Kevin Thorn
Kevin Thorn is an Emeritus Research Chemist in the USGS Water Resources Mission Area.
I was a Research Chemist in the Water Mission Area from 1982 to 2019, and was the lead for the Carbon and Nitrogen Biogeochemistry project in the former National Research Program, specializing in the application of Nuclear Magnetic Resonance (NMR) spectroscopy to environmental and organic geochemistry. Research topics include the structure and reactivity of soil and aquatic humic substances and natural organic matter (NOM), the environmental chemistry and bioremediation of nitroaromatic munitions, including 2,4,6-trinitrotoluene (TNT), biodegradation of crude oil, the biogeochemical cycling of nitrogen in soil and water, and soil aquifer treatment of reclaimed water.
Education and Certifications
B.A., Chemistry and Biochemistry, Bowdoin College, Brunswick, Maine, 1978.
M.S., Agricultural Biochemistry and Nutrition, University of Arizona, Tucson, 1981.
Ph.D., Agricultural Biochemistry and Nutrition, University of Arizona, Tucson, 1984.
Science and Products
Order of functionality loss during photodegradation of aquatic humic substances
N-15 NMR study of the immobilization of 2,4- and 2,6-dinitrotoluene in aerobic compost
Alkaline hydrolysis/polymerization of 2,4,6-Trinitrotoluene: Characterization of products by 13C and 15N NMR
Development and Application of Pyrolysis Gas Chromatography/Mass Spectrometry for the Analysis of Bound Trinitrotoluene Residues in Soil
Water-quality changes and organic-carbon characterization during recharge with recycled water at a research basin in Montebello Forebay, Los Angeles County, California, 1991-1996
15N NMR investigation of the reduction and binding of TNT in an aerobic bench scale reactor simulating windrow composting
15N NMR investigation of the covalent binding of reduced TNT amines to soil humic acid, model compounds, and lignocellulose
Chemical and optical changes in freshwater dissolved organic matter exposed to solar radiation
Nitrite fixation by humic substances: Nitrogen-15 nuclear magnetic resonance evidence for potential intermediates in chemodenitrification
Biodegradation of crude oil into nonvolatile organic acids in a contaminated aquifer near Bemidji, Minnesota
Covalent binding of aniline to humic substances. 2. 15N NMR studies of nucleophilic addition reactions
Covalent binding of aniline to humic substances. 1. Kinetic studies
Science and Products
- Publications
Filter Total Items: 33
Order of functionality loss during photodegradation of aquatic humic substances
The time course photodegradation of the Nordic aquatic fulvic and humic acids and Suwannee River XAD-4 acids subjected to UV irradiation with an unfiltered medium pressure mercury lamp was studied by liquid-state 13C nuclear magnetic resonance. Photodecarboxylation was a significant pathway in all cases. Decreases in ketone, aromatic, and O-alkyl carbons were observed throughout the course of theAuthorsKevin A. Thorn, Steven J. Younger, Larry G. CoxN-15 NMR study of the immobilization of 2,4- and 2,6-dinitrotoluene in aerobic compost
Large-scale aerobic windrow composting has been used to bioremediate washout lagoon soils contaminated with the explosives TNT (2,4,6-trinitrotoluene) and RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) at several sites within the United States. We previously used 15N NMR to investigate the reduction and binding of T15NT in aerobic bench -scale reactors simulating the conditions of windrow compostinAuthorsKevin A. Thorn, J.C. Pennington, Kay R. Kennedy, Larry G. Cox, C.A. Hayes, B.E. PorterAlkaline hydrolysis/polymerization of 2,4,6-Trinitrotoluene: Characterization of products by 13C and 15N NMR
Alkaline hydrolysis has been investigated as a nonbiological procedure for the destruction of 2,4,6-trinitrotoluene (TNT) in explosives contaminated soils and munitions scrap. Nucleophilic substitutions of the nitro and methyl groups of TNT by hydroxide ion are the initial steps in the alkaline degradation of TNT. Potential applications of the technique include both in situ surface liming and ex sAuthorsKevin A. Thorn, Philip G. Thorne, Larry G. CoxDevelopment and Application of Pyrolysis Gas Chromatography/Mass Spectrometry for the Analysis of Bound Trinitrotoluene Residues in Soil
TNT (trinitrotoluene) is a contaminant of global environmental significance, yet determining its environmental fate has posed longstanding challenges. To date, only differential extraction-based approaches have been able to determine the presence of covalently bound, reduced forms of TNT in field soils. Here, we employed thermal elution, pyrolysis, and gas chromatography/mass spectrometry (GC/MS)AuthorsJ.M. Weiss, A.J. Mckay, C. Derito, C. Watanabe, K. A. Thorn, E.L. MadsenWater-quality changes and organic-carbon characterization during recharge with recycled water at a research basin in Montebello Forebay, Los Angeles County, California, 1991-1996
During the early 1990s, the U.S. Geological Survey (USGS) investigated water-quality changes that occur in treated municipal wastewater (recycled water) at a small research basin constructed in the Montebello Forebay of the Central Ground-Water Basin in south-central Los Angeles County. The instrumented research basin is located on a 1/2-acre site at the upgradient end of the San Gabriel River CoaAuthorsRoy A. Schroeder15N NMR investigation of the reduction and binding of TNT in an aerobic bench scale reactor simulating windrow composting
T15NT was added to a soil of low organic carbon content and composted for 20 days in an aerobic bench scale reactor. The finished whole compost and fulvic acid, humic acid, humin, and lignocellulose fractions extracted from the compost were analyzed by solid-state CP/MAS and DP/MAS 15N NMR. 15N NMR spectra provided direct spectroscopic evidence for reduction of TNT followed by covalent binding ofAuthorsK. A. Thorn, J.C. Pennington, C.A. Hayes15N NMR investigation of the covalent binding of reduced TNT amines to soil humic acid, model compounds, and lignocellulose
The five major reductive degradation products of TNT-4ADNT (4-amino-2,6-dinitrotoluene), 2ADNT (2-amino-4,6-dinitrotoluene), 2,4DANT (2,4-diamino-6-nitrotoluene), 2,6DANT (2,6-diamino-4-nitrotoluene), and TAT (2,4,6-triaminotoluene)-labeled with 15N in the amine positions, were reacted with the IHSS soil humic acid and analyzed by 15N NMR spectrometry. In the absence of catalysts, all five aminesAuthorsK. A. Thorn, K. R. KennedyChemical and optical changes in freshwater dissolved organic matter exposed to solar radiation
We studied the chemical and optical changes inthe dissolved organic matter (DOM) from twofreshwater lakes and a Sphagnum bog afterexposure to solar radiation. Stable carbonisotopes and solid-state 13C-NMR spectraof DOM were used together with optical andchemical data to interpret results fromexperimental exposures of DOM to sunlight andfrom seasonal observations of two lakes innortheastern PennsylAuthorsC.L. Osburn, D.P. Morris, K. A. Thorn, R.E. MoellerNitrite fixation by humic substances: Nitrogen-15 nuclear magnetic resonance evidence for potential intermediates in chemodenitrification
Studies have suggested that NO− 2, produced during nitrification and denitrification, can become incorporated into soil organic matter and, in one of the processes associated with chemodenitrification, react with organic matter to form trace N gases, including N2O. To gain an understanding of the nitrosation chemistry on a molecular level, soil and aquatic humic substances were reacted with 15N-laAuthorsK. A. Thorn, M.A. MikitaBiodegradation of crude oil into nonvolatile organic acids in a contaminated aquifer near Bemidji, Minnesota
As the result of a pipeline burst, a body of light aliphatic crude oil floats atop the groundwater in a shallow sand and gravel aquifer in a remote area outside Bemidji, Minnesota. Biodegradation has resulted in the formation of a plume of DOC downgradient from the oil body. Groundwater has also been contaminated in an area known as the spray zone, from vertical infiltration of DOC resulting fromAuthorsK. A. Thorn, G. R. AikenCovalent binding of aniline to humic substances. 2. 15N NMR studies of nucleophilic addition reactions
Aromatic amines are known to undergo covalent binding with humic substances in the environment. Although previous studies have examined reaction conditions and proposed mechanisms, there has been no direct spectroscopic evidence for the covalent binding of the amines to the functional groups in humic substances. In order to further elucidate the reaction mechanisms, the Suwannee River and IHSS soiAuthorsK. A. Thorn, P.J. Pettigrew, W.S. Goldenberg, E.J. WeberCovalent binding of aniline to humic substances. 1. Kinetic studies
The reaction kinetics for the covalent binding of aniline with reconstituted IHSS humic and fulvic acids, unfractionated DOM isolated from Suwannee River water, and whole samples of Suwannee River water have been investigated. The reaction kinetics in each of these systems can be adequately described by a simple second-order rate expression. The effect of varying the initial concentration of aniliAuthorsE.J. Weber, D.L. Spidle, K. A. Thorn