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Combined
Abiotic and Biotic Dechlorination of TCE in a Low
Permeability Aerobic Aquifer
Edward Sullivan, The Whitman Companies, Inc., East
Brunswick, NJ
Impact
of Crude Oil Bioremediation in Soil on Groundwater Quality
James L. Brown, Lockheed Martin/REAC, Edison, NJ
Combined
Use of EHC™ plus KB-1™ Dehalococcoides Inoculant for
Accelerated ISCR- First Full-Scale Field Application in
Ohio, USA
Josephine Molin, Adventus Americus, Inc., Freeport, IL
Bioremediation
of Hexahydro-1,3,5-trinitro-1,2,5-triazine (RDX) and
1,3,5,7-tetranitroperhydro-1,3,5,7-tetrazocine (HMX)-
Contaminated Sediments
Man Jae Kwon, University of Illinois at
Urbana/Champaign, Urbana, IL
Bioremediation
of Soil Contaminated with Organolead Compounds -
Laboratory and Field Studies
Josef Winter, Universität Karlsruhe, Karlsruhe,
Germany
Anaerobic
Bioremediation Results Lead to Alternative Cleanup Levels
for Chloroethane Contaminated Groundwater at Connecticut
Site
Michael E. Miller, Camp Dresser & McKee, Inc.,
Cambridge, MA
Combined
Abiotic and Biotic Dechlorination of TCE in a Low
Permeability Aerobic Aquifer
Edward Sullivan, P.G.,
The Whitman Companies, Inc., 116 Tices Lane, Unit B-1,
East Brunswick, New Jersey. Tel. 732-30909-5858, Fax 732-30909-09466, Email:
esullivan@whitmanco.com
Daniel W. Elliott, Ph.D., The Whitman Companies, Inc., 116
Tices Lane, Unit B-1, East Brunswick, New Jersey. Tel. 732-30909-5858, Fax 732-30909-09466,
delliot@whitmanco.com
Christopher DelMonico, The Whitman Companies, Inc. etc.
116 Tices Lane, Unit B-1, East Brunswick, New Jersey. Tel. 732-30909-5858, Fax 732-30909-09466, Email:
cdelmonico@whitmanco.com
Eric C. Hince; Geovation Consultants, Inc., 468 Route 17A,
Florida, NY, 10921, Tel: 845-651-4141, Fax: 845-651-0040,
Email: echince@geovation.com
A pilot study was conducted
using nanoscale zero valent iron (nZVI) and emulsified soy
oil to promote dual abiotic/biotic degradation of TCE in
groundwater at a site in New Jersey.
Most of the contaminant mass is bound within a low
permeability silt unit situated at a depth of
approximately 20 feet. Aqueous TCE concentrations of up to 230 mg/L were present
within the silt unit whereas concentrations in the
overlying more permeable sandy unit were two orders of
magnitude lower. Prior
to the injection of the amendments ORP and DO levels
indicated aerobic conditions, there was little to no
evidence that biodegradation was occurring and low pH
levels were likely inhibiting microbial activity.
The nZVI and emulsified oil
were injected into three injection points which targeted
the silt unit. Pneumatic
and hydraulic fracturing techniques were used to enhance
the distribution of the amendments.
Within days after the injections, ORP and DO levels
dropped significantly to levels as low as -500 mV and
indicated anoxic conditions in the range of sulfate
reduction to methanogenesis had been achieved.
In addition, pH levels had increased to near
neutral.
Six months after the
injection ORP levels were still below -100 mV and continue
to decrease downgradient of the pilot study area, and DO
levels are still anoxic.
Post-injection VOC data showed a significant drop
in TCE concentrations in the injection area deep well
(MW-17D) from 241 mg/L to 13 mg/L by month six.
Concentrations of c-DCE increased from ND to 450
mg/L in MW-17D indicating the near complete transition of
TCE to c-DCE had occurred at that location by month six.
Post-injection TCE
concentrations increased significantly in the sand unit
(from 1.4 mg/L to 220 mg/L by month two) indicating that
the fracturing techniques and/or the surfactant properties
of the oil emulsion had mobilized TCE mass from the silt
unit. An
electrical imaging (EI) survey and molar concentration
trends confirmed that TCE mass had been mobilized.
However, by month six, TCE concentrations had
dropped significantly to 0.12 mg/L.
Concentrations of c-DCE and ethene increased
appreciably indicating the complete dechlorination of the
mobilized TCE mass is taking place.
Fluorescence in-situ
hybridization (FISH) and microscopic counts of Firmicutes
(suspected fermenting bacteria), Deltaproteobacteria
and Dehalococcoides
ethenogenes (D.
ethenogenes) indicated that an anaerobic consortium
capable of microbial dechlorination of TCE developed in
response to the nZVI-oil injections.
Total cell counts (DAPI staining) indicated that
microbial populations increased by one to two orders of
magnitude in the treatment zone groundwater after the
injections. After
the initial increase, D.
ethenogenes counts were seen to decrease in months
three through six of the study.
The decrease in D. ethenogenes counts combined with an increase in CO2 and
methane concentrations could indicate that anaerobic
oxidation of VC and c-DCE may be occurring.
Impact
of Crude Oil Bioremediation in Soil on Groundwater Quality
James L. Brown, Lockheed Martin/REAC, 2890
Woodbridge Avenue, Edison, NJ 08837, Tel: 732-494-4060,
Fax: 732-404-4021, Email: james.l.brown@lmco.com
Harry Allen, U.S. EPA/ERT, 2890 Woodbridge Avenue, Edison,
NJ 08837, Tel: 732-321-6747
Email: allen.harry@epa.gov
Crude oil-contaminated soil
in oil well fields of western NY is currently being
treated in on-site bioremediation treatment cells.
The goal is to develop simple, effective, low-cost
bioremediation methods suitable for use by small,
independent oil producers in NY and PA.
Guidelines for treating spilled crude oil in soil
must address the potential for groundwater contamination.
A laboratory study was conducted to simulate
construction and operation of a bioremediation treatment
cell immediately after an inland crude oil spill. The study represents a worst-case scenario for adverse
groundwater impacts during treatment.
The simulation included mixing TPH-soil with
bulking agents prior to treatment.
Thereafter, soil was undisturbed.
Soil for the study was obtained from an Allegany,
NY bioremediation treatment cell where treatment was
complete. Treated
soil from the site contained less than 1% total petroleum
hydrocarbons (TPHs), and non-detectable levels of 4-6 ring
polycyclic aromatic hydrocarbons (PAHs).
This soil was spiked with 1%, 2%, 3%, 4% and 5%
fresh crude oil. Results
from these treatments were compared to results from the
unspiked control. Soil
was fertilized and limed in accordance with current EPA/REAC
draft guidelines for bioremediation treatment cells.
After spiking with crude oil, soil was lightly
mixed eight times over two days.
Each mixing event required less than one minute.
Between mixing events, soil was placed in test
columns and tamped down to a bulk density of 1.0 g/cc.
Fifteen cm of this soil was placed over 40 cm of
sand in glass cylinders 55 cm in height, with an inside
diameter of 7.5 cm. Columns
contained permeable, fritted glass bottoms with built-in
funnels for leachate collection.
Soil remained static during
the study. Test
columns were seeded with a mixture of four TPH-tolerant
grasses: annual ryegrass (Lolium multiflorum),
perennial ryegrass (L. perenne), tall fescue (Festuca
arundinacea), and oats (Avena sativa).
The study duration was 16 weeks.
Leachate was sampled
after 1, 2, 4, 8 and 16 weeks.
A special sampling device was used to prevent loss
of volatile compounds during sampling.
Samples were analyzed for benzene, toluene,
ethylbenzene, and xylenes (BTEX).
The highest BTEX concentrations in leachate were
recorded, and compared to permissible concentrations under
the federal Safe Drinking Water Act. Benzene was of
greatest concern due to its 5 Fg/L drinking water
standard.
Benzene
was present at 582 mg/L in crude oil used for this test.
When soil was mixed to simulate addition of bulking
agents, benzene volatilized completely.
Therefore, benzene was not detectable in any
leachate samples. Toluene,
ethylbenzene and xylenes did remain in soil after mixing.
These compounds were present in leachate, but at
concentrations well below federal drinking water
standards. Results
of this study indicate there may be no adverse impact to
groundwater during bioremediation of freshly spilled crude
oil in soils of NY and PA.
Combined
Use of EHCTM plus KB-1TM Dehalococcoides
Inoculant for Accelerated ISCR – First Full-Scale Field
Application in Ohio, USA
Josephine
Molin,
Environmental Engineer, Adventus Americas, Inc., 2871 W.
Forest Road,
Suite 2,
Freeport, IL 61032, Tel: 815-235-3503, Fax: 815-235-3506,
Email: jmolin@adventus.us
Jim Mueller, Director of Remedial Solutions &
Strategies, Adventus Americas, Inc., 2871 W.
Forest
Road, Suite 2, Freeport, IL 61032 Tel: 815-235-3503, Fax:
815-235-3506, Email:
jmueller@adventus.us
Robin Corzatt, Project Manager, Hull & Associates,
Inc., 6397 Emerald Parkway, Suite 200,
Dublin,
OH 43016, Tel: 614-793-8777, Fax: 614-793-9070, Email:
rcorzatt@hullinc.com
James W. Smith, P.E., Senior Project Manager, T H
Agriculture & Nutrition, L.L.C. 15313 West
95th
Street, Lenexa, KS 66219, Tel: 913-888-2922, Email:
JSmith8211@aol.com
Groundwater
at a former manufacturing facility in Ohio is impacted by
TCE (370 to 750 ug/L; remedial objective = 5 ug/L) and its
recognized anaerobic daughter products 1,2-DCE (2,800 to
5,200 ug/L; remedial objective = 70 ug/L) and VC (390 to
510 ug/L; remedial objective = 2 ug/L). Groundwater
collection trenches totaling over 330 ft in length were
previously constructed downgradient of the suspected
source areas. The trenches measure about 2 ft wide and are
filled with washed river gravel from about 5 to 12 ft bgs.
The groundwater table is generally at 6 ft bgs. EHCTM was injected into the gravel zone to convert the
existing trenches into in situ permeable reactive barriers
(PRB) that would treat the groundwater as it flows through
the reactive zones. In February 2006, a total of 11,850
lbs of EHC was injected into a total 30 injection points
strategically located about 10 ft off-center throughout
the existing trenches. Each injection point received about
400 lbs of EHC delivered as 170 to 230 USG of slurry
containing between 19 to 25% solids, resulting in an EHC
application rate of 2.7 to 5.3% to soil mass within the
trenches.
Immediately,
following the EHC injections, KB-1TM Dehalococcoides inoculum (SiREM)
was added to better ensure fast removal of cis-DCE.
Approximately 800 ml of concentrated cell KB-1 inoculant
was injected close to each of 26 EHC injection points
within two depth intervals of the trenches. The KB-1
injections employed a Geoprobe® and a drop-hose (PEtubing). Argonne gas was used to pressurize the system and the volume
injected was measured using a “syringe-type system”.
Details
of the EHC and KB-1 injection processes will be presented
along with remedial performance and cost data associated
with the remedial strategy.
Bioremediation
of Hexahydro-1,3,5-trinitro-1,3,5-triazine
(RDX) and
1,3,5,7-tetranitroperhydro-1,3,5,7-tetrazocine
(HMX)-Contaminated Sediments
Student
Presenter
Man
Jae Kwon,
University of Illinois - Urbana Champaign, Dept of Civil
and Environmental Engineering, NCEL 205 N. Mathews,
Urbana, IL, 61801, Tel: 217-333-6851, Fax: 217-333-6967,
Email: mankwon@uiuc.edu
Kevin T. Finneran, University of Illinois - Urbana
Champaign, Dept of Civil and Environmental Engineering,
NCEL 205 N. Mathews, Urbana, IL, 61801, Tel: 217-333-1514,
Fax: 217-333-6967, Email: finneran@uiuc.edu
The explosives RDX and HMX
are significant contaminants in soil and groundwater at DoD facilities.
Adsorbed mass continuously leaches into groundwater and
migrates to distal areas.
This study investigated electron shuttling
mediated-biodegradation of RDX and HMX from two
environments.
Batch experiments were performed with RDX-contaminated
aquifer sediment from Picatinny Arsenal, NJ and with
shallow-depth sediment contaminated by both RDX and HMX
from Joliet, IL. Several
different electron acceptors/shuttles including humic
substances (HS) and anthraquinone-2,6-disulfonate (AQDS),
an HS analog, were incubated with
acetate as an electron donor.
In aquifer sediment catalytic concentrations of
AQDS and HS stimulated RDX reduction; RDX was below detect
in 20 and 45d with AQDS and HS, respectively; nitroso
metabolites did not accumulate in these incubations.
Acetate alone did not stimulate the same rate of RDX
degradation; 58mM RDX decreased to only 45mM
during the first 60d and the nitroso metabolites
accumulated in the absence of electron shuttles. RDX was
not reduced in sterilized or unamended sediment
incubations.
In Joliet sediment RDX has been reduced by 20% within 45d in
the presence of both acetate and HS, likely due to higher
initial RDX concentration. The initial concentrations of
RDX (150mg/kg) and HMX (28mg/kg) are higher than their
water solubility (RDX: 40mg/l;
HMX: 6mg/l). Therefore adsorbed
mass may continuously partition into the aqueous phase
until equilibrium. HMX
has not been reduced, suggesting that HMX is more
recalcitrant than RDX.
These results indicate that indigenous
microorganisms in sediments can utilize electron shuttles
to stimulate RDX/HMX biodegradation. This strategy will
provide rapid and effective reduction of explosives in
contaminated systems. Upcoming experiments will include
DNA quantification using real-time PCR and total microbial
community analysis using amplified rDNA restriction
analysis (ARDRA) to identify the dominant microorganisms
associated with HS-mediated RDX/HMX biotransformation.
Bioremediation
of Soil Contaminated with Organolead Compounds -
Laboratory and Field Studies
C.
Gallert, PD Dr. rer. nat. habil., Dept. Biology for Engineers and Biotechnology of Wastewater,
University Karlsruhe, Am Fasanengarten, 76128 Karlsruhe,
Tel: 0721-6083274, Email: Claudia.Gallert@iba.uka.de
J. Winter, Prof. Dr. rer. nat. habil., Dept.
Biology for Engineers and
Biotechnology of Wastewater, Faculty of Civil Engineering,
Universität Karlsruhe, Am Fasanengarten, D-76128
Karlsruhe, Tel: 0721-6082297, Fax: 0721- 694826, Email:
Josef.Winter@iba.uka.de
Tetraethyllead (TEL) and
tetramethyllead (TML) were produced world-wide as
anti-knocking additives for gasoline to increase octane
numbers, causing an ubiquiteous pollution with
tetraalkyllead (TAL) compounds and derivatives. For
gasoline production in 1970 in the United States of
America 279000 metric tons of organolead were comsumed.
Another 326000 metric tons of organolead compounds were
added worldwide to improve the burning quality of
gasoline. Since the 1980´s the TAL in gasoline was
replaced by methyl-tertiary-butylether (MTBE). In future
the MTBE in unleaded gasoline presumably may be replaced
by ethanol.
Whereas an ubiquiteous
distribution of low concentrations of organolead compounds
and of much higher amounts of inorganic lead was caused by
car exhaustive gases in the upper layers of soil,
spillages of highly toxic tetraalkyllead (TAL) compounds
during production, transportation or blending at oil
refineries and petrol stations caused more severe soil and
groundwater contaminations.
In Germany TEL and TML were
manufactured by two chemical factories until the end of
the 1980´s. At both production sites significant amounts
of organolead compounds were spilled and drained into the
underground and still endanger the aquifer. The subsurface
soil contains mainly fluvial sand deposits with a
hydraulic conductivity of 3.5 x 10-4 m s-1.
On average, groundwater saturation starts about 3 m below
the ground level and the groundwater flow is about 70 m.year-1.
Little oxygen is found in the groundwater upstream and no
oxygen in the groundwater downstream of the industrial
site.
Spillage of tetraethyl lead
(TEL) and tetramethyl lead (TML) caused severe soil and
groundwater contaminations at all TEL manufacturing sites
and at gasoline distribution stations not only in Germany,
but also in other gasoline producing countries (e.g. in
Italy, etc.). During the regular production process
volatile alkyl lead compounds were absorbed from the
off-gas of TEL or TML production sites by the use of
heavy-boiling oil fractions (hydrocarbons). The oily TEL
or TML concentrates or TEL-/TML-containing production
fluids were apparently spilled by inaccurate handling and
migrated into the underground.
The nonionic TEL is stable in
heavy oil phases but is unstable in moist soil and, once
it is dispersed in the water phase, is subjected to
chemical and/or biological dealkylation reactions. The
first dealkylation products are very stable ionic, water
soluble tri- and dialkyl lead compounds, which are motile
in the water-saturated zone and cause a severe groundwater
problem. The conversion of organolead compounds by
degradation of the alkyl moieties into inorganic, less
toxic lead (succeded by immobilisation of the Pb-ions to
PbCO3 or Pb5PO4Cl)
reduces the environmental risk.
Suitable conditions for
chemical and microbiological transformation of alkyl lead
to inorganic lead may allow in situ remediation of
contaminated sites. Microbiological dealkylation of
organolead compounds was reported in laboratory and field
studies. However, the biological oxidation required an
electron acceptor such as oxygen.
In a laboratory study, 10-L
glass columns were filled with TEL contaminated soil (~
300 mg TEL/kg soil and ~ 530 mg oil hydrocarbons/kg soil)
from a TEL/TML-manufactoring site and dealkylation
activity was monitored. In each of three parallel columns
oxygen-saturated water (ca. 30 mg O2/L;
saturation with pure oxygen) or oxygen-saturated water
plus a mineral mix to supply essential minerals for the
microorganims was circulated to improve the conditions for
the autochthonic soil microflora. At a pumping rate of 2.2
l per day and a retention time of the water/mineral mix in
the columns of 1.4 days oxygen limitation was prevented.
The formation and degradation of the tri- and dialkylated
species in the circulating water was observed with time.
Measurement of oxygen levels in the water leaving the
columns with mineral addition revealed a much lower
residual oxygen concentration of 2.8 – 3.6 mg/l compared
to the leachate of the columns with just water circulation
(13.4 mg/l). This indicated an accelerated respriation
activity and therefore an enhanced microbial activity in
the nutrient-enriched soil environment.
The soil columns were run more
than two years at different alkyllead concentrations. Most
of the tetra- and trialkyllead was chemically converted
and microbiologically degraded to inorganic lead
precipitates, carbon dioxide and water. A significant
viable population of microorganisms was found in the
columns desipte of the alkyllead toxicity and the poor
supply with nutrients and a suitable carbon source even
after 3 years.
At the contaminated site, the
groundwater was enriched with oxygen by air injection
through air-injection wells. Air injection caused a
groundwater circulation and the oxygen-enriched
groundwater led to a degradation of the TEL/TML-contaminants.
For final sanitation of the
alkyllead-contaminated site, the hot spot of the
contamination was excavated and thermally purified. The
heated soil was refilled in order to reduce the time
requirement for biological sanitation. The residual
groundwater pollution downstream of the polluted site was
treated by pumping out the groundwater through groundwater
wells at the end of the industrial area, oxygen-treatment
of the groundwater that contained still low levels of tri-
and di-alkyllead compounds in a special basin and
re-infiltration at the upstream end of the area for final
microbial purification in the soil .
Anaerobic
Bioremediation Results Lead to Alternative Cleanup Levels
for Chloroethene Contaminated Groundwater at Connecticut
Site
Michael E. Miller, CDM, 50 Hampshire Street,
Cambridge, MA, 02139, Tel: 617-452-6295, Fax:
617-452-8295, Email: millerme@cdm.com
Kevin P. Molloy, CDM, 50 Hampshire Street, Cambridge, MA,
02139, Tel: 617-452-6328, Fax: 617-452-8328, Email:
molloykp@cdm.com
William K. Glynn, CDM, 50 Hampshire Street, Cambridge, MA,
02139, Tel: 617-452-6280, Fax: 617-452-8280, Email:
glynnwk@cdm.com
Trichloroethene (TCE) in the groundwater beneath a
manufacturing facility in Connecticut is being treated
utilizing a combined system of in situ enhanced anaerobic
bioremediation (EAB) and groundwater control with the old
pump and treat system.
EAB was initiated by injection of sodium lactate
(carbon source) into the upgradient third of the
contaminant plume. Simultaneously,
groundwater control was maintained with an extraction well
located at the downgradient property boundary, with tray
aerator and activated carbon treatment. Horizontal wells
from the old pump and treat system were also utilized to
enhance delivery of the carbon source.
At the start of biostimulation, TCE concentrations
ranged from 5,000 ug/L to 20,000 ug/L. Within one year, more than 50% of the TCE was transformed
into cis-1,2-dichloroethene and vinyl chloride, while
final daughter product ethene concentrations reached as
high as 700 ug/L. The
pilot test results indicated that the treatment time could
be reduced by over 20 years and save up to $600,000, in
comparison to continued operation of the original
groundwater pump and treat system. Similar application of
EAB to the remainder of the plume is planned.
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