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United States Department of Energy: Publications

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Report Of The Poplar Working Group, Steve Strauss Jan 1999

Report Of The Poplar Working Group, Steve Strauss

United States Department of Energy: Publications

Poplars consist of all species of the genus Populus, including cottonwoods, aspens, and the many interspecies hybrids in common use (Dickmann and Stuart 1983). Our working group focused on the fungal pathogens, arthropod herbivores, and weed competitors of Populus in the United States. However, bacterial and viral diseases of Populus are significant in Europe, and genetic engineering approaches toward their control or management are being studied. The key aspects of poplar biology important to understanding the use of pest resistance genes are described below.

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2h Solid-State Nmr Investigation Of Terephthalate Dynamics And Orientation In Mixed-Anion Hydrotalcite-Like Compounds, Robert S. Maxwell, Ravi K. Kukkadapu, James E. Amonette, Herman Cho Jan 1999

2h Solid-State Nmr Investigation Of Terephthalate Dynamics And Orientation In Mixed-Anion Hydrotalcite-Like Compounds, Robert S. Maxwell, Ravi K. Kukkadapu, James E. Amonette, Herman Cho

United States Department of Energy: Publications

The dynamics and orientations of interlayer terephthalate (TA) anions in mixed-anion hydrotalcite-like compounds [Mg1-x Alx(OH)2](AyB1-y)x/2•nH2O, where A = p-C6D4(COO)22- and B ) CO32-] were investigated by 2H variable-temperature solid-state nuclear magnetic resonance (NMR) spectroscopy. Two dominant 003 d spacings, 7.6 and 14.2 Å, were observed by X-ray diffraction (XRD) in these samples, suggesting that there were at least two interlayer environments. Over the range of layer charges studied (0.37 ≥ x ≥ 0.29), the intensity …

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Metal Oxide Surfaces And Their Interactions With Aqueous Solutions And Microbial Organisms, Gordon E. Brown Jr., Victor Henrich, William Casey, David Clark, Carrick Eggleston, Andrew Felmy Andrew Felmy, D. Wayne Goodman, Michael Gratzel, Gary Maciel, Maureen I. Mccarthy, Kenneth H. Nealson, Dimitri Sverjensky, Michael Toney, John M. Zachara Jan 1999

Metal Oxide Surfaces And Their Interactions With Aqueous Solutions And Microbial Organisms, Gordon E. Brown Jr., Victor Henrich, William Casey, David Clark, Carrick Eggleston, Andrew Felmy Andrew Felmy, D. Wayne Goodman, Michael Gratzel, Gary Maciel, Maureen I. Mccarthy, Kenneth H. Nealson, Dimitri Sverjensky, Michael Toney, John M. Zachara

United States Department of Energy: Publications

During the past decade, interest in chemical reactions occurring at metal oxide-aqueous solution interfaces has increased significantly because of their importance in a variety of fields, including atmospheric chemistry, heterogeneous catalysis and photocatalysis, chemical sensing, corrosion science, environmental chemistry and geochemistry, metallurgy and ore beneficiation, metal oxide crystal growth, soil science, semiconductor manufacturing and cleaning, and tribology. The metal oxide-aqueous solution interface is reactive due to acid-base, ligand-exchange, and/or redox chemistry involving protons (hydronium ions), hydroxyl groups, aqueous metal ions, and aqueous organic species and also complexes among these species. Interfacial localization of those species (adsorption) may result from electrostatic, …

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Climate Change Impacts On The Potential Productivity Of Corn And Winter Wheat In Their Primary United States Growing Regions, Robert Brown, Norman Rosenberg Jan 1999

Climate Change Impacts On The Potential Productivity Of Corn And Winter Wheat In Their Primary United States Growing Regions, Robert Brown, Norman Rosenberg

United States Department of Energy: Publications

We calculate the impacts of climate effects inferred from three atmospheric general circulation models (GCMs) at three levels of climate change severity associated with change in global mean temperature (GMT) of 1.0, 2.5 and 5.0 _C and three levels of atmospheric CO2 concentration ([CO2]) – 365 (no CO2 fertilization effect), 560 and 750 ppm – on the potential production of dryland winter wheat (Triticum aestivum L.) and corn (Zea mays L.) for the primary (current) U.S. growing regions of each crop. This analysis is a subset of the Global Change Assessment Model (GCAM) which has …

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Below-Ground Respiratory Responses Of Sugar Maple And Red Maple Saplings To Atmospheric Co2 Enrichment And Elevated Air Temperature, Nelson Edwards, Richard Norby Jan 1999

Below-Ground Respiratory Responses Of Sugar Maple And Red Maple Saplings To Atmospheric Co2 Enrichment And Elevated Air Temperature, Nelson Edwards, Richard Norby

United States Department of Energy: Publications

The research described in this paper represents a part of a much broader research project with the general objective of describing the effects of elevated [CO2] and temperature on tree growth, physiological processes, and ecosystem-level processes. The specific objective of this research was to examine the below-ground respiratory responses of sugar maple (Acer saccharum Marsh.) and red maple (Acer rubrum L.) seedlings to elevated atmospheric [CO2] and temperature. Red maple and sugar maple seedlings were planted in the ground in each of 12 open-top chambers and exposed from 1994 through 1997 to ambient air …

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Biogenic Iron Mineralization Accompanying The Dissimilatory Reduction Of Hydrous Ferric Oxide By A Groundwater Bacterium, James K. Fredrickson, John M. Zachara, David Kennedy, Hailang Dong, Tullis Onstott, Nancy Hinman, Shu-Mei Li Jan 1998

Biogenic Iron Mineralization Accompanying The Dissimilatory Reduction Of Hydrous Ferric Oxide By A Groundwater Bacterium, James K. Fredrickson, John M. Zachara, David Kennedy, Hailang Dong, Tullis Onstott, Nancy Hinman, Shu-Mei Li

United States Department of Energy: Publications

Dissimilatory iron-reducing bacteria (DIRB) couple the oxidation of organic matter or H2 to the reduction of iron oxides. The factors controlling the rate and extent of these reduction reactions and the resulting solid phases are complex and poorly understood. Batch experiments were conducted with amorphous hydrous ferric oxide (HFO) and the DIRB Shewanella putrefaciens, strain CN32, in well-defined aqueous solutions to investigate the reduction of HFO and formation of biogenic Fe(II) minerals. Lactate-HFO solutions buffered with either bicarbonate or 1,4-piperazinediethanesulfonic acid (PIPES) containing various combinations of phosphate and anthraquinone-2,6-disulfonate (AQDS), were inoculated with S. putrefaciens CN32. AQDS, a humic …

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Influence Of Iron Oxide Inclusion Shape On Coii/Iiiedta Reactive Transport Through Spatially Heterogeneous Sediment, James E. Szecsody, Ashley Chilakapati, John M. Zachara, Amanda Garvin Jan 1998

Influence Of Iron Oxide Inclusion Shape On Coii/Iiiedta Reactive Transport Through Spatially Heterogeneous Sediment, James E. Szecsody, Ashley Chilakapati, John M. Zachara, Amanda Garvin

United States Department of Energy: Publications

Multisolute reactive transport was investigated in chemically heterogeneous systems to determine the influence of the shapes of the reactive heterogeneities (iron oxide inclusions) by comparison of two-dimensional heterogeneous experiments with spatially averaged models that had differing inclusion characterization. Eleven reactions were considered in this system, starting with absorption of the initial solute (CoIIEDTA) to Fe oxides, followed by two competing surface reactions: oxidation forming CoIIIEDTA and Fe dissolution forming FeIIIEDTA and Co2+. Spatial moments of the eight mobile species were compared between data and models. One spatially averaged model (homogenous equivalent), which incorporated inclusion …

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Bacterial Reduction Of Crystalline Fe3+ Oxides In Single Phase Suspensions And Subsurface Materials, John M. Zachara, James K. Fredrickson, Shu-Mei Li, David W. Kennedy, Steven C. Smith, Paul L. Gassman Jan 1998

Bacterial Reduction Of Crystalline Fe3+ Oxides In Single Phase Suspensions And Subsurface Materials, John M. Zachara, James K. Fredrickson, Shu-Mei Li, David W. Kennedy, Steven C. Smith, Paul L. Gassman

United States Department of Energy: Publications

Microbiologic reduction of synthetic and geologic Fe3+ oxides associated with four Pleistocene- age, Atlantic coastal plain sediments was investigated using a dissimilatory Fe reducing bacterium (Shewanella putrefaciens, strain CN32) in bicarbonate buffer. Experiments investigated whether phosphate and anthraquinone-2, 6-disulfonate, (AQDS, a humic acid analogue) influenced the extent of crystalline Fe3+ oxide bioreduction and whether crystalline Fe3+ oxides in geologic materials are more or less reducible than comparable synthetic phases. Anaerobic incubations (108 organisms/mL) were performed both with and without PO4 and AQDS that functions as an electron repository and shuttle. The production of …

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Chemical Information On Tank Supernatants, Cs Adsorption From Tank Liquids Onto Hanford Sediments, And Field Observations Of Cs Migration From Past Tank Leaks, R. J. Serne, John M. Zachara, D. S. Burke Jan 1998

Chemical Information On Tank Supernatants, Cs Adsorption From Tank Liquids Onto Hanford Sediments, And Field Observations Of Cs Migration From Past Tank Leaks, R. J. Serne, John M. Zachara, D. S. Burke

United States Department of Energy: Publications

Borehole gamma-logging profiles beneath the SX-Tank Farm suggest that contamination from Cs-137 extends to at least a depth of 40 m (130 ft), and may extend even deeper. What is presently not known is the pathway that Cs-137 has taken to reach these depths. In this report we provide an analysis of the chemistry of tank supernates with emphasis on the REDOX waste stream disposed in SX tanks, Cs chemistry in aqueous solutions and adsorption properties onto minerals, available data on Cs adsorption onto Hanford sediments, and information on Cs migration from other Hanford tank leaks that have been studied. …

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Synthesis Of A Low-Carbonate High-Charge Hydrotalcite-Like Compound At Ambient Pressure And Atmosphere, Ravi K. Kukkadapu, Marc S. Witkowski, James E. Amonette Jan 1997

Synthesis Of A Low-Carbonate High-Charge Hydrotalcite-Like Compound At Ambient Pressure And Atmosphere, Ravi K. Kukkadapu, Marc S. Witkowski, James E. Amonette

United States Department of Energy: Publications

Hydrotalcite (HT), a clay mineral, is constructed of brucite-like layers [Mg(OH)2] in which substitution of Al3+ for Mg2+ at a mole ratio of 1:3 yields a net positive charge. This layer charge is compensated by exchangeable CO3 2- anions located (along with adsorbed water molecules) in the interlayer region. Numerous analogues of HT [i.e., “hydrotalcite-like” compounds (HTLCs)] have been synthesized with a variety of M2+/M3+ combinations,M2+/M3+ ratios, and interlayer anions.1-10 The compositions of these HTLCs are usually expressed using a generalized form of the formula for a substituted brucite, …

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A Lagrangian Dispersion Model For Predicting Co2 Sources, Sinks, And Fluxes In A Uniform Loblolly Pine (Pinus Taeda L.) Stand, Gabriel Katul, Ram Oren, David Ellsworth, Cheng-I Hsieh, Nathan Phillips, Keith Lewin Jan 1997

A Lagrangian Dispersion Model For Predicting Co2 Sources, Sinks, And Fluxes In A Uniform Loblolly Pine (Pinus Taeda L.) Stand, Gabriel Katul, Ram Oren, David Ellsworth, Cheng-I Hsieh, Nathan Phillips, Keith Lewin

United States Department of Energy: Publications

A canopy Lagrangian turbulent scalar transport model for predicting scalar fluxes, sources, and sinks within a forested canopy was tested using CO2 concentration and flux measurements. The model formulation is based on the localized near-field theory (LNF) proposed by Raupach [1989a, b]. Using the measured mean CO2 concentration profile, the vertical velocity variance profile, and the Lagrangian integral timescale profile within and above a forested canopy, the proposed model predicted the CO2 flux and source (or sink) profiles. The model testing was carried out using eddy correlation measurements at 9 m in a uniform 13 m tall …

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Byproduct Formation During The Reduction Of Tce By Zero-Valence Iron And Palladized Iron, Liyuan Liang, Nic Korte, J. D. Goodlaxson, Jay Clausen, Quintus Fernando, Rosy Muftikian Jan 1997

Byproduct Formation During The Reduction Of Tce By Zero-Valence Iron And Palladized Iron, Liyuan Liang, Nic Korte, J. D. Goodlaxson, Jay Clausen, Quintus Fernando, Rosy Muftikian

United States Department of Energy: Publications

Trichlorothene (TCE) was reduced with zero-valence iron and palladized iron in zero-head-space extractors. Progress of the reaction in these batch studies was monitered with purge-and-trap gas chromatography and a flame ionization detector. When a 5 ppm initial concentration of TCE reacts with zero-valence iron, approximately 140 ppb of vinyl chloride persists for as long as 73 days. The concentration of vinyl chloride (approximately 10 ppb) remaining with palladized iron is approximately and order of magnitude less than when zero-valence iron is the reductant. These data suggest that volatile byproducts may be under-represented in other published data regarding reduction in zero-valence …

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A General Protocol For Restoration Of Regulated Rivers, Jack A. Stanford, J. V. Ward, William J. Liss, Christopher A. Frissell, Richard N. Williams, James A. Lichatowich, Charles C. Coutant Jan 1996

A General Protocol For Restoration Of Regulated Rivers, Jack A. Stanford, J. V. Ward, William J. Liss, Christopher A. Frissell, Richard N. Williams, James A. Lichatowich, Charles C. Coutant

United States Department of Energy: Publications

Large catchment basins may be viewed as ecosystems in which natural and cultural attributes interact. Contemporary river ecology emphasizes the four-dimensional nature of the river continuum and the propensity for riverine biodiversity and bioproduction to be largely controlled by habitat maintenance processes, such as cut and fill alluviation mediated by catchment water yield. Stream regulation reduces annual flow amplitude, increases baseflow variation and changes temperature, mass transport and other important biophysical patterns and attributes. As a result, ecological connectivity between upstream and downstream reaches and between channels, ground waters and floodplains may be severed. Native biodiversity and bioproduction usually are …

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Microbial Reduction Of Crystalline Iron(Iii) Oxides: Influence Of Oxide Surface Area And Potential For Cell Growth, Eric E. Roden, John M. Zachara Jan 1996

Microbial Reduction Of Crystalline Iron(Iii) Oxides: Influence Of Oxide Surface Area And Potential For Cell Growth, Eric E. Roden, John M. Zachara

United States Department of Energy: Publications

Quantitative aspects of microbial crystalline iron- (III) oxide reduction were examined using a dissimilatory iron(III) oxide-reducing bacterium (Shewanella alga strain BrY). The initial rate and long-term extent of reduction of a range of synthetic iron(III) oxides were linearly correlated with oxide surface area. Oxide reduction rates reached an asymptote at cell concentrations in excess of ≈1 x 109/m2 of oxide surface. Experiments with microbially reduced goethite that had been washed with pH 5 sodium acetate to remove adsorbed Fe(II) suggested that formation of a Fe(II) surface phase (adsorbed or precipitated) limited the extent of iron(III) oxide …

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Speciation Of Uranium In Fernald Soils By Molecular Spectroscopic Methods: Characterization Of Untreated Soils, David E. Morris, Patrick G. Allen, John M. Berg, Catherine J. Chisholm-Brause, Steven Conradson, Robert Donohoe, Nancy Hess, John Musgrave, C. Drew Tait Jan 1996

Speciation Of Uranium In Fernald Soils By Molecular Spectroscopic Methods: Characterization Of Untreated Soils, David E. Morris, Patrick G. Allen, John M. Berg, Catherine J. Chisholm-Brause, Steven Conradson, Robert Donohoe, Nancy Hess, John Musgrave, C. Drew Tait

United States Department of Energy: Publications

A combination of X-ray absorption, optical luminescence, and Raman vibrational spectroscopies along with ancillary techniques such as energy dispersive scanning electron microscopy and powder X-ray diffraction have been used to determine the chemical form of uranium in contaminated soils from the United States Department of Energy’s (DOE) former uranium production facility located at Fernald, OH (30 km NW of Cincinnati). The analyses described here have been carried out on soil samples prior to the application of various decontamination technologies under development within the DOE’s Uranium in Soils Integrated Demonstration Project. X-ray absorption studies have shown that ~75-95% of the uranium …

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Models For Association Of Metal Ions With Heterogeneous Envimnmeatal Sorbents. 1 . Complexation Of Co(Ll) By Leonardiie Humic Acid As A Function Of Ph And Nac104 Concentration, John Westall, John Jones, Gary Turner, John M. Zachara Jan 1995

Models For Association Of Metal Ions With Heterogeneous Envimnmeatal Sorbents. 1 . Complexation Of Co(Ll) By Leonardiie Humic Acid As A Function Of Ph And Nac104 Concentration, John Westall, John Jones, Gary Turner, John M. Zachara

United States Department of Energy: Publications

A discrete log K spectrum model has been developed to represent the binding of protons and Co(II) to leonardite humic acid (LHA) over a wide variation of solution composition: pH 4.5-9.5, [NaC1O4] 0.01 - 0.1 M, TCo 200 nM-500 µM. The model is internally selfconsistent over the range indicated without an explicit electrostatic term. The LHA was represented by four acid sites (HLi = H+ + Li-) with a fixed pKa spectrum: pKa = 4, 6, 8, and 10. From the acid base titration data, total concentrations of these sites …

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The Influence Of Uranyl Hydrolysis And Multiple Site-Binding Reactions On Adsorption Of U(Vi) To Montmorillonite, James P. Mckinley, John M. Zachara, Steven C. Smith, Gary D. Turner Jan 1995

The Influence Of Uranyl Hydrolysis And Multiple Site-Binding Reactions On Adsorption Of U(Vi) To Montmorillonite, James P. Mckinley, John M. Zachara, Steven C. Smith, Gary D. Turner

United States Department of Energy: Publications

Adsorption of uranyl to SWy- 1 montmorillonite was evaluated experimentally and results were modeled to identify likely surface complexation reactions responsible for removal ofuranyl from solution. Uranyl was contacted with SWy- 1 montmorillonite in a NaC104 electrolyte solution at three ionic strengths (I = 0.001, 0.01, 0.1), at pH 4 to 8.5, in a N2(g) atmosphere. At low ionic strength, adsorption decreased from 95% at pH 4 to 75% at pH 6.8. At higher ionic strength, adsorption increased with pH from initial values less than 75%; adsorption edges for all ionic strengths coalesced above a pH of 7. A …

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Kemod: A Mixed Chemical Kinetic And Equilibrium Model Of Aqueous And Solid Phase Geochemical Reactions, G. T. Yeh, G. A. Iskra, J. E. Szecsody, John M. Zachara, G. P. Streile Jan 1995

Kemod: A Mixed Chemical Kinetic And Equilibrium Model Of Aqueous And Solid Phase Geochemical Reactions, G. T. Yeh, G. A. Iskra, J. E. Szecsody, John M. Zachara, G. P. Streile

United States Department of Energy: Publications

This report presents the development of a mixed chemical Kinetic and Equilibrium MODel (KEMOD), in which every chemical species can be treated either as a equilibrium-controlled or as a kinetically controlled reaction. The reaction processes include aqueous complexation, adsorption/ desorption, ion exchange, precipitation/dissolution, oxidation/reduction, and acid/base reactions. Further development and modification of KEMOD can be made in: (1) inclusion of species switching solution algorithms, (2) incorporation of the effect of temperature and pressure on equilibrium and rate constants, and (3) extension to high ionic strength.

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Adsorption-Dissolution Reactions Affecting The Distribution And Stability Of Coii Edta In Iron Oxide-Coated Sand, James E. Szecsody, John M. Zachara, Patrick Bruckhart Jan 1994

Adsorption-Dissolution Reactions Affecting The Distribution And Stability Of Coii Edta In Iron Oxide-Coated Sand, James E. Szecsody, John M. Zachara, Patrick Bruckhart

United States Department of Energy: Publications

The time-variant chemical behavior of CoIIEDTA (and other metal-EDTA complexes) was investigated in suspensions of iron oxide-coated sand to identify equilibrium and kinetic reactions that control the mobility of MeIIEDTA complexes in subsurface environments. Batch experiments were conducted to evaluate the adsorption as a function of pH, concentration, and time and to quantify the rate-controlling step(s) of dissolution of the iron oxide by EDTA complexes. Ionic Co2+ exhibited typical cation-like adsorption, whereas MeIIEDTA adsorption was ligand-like, increasing with decreasing pH. Adsorption isotherms for all reactive species exhibited Langmuir behavior, with site saturation occurring …

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Interaction Of Hydrophobic Organic Compounds With Mineral-Bound Humic Substances, Ellyn M. Murphy, John M. Zachara, Steven Smith, Jerry Phillips, Thomas Wletsma Jan 1994

Interaction Of Hydrophobic Organic Compounds With Mineral-Bound Humic Substances, Ellyn M. Murphy, John M. Zachara, Steven Smith, Jerry Phillips, Thomas Wletsma

United States Department of Energy: Publications

The sorption of hydrophobic organic compounds (HOC) on mineral-associated peat humic acid (PHA) was evaluated under different pH and electrolyte regimes. Relative size distribution measurements indicated that PHA was “coiled” in solution at high ionic strength (I) and elongated at low I. The sorption of PHA to hematite and kaolinite varied with I and electrolyte cation, suggesting that the configuration of the humic acid in solution influenced its structure on the mineral surface. The sorption maxima for PHA on kaolinite indicated that PHA occupies twice the mineral surface area at low I (0.005) as that observed at …

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Light, Chlorophyll, Carboxylase Activity And Co2 Fixation At Various Depths In The Chlorenchyma Of Opuntia Ficus-Indica (L.) Miller Under Current And Elevated Co2, Park S. Nobel, Muyi Cui, Alvaro A. Israel Jan 1994

Light, Chlorophyll, Carboxylase Activity And Co2 Fixation At Various Depths In The Chlorenchyma Of Opuntia Ficus-Indica (L.) Miller Under Current And Elevated Co2, Park S. Nobel, Muyi Cui, Alvaro A. Israel

United States Department of Energy: Publications

Mature cladodes of Opuntia ficus-indica (L.) Miller have a thick chlorenchyma (about 4 mm) with a relatively high chlorophyll content (0-65 g m-2), suggesting that light may be greatly attenuated and hence CO2 fixation negligible in the inner part of this tissue. Indeed, blue light (400-470 nm) and red light (670-685 nm) were 99% attenuated in the outer 2 mm of the chlorenchyma when the cladodes developed under both current and elevated CO2 concentrations. Nevertheless, the nocturnal acidity increase and 14C accumulation following a brief exposure to 14CO2 at night decreased only 22 …

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A Technical Approach To Groundwater Contamination Problems, Jacqueline C. Burton, Catherine Leser, Candace M. Rose Jun 1993

A Technical Approach To Groundwater Contamination Problems, Jacqueline C. Burton, Catherine Leser, Candace M. Rose

United States Department of Energy: Publications

Argonne National Laboratory has been performing technical investigations at sites in Nebraska and Kansas that have identified groundwater contamination by carbon tetrachloride. This comprehensive program will ultimately provide the affected communities with safe drinking water. The first step in the program is to evaluate the available data and identify sites that will require an Alternate Water Supply Study (AWSS). The objective of the AWSS is to identify options for providing a safe drinking water supply to all users, in compliance with the Safe Drinking Water Act. The AWSS consists of an engineering and cost evaluation followed by implementation of the …

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Transport Of Co2+ In A Physically And Chemically Heterogeneous Porous Medium, Mark L. Brusseau, John M. Zachara Jan 1993

Transport Of Co2+ In A Physically And Chemically Heterogeneous Porous Medium, Mark L. Brusseau, John M. Zachara

United States Department of Energy: Publications

The fate of radionuclides in the subsurface is of critical importance to the planning, siting, and evaluation of repositories for radioactive wastes. Mathematical models are an integral component of this process. An accurate understanding of radionuclide transport is required to successfully formulate and use these models. It is well-known that the subsurface is both physically and chemically heterogeneous. Recent research has shown that the resultant spatial variability of hydraulic conductivity and of sorption capacity can significantly affect solute transport in the subsurface. The impact of hydraulic conductivity variability and sorption capacity variability on the transport of radionuclides is, therefore, of …

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Dynamic Fish Growth Modeling For Tailwater Fishery Management, Ming Shiao, Gary Hauser, Gary Chapman, Bruce Yeager, Tom Mcdonough, Jim Ruane Jan 1992

Dynamic Fish Growth Modeling For Tailwater Fishery Management, Ming Shiao, Gary Hauser, Gary Chapman, Bruce Yeager, Tom Mcdonough, Jim Ruane

United States Department of Energy: Publications

Tailwater fisheries below hydroprojects are affected by variable flows and water quality in dam releases. The Tennessee Valley Authority (TVA) identified undesirable flow regimes, low dissolved oxygen (DO) concentrations, and undesirable temperatures as having the greatest biological impact on tailwater, and steps are being taken to mitigate impacts at numerous dams. To help evaluate mitigation efforts, an interdisciplinary team of water quality modelers, fisheries biologists, and environmental engineers developed a one-dimensional dynamic fish growth model. This model was coupled with previously developed dynamic flow and water quality models. The model results were compared to (1) fish growth data in Norris …

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Structural And Non-Structural Alternatives For Accommodating Larger Floods At Dams, Louis E. Buck Jan 1992

Structural And Non-Structural Alternatives For Accommodating Larger Floods At Dams, Louis E. Buck

United States Department of Energy: Publications

This paper provides an overview of structural and non-structural alternatives for accommodating larger floods at dams. The first two alternatives discussed, raising the height of the project and/or lowering the reservoir pool, can be used to prevent overtopping by increasing the available floodwater detention storage in the reservoir. Data gathered by an ASCE task committee survey on modifications that include increased storage by raising project height are summarized and discussed. The third alternative discussed, early warning systems, can provide a low cost alternative to structural modifications. Case studies for the warning systems at the Santee Cooper North Dam and the …

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Integrated Assessment Of Temperature Change Impacts On The Tva Reservoir And Power Supply Systems, B. A. Miller, V. Alavian, M. D. Bender, D. J. Benton, P. Ostrowski Jr., J. A. Parsly, M. C. Shiao Jan 1992

Integrated Assessment Of Temperature Change Impacts On The Tva Reservoir And Power Supply Systems, B. A. Miller, V. Alavian, M. D. Bender, D. J. Benton, P. Ostrowski Jr., J. A. Parsly, M. C. Shiao

United States Department of Energy: Publications

Power systems often depend upon reservoir operations to generate hydropower, as well as to support thermal (nuclear and fossil) power generation. Thermal power plants frequently utilize reservoirs/rivers to provide condenser cooling water, dissipate thermal waste discharges, and/or supply safety intake water for emergency cooling systems at nuclear plants. Support of power production, however, must usually be balanced against other reservoir multiple uses such as flood control, navigation, recreation, water supplies, and environmental management.

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Contaminated Sediment Transport During Floodsl, Thomas A. Fontaine Jan 1992

Contaminated Sediment Transport During Floodsl, Thomas A. Fontaine

United States Department of Energy: Publications

Over the past 48 years, operations and waste disposal activities at Oak Ridge National Laboratory have resulted in the contamination of parts of the White Oak Creek catchment. The contaminants presenting the highest risk to human health and the environment are particle reactive and are associated with the soils and sediments in the White Oak Creek drainage system. The erosion of these sediments during floods can result in the transport of contaminants both within the catchment and off-site into the Clinch River. A data collection program and a modeling investigation are being used to evaluate the probability of contaminated sediment …

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Hydraulic Risk Of Flood Disaster Reduction At Dams, Shou-Shan Fan Jan 1992

Hydraulic Risk Of Flood Disaster Reduction At Dams, Shou-Shan Fan

United States Department of Energy: Publications

Floods are major natural hazards, not totally predictable and manageable, at least at the present time. We believe that floods, no matter how violent, need not cause major damage. Loss of lives can be prevented and economic catastrophe minimized if a decision maker has accurate prior information on major flood characteristics, such as the magnitude and arrival time of the flood and its potential damages.

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Cadmium Adsorption On Iron Oxides In The Presence Of Alkaline-Earth Elements, Christina Cowan, John M. Zachara, Charles T. Resch Jan 1991

Cadmium Adsorption On Iron Oxides In The Presence Of Alkaline-Earth Elements, Christina Cowan, John M. Zachara, Charles T. Resch

United States Department of Energy: Publications

Cadmium sorption on Fe2O3 • H2O(am) in the presence of alkaline-earth cations was investigated with emphasis on the Cd-Ca binary system. In binary-element sorption experiments with Ca, Mg, Sr, and Ba, competition was observed primarily in Cd-Ca binary mixtures, which were studied at three ionic strengths (0.5, 0.1, and 0.005 M). The extent of competition increased with increasing Ca concentration. In single-element experiments changes in ionic strength (between 0.005 and 0.5 M) did not influence Cd sorption but did affect Ca sorption, implying that a portion of the Ca surface complexes were outer sphere. The …

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Transformation Of 1-Aminonapththalene At The Surface Of Smectite Clays, Calvin C. Ainsworth, Bruce D. Mcveety, Steven C. Smith, John M. Zachara Jan 1991

Transformation Of 1-Aminonapththalene At The Surface Of Smectite Clays, Calvin C. Ainsworth, Bruce D. Mcveety, Steven C. Smith, John M. Zachara

United States Department of Energy: Publications

One-aminonaphthalene is sorbed onto the Na-saturated smectite clays, montmorillonite and hectorite, by cation exchange. In the presence of Fe3+ either in the clay structure or on the clay surface, sorption is followed by the formation of a blue-colored complex, with the continuous disappearance of aminonaphthalene from solution and the clay surface. The rate of aminonaphthalene disappearance decreases as pH increases. With time, four major products that appear to be structural isomers of N(4- aminonaphthyl)-1-naphthylamine are produced. A simplified model of this transformation is suggested to be the oxidation by Fe3+ of sorbed aminonaphthalene forming a radical cation-clay complex. …

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