Sponsored
by API
To
Degrade or Not To Degrade: Isotopic and Microcosm
Evidence for Anaerobic Biodegradation of TBA
David
Hull, LFR Inc.,
Braintree, MA
The
Utility of Stable Isotope Analysis: Lessons Learned from
Numerous Practical Applications to the Management of Fuel
Oxygenate Contamination
Joseph E. Haas II, New York State Department of
Environmental Conservation, Stony Brook, NY
Biodegradation
of Tert-Butyl Alcohol by Mixed Culture KR1
Kimberly M. Reinauer, University of Illinois- Urbana
Champaign, Urbana, IL
U.S.
Operating Experience with Biologically-Active GAC Systems
for MTBE and TBA Treatment
T. Ebihara, LFR Inc., Elgin, IL
Ex Situ Bioreactor Treatment of
Tertiary Butyl Alcohol at a New Hampshire Site
Joseph E. O’Connell, Environmental Resolutions, Inc.,
Lake Forest, CA
Pulsed Air Sparging for MTBE and TBA
Source Zone Remediation
Xiaomin Yang, Atlantic Richfield Company, A BP
affiliated company, Warrenville, IL
To
Degrade or Not To Degrade: Isotopic and Microcosm
Evidence for Anaerobic Biodegradation of TBA
David H. Hull P.G.,
LFR Inc., 4190 Douglas Boulevard, Suite 200, Granite Bay
CA 95746, Tel: 916-786-0320, Email: david.hull@lfr.com
Eric M. Nichols P.E., LFR Inc., 78 Piscassic
Road, Newfields NH 03856, Tel: 603-773-9779, Email:
eric.nichols@lfr.com
Rick Ahlers P.E., LFR Inc., 3150 Bristol St., Suite 250,
Costa Mesa CA 92626, Tel: 714-444-0111, Email:
rick.ahlers@lfr.com
Scott Martin P.G., Kinder Morgan Energy Partners, L.P.,
1100 Town & Country Road, Orange CA 92868,
Tel: 714-560-4775, Email: scott_martin@kindermorgan.com
Recent laboratory and field
evidence concerning aerobic and anaerobic biodegradation
of MTBE and TBA suggest that MTBE is biodegraded in
groundwater under both aerobic and anaerobic conditions,
and that TBA is degraded primarily under aerobic
conditions. Evidence cited includes temporal and
spatial concentration trends and ratios of contaminants of
concern, relationships between various biogeochemical
parameters, and laboratory microcosm data. More
recently, compound-specific stable isotope analysis has
been useful for providing evidence for and discrimination
between aerobic and anaerobic biodegradation of MTBE.
Anaerobic biodegradation of MTBE produces relatively large
enrichment in heavy carbon and hydrogen isotopes; whereas,
aerobic biodegradation of MTBE produces relatively less
enrichment in heavy carbon isotopes, but relatively large
enrichment in heavy hydrogen isotopes. As compared to MTBE,
evidence for biodegradation of TBA under strongly
anaerobic conditions is less abundant.
This paper presents a
summary of evidence collected from a large-scale MTBE and
TBA groundwater plume in southern California. Redox
conditions within the plume vary depending on location
with respect to the plume core and to the source zone.
Groundwater in the source zone exhibits strongly anaerobic
conditions (methanogenic, and sulfate and iron reducing)
where petroleum hydrocarbons and BTEX compounds, in
addition to MTBE and TBA, are both present and absent at
various locations. More moderately anaerobic
conditions (nitrate reducing) to mildly aerobic conditions
predominate near the plume fringes. Data analysis
from these various plume areas includes historical
contaminant concentration trends, TBA:MTBE ratios,
biogeochemical parameters, MTBE and TBA biodegradation
by-products analysis including HIBA, and stable carbon and
hydrogen isotope ratios for MTBE and TBA. Data from
representative aerobic and anaerobic respirometric
microcosms will also be presented, including microbial
speciation and degradation capabilities and enrichment of
stable isotopes. Evidence for anaerobic degradation
of TBA will be discussed.
The
Utility of Stable Isotope Analysis: Lessons Learned from
Numerous Practical Applications to the Management of Fuel
Oxygenate Contamination
Joseph E. Haas II, New
York State Department of Environmental Conservation, SUNY
Building Number 40, Stony Brook, NY, 11790-2356, Tel:
631-444-0332, Fax: 631-444-0328, Email: jehaas@gw.dec.state.ny.us
The analysis of the ratios
of the stable isotopes of carbon and the ratios of the
stable isotopes hydrogen has gained creditability as a
tool to assess and or to quantity the potential role of
biodegradation at sites contaminated with fuel oxygenates
such as Methyl Tertiary Butyl Ether (MTBE). The utility of
such analysis to the management of such contamination is a
function of many factors not the least of which are the
cost and availability of analytical services, the
reliability of the data and the usefulness of the data in
revealing and or supporting the appropriate the role of
biodegradation as a practical component of the overall
management of the contamination.
Stable isotope data has
recently been acquired and the analysis applied to the
management of fuel oxygenates contamination at a number of
well-characterized sites in Long Island New York. The
stable isotope work was undertaken in conjunction with the
management decision-making for the sites in which
biodegradation was likely to be a component of varying
importance. The importance of the analysis of the stable
isotope data with respect to the management of the
contamination ranged from a low of supplying an additional
line of evidence of the functionality of biodegradation to
a high of being the basis of the quantification of the
biodegradation rate needed as a key component of a
monitored natural attenuation strategy.
The methods and utility of
the application of the analysis to the management of each
site is detailed including information on the development
of sampling plans, the cost and availability of analytical
services, the reliability of the data and the usefulness
of that data with respect to the role of biodegradation as
a practical component of the overall management of the
contamination.
Biodegradation
of Tert-Butyl
Alcohol by Mixed Culture KR1
Student
Presenter
Kimberly M. Reinauer,
University of Illinois- Urbana Champaign, Dept. of Civil
and Environmental Engineering, NCEL 205 N. Mathews,
Urbana, IL, 61801, Tel: 217-333-8121, Fax: 217-333-6967,
Email: kreinau2@uiuc.edu.
Xiaomin Yang, Atlantic Richfield Company, BP, Mail Code
2N, 28100 Torch Parkway, Warrenville, IL 60555 Tel:
630-836-7176, Fax: 630-836-7193, Email: Xiaomin.Yang@bp.com
Kevin T. Finneran, University of Illinois- Urbana
Champaign, Dept. of Civil and Environmental Engineering,
NCEL 205 N. Mathews, Urbana, IL, 61801 , Tel:
217-244-7956, Fax: 217-333-6967, Email: finneran@uiuc.edu
Tert-butyl
alcohol (TBA), a metabolite of methyl tert-butyl
ether (MTBE) and a fuel oxygenate, is often considered
recalcitrant in contaminated groundwater and a rate
limiting step in MTBE degradation.
TBA is miscible in water; it is difficult to treat
with traditional air sparging or adsorption techniques.
Biofilms that form on granular activated carbon (GAC)
units can degrade TBA.
The goal of this work was to optimize TBA
degradation in a Bio-GAC reactor as part of a pump and
treat system for contaminated groundwater.
A mixed culture, KR1,
was enriched from a GAC sample in a bicarbonate-buffered
freshwater media. Transfers
over a one month period enriched a culture that degrades
TBA under growth conditions as the sole carbon and energy
source and is physiologically different than other
cultures enriched from the same GAC material.
TBA was degraded to 10% of the initial
concentration (2mM) within 5 days after initial
inoculation and continuously degrades within 1 day of
re-amendment. Resting
cell suspensions mineralized 70% of the TBA within 12
hours. Mineralization
data suggest that transformation will not stop at
intermediate metabolites but rather continue to innocuous
end products. Performance
optimization with resting cells was conducted to
investigate kinetics and extent of TBA degradation as
influenced by oxygen, pH and temperature.
Culture longevity was investigated, and cultures
starved for periods of 7, 14, and 21 days were able to
degrade TBA, indicating that the culture will recover
after periods of no TBA loading.
Current work focuses on
isolating a pure culture from the enrichment that
effectively degrades TBA.
A packed bed GAC reactor will be developed using
KR1, or isolate, as an inoculum for continuous treatment
of low concentration TBA.
This work will investigate inoculation strategies,
oxygen delivery and substrate interactions, which will
then be extrapolated to a full-scale pump and treat
system.
U.S.
Operating Experience with Biologically-Active GAC Systems
for MTBE and TBA Treatment
Tatsuji
Ebihara,
LFR Inc., 630 Tollgate Road, Elgin, IL, Tel: 847-695-8855,
Fax: 847-695-7799, Email: tat.ebihara@lfr.com
Ten field applications of
biologically-active granular activated carbon (BioGAC)
systems were evaluated for the purpose of developing
operating guidelines for reliable ex
situ treatment of oxygenate-impacted groundwater. Average
flow rates of these systems ranged from 1 to 65 gallons
per minute (gpm). Average influent methyl tertiary-butyl
ether (MTBE) concentrations ranged from 0.003 to 3.7 mg/L
and average tertiary-butyl alcohol (TBA) concentrations
ranged from 0.016 to 2.5 mg/L. These systems reliably
achieved non-detectable effluent concentrations of
petroleum hydrocarbons and ethers, and less than 30 to 40
mg/L TBA. In some cases high influent organic
concentrations led to transient oxygen limitation
conditions and temporarily elevated TBA concentrations in
the effluent of the first or second stage of the BioGAC
process. Despite these transient conditions, the effluent
of the final stage of the BioGAC process achieved less
than 30 to 40 mg/L TBA. The most critical parameter for
proper operation of BioGAC systems was the maintenance of
dissolved oxygen (DO) conditions within the lead BioGAC
bed and subsequent GAC beds in series.
Pulsed
Air Sparging for MTBE and TBA Source Zone Remediation
Xiaomin Yang,
Atlantic Richfield Company, A BP affiliated company. 28100
Torch Parkway, MC 2N, Warrenville, IL 60555. Tel: (630)
836-7176. Email: Xiaomin.Yang@bp.com
Shankar Subramanian,
URS Corporation. 100 South Wacker Suite 500, Chicago, IL
60606. Tel: (312) 577-7410. Email: Shankar_Subramanian@URSCorp.com
Timothy Dull, URS Corporation. 100 South Wacker Suite 500,
Chicago, IL 60606.
Tel: (312) 697-7227. Email: Timothy_Dull@URSCorp.com
Thomas Tunnicliff, Atlantic Richfield Company, A BP
affiliated company. Tel: (618) 254-9074. Email: thomas.tunnicliff@BP.com
Greg Jevyak, Atlantic Richfield Company, A BP affiliated
company. Tel: (618) 254-9866. Email: gregory.jevyak@BP.com
The effectiveness of pulsed
air sparging on MTBE and TBA removal from source area was
investigated in a pilot scale study. The results suggested
that pulsed air sparging is a viable, cost effective
technology to remediate MTBE and TBA contaminated soil and
groundwater. The data collected also provide reliable
engineering design basis of a pulsed air sparging system
to treat MTBE/TBA in soil and groundwater. Numerous
parameters were monitored to evaluate the groundwater MTBE
and TBA reduction rates and to understand the removal
mechanisms – volatilization vs. aerobic biodegradation.
The MTBE first order reduction rate constants
ranged from 0.04 per day to 0.06 per day in the
MTBE source area while the benzene reduction rate
constants varied from 0.04 per day to 0.07 per day. The
effectiveness of pulsed air sparging on benzene and MTBE
treatment was approximately equal. MTBE at more than 10
ppmv level was also detected in the soil vapor collected
from the headspace of groundwater monitoring points,
indicating material contribution of MTBE volatilization to
the total MTBE removal. As an intermediate product of MTBE
aerobic biodegradation, TBA accumulated in groundwater in
the first six months of the pulsed air sparging operation.
MTBE carbon and hydrogen stable isotope ratio analysis was
also conducted to verify the MTBE aerobic biodegradation.
TBA concentration started to decrease after six months of
air sparging, and its reduction rates were between 0.05
per day to 0.08 per day, and TBA aerobic biodegradation is
the dominating mechanism of TBA removal. In addition, the
field observations suggested that the pulsed operation
dramatically eased, if not eliminated, the groundwater
depletion created injecting air into subsurface, thus
mitigating the risk of groundwater spread and alleviating
MTBE rebound potential. We believe that this is the set of
field supporting this speculation.
Top
|
