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National Research Program

Biogeochemistry and Environmental Chemistry of Nitrogen

Some of the major unresolved questions in the biogeochemical cycling of nitrogen in soil and water concern the structure and reactivity of nitrogen in soil and aquatic humic substances, and in refractory organic matter in general. This project addresses the following questions using N-15 NMR and other techniques. 1) What are the chemical forms of nitrogen in soil organic matter, sedimentary organic matter, and the dissolved, colloidal, and particulate phases of organic matter in aquatic ecosystems? 2) How much of the nitrogen in humic substances derives from selective preservation of microbial constituents and secondary plant metabolites versus abiotic incorporation of inorganic or low molecular weight organic forms? 3) What are the abiotic reaction mechanisms through which nitrogen is incorporated into humic substances? 4) How is nitrogen in humic substances remineralized microbially or abiotically (e.g. photochemical release)? These questions relate ultimately to the specific problems of nitrate contamination in surface and groundwater, coastal eutrophication, forest decline, and the production of the greenhouse gases CO2, N2O, NO, and NO2.

 

Kevin A. Thorn

Research Chemist

National Research Program, Water Resources Discipline, United States Geological Survey

B.A. Bowdoin College, Brunswick, Maine

    

M.S., Ph.D. University of Arizona, Tucson

Research Specialization

Structure and Reactivity of Soil and Aquatic Humic Substances and Natural Organic Matter

Application of NMR Spectroscopy to Environmental Chemistry

Biogeochemical Cycling of Nitrogen in Soil and Water

Bioremediation of Nitroaromatics and Munitions

Soil Aquifer Treatment of Reclaimed Water

Crude Oil Biodegradation


 

Links:

USGS- National Research Program    Toxic Substances Hydrology Program    Postdoctoral Opportunites

BEMIDJI RESEARCH SITE- Crude Oil Contamination in the Shallow Subsurface

INTERNATIONAL HUMIC SUBSTANCES SOCIETY- IHSS Website

DOWN-LOADABLE NMR SPECTRA OF IHSS SAMPLES     Menu

Selected Recent Publications

Thorn, K. A. Reduction and Incorporation of Nitrate Nitrogen into Aquatic NOM Upon UV Irradiation Examined by 15N NMR, Division of Environmental Chemistry Preprints of Papers, 223rd National Meeting of the American Chemical Society, Orlando, FL; American Chemical Society; 2002, Vol. 42(1), p 537-542.

Osburn, C. L.; Morris, D. P.; Thorn, K. A.; Moeller, R. E. Chemical and optical changes in freshwater dissolved organic matter exposed to solar radiation. Biogeochemistry 2001, 54, 251-278. On-line Abstract

Thorn, K. A.; Mikita, M. A. Nitrite fixation by humic substances: 15N Nuclear Magnetic Resonance Evidence for Potential Intermediates in Chemodenitrification. Soil Sci. Soc. Am. J. 2000, 64, 568-582. On-line Abstract

Thorn, K. A.; Aiken, G. R. Biodegradation of Crude Oil into Nonvolatile Organic Acids in a Contaminated Aquifer Near Bemidji, Minnesota. Organic Geochemistry, 1998, 29, 909-931. On-line Abstract

Roy A. Schroeder, Ed., 2003, Water-Quality Changes and Organic-Carbon Characterization During Recharge with Recycled Water at a Research Basin in Montebello Forebay, Los Angeles, California, U.S. Geological Survey Water-Resources Investigations Report 03-4146. Water Resources Investigation Report, on-line

Aromatic Amines and Explosives Remediation

Thorn, K.A.; Thorne, P.G.; Cox, L.G. Alkaline Hydrolysis/Polymerization of 2,4,6-Trinitrotoluene: Characterization of Products by 15N NMR. Environ. Sci. & Technol. 2004, 38, 2224-2231. On-line Abstract

Weiss, J.M.; McKay, A.J.; Derito, C.; Watanabe, C.; Thorn, K.A.; Madsen, E.L. Development and Application of Pyrolysis Gas Chromatogaphy/Mass Spectrometry for the Analysis of Bound Trinitrotouene Residues in Soil. Environ. Sci. & Technol. 2004, 38, 2167-2174. On-line Abstract

Weber, E. J.; Spidle, D. J.; Thorn, K. A. Covalent Binding of Aniline to Humic Substances. 1. Kinetic Studies. Environ. Sci. & Technol. 1996, 30, 2755-2763. On-line Abstract

Thorn, K. A.; Pettigrew, P. J.; Goldenberg, W. S.; Weber,E. J. Covalent Binding of Aniline to Humic Substances. 2. 15N NMR Studies of Nucleophilic Addition Reactions. Environ. Sci. & Technol. 1996, 30, 2764-2775. On-line Abstract

Thorn, K. A.; Goldenberg, W. S.; Younger, S. J.; Weber, E. J. Covalent Binding of Aniline to Humic Substances: Comparison of Nucleophilic Addition, Enzyme-, and Metal-Catalyzed Reactions by 15N NMR. In Humic and Fulvic Acids: Isolation, Structure, and Environmental Role; J. S. Gaffney; N. A. Marley and S. B. Clark, Eds.; American Chemical Society, 1996a; pp 299-326.On-line Abstract

Pennington, J. C., Thorn, K. A., Gunnison, D., McFarland, V. A., Thorne, P. G., Inouye, L. S., Fredrickson, H., Leggett, D. C., Ringleberg, D., Jarvis, A. S., Felt, D. R., Lutz, C. H., Hayes, C. A., Clark, J. U., Richmond, M., O'Neal, B., and Porter, B. E. (1998). "Explosives conjugation products in remediation matrices: Interim Report 2," Technical Report SERDP-98-12, U.S.Army Engineer Waterways Experiment Station, Vicksburg, MS.

Pennington, J. C.; Thorn, K. A.; Inouye, L. S.; McFarland, V. A.; Jarvis, A. S.; Lutz, C. H.; Hayes, C. A.; Porter, B. E. Explosives conjugation products in remediation matrices: Final report; U.S. Army Engineer Research and Development Center: Vicksburg, MS., 1999. http://www.wes.army.mil/el/elpubs/pdf/trserdp99-4.pdf

Thorn, K. A.; Pennington, J. C.; Hayes, C. A. 15N NMR Investigation of the Reduction and Binding of TNT in an Aerobic Bench Scale Reactor Simulating Windrow Composting. Environ. Sci. Technol. 2002, 36, 3797-3805. On-line Abstract   Article in PDF Format   (Journal access may be limited by subscription considerations.)

Thorn, K. A.; Kennedy, K. R. 15N NMR Investigation of the Covalent Binding of Reduced TNT Amines to Soil Humic Acid, Model Compounds, and Lignocellulose. Environ. Sci. Technol. 2002, 36, 3787-3796. On-line Abstract Article in PDF Format (Journal access may be limited by subscription limitations.)

Pennington, J. C.; Thorn, K. A.; Hayes, C. A.; Porter, B. E.; Kennedy, K. R. “Immobilization of 2,4- and 2,6-Dinitrotoluenes in Soils and Compost,” ERDC/EL TR-03-2, US Army Engineer Research and Development Center, 2003. http://www.wes.army.mil/el/elpubs/pdf/trel03-2.pdf

Pennington, J. C.; Thorn, K. A.; Cox, L. G.; MacMillan, Denise K.; Yost, Sally; Laubscher, Randy D.“Photochemical Degradation of Composition B and its Components” ERDC/EL TR-07-16, US Army Engineer Research and Development Center, 2007. http://el.erdc.usace.army.mil/elpubs/pdf/trel07-16.pdf


Contacts:

Kevin A. Thorn, Research Chemist
U.S. Geological Survey
P.O. Box 25046
National Water Quality Laboratory
Center Avenue and 10th Street
Bldg. 95, M.S. 408, Denver Federal Center
Denver, CO. 80225-0046
Tel. 303-236-3979, Fax 303-236-3934
kathorn@usgs.gov

     

Larry G. Cox, Chemist
Contract Employee
P.O. Box 25046
National Water Quality Laboratory
Center Avenue and 10th Street
Bldg. 95, M.S. 408, Denver Federal Center
Denver, CO. 80225-0046
Tel. 303-236-3968, Fax 303-236-3934
lgcox@usgs.gov

     

 

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Last modified: 04/03/08
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