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The Storage of Organic Matter in Bottom Deposits of Lake Dallas

Description: The purpose of this investigation is to find which season of the year organic matter increases most in the bottom deposits of Lake Dallas, the reason for the increase, and the amount of organic matter increase from year to year. It is hoped that this study will be beneficial in understanding the conditions in artificial reservoirs.
Date: 1941
Creator: Williams, Cyrus Paul
Partner: UNT Libraries

The Contribution of Microarthropods to Aboveground Foodwebs: A Review and Model of Belowground Transfer in a Coniferous Forest

Description: A food web model of predator arthropods and microarthropods was developed based upon data collected at SRS. The model indentifies numerous connections because of the diversity of species. Relationships vary over time and many predators feed on their own group. The model demonstrates the importance of detrital food webs in belowground and aboveground transfers in the ecosystem.
Date: February 15, 1999
Creator: Johnston, J.M.
Partner: UNT Libraries Government Documents Department

Comparison of organic constituents found in the condensed andvapor phases of tanks 241-BY-108, 241-BY-110, and 241-C-102

Description: Results from vapor and condensed-phase sampling of tanks 241-BY-108, 241-BY-110, and 241-C-102 were reviewed and compared in this report. Both vapor and condensed-phase samples from tanks 241-BY-108 and 241-C-102 indicate the presence of organic solvent. The organic solvent remaining in these tanks are predominantly the heavier fractions of normal paraffin hydrocarbons (NPHS) (i.e., dodecane, tridecane, and tetradecane) and tributyl phosphate (TBP). As was found for the organic solvent in tank 241-C-103, the flash point for the 241-BY-108 and 241-C-102 organic solvent is well above current tank temperatures. Differences between the measured headspace organic vapor concentrations and the organic vapor concentrations estimated from condensed-phase data indicate that the tank headspaces are not in equilibrium with the organic solvent detected in the waste. Non-equilibrium is the result of air flow through these tanks from passive ventilation. This is important because an equilibrium difference allows calculation of effective organic pool size in the tanks. Calculations based on estimated tank ventilation rates and headspace characterization data indicate that tanks 241-BY-108 and 241-C-102 contain significant amounts of organic solvent (i. e., more than a 1 m{sup 2} pool). Tank 24 1 -BY- I I 0 core samples did not contain measurable quantities of NPHs or TBP, though the semivolatile NPHs were observed in tank headspace samples. The total effective surface area of organic solvent in tank 24 1 -BY- I 1 0 is estimated to be less than 1 m{sup 2}; consequently, this tank was not anticipated to contain a significant amount of solvent. An additional observation from the comparison of vapor and condensed-phase sample data is that headspace vapor sampling can detect the presence of organic solvent, even if a surface pool does not exist. Analyses of condensed-phase samples from tank 241-BY-108 show no organic solvent in the top 50 cm of waste. However, ...
Date: September 27, 1996
Creator: Stauffer, L.A.
Partner: UNT Libraries Government Documents Department

Tritium Deposition in Pine Trees and Soil from Atmospheric Releases of Molecular Tritium

Description: Much of the tritium found in soil and leaf litter near a chemical separations facility is incorporated into soil organic matter in a stable non-exchangeable form. Formation of this ''bound'' tritium seems to result from the uptake of molecular tritium (HT) by living pine needles. Soil and litter microbes convert HT to HTO more rapidly, but no measurable organic tritium is formed. This report discusses this study.
Date: February 16, 1982
Creator: Murphy, C.E. Jr.
Partner: UNT Libraries Government Documents Department

Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

Description: For stabilization of heavy metals at contaminated sites, the three way interaction among soil organic matter (OM)-microbes-plants, and their effect on heavy metal binding is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using a soil aging system, the humification of plant matter such as wheat straw was probed along with the effect on microbial community on soil from the former McClellan Air Force Base.
Date: December 31, 2004
Creator: Fan, Teresa W.-M.; Higashi, Richard M.; Crowley, David; Cassel, Andrew N. Lane: Teresa A. & Green, Peter G.
Partner: UNT Libraries Government Documents Department

Effects of Heavy, Tracked-Vehicle Disturbance on Forest Soil Properties at Fort Benning, Georgia

Description: The purpose of this report is to describe the effects of heavy, tracked-vehicle disturbance on various measures of soil quality in training compartment K-11 at Fort Benning, Georgia. Predisturbance soil sampling in April and October of 2002 indicated statistically significant differences in soil properties between upland and riparian sites. Soil density was less at riparian sites, but riparian soils had significantly greater C and N concentrations and stocks than upland soils. Most of the C stock in riparian soils was associated with mineral-associated organic matter (i.e., the silt + clay fraction physically separated from whole mineral soil). Topographic differences in soil N availability were highly dependent on the time of sampling. Riparian soils had higher concentrations of extractable inorganic N than upland soils and also exhibited significantly greater soil N availability during the spring sampling. The disturbance experiment was performed in May 2003 by driving a D7 bulldozer through the mixed pine/hardwood forest. Post-disturbance sampling was limited to upland sites because training with heavy, tracked vehicles at Fort Benning is generally confined to upland soils. Soil sampling approximately one month after the experiment indicated that effects of the bulldozer were limited primarily to the forest floor (O-horizon) and the surface (0-10 cm) mineral soil. O-horizon dry mass and C stocks were significantly reduced, relative to undisturbed sites, and there was an indication of reduced mineral soil C stocks in the disturbance zone. Differences in the surface (0-10 cm) mineral soil also indicated a significant increase in soil density as a result of disturbance by the bulldozer. Although there was some tendency for greater soil N availability in disturbed soils, the changes were not significantly different from undisturbed controls. It is expected that repeated soil disturbance over time, which will normally occur in a military training area, would simply intensify the ...
Date: May 20, 2004
Creator: Garten, C.T.,JR.
Partner: UNT Libraries Government Documents Department

Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers

Description: Rivers are generally supersaturated with respect to carbon dioxide, resulting in large gas evasion fluxes that can be a significant component of regional net carbon budgets. Amazonian rivers were recently shown to outgas more than ten times the amount of carbon exported to the ocean in the form of total organic carbon or dissolved inorganic carbon. High carbon dioxide concentrations in rivers originate largely from in situ respiration of organic carbon, but little agreement exists about the sources or turnover times of this carbon. Here we present results of an extensive survey of the carbon isotope composition ({sup 13}C and {sup 14}C) of dissolved inorganic carbon and three size-fractions of organic carbon across the Amazonian river system. We find that respiration of contemporary organic matter (less than 5 years old) originating on land and near rivers is the dominant source of excess carbon dioxide that drives outgassing in mid-size to large rivers, although we find that bulk organic carbon fractions transported by these rivers range from tens to thousands of years in age. We therefore suggest that a small, rapidly cycling pool of organic carbon is responsible for the large carbon fluxes from land to water to atmosphere in the humid tropics.
Date: June 23, 2005
Creator: Mayorga, E; Aufdenkampe, A K; Masiello, C A; Krusche, A V; Hedges, J I; Quay, P D et al.
Partner: UNT Libraries Government Documents Department

Systems engineering study: tank 241-C-103 organic skimming,storage, treatment and disposal options

Description: This report evaluates alternatives for pumping, storing, treating and disposing of the separable phase organic layer in Hanford Site Tank 241-C-103. The report provides safety and technology based preferences and recommendations. Two major options and several varations of these options were identified. The major options were: 1) transfer both the organic and pumpable aqueous layers to a double-shell tank as part of interim stabilization using existing salt well pumping equipment or 2) skim the organic to an above ground before interim stabilization of Tank 241-C-103. Other options to remove the organic were considered but rejected following preliminary evaluation.
Date: October 23, 1996
Creator: Klem, M.J.
Partner: UNT Libraries Government Documents Department

Biomass Crop Production: Benefits for Soil Quality and Carbon Sequestration

Description: Research at three locations in the southeastern US is quantifying changes in soil quality and soil carbon storage that occur during production of biomass crops compared with row crops. After three growing seasons, soil quality improved and soil carbon storage increased on plots planted to cottonwood, sycamore, sweetgum with a cover crop, switchgrass, and no-till corn. For tree crops, sequestered belowground carbon was found mainly in stumps and large roots. At the TN site, the coarse woody organic matter storage belowground was 1.3 Mg ha{sup {minus}1}yr{sup {minus}1}, of which 79% was stumps and large roots and 21% fine roots. Switchgrass at the AL site also stored considerable carbon belowground as coarse roots. Most of the carbon storage occurred mainly in the upper 30 cw although coarse roots were found to depths of greater than 60 cm. Biomass crops contributed to improvements in soil physical quality as well as increasing belowground carbon sequestration. The distribution and extent of carbon sequestration depends on the growth characteristics and age of the individual biomass crop species. Time and increasing crop maturity will determine the potential of these biomass crops to significantly contribute to the overall national goal of increasing carbon sequestration and reducing greenhouse gas emissions.
Date: August 29, 1999
Creator: Bandaranayake, W.; Bock, B.R.; Houston, A.; Joslin, J.D.; Pettry, D.E.; Schoenholtz, S. et al.
Partner: UNT Libraries Government Documents Department

Project plan for resolution of the organic waste tank safety issues at the Hanford Site

Description: A multi-year project plan for the Organic Safety Project has been developed with the objective of resolving the organic safety issues associated with the High Level Waste (HLW) in Hanford`s single-shell tanks (SSTS) and double-shell tanks (DSTs). The objective of the Organic Safety Project is to ensure safe interim storage until retrieval for pretreatment and disposal operations begins, and to resolve the organic safety issues by September 2001. Since the initial identification of organics as a tank waste safety issue, progress has been made in understanding the specific aspects of organic waste combustibility, and in developing and implementing activities to resolve the organic safety issues.
Date: October 3, 1996
Creator: Meacham, J.E.
Partner: UNT Libraries Government Documents Department

Canaveral ODMDS Dredged Material Erosion Rate Analysis

Description: In this study, the erosion properties of four sediments related to the Canaveral Ocean Dredged Material Disposal Site have been determined as a function of density, consolidation, and shear stress by means of a high shear stress sediment erosion flume at Sandia National Laboratories. Additional analysis was completed for each sediment to determine mineralogy, particle size, and organic content. This was done to support numerical modeling efforts, aid in effective management, and minimize environmental impact. The motivation for this work is based on concerns of dredged material transporting beyond the designated site and estimates of site capacity.
Date: July 1, 2001
Partner: UNT Libraries Government Documents Department

Analysis of mineral trapping for CO{sub 2} disposal in deep aquifers

Description: CO{sub 2} disposal into deep aquifers has been suggested as a potential means whereby atmospheric emissions of greenhouse gases may be reduced. However, our knowledge of the geohydrology, geochemistry, geophysics, and geomechanics of CO{sub 2} disposal must be refined if this technology is to be implemented safely, efficiently, and predictably. As a prelude to a fully coupled treatment of physical and chemical effects of CO{sub 2} injection, we have analyzed the impact of CO{sub 2} immobilization through carbonate precipitation. A survey of all major classes of rock-forming minerals, whose alteration would lead to carbonate precipitation, indicated that very few minerals are present in sufficient quantities in aquifer host rocks to permit significant sequestration of CO{sub 2}. We performed batch reaction modeling of the geochemical evolution of three different aquifer mineralogies in the presence of CO{sub 2} at high pressure. Our modeling considered (1) redox processes that could be important in deep subsurface environments, (2) the presence of organic matter, (3) the kinetics of chemical interactions between the host rock minerals and the aqueous phase, and (4) CO{sub 2} solubility dependence on pressure, temperature and salinity of the system. The geochemical evolution under both natural background and CO{sub 2} injection conditions was evaluated. In addition, changes in porosity were monitored during the simulations. Results indicate that CO{sub 2} sequestration by matrix minerals varies considerably with rock type. Under favorable conditions the amount of CO{sub 2} that may be sequestered by precipitation of secondary carbonates is comparable with and can be larger than the effect of CO{sub 2} dissolution in pore waters. The precipitation of ankerite and siderite is sensitive to the rate of reduction of ferric mineral precursors such as glauconite, which in turn is dependent on the reactivity of associated organic material. The accumulation of carbonates in the rock matrix ...
Date: July 20, 2001
Creator: Xu, Tianfu; Apps, John A. & Pruess, Karsten
Partner: UNT Libraries Government Documents Department

Quantitative Chemical Analysis of the Soils of Erath County, Texas

Description: A chemical analysis of representative samples of Windthorst sand, Denton sand, and Denton clay has been made, and this analysis shows that their composition has a strict correlation with respect to their geological origins. The analyses of the different soils have shown the Windthorst sand to be highly deficient in all of the essential elements, whereas the Denton sand is deficient in only one; namely, phosphorus. The analysis of the Denton clay showed it to be highly fertile. From the consideration of the pH and the lime content, it has been determined to some extent what crops will grow in each of the soils.
Date: June 1938
Creator: Barnes, Benjamin F.
Partner: UNT Libraries

Migration and Entrapment of DNAPLs in Heterogeneous Systems: Impact of Waste and Porous Medium Composition

Description: Dense nonaqueous phase liquids (DNAPLs) pose a significant threat to soil and groundwater at Department of Energy (DOE) sites. Evidence suggests that subsurface wettability variations are present at many of these sites as a result of spatical and temporal variations in aqueous phase chemistry, contaminant aging, mineralogy and organic matter. The presence of such heterogeneity may significantly influence DNAPL migration and entrapment in the saturated zone.
Date: January 10, 2005
Creator: Abriola, Linda M. & Demond, Avery H.
Partner: UNT Libraries Government Documents Department

Estimation of Particle Flux and Remineralization Rate from Radioactive Disequilibrium

Description: Reactive radionuclides, such as the thorium isotopes, show measurable deficiencies in the oceanic water column because of their removal by chemical scavenging due to the particle flux. Measurement of the deficiency, coupled with measurement of the radionuclide concentration in particles, allows a determination of the effective particle sinking velocity. Results to date suggest that the effective particle sinking velocity is remarkably invariant with depth. This leads to the tentative suggestion that POC concentration profiles may, to a good approximation, be used directly to determine length scales for the remineralization of sinking organic matter. Further measurements are in progress to test this idea and to evaluate its limitations. Knowledge of the remineralization length scale is essential to an evaluation of the efficiency of the biological pump as a means for deep sequestering of carbon in the ocean.
Date: May 24, 2004
Creator: Bacon, Michael P. & Francois, Roger
Partner: UNT Libraries Government Documents Department


Description: A goal of the Mesaverde project was to better define the depositional system of the Mesaverde in hopes that it would provide insight to new or by-passed targets for oil exploration. The new, detailed studies of the Mesaverde give us a better understanding of the lateral variability in depositional environments and facies. Recognition of this lateral variability and establishment of the criteria for separating deltaic, strandplain-barrier, and estuarine deposits from each other permit development of better hydrocarbon exploration models, because the sandstone geometry differs in each depositional system. Although these insights will provide better exploration models for gas exploration, it does not appear that they will be instrumental in finding more oil. Oil in the Mesaverde Group is produced from isolated fields on the Chaco slope; only a few wells define each field. Production is from sandstone beds in the upper part of the Point Lookout Sandstone or from individual fluvial channel sandstones in the Menefee. Stratigraphic traps rather than structural traps are more important. Source of the oil in the Menefee and Point Lookout may be from interbedded organic-rich mudstones or coals rather than from the Lewis Shale. The Lewis Shale appears to contain more type III organic matter and, hence, should produce mainly gas. Outcrop studies have not documented oil staining that might point to past oil migration through the sandstones of the Mesaverde. The lack of oil production may be related to the following: (1) lack of abundant organic matter of the type I or II variety in the Lewis Shale needed to produce oil, (2) ineffective migration pathways due to discontinuities in sandstone reservoir geometries, (3) cementation or early formation of gas prior to oil generation that reduced effective permeabilities and served as barriers to updip migration of oil, or (4) erosion of oilbearing reservoirs from ...
Date: May 21, 2000
Creator: Ridgley, Jennie
Partner: UNT Libraries Government Documents Department

Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

Description: The myriad of human activities including strategic and energy development at various DOE installations have resulted in the contamination of soils and waterways that can seriously threaten human and ecosystem health. Development of efficacious and economical remediation technologies is needed to ameliorate these immensely costly problems. Bioremediation (both plant and microbe-based) has promising potential to meet this demand but still requires advances in fundamental knowledge. For bioremediation of heavy metals, the three-way interaction of plant root, microbial community, and soil organic matter (SOM)1 in the rhizosphere is critically important for long-term sustainability but often underconsidered. Particularly urgent is the need to understand processes that lead to metal ion stabilization in soils, which is crucial to all of the goals of bioremediation: removal, stabilization, and transformation. This project will build on the knowledge that we have generated on the role of root exudation and metabolism for metal mobilization and accumulation, to address the following objectives: (1) Identify molecular markers and characterize the chemical nature of recalcitrant SOM pools that are involved in below ground metal ion interactions, which are likely to be markers for sustainable sequestration; (2) Utilize (1) to determine plant and microbial factors that contribute to sustainable metal sequestration or mobility, as well as bioavailability; (3) Utilize information from (1) and (2) to explore efficacious means for enhancing sustainable phytostabilization of heavy metals in the subsurface zone.
Date: June 25, 2001
Creator: Fan, Teresa W. M.; Higashi, Richard M. & Crowley
Partner: UNT Libraries Government Documents Department

DOE final report: Studies on the microbial formation of methane

Description: The microbial formation of methane is carried out by methanogens which are found wherever active anaerobic degradation of organic matter occurs. We developed a procedure for reliable culture of 'Methanococus jannaschii' which yields 8 g wet weight of cells per liter of medium. To initiate a study of proteomics, this organism was grown at two levels of hydrogen partial pressure, very low (650 Pa) and high (178 kPa). When cells were exposed to hydrogen excess conditions, they possessed very low or undetectable levels of four flagella-related polypeptides, whereas, when hydrogen became limiting, these proteins were synthesized. Thus, use of proteomics showed, for the first time, that this methanogen can regulate expression of proteins, and these experiments open the door for general studies of regulation in this hyperthermophile.
Date: April 1, 2001
Creator: Wolfe, Ralph S.
Partner: UNT Libraries Government Documents Department