPLS AT SUBSURFACE SAND/CLAY
INTERFACES
G. Kyle, S. Wetzel and M.K.
Banks, Department of Civil Engineering, Kansas
State University, Manhattan, KS 66506FATE OF PYRENE IN THE RHIZOSPHERE
Euisang Lee1, M.K. Banks1, and A.P. Schwab2,
1Department of Civil Engineering and
2Department of Agronomy, Kansas State
University, Manhattan, KS 66506ABSORPTION OF HEAVY METAL TOXIC
WASTE FROM DILUTE SOLUTIONS
Zbigniew Lewandowski, Frank Roe, Maren Twedt,
Duy Nguyen and Prasad Surapanini, Center for
Biofilm Engineering, Montana State University,
Bozeman, MT 59717TRANSPORT OF TNT IN MUNITIONS
CONTAMINATED SOILS
Zhengming Li, B.L. Woodbury, J.L. Martin,
S.D. Comfort and P.J. Shea, University of Nebraska,
Lincoln, NE 68583-0915THE INFLUENCE OF MULTIPLE
COLLISIONS AND SLOW DESORPTION ON
BACTERIAL STICKING COEFFICIENTS AND
DISPERSION IN POROUS MEDIA
B.E. Logan, K. Blue, W. Johnson and R.G. Arnold,
Department of Chemical and Environmental
Engineering, University of Arizona, Tucson, AZ
85721VEGETATIVE BIOREMEDIATION OF
PHENANTHRENE
A. Malathi1, M.K. Banks1
and A.P. Schwab2, 1Department of Civil
Engineering, and 2Department of Agronomy,
Kansas State University, Manhattan, KS 66506MICROBIAL ECOLOGY AND
TRANSFORMATIONS ASSOCIATED WITH
MUNITIONS CONTAMINATED SOILS
J.L. Martin, Zhengming Li, T.A. Kokjohn, P.J. Shea
and S.D. Comfort, University of Nebraska,
Lincoln, NE 68583-0915COLONIZATION AND BIOFILM
FORMATION IN GRANULAR ACTIVATED
CARBON FLUIDIZED BED REACTORS
TREATING CONTAMINATED
GROUNDWATER
A. Massol-Deya1, R.F. Hickey1,2, and J.M. Tiedje1,
1NSF Center for Microbial Ecology, E. Lansing,
MI 48824; and 2Michigan Biotechnology Institute, Lansing, MI
48909GROUTING AS A HYDROLOGICAL
CONTROL FOR ACID ROCK DRAINAGE
REDUCTION AT THE MIKE HORSE MINE
NEAR LINCOLN, MT
A.L. McCloskey and T.F. McIntyre, Mine Waste Technology Pilot
Program (MWTPP), MSE, Inc., Butte, MT 59701EFFECT OF GROWTH CONDITIONS ON THE
BIODEGRADATION KINETICS OF TOLUENE
BY P. PUTIDA 54G IN A VAPOR PHASE
BIOREACTOR
Raj Mirpuri, Warren Jones,
Eva Krieger and Gordon McFeters, Center for
Biofilm Engineering, Montana State University,
Bozeman, MT 59717PHOTOCATALYTIC OXIDATION OF
CHLOROFORM BY TITANIUM DIOXIDE
Cathy Mohs and Kenneth J. Klabunde,
Department of Chemistry, Kansas State
University, Manhattan, KS 66506ANACONDA REVEGETATION
TREATABILITY STUDY
R.J. Montgomery, Atlantic Richfield Company,
307 E. Park Ave., Suite 400, Anaconda, MTFLUORESCENT IMMUNOASSAY
VISUALIZATION OF SORBED POLLUTANTS
Wesley K. Moore1, Deborah J. Mossman1, A.
Paul Schwab2 and Thomas L. Feldbush3,
1Department of Civil Engineering, Coordinated
Engineering Program, University of Missouri-
Columbia, 5100 Rockhill Road, Kansas City, MO
64110-2499; 2Department of Agronomy, Kansas
State University; 3Associate Dean of Medicine,
Northwestern UniversityPLANT GROWTH ON ASH DISPOSAL PONDS
F. Munshower, Reclamation Research Unit,
Montana State University, Bozeman, MT 59717EXPERIMENTAL AND MODELING STUDIES
OF THE FATE OF ORGANIC
CONTAMINANTS IN THE PRESENCE OF
ALFALFA PLANTS
N. Muralidharan1, Lawrence C. Davis2, John C. Tracy3, Larry E.
Erickson1 and Ryan Green1, 1Department of
Chemical Engineering, Kansas State University,
Manhattan, KS 66506; 2Department of
Biochemistry, Kansas State University,
Manhattan, KS 66506; and 3Department of Civil
Engineering, South Dakota State University,
Brookings, SD 57007THE SUSTAINABLE PROCESS INDEX (SPI)
EVALUATING PROCESSES ACCORDING TO
ENVIRONMENTAL COMPATIBILITY
M. Narodoslawsky and C. Krotscheck, Institute of
Chemical Engineering, Graz University of
Technology, Inffeldgasse 25, A-8010 Graz,
AustriaFIELD SCALE SOLUTE TRANSPORT IN
SPATIALLY VARIABLE SOILS
S. Nedunuri and Rao S. Govindaraju, Department of Civil
Engineering, Seaton Hall, Kansas State
University, Manhattan, KS 66506REVEGETATION OF STREAMBANK
TAILINGS, SILVER BOW CREEK, MONTANA
D. Neuman, F. Munshower, D. Dollhopf, S.
Jennings and J. Goering, Reclamation Research
Unit, Montana State University, Bozeman, MT
59715REVEGETATION OF COARSE TACONITE
IRON ORE TAILING USING MUNICIPAL
SOLID WASTE COMPOST
M.R. Norland and D.L. Veith, Reclamation Technology, U.S. Bureau
of Mines, Twin Cities Research Center, 5629
Minnehaha Ave. South, Minneapolis, MN 55417-
3099SUBSTRATE INTERACTIONS DURING
TRICHLOROETHENE DEGRADATION BY
NITRIFYING CULTURES
M.H. Ochoa and J.B. Hughes, Department of Environmental
Science and Engineering, Rice University, PO Box
1892, Houston, TX 77251PENTACHLOROPHENOL INTERACTIONS
WITH AQUIFER SOLIDS
R.A. Petrie, J.E. McLean and R.C. Sims, Utah Water Research
Laboratory, Utah State University, Logan, UT
84322-8200PULSED NUTRIENT DELIVERY FOR
CONTROL OF PORE PLUGGING
B.M. Peyton, R.S. Skeen and B.S. Hooker, Engineering
Technology Center (P7-41), Pacific Northwest
Laboratory, Richland, WA 99332BERKELEY PIT SYSTEMS CONFIGURATION
J. Powers1, R. Luyendijk1, J. Mathur2, V. Ceci3
and D. Eyman4, 1Waste Policy Institute, 1872
Pratt Drive, Suite 1600, Blacksburg, VA 24060,
(703) 231-3324; 2U.S. Department of Energy,
Office of Environmental Restoration and Waste
Management, Trevion II, EM-551, Room 426,
12800 Middlebrook Road, Germantown, MD
20874, (301) 990-7922; 3BDM/GER Quince
Diamond, 555 Quince Orchard Road, Suite 400,
Gaithersburg, MD 20878-1437, (301) 212-6208;
and 4Waste Policy Institute, Quince Diamond
Executive Center, 555 Quince Orchard Road,
Suite 600, Gaithersburg, MD 20878-1437, (301)
990-7200.CLAY COLLOID-ASSOCIATED TRANSPORT
OF CONTAMINANTS INTO THE
SUBSURFACE
R.N Prabhushankar1, Lakshmi
N. Reddi1 and A. Paul Schwab2, 1Department of
Civil Engineering, and 2Department of Agronomy,
Kansas State University, Manhattan, KS 66506ANALYSIS OF MICROBIAL ACTIVITY AND
THE BIOCORROSION OF METALS
S. Rao1, L.L. Barton2 and T.J. Ross1, 1Environmental
Scanning Electron Microscope Laboratory,
Department of Civil Engineering; and
2Laboratory of Microbial Chemistry, Department
of Biology, the University of New Mexico,
Albuquerque, NM 87131PERFORMANCE EVALUATION OF
VIBRORECOVERY AS REMEDIATION
TECHNOLOGY AT HAZARDOUS WASTE
SITES
Lakshmi N. Reddi and Hui Wu,
Department of Civil Engineering, Kansas State
University, Manhattan, KS 66506BIOTRANSFORMATION OF THE
EXPLOSIVES 2,4,6-TRINITROTOLUENE AND
1,3,5-TRIAZA 1,3,5-
TRINITROCYCLOHEXANE BY
CLOSTRIDIUM BIFERMENTANS
Karl M. Regan and Ronald L. Crawford, Institute for
Molecular and Agricultural Genetic Engineering
(IMAGE), Food Research Center 103, University
of Idaho, Moscow, ID 83844-1052STABILIZATION OF FOUNDRY WASTE
WITH CLAY BINDERS AND ITS
UTILIZATION
G. Rieck and Lakshmi N.
Reddi, Department of Civil Engineering, Kansas
State University, Manhattan, KS 66506ENHANCED BIODEGRADATION OF
XENOBIOTICS IN THE RHIZOSPHERE:
POTENTIAL FOR BIOREMEDIATION
Jerome Rigot and Fumio Matsumura, Department
of Environmental Toxicology, University of
California, DavisA STUDY OF MICROBIAL COMMUNITIES IN
LEAD-CONTAMINATED SOILS
T.M Roane and S.T. Kellogg, Microbiology, Molecular
Biology & Biochemistry Department, University
of Idaho, Moscow, ID 83843MODELING THE FATE OF POLYNUCLEAR
AROMATIC HYDROCARBONS IN THE
RHIZOSPHERE
S. Santharam, L.E. Erickson
and L.T. Fan, Department of Chemical
Engineering, Kansas State University, Manhattan,
KS 66506BIODEGRADATION OF PAHS BY TWO
BACTERIAL SPECIES ISOLATED FROM
COAL GASIFICATION SITE SOILS
J.R. Schneider, R.J. Grosser, K. Jayasimhulu and D.
Warshawsky, Department of Environmental
Health, University of Cincinnati, Cincinnati, OH
45267-0056SUPERCRITICAL WATER OXIDATION
TECHNOLOGY DEVELOPMENT PATHS FOR
PREVENTION OF CORROSION AND
DEPOSITION
C. Shapiro, K. Garcia, C. Barnes and J. Beller,
Idaho National Engineering Laboratory,
EG&G Idaho Inc., PO Box 1625,
Idaho Falls, ID 83415-3765STUDIES IN APPLYING PSEUDOMONAS
CEPACIA PR1-(pTOM31C) TO A TCE
BIOREACTOR
Robert Sharp1, Malcolm Shields2, Tracy Moody2 and Warren Jones1,
1Center for Biofilm Engineering, Montana State
University, Bozeman, MT 59717; and 2Center for
Diagnostics and Bioremediation, University of
West Florida, Pensacola, FLPATHWAY AND PRODUCTS OF PCB
DECHLORINATION IN CONTAMINATED
SEDIMENTS: REDUCTION OF HEALTH
HAZARDS AND ENHANCEMENT OF
MICROBIAL ACTIVITIES
Roger C. Sokol, Charlotte M. Bethoney and G-Yull Rhee, School of
Public Health, State University of New York at
Albany and Wadsworth Laboratories, NYS
Department of Health, Albany, NY 12201-0509BIODEGRADATION OF TRINITROTOLUENE
BY PHANEROCHAETE CHRYSOSPORIUM
J.D. Stahl and S.D. Aust, Biotechnology Center,
Utah State University, Logan, UT 84322-4705FIELD ANALYSIS: PHYSICAL AND
BIOLOGICAL BTEX REMOVAL IN A SANDY
AQUIFER
P.J. Sturman1, A.B. Cunningham1,
J. Wolfram2 and S. Niehaus3, 1Center for Biofilm
Engineering, Montana State University, Bozeman,
MT; 2Idaho National Engineering Laboratory,
Idaho Falls, ID; and 3Gosling-Czubak Associates,
Traverse City, MISORPTION OF NONIONIC ORGANIC
COMPOUNDS IN SOIL-WATER SYSTEMS
CONTAINING A MICELLE-FORMING
SURFACTANT
S. Sun, W.P. Inskeep and S.A.
Boyd, Department of Plant, Soil and
Environmental Science, Montana State University,
Bozeman, MT; and Department of Crop and Soil
Science, Michigan State University, East Lansing,
MICORROSION TEXTURES OF SIMULATED
NUCLEAR WASTE GLASS AND NUCLEAR
WASTE SLAG WHEN EXPOSED TO WATER
VAPOR HYDRATION AT 200 C
W. Svee and F. Diebold, Chemistry and Geochemistry
Department, Montana College of Mineral Science
and Technology, Butte, MT 59701-8997DISSOLUTION OF ENTRAPPED
NONAQUEOUS PHASE LIQUIDS IN SANDY
SOILS
David C. Szlag and Tissa Illangasekare,
Department of Civil, Environmental and
Architectural Engineering, University of
Colorado, Boulder, CO 80309-0428, 303-492-
6644ANAEROBIC BACTERIAL SYSTEMS
RESULT IN THE REMOVAL OF SOLUBLE
URANIUM
B.M. Thomson1, L.L. Barton2, K.
Steenhoudt1 and M.D. Tucker1, 1Department of
Civil Engineering and 2Department of Biology,
University of New Mexico, Albuquerque NM
87131CONGENER-SPECIFIC EFFECTS OF DIOXINS
ON NEURAL CELL CULTURES AND BRAIN
SLICES
E. Tiffany-Castiglioni, W.H.
Hanneman, M.E. Legare, S.J. Hong, R. Barhoumi,
R.C. Burghardt and S. Safe, Department of
Veterinary Anatomy and Public Health,
Department of Veterinary Physiology and
Pharmacology, Texas A&M University, College
Station, TX 77843EFFECTS OF CLIMATE VARIABILITY ON
PHYTOREMEDIATION SYSTEM
PERFORMANCE
J.C. Tracy and H. Ramireddy, Northern Great Plains Water
Resources Research Center and Department of
Civil Engineering, South Dakota State University,
Brookings, SD 57007BIOPRECIPITATION OF URANIUM FROM
MINE DRAINAGE
M. Truex, B.M. Peyton and
Y. Gorby, Pacific Northwest Laboratory,
Richland, WA 99352SUPPRESSION OF BIOREMEDIATION BY
PHANEROCHAETE CHRYSOSPORIUM BY
SOIL MICROBES
B. Tucker, C. Radtke, K. Sun-Il and A.J. Anderson,
Department of Biology, Program in Toxicology,
Utah State University, Logan, UT 84322-5305SYSTEMATIC APPROACH FOR PROCESS
SYNTHESIS INCORPORATING IN-PLANT
WASTE TREATMENT
J.B. Varga2, F. Friedler l,2, and L.T. Fan1,1Department of
Chemical Engineering, Kansas State University,
Manhattan, KS 66506; and 2Department of
Systems Engineering, Chemical Engineering
Institute, Hungarian Academy of Sciences,
Veszprem, Pf. 125, H-8201, HungaryENTRAPMENT OF NONAQUEOUS PHASE
CONTAMINANTS IN HETEROGENEOUS
SOILS
Gabriele Walser and Tissa Illangasekare,
Dept. of Civil Engineering,
University of Colorado, Boulder, CO 80309-0428EFFECTS OF INCREASING LOADING ON A
CONTINUOUSLY FED METHANOTROPHIC
BIOREACTOR TREATING AQUEOUS
TRICHLOROETHYLENE
G.A. Walter1, H.D. Stensel1 and S.E. Strand2,
1Department of Civil Engineering, FX-10; and 2College of Forest
Resources, AR-10, University of Washington,
Seattle, WA 98195A FIELD-PRACTICAL ASSAY FOR RAPID
DETECTION OF CHLOROPHENOLS
K.S. Washburn and T.D. Phillips, Toxicology,
Department of Veterinary Anatomy and Public
Health, Texas A&M University, College Station,
TX 77843MODELING AND MASS-TRANSFER
EVALUATION IN VAPOR-PHASE
BIOREACTORS
C. Wend and W. Jones,
Center for Biofilm Engineering, Montana State
University, Bozeman, MT 59717TRANSPORT OF DODECANE IN SAND AND
CLAY COLUMNS
S. Wetzel, G. Kyle and M.K. Banks,
Department of Civil Engineering,
Kansas State University, Manhattan, KS 66506THE NAOMI PROGRAM: DEVELOPING
HAZARDOUS SUBSTANCE PROGRAMS AT
NATIVE AMERICAN AND OTHER
MINORITY EDUCATIONAL INSTITUTIONS
D.R. Wildcat1, G.L. Godfrey1, D.L. Tillison1
and S.C. Grant2, 1Haskell Indian Nations
University, Dept. of Natural and Social Sciences,
155 Indian Ave., Box 1227, Lawrence, KS 66046;
and 2Great Plains-Rocky Mountain Hazardous
Substance Research Center, Kansas State
University, 101 Ward Hall, Manhattan, KS 66506-
2502PROFILING OF A VOLATILE ORGANIC
COMPOUND SOURCE AREA USING CONE
PENETROMETER TESTS
P. Williamson and V. Prabhakar, Roux Associates,
Inc., 1401 17th Street, Suite 400, Denver, CO 80202POLLUTION PREVENTION TOOLKITS FOR
SMALL QUANTITY GENERATORS
W.E. Woldt, M.F. Dahab and Jan Hygnstrom,
Department of Biological Systems Engineering,
253 L.W. Chase Hall, University of Nebraska,
Lincoln, NE 68583-0771BIOPROCESSING SCENARIOS FOR MIXED
HAZARDOUS WASTE
J.H. Wolfram and R.D. Rogers, EG&G Idaho Inc.,
Idaho Falls, ID 83415A STUDY OF THE DISSOLUTION RATE-
LIMITED BIOREMEDIATION OF SOILS
CONTAMINATED BY RESIDUAL
HYDROCARBONS
Xiaoqing Yang, Larry E. Erickson and L.T. Fan,
Department of Chemical Engineering, Durland Hall, Kansas State
University, Manhattan, KS 66506-5102ENUMERATION AND ACTIVITY OF
MICROBES IN THE UNSATURATED ZONE
OF PRISTINE AND AGRICULTURE SOILS
W. Yu1, C.S. Clennan1, D. Sotomayor2, M.K.
Banks1 and C.W. Rice2, 1Department of Civil
Engineering, and 2Department of Agronomy,
Kansas State University, Manhattan, KS 66506