Dr. Klaus J. Stetzenbach

Director
Harry Reid Center for Environmental Studies
Phone: (702) 895-3742
Fax: (702) 895-3094
E-Mail: stetzenb@nevada.edu

Education:

Post Doctoral Studies, Ground Water Tracers, Department of Hydrology and Water Resources, University of Arizona
Ph.D., Analytical Chemistry, University of Arizona, 1980
B.S., Chemistry, University of Arizona, 1969

Major Teaching Responsibilities:

Chromatography

Research Interests:

Analytical methodology for the detection of ground water tracers; ground water/aquifer geochemical interactions; ultra trace measurements of elements dissolved in ground water; high resolution ICP-MS for the measurement of long lived radionuclides.

Specific Projects:

Ground Water Tracers:
Ground water tracers provide information on direction and speed of water movement and that of contaminants that might be conveyed by the water. Tracers can also be used to measure effective porosity, hydraulic conductivity, dispersivity and solute distribution coefficients. They can be naturally occurring compounds or elements or they can be completely foreign to the environment. The latter is generally preferred. For most applications tracers should be conservative, that is, move at the same rate as the water and not sorb to aquifer materials. Tracers must have a number of properties to be functional. Regardless of the desired properties, the chemical and physical behavior of a tracer in ground water and the porous medium under study must be understood. Good estimates of tracer behavior can be obtained from laboratory studies.

Ground Water Fingerprinting:
The purpose of this project is to use trace element chemistry to determine similarities (or differences) between waters from different sources. A detailed chemical analysis of over 50 elements is performed on the water and then multivariate statistical techniques are used to establish relationships and differences between the waters and eventually their sources. This extensive analysis of the ground waters and their associated aquifer materials (i.e., felsic tuffs and Paleozoic carbonate rocks) from the Nevada Test Site (NTS) is performed in order to characterize the ground water chemistry, determine the nature of ground water/aquifer interactions, and, ultimately, to determine the ground water flow regime in the NTS region. In the event of such a scenario, an understanding of ground water flow on the NTS would be imperative to properly remediate the system and to assure that the local environment, which includes Ash Meadows National Wildlife Refuge and Death Valley National Park, would not be compromised.

High Resolution ICP-MS:
The measurement of environmental concentrations (fCI/ml) of low specific activity radionuclides (i.e., long lived radionuclides, x-ray or soft- and - emitters ) presents particular problems to radiochemists, with time consuming extractions, preconcentrations and separations often being required. In the last few years a new analytical technique based on inductively coupled plasma- mass spectrometry (ICP-MS) has been proven to be superior to conventional radiation techniques for the measurement of environmental concentration of radionuclides such as ⁹⁹Tc, ¹²⁹I, ²⁴⁷Np and ²³⁹Pu. Using this analytical technique extremely high sensitivity (fCI/ml) measurements can be carried out in minutes with minimal or no sample preparation. The purpose of this research is to develop, evaluate, and establish analytical protocols for a novel high-resolution, high sensitivity and interference free inductively coupled plasma mass spectrometer (HR-ICP-MS) for the measurement of trace and ultra trace concentrations of radionuclides which are difficult to detect by traditional radiation detection methods.

Selected Publications:

Johannesson, K. H., Lyons, W. B., Yelken, M. A., Gaudette, H. E., and Stetzenbach, K. J., 1996. Geochemistry of the rare earth elements in hypersaline and dilute acidic natural terrestrial waters: Complexation behavior and middle rare earth enrichments,
Chemical Geology, 133, 125-144.

Johannesson, K. H., Stetzenbach, K. J., Hodge, V. F., Kreamer, D. K., and Zhou, X. 1997. Delineation of groundwater flow systems in the southern Great Basin using aqueous rare earth element distributions. Ground Water, Accepted.

Johannesson, K. H., Stetzenbach, K. J., Hodge, V. F., and Lyons, W. B. 1996. Rare earth element complexation behavior in circumneutral pH groundwaters: Assessing the role of carbonate and phosphate ions. Earth and Planetary Science Letters, in press.

Johannesson, K. H., Stetzenbach, K. J., Kreamer, D. K., and Hodge, V. F. 1996. Multivariate statistical analysis of arsenic and selenium concentrations in groundwaters from south-central Nevada and Death Valley, California. Journal of Hydrology, in press.

Kreamer, D. K., Hodge, V. F., Rabinowitz, I., Johannesson, K. H., and Stetzenbach, K. J. 1996. Trace Element Geochemistry in Water from Selected Springs in Death Valley National Park, California. Ground Water, 34, No. 1, 95-103

Johannesson, K. H., Stetzenbach, K. J., and Hodge, V. F. 1995. Speciation of the rare earth element neodymium in groundwaters of the Nevada Test Site and Yucca Mountain and implications for actinide solubility. Applied Geochemistry, 10, 565-572.

Johannesson, K. H., Lyons, W. B., Stetzenbach, K. J., and Byrne, R. H. 1995. The solubility control of the rare earth elements in natural terrestrial waters and the significance of PO₄^3- and CO₃^2- in limiting dissolved rare earth concentrations: A review of recent information. Aquatic Geochemistry, 1, 157-173.

Stetzenbach, K. J., Amano, M., Kreamer, D. K., and Hodge, V. F. 1994. Testing the Limits of ICP- MS: Determination of Trace Elements in Ground Water at the Part-Per-Trillion Level. Ground Water, 32 (6): 976-985.

Stetzenbach, K. J., and Thompson, G. M. 1983. A New Method for Simultaneous Measurement of Cl^-, Br^-, N0₃^-, SCN^-, and I^- at sub-ppm Levels in Groundwater. Ground Water 21 (1): 36-41.

Stetzenbach, K. J., Jensen, S. L., and Thompson, G. M. 1982. Trace Enrichment of Fluorinated Organic Acids Used as Groundwater Tracers by Liquid Chromatography. Environmental Science and Technology 16 (5): 250-254.

Send comments to the Department of Chemistry.
Last updated 03-04-2000.