Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer
Paul B. Hatzinger A F , John Karl Böhlke B , Neil C. Sturchio C , Baohua Gu D , Linnea J. Heraty C and Robert C. Borden E
A Shaw Environmental, Inc., Lawrenceville, NJ 08648, USA.
B US Geological Survey, Reston, VA 20192, USA.
C University of Illinois at Chicago, Chicago, IL 60607, USA.
D Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
E North Carolina State University, Raleigh, NC 27695, USA.
F Corresponding author. Email: email@example.com
Environmental Chemistry 6(1) 44-52 http://dx.doi.org/10.1071/EN09008
Submitted: 15 January 2009 Accepted: 2 February 2009 Published: 3 March 2009
Environmental context. Perchlorate (ClO4–) and nitrate (NO3–) are common co-contaminants in groundwater, with both natural and anthropogenic sources. Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater. Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations. However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions. In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4– (Cl and O) and NO3– (N and O) resulting from biodegradation in an aquifer.
Abstract. An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br– as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (ε18O/ε37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ~0.8 (ε18O/ε15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (ε18O/ε37Cl, ε18O/ε15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent ε values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.
Brandhuber P., Clark S., Perchlorate Occurrence Mapping 2005 (American Water Works Association: Washington, DC).
Dasgupta P. K.Dyke J. V.Kirk A. B.Jackson W. A.2006Perchlorate in the United States: analysis of relative source contributions to the food chain.Environ. Sci. Technol.406608doi:10.1021/ES061321Z
Rajagopalan S.Anderson T. A.Fahlquist L.Rainwater K. A.Ridley M.Jackson W. A.2006Widespread presence of naturally occurring perchlorate in high plains of Texas and New Mexico.Environ. Sci. Technol.403156doi:10.1021/ES052155I
Ericksen G. E.1983The Chilean nitrate deposits.Am. Scientist71366
Hatzinger P. B.2005Perchlorate biodegradation for water treatment.Environ. Sci. Technol.39239Adoi:10.1021/ES053280X
Stroo H., Ward C. H. (Eds), In Situ Bioremediation of Perchlorate in Groundwater 2008 (Springer: New York).
Emerging technologies for enhanced in situ biodenitrification (EISBD) of nitrate-contaminated ground water, Technology Overview Document ITRC/EISBD-1 2000 (Interstate Technology and Regulatory Cooperation Work Group). Available at http://www.itrcweb.org/Documents/EISBD-1.pdf [Verified 13 February 2009]
Performance monitoring of MNA remedies for VOCs in ground water, EPA/600/R-04/027 2004 (National Risk Management Research Laboratory, Office of Research and Development, US Environmental Protection Agency: Cincinnati, OH).
Sturchio N. C.Böhlke J. K.Beloso A. D.JrStreger S. H.Heraty L.Hatzinger P. B.2007Oxygen and chlorine fractionation during perchlorate biodegradation: laboratory results and implications for forensics and natural attenuation studies.Environ. Sci. Technol.412796doi:10.1021/ES0621849
Borden R. C., Zawtocki C. E., Lieberman M. A., Edible oil barriers for treatment of perchlorate contaminated groundwater. Final Report ER-0221 2006 (Environmental Security Technology Certification Program: Arlington, VA). Available at http://www.estcp.org/Technology/upload/ER-0221-FR-01-3.pdf [Verified 13 February 2009]
Borden R. C.2007Effective distribution of emulsified edible oil for enhanced in situ anaerobic bioremediation.J. Contam. Hydrol.941doi:10.1016/J.JCONHYD.2007.06.001
Borden R. C.2007Concurrent bioremediation of perchlorate and 1,1,1-trichloroethane in an emulsified oil barrier.J. Contam. Hydrol.9413doi:10.1016/J.JCONHYD.2007.06.002
Böhlke J. K.Sturchio N. C.Gu B.Brown G. M.Horita J.Jackson W. A.Batista J.Hatzinger P. B.2005Perchlorate isotope forensics.Anal. Chem.777838doi:10.1021/AC051360D
Tobias C. R.Böhlke J. K.Harvey J. W.2007The oxygen-18 isotope approach for measuring aquatic metabolism in high-productivity waters.Limnol. Oceanogr.521439
US Geological Survey, Reston Dissolved Gas Laboratory. Available at http://water.usgs.gov/lab/dissolved-gas/ [Verified 9 February 2009]
Gu B.Brown G. M.Maya L.Lance M. J.Moyer B. A.2001Regeneration of perchlorate (ClO4–)-loaded anion exchange resins by novel tetrachloroferrate (FeCl4–) displacement technique.Environ. Sci. Technol.353363doi:10.1021/ES010604I
Bao H.Gu B.2004Natural perchlorate has a unique oxygen isotope signature.Environ. Sci. Technol.385073doi:10.1021/ES049516Z
Sturchio N. C., Böhlke J. K., Gu B., Horita J., Brown G. M., Beloso A. D.Jr, Patterson L. I., Hatzinger P. B., Jackson W. A., Batista J., Stable isotopic composition of chlorine and oxygen in synthetic and natural perchlorate, in Perchlorate: Environmental Occurrence, Interactions, and Treatment (Eds B. Gu, J. D. Coates) 2006, pp. 93–110 (Springer: New York).
Gu B.Tio J.Wang W.Ku Y.Dai S.2004Raman spectroscopic detection for perchlorate at low concentrations.Appl. Spectrosc.58741doi:10.1366/000370204872890
Sigman D. M.Casciotti K. L.Andreani M.Barford C.Galanter M.Böhlke J. K.2001A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater.Anal. Chem.734145doi:10.1021/AC010088E
Casciotti K. L.Sigman D. M.Hastings M.Böhlke J. K.Hilkert A.2002Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method.Anal. Chem.744905doi:10.1021/AC020113W
Böhlke J. K.Mroczkowski S. J.Coplen T. B.2003Oxygen isotopes in nitrate: new reference materials for 18O : 17O : 16O measurements and observations on nitrate–water equilibration.Rapid Com. Mass Spec.171835doi:10.1002/RCM.1123
Coates J. D.Achenbach L. A.2004Microbial perchlorate reduction: rocket-fuelled metabolism.Nat. Rev. Microbiol.2569doi:10.1038/NRMICRO926
Chaudhuri S. K.O’Conner S. M.Gustavson R. L.Achenbach L. A.Coates J. D.2002Environmental factors that control microbial perchlorate reduction.Appl. Environ. Microbiol.684425doi:10.1128/AEM.68.9.4425-4430.2002
Giblin T.Herman D.Deshusses M. A.Frankenberger W. T.2000Removal of perchlorate in ground water with a flow-through bioreactor.J. Environ. Qual.29578
Farhan Y. H., Hatzinger P. B., Modeling the biodegradation kinetics of perchlorate in the presence of oxygen and nitrate as competing electron acceptors. Bioremediat. J. 2009, in press.
Coleman M. L.Ader M.Chaudhuri S.Coates J. D.2003 Microbial isotopic fractionation of perchlorate chlorine.Appl. Environ. Microbiol.694997doi:10.1128/AEM.69.8.4997-5000.2003
Sturchio N. C.Hatzinger P. B.Arkins M. D.Suh C.Heraty L. J.2003Chlorine isotope fractionation during microbial reduction of perchlorate.Environ. Sci. Technol.373859doi:10.1021/ES034066G
Cline J. D.Kaplan I. R.1975Isotopic fractionation of dissolved nitrate during denitrification in the eastern tropical North Pacific Ocean.Mar. Chem.3271doi:10.1016/0304-4203(75)90009-2
Mariotti A.Germon J. C.Hubert P.Kaiser P.Letolle R.Tardieux A.Tardieux P.1981Experimental determination of nitrogen kinetic isotope fractionation: some principles; illustration for the denitrification and nitrification processes.Plant Soil62413doi:10.1007/BF02374138
Barford C. C.Montoya J. P.Altabet M. A.Mitchell R.1999Steady-state nitrogen isotope effects of N2 and N2O production in Paracoccus denitrificans.Appl. Environ. Microbiol.65989
Granger J.Sigman D. M.Lehmann M. F.Tortell P. D.2008Nitrogen and oxygen isotope fractionation during dissimilatory nitrate reduction by denitrifying bacteria.Limnol. Oceanogr.532533
Kawanishi T.Hayashi Y.Kihou N.Yoneyama T.Ozaki Y.1993Dispersion effect on the apparent nitrogen isotope fractionation factor associated with denitrification in soil: evaluation by a mathematical model.Soil Biol. Biochem.25349doi:10.1016/0038-0717(93)90134-W
Abe Y.Hunkeler D.2006Does the Rayleigh equation apply to evaluate field isotope data in contaminant hydrology?Environ. Sci. Technol.401588doi:10.1021/ES051128P
Mariotti A.Simon B.Landreau A.198815N isotope biogeochemistry and natural denitrification process in groundwater: application to the chalk aquifer of northern France.Geochim. Cosmochim. Acta521869doi:10.1016/0016-7037(88)90010-5
Brandes J. A.Devol A. H.1997Isotopic fractionation of oxygen and nitrogen in coastal marine sediments.Geochim. Cosmochim. Acta611793doi:10.1016/S0016-7037(97)00041-0
Urbansky E. T.2002Perchlorate as an environmental contaminant.Environ. Sci. Pollut. Res.9187doi:10.1007/BF02987487
Brown G. M., Gu B., The chemistry of perchlorate in the environment, in Perchlorate: Environmental Occurrence, Interactions, and Treatment (Eds B. Gu, J. D. Coates) 2006, pp. 17–48 (Springer: New York).
Espenson J. H., The problem and perversity of perchlorate, in Perchlorate in the Environment (Ed. E. T. Urbansky) 2000, pp. 1–8 (Springer: New York, NY).
Smith R. L.Howes B. L.Duff J. H.1991Denitrification in nitrate-contaminated groundwater: occurrence in steep vertical geochemical gradients.Geochim. Cosmochim. Acta551815doi:10.1016/0016-7037(91)90026-2
Granger J.Sigman D. M.Needoba J. A.Harrison P. J.2004Coupled nitrogen and oxygen isotope fractionation of nitrate during assimilation by cultures of marine phytoplankton.Limnol. Oceanogr.491763
Lehmann M. F.Reichert P.Bernasconi S. M.Barbieri A.Mckenzie J. A.2003Modelling nitrogen and oxygen isotope fractionation during denitrification in a lacustrine redox-transition zone.Geochim. Cosmochim. Acta672529doi:10.1016/S0016-7037(03)00085-1
Böttcher J.Strebel O.Voerkelius S.Schmidt H. L.1990Using isotope fractionation of nitrate–nitrogen and nitrate–oxygen for evaluation of microbial denitrification in a sandy aquifer.J. Hydrol.114413doi:10.1016/0022-1694(90)90068-9
Sigman D. M.Granger J.DiFiore P. J.Lehmann M. M.Ho R.Cane G.van Geen A.2005Coupled nitrogen and oxygen isotope measurements of nitrate along the eastern North Pacific margin.Global Biogeochem. Cy.19GB4022doi:10.1029/2005GB002458
Young E. D.Galy A.Nagahara H.2002Kinetic and equilibrium mass-dependent isotope fractionation laws in nature and their geochemical and cosmochemical significance.Geochim. Cosmochim. Acta661095doi:10.1016/S0016-7037(01)00832-8
Morasch B.Richnow H. H.Schink B.Meckenstock R. U.2002Carbon and hydrogen stable isotope fractionation during aerobic bacterial degradation of aromatic hydrocarbons.Appl. Environ. Microbiol.685191doi:10.1128/AEM.68.10.5191-5194.2002
Meckenstock R. U.Morasch B.Griebler C.Richnow H. H.2004Stable isotope fractionation as a tool to monitor biodegradation in contaminated aquifers.J. Contam. Hydrol.75215doi:10.1016/J.JCONHYD.2004.06.003