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Publications

Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).

Filter Total Items: 4098

Anaerobic oxidation of [1,2-14C]Dichloroethene under Mn(IV)-reducing conditions Anaerobic oxidation of [1,2-14C]Dichloroethene under Mn(IV)-reducing conditions

Anaerobic oxidation of [1,2-14C]dichloroethene to14CO2 under Mn(IV)-reducing conditions was demonstrated. The results indicate that oxidative degradation of partially chlorinated solvents like dichloroethene can be significant even under anoxic conditions and demonstrate the potential importance of Mn(IV) reduction for remediation of chlorinated groundwater contaminants.
Authors
Paul M. Bradley, James Landmeyer, Richard S. Dinicola

Sources and age of aquatic humus Sources and age of aquatic humus

As aquatic scientists have recognized the diversity of processes controlled by or dependent upon aquatic humus, it has become important to learn more about the genesis, chemical properties, and concentration of humic substances in aquatic ecosystems. There are three classes of aquatic humus (fulvic acids, humic acids, and humin), all of which share the characteristics of being...
Authors
Diane M. McKnight, George R. Aiken

Predictive double-layer modeling of metal sorption in mine-drainage systems Predictive double-layer modeling of metal sorption in mine-drainage systems

Previous comparison of predictive double-layer modeling and empirically derived metal-partitioning data has validated the use of the double-layer model to predict metal sorption reactions in iron-rich mine-drainage systems. The double-layer model subsequently has been used to model data collected from several mine-drainage sites in Colorado with diverse geochemistry and geology. This...
Authors
K. S. Smith, J. F. Ranville, D.L. Macalady

Fundamentals of isotope geochemistry Fundamentals of isotope geochemistry

The dominant use of isotopes in catchment research in the last few decades has been to trace sources of waters and solutes. Generally, such data were evaluated with simple mixing models to determine how much was derived from either of the two (sometimes three) constant-composition sources. This chapter illustrates the environmental isotopes that are natural and anthropogenic isotopes...
Authors
Carol Kendall, Eric A. Caldwell

Isotopes as indicators of environmental change Isotopes as indicators of environmental change

In addition to providing an understanding of processes within a catchment system, isotopic techniques have been instrumental in providing reconstructions of catchment climate and other environmental indicators at various time scales. Many recent changes are a direct consequence of anthropogenic activities. Isotopic analysis serves as a valuable tool for distinguishing between natural...
Authors
James B. Shanley, Elise Pendall, Carol Kendall, Lora R. Stevens, Robert L. Michel, Patrick J. Phillips, Richard Forester, David L. Naftz, Beiling Liu, Libby Stern, Brent B. Wolfe, C. Page Chamberlain, Steven W. Leavitt, T. H. Heaton, Bernhard Mayer, L. DeWayne Cecil, W. Berry Lyons, Brian G. Katz, Julio L. Betancourt, Diane M. McKnight, Joel D. Blum, Thomas W.D. Edwards, Harold R. House, Emi Ito, Ramon O. Aravena, Joseph F. Whelan

Using transport model interpretations of tracer tests to study microbial processes in groundwater Using transport model interpretations of tracer tests to study microbial processes in groundwater

It has long been known that microorganisms affect the geochemistry of groundwater. But despite this recognition, little detailed information is available regarding the rates and the factors controlling microbial processes in groundwater. Part of the reason stems from the relatively inaccessible nature of most groundwater and the difficulties encountered in obtaining representative...
Authors
Richard L. Smith, Stephen P. Garabedian
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