|
Microbial
Characterization of Contaminated Sediments Using Dual
Stain Flow Cytometry
Cyndee
Gruden, University of Michigan, Ann Arbor, MI
Anna Khijniak, University of Michigan, Ann Arbor, MI
Peter
Adriaens, University of Michigan, Ann Arbor, MI
Enhanced
Solid-Phase Bioremediation of PAH-Impacted Dredged Marine
Sediments from the Tar Site in Sidney, Nova Scotia, Canada
Alan
G. Seech, Grace Bioremediation Technologies, Mississauga,
Ontario, Canada
Geoffrey
Bell, M.Sc., Grace Bioremediation Technologies,
Mississauga, Ontario, Canada
James
Mueller, Ph.D., URS/Dames
& Moore, Rolling Meadows, IL
The
Effect of Plants on the Dynamics of Heavy Metals in
Wetland Sediments
Shangping
Xu, Princeton University, Princeton, NJ
Peter
Jaffe, Princeton University, Princeton, NJ
Results
of Interspecies Toxicity Comparison Testing Associated
with Contaminated Sediment Management
Meg
R. Pinza, Battelle Marine Sciences Laboratory,
Sequim, WA
Jeffrey
A. Ward, Battelle
Marine Sciences Laboratory,
Sequim,
WA
Nancy P. Kohn, Battelle Marine Sciences
Laboratory, Sequim,
WA
Biological
Effects Associated withSediment Contamination in San
Francisco Bay
Dr
S. Ian Hartwell, NOAA/NOS, Silver Spring, MD
Dr. M. Jawed Hameedi, NOAA/NOS, Silver Spring, MD
Sediment
MTBE Interactions at a Full Scale Site in Montana: Natural
Attenuation and Toxicity
Ronald
C. Sims, Utah State University, Logan, UT
Aaron Swank, Utah State University, Logan, UT
Potential
for Dehalogenation of Dioxin in Marine and Estuarine
Sediments
Donna
E. Fennell, Rutgers University, New Brunswick, NJ
Young-Beom
Ahn, Rutgers University, New Brunswick, NJ
Lee J. Kerkhof, Rutgers University, New Brunswick, NJ
Max M. Häggblom,
Rutgers University, New Brunswick, NJ
Microbial
Characterization of Contaminated Sediments Using Dual
Stain Flow Cytometry
Cyndee Gruden,
and Anna Khijniak, Civil and Environmental
Engineering, The University of Michigan, Ann Arbor, MI
48109-2125, Tel: 734-764-6350, Fax: 734-763-2275
Peter
Adriaens,
Civil and Environmental Engineering, The University of
Michigan, Ann Arbor, MI 48109-2125, Tel: 734-764-1464,
Fax: 734-763-2275
The
successful design and scaling of bioremediation
applications depends on the accurate qualitative and
quantitative demonstration of causal relationships between
the control strategy and enhanced microbial presence or
activity. Microbial
sensing in sediment environments is a challenging endeavor
due to (among others) matrix interferences and ecological
complexity. The
advent of sensitive molecular techniques has afforded new
opportunities to overcome these challenges by taking
advantage of general or specific genetic probes to
quantitatively detect and determine activity of
biodegrading populations.
A biostimulation approach using low-level hydrogen
gas amendments was applied to enhance the dechlorination
of halogenated aromatics (hexachlorobenzene, dibenzo-p-dioxins)
in estuarine river sediments.
Prior sediment characterization had indicated the
microbial potential for natural dechlorination activity,
but the causative microbial populations had not been
determined. Using
a redox-active stain (CTC, a tetrazolium compound)
specific for the hydrogenase enzyme complex, a direct
relationship between hydrogen concentration and enzyme
activity, as well as an optimal range for enhanced
dechlorination activity, was established. Using flow
cytometric techniques, the elevated hydrogen and
dechlorination activity were shown to correspond to the
emergence of a previously recessive populations.
Preliminary data indicated no statistically
significant difference (two-tailed t-test; a=
0.05) between direct counts (EPM) and flow cytometric
quantification (1x104 to 1x108/mL)
or metabolic activity assessment (~ 3-90%) of indigenous
sediment bacteria using a non-specific stain (Picogreen),
CTC, and a membrane integrity stain (propidium iodide).
These demonstrations indicate the wide
applicability of molecular tools to help establish the
causal relationship between control strategies and
microbial activity, and to increase the confidence in
applying bioremediation techniques to decontaminate
natural environmental systems.
Enhanced
Solid-phase Bioremediation of PAH-impacted Dredged Marine
Sediments from the Tar Ponds Site in Sydney Nova Scotia,
Canada
Alan
Seech, Ph.D.,
Grace Bioremediation Technologies, 1345 Fewster Drive,
Mississauga, Ontario L4W 2A5, Tel:
905-273-5374 ext 221, Fax: 905-273-4367
Geoffrey
Bell, M.Sc.,
Grace Bioremediation Technologies, 1345 Fewster Drive,
Mississauga, Ontario L4W 2A5, Tel:
905-273-5374 ext 225, Fax: 905-273-4367
James
Mueller, Ph.D., URS/Dames
& Moore, 1701 Golf Road, Tower One, Suite 1000, Rolling
Meadows, Illinois 60008, Tel: 847 228-0707 ext 131, Fax:
847 228-1115
A
solid-phase bioremediation technology offered by W.R.
Grace under the trade name DARAMEND®, has been
applied successfully to soils and sediments containing
PAHs, chlorinated pesticides, and organic explosive
compounds at several sites in North America.
For removal of PAHs, the technology utilizes
organic (DARAMEND products) and inorganic (i.e. nutrients,
pH modifiers) amendments to optimize the aerobic activity
of microorganisms indigenous to a soil or waste resulting
in enhanced destruction of organic contaminants.
In January 2002, GRACE began an ongoing bench scale
treatability investigation using PAH-impacted dredged
sediment from the Tar Ponds site in Sydney Nova Scotia,
one of the largest contaminated sites in Canada.
It is estimated that more than 500,000 tons of
sediment at the site are in need of remediation.
In addition to PAHs, the sediment contains PCBs,
petroleum hydrocarbons, and heavy metals. The treatability
investigation was designed to evaluate five different
treatment protocols and a moist, biotic control.
Treatments consist of different DARAMEND
applications, or combinations of DARAMEND with inorganic
nutrients. The
mean initial PAH concentration of the sediment used in the
treatability work was 4,386 mg/kg.
The sediment was spiked with 14C-phenanthrene
to enable estimation of the rate at which this PAH was
mineralized. Radioactive
CO2 produced by mineralization of the
phenanthrene was captured using caustic (2N NaOH) traps
and measuring the amount of radioactivity in the traps
with a Beckman LS6500 Liquid Scintillation Counter.
Volatilization of PAHs from sediment in the microcosms was
monitored using traps containing activated carbon.
Extractable concentrations of PAHs are being measured
throughout the treatability investigation.
Completion of the ongoing study is expected by
September of 2002. The
results will be presented in detail.
DARAMEND(R)
is a registered trademark of W.R. Grace & Co.
-Conn.
The
Effect of Plants on the Dynamics of Heavy Metals in
Wetland Sediments
Shangping
Xu,
Department of Civil and Environmental Engineering,
Princeton University, Princeton, NJ 08544
Peter R. Jaffe,
Princeton University,
Department
of Civil and Environmental Engineering, Princeton
University, Princeton, NJ 08544, Tel: 609-258-4653, Fax:
609-258-2760
Toxicity and mobility
of heavy metals in sediments are controlled by their
speciation. In
wetland sediments, heavy metal speciation is governed by
the spatial redox profiles that are determined by the
sequential utilization of various electron acceptors
during the biodegradation of organic materials.
In addition to the redox reactions some heavy
metals may undergo (e. g., Cr(VI)
Cr(III) where the former is more mobile and toxic),
sulfide produced through sulfate reduction in anaerobic
environments can sequester a variety of heavy metals.
In aerobic environments, Fe(III) and Mn(IV)
hydroxides are good sorbents that could immobilize heavy
metals. However,
when these hydroxides are reduced, heavy metals could be
released into the dissolved.
Wetland plants could control the redox profile and
hence the dynamics of heavy metals through transport of
oxygen to the rhizosphere, organic exudation,
evapotranspiration, and uptake of nutrients like nitrate.
The objective of this research is to obtain a mechanically
based understanding of heavy metals dynamics in sediments
in the presence of plants. Experiments are being conducted
where a solution containing nutrients, various electron
acceptors (nitrate, Fe(III) and sulfate), acetate, and
chromium is pumped into microcosms with and without
wetland plants. At the bottom of the microcosms, water is
drained at a constant rate. Vertical profiles and dynamics
of important redox species such as sulfide and iron are
monitored voltametrically with gold-amalgam
microelectrodes. Concentration of Cr(VI) is determined via
a spectrophotometric technique. Dynamics of chromium, its
relation with important redox species and the presence of
plants are then analyzed. A reactive transport model has
been developed, to aid in the interpretation of the
experimental results.
Results
of Interspecies Toxicity Comparison Testing Associated
with Contaminated Sediment Management
Meg
R. Pinza,
Battelle Marine Sciences Laboratory, 1529 West Sequim Bay
Road, Sequim, WA 98383,
Tel: 360-681-4570,
Fax: 360-681-3699
Jeffrey A. Ward,
Battelle Marine Sciences Laboratory, 1529 West
Sequim Bay Road, Sequim, WA
98383, Tel: 360-681-4570,
Fax: 360-681-3681
Nancy P. Kohn,
Battelle Marine Sciences Laboratory, 1529 West Sequim Bay
Road, Sequim, WA 98383,
Tel: 360-681-4570,
Fax: 360-681-3681
Contamination of
marine and estuarine sediment by polynuclear aromatic
hydrocarbons (PAHs), pesticides, polychlorinated biphenyls
(PCBs), and tributyltin (TBT) is a serious concern for the
management of sediment in Puget Sound.
Many studies have been conducted in the Puget Sound
confirming that these contaminants are present in sediment
at varying concentrations.
Because many of these contaminants produce
sublethal effects following chronic exposure, there is
concern that current toxicity tests approved by the Puget
Sound Dredge Disposal Analysis (PSDDA, 1988) may not be
sufficiently sensitive to adequately assess the
environmental risk posed by these persistent chemicals
when they are present at low to moderate concentrations.
This is especially important if bioassay testing is
used in pre- and post-characterization to support
remediation activities.
This project focused on the use of field-collected
sediment from Puget Sound to determine the comparative
sensitivities of two standard toxicity tests (10-day
amphipod mortality, and the juvenile polychaete growth
test) with the recently developed, 28-day L.
plumulosus chronic test (measuring mortality, growth,
and reproduction). The
experiment was performed using sediment contaminated to
varying degrees with a mixture of persistent contaminants. Sediment from eight field sites was collected, composited,
and submitted for chemical analysis.
Based on the chemical screen, five sites were
chosen for toxicological evaluations.
The toxicity experiments followed the EPA protocol
for the 28-d full-life-cycle chronic Leptocheirus
plumulosus test (EPA/600/R-01/020) and the PSEP protocols for the10-d
acute amphipod sediment toxicity test with Eohaustorius estuarius
(PSEP 1991) and the 20-d growth test with Neanthes
arenaceodentata.
The results from each of the three toxicity tests
were compared to determine the relative sensitivity of
each species and the different endpoints to the
field-collected sediment.
Biological
Effects Associated With Sediment Contamination in San
Francisco Bay
Dr.
S. Ian Hartwell,
NOAA/NOS, Center for Coastal Monitoring and Assessment,
1305 East West Hwy. (SSMC4, N/SCI-1), Silver Spring, MD
20910, Tel: 301-713-3028, Fax: 301-713-4388 Email:
ian.hartwell@noaa.gov
Dr.
M. Jawed Hameedi, NOAA/NOS,
Center for Coastal Monitoring and Assessment, 1305
East West Hwy. (SSMC4, N/SCI-1), Silver Spring, MD 20910
In
2000, NOAA initiated a 2-year comprehensive study to
describe biological effects associated with sediment
contamination in San Francisco Bay. The objectives of the
study are to; (1) estimate the spatial extent and patterns
of chemical contamination, toxicity, and macrobenthic
community structure, (2) identify the incidence and
severity of sediment toxicity, (3) estimate relationships
between toxicant concentrations and measures of sediment
toxicity and, (4) describe spatial associations among
sediment contaminants, toxicity test results and,
macrobenthic assemblages. The study area extends from the
Delta to the Golden Gate to Guadelupe Slough using a
stratified-random design. The technical basis for
stratification, the apportionment of sampling effort into
the strata, and their sizes and dimensions were determined
collaboratively with study partners and coastal resource
managers. In 2000, sediment and biological samples were
collected from 86 sites. An additional 96 sites were
sampled in 2001. Preliminary analyses of samples indicate
that chemical contamination is widespread throughout the
estuary. Elevated contaminant levels in tributaries and
harbors/marinas were site specific with locally very high
concentrations. Source and deposition patterns were
contaminant-specific. Open water sites had marginally
higher concentrations of contaminants in southern San
Francisco Bay than in San Pablo or Suisun Bays. Aggregate
toxicity index results correlated with ERM quotients.
Benthic community response to contaminants was confounded
with salinity and bottom type, but correlations with
contaminant levels were evident. Introduced species were
the dominant biota at many sites, which complicated
analyses. Additional analyses will be conducted when
YR2001 data are available.
Sediment-MTBE
Interactions at a Full Scale Site in Montana: Natural
Attenuation and Toxicity
Ronald
C. Sims
and Aaron Swank, Utah Water Research Laboratory,
Utah State University, Logan, Utah, Tel: 435-797-3157,
Fax: 435-797-3663, Email: rcsims@cc.usu.edu
The study site for
this project is a gasoline station on the Flathead Indian
Reservation in Ronan, MT that leaked methyl tertiary-butyl
ether (MTBE) from an underground storage tank in 1993.
MTBE has moved 450 m from the source area to Spring Creek,
and biodegradation has been observed in the groundwater/
surface water interface (GSI) zone. The Montana
Department of Environmental Quality is interested in an
evaluation of the potential application of monitored
natural attenuation (MNA) for treatment of the
contaminated aquifer. Research at the UWRL has focused
on two specific aspects of MTBE MNA at the Ronan site: (1)
toxicity of MTBE and metabolites, and reduction in
toxicity as a result of biotransformation, and (2) rate of
biotransformation of MTBE as affected by seasonal changes
in temperature at the site. The measured Microtox Acute
toxicity EC50 value for MTBE was 12 mg/l; for the
intermediate tertiary butyl-alcohol was 3,580 mg/L. MTBE
concentrations at the site range from 80 mg/L near the
source area to ppb levels near Spring Creek. The
Bio-Noble flash assay was also used to determine the
toxicity of aquifer sediments, and all sediments near and
within the GSI zone exhibited no toxicity to the test
microorganisms. Results indicate a detoxification pathway
for the transformation from MTBE to
TBA. Bio-kinetic values were determined for MTBE
biodegradation over the temperature range typical for the
Ronan site, and this information was used along with
ground water velocity values to evaluate the effect of
temperature and flow on the rate and extent of MNA.
Results demonstrated that MNA for MTBE at the Ronan site
is influenced by toxicity and by temperature and ground
water flow.
Potential for Dehalogenation of Dioxins in Marine and
Estuarine Sediments
Donna
E. Fennell,
Department of Environmental Sciences, 14 College Farm
Road, Room 231, ENR, Rutgers University, New Brunswick, NJ
08901, Tel: 732-932-8750, Fax: 732-932-8644
Email: dfennell@aesop.rutgers.edu
Young-Beom
Ahn,
Department of Biochemistry and Microbiology, 76 Lipman
Drive, Room 222 Lipman Hall, Rutgers University, New
Brunswick, NJ 08901, Tel: 732-932-9763 ext. 222, ext. 321
Fax: 732-932-8965, Email: ybahn@aesop.rutgers.edu
Lee
J. Kerkhof,
Institute of Marine and Coastal Sciences, Cook College,
Rutgers, The State University of New Jersey, 305C Marine
Sciences Building, 71 Dudley Road, New Brunswick, NJ
08901-8525
Tel:
732-932-6555 ext. 335, ext. 317, Fax: 732-932-6520, Email:
kerkhof@imcs.rutgers.edu
Max
M. Häggblom,
Department of
Biochemistry and Microbiology and The Biotechnology Center
for Agriculture and the Environment, Rutgers, The State
University of New Jersey, 76 Lipman Drive, Room 326 Lipman
Hall, New Brunswick, NJ 08901-8525, Tel: 732-932-9763 ext.
321, ext. 326, Fax:
732-932-8965, Email: haggblom@aesop.rutgers.edu
The
ability of native microbial communities to transform
dioxin congeners was investigated in sediments from San
Diego Bay, CA and Arthur Kill, NY/NJ, among others.
We tested various electron donors and alternate
halogenated substrates—“haloprimers”—to determine
their relative effectiveness for stimulation of the
dehalogenation of polychlorinated dibenzo-p-dioxins and
furans (PCDD/Fs). Substrates
with analogous chemical structures to the dioxins, e.g.
halophenols, halobenzenes, and haloanisoles were used as
haloprimers. The
haloprimers have far greater solubilities than that of
dioxin and could serve to selectively stimulate a
population of dehalogenating bacteria that could, in turn,
dehalogenate PCDD/Fs. Stimulation of dehalogenation was
attempted under methanogenic and sulfate-reducing
conditions. Dechlorination
of PCDD proceeded to a much greater extent under
methanogenic conditions than sulfate-reducing conditions.
Enrichments supplied with haloprimers showed more
extensive dechlorination than those without haloprimers
did. Addition
of haloprimer plus electron donor resulted in more rapid
onset of dioxin dehalogenation than addition of electron
donor alone. Furthermore, the structure of the haloprimer
had a significant impact on the time required for onset of
PCDD/F dehalogenation. Bioprocess modeling and
biomolecular community structure analysis are being used
to further our understanding of the microbial populations
responsible for the dehalogenation in these systems. In
the future, a combination of in situ treatment, natural
attenuation, sequestration/capping, and dredging of
hotspots will most likely accomplish sediment restoration. In situ bioremediation of PCDD/Fs may offer one alternative
for cleanup of contaminated areas.
Top
|
