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Characterization Activities Conducted at the 183-DR Site in Support of an In Situ Gaseous Reduction Demonstration

Description: In Situ Gaseous Reduction (ISGR) is a technology developed by DOE for the remediation of soil waste sites contaminated with hexavalent chromium. This document presents information associated with characterization activities conducted at the 183-DR site at Hanford, which is associated with a significant groundwater contaminant plume and was formerly a water treatment facility that utilized chromate as a corrosion inhibitor. Geotechnical and chemical data were collected during the excavation of trenches and the drilling of two vadose zone boreholes to support a possible ISGR demonstration at 183-DR. Although elevated total chromium and trace levels of hexavalent chromium were identified from one of the trenches and one of the boreholes, it appears that the boreholes missed the vadose zone contaminant source responsible for the chromium groundwater plume located downgradient of the 183-DR site. Recommendations are provided, however, for future work at 183-DR that may serve to identify the source for the groundwater plume and possibly provide an opportunity for an ISGR demonstration.
Date: March 30, 2001
Creator: Thornton, Edward C.; Gilmore, Tyler J.; Olsen, Khris B.; Schalla, Ronald & Cantrell, Kirk J.
Partner: UNT Libraries Government Documents Department

Investigation of Hexavalent Chromium Flux to Groundwater at the 100-C-7:1 Excavation Site

Description: Deep excavation of soil has been conducted at the 100-C-7 and 100-C-7:1 waste sites within the 100-BC Operable Unit at the Department of Energy (DOE) Hanford Site to remove hexavalent chromium (Cr(VI)) contamination with the excavations reaching to near the water table. Soil sampling showed that Cr(VI) contamination was still present at the bottom of the 100-C-7:1 excavation. In addition, Cr(VI) concentrations in a downgradient monitoring well have shown a transient spike of increased Cr(VI) concentration following initiation of excavation. Potentially, the increased Cr(VI) concentrations in the downgradient monitoring well are due to Cr(VI) from the excavation site. However, data were needed to evaluate this possibility and to quantify the overall impact of the 100-C-7:1 excavation site on groundwater. Data collected from a network of aquifer tubes installed across the floor of the 100-C-7:1 excavation and from temporary wells installed at the bottom of the entrance ramp to the excavation were used to evaluate Cr(VI) releases into the aquifer and to estimate local-scale hydraulic properties and groundwater flow velocity.
Date: November 16, 2012
Creator: Truex, Michael J.; Vermeul, Vincent R.; Fritz, Brad G.; Mackley, Rob D.; Horner, Jacob A.; Johnson, Christian D. et al.
Partner: UNT Libraries Government Documents Department

Effect of Cr addition on γ-γ' cobalt-based Co-Mo-Al-Ta class of superalloys: a combined experimental and computational study

Description: This article deals with effect of Cr addition (10 at.%) on the partitioning behavior and the consequent effect on mechanical properties for tungsten-free γ-γ' cobalt-based superalloys with base alloy compositions of Co–30Ni–10Al–5Mo–2Ta (2Ta) and Co–30Ni–10Al–5Mo–2Ta–2Ti (2Ta2Ti).
Date: June 12, 2017
Creator: Nithin, B.; Samanta, A.; Makineni, S. K.; Alam, Talukder; Pandey, P.; Singh, Abhishek K. et al.
Partner: UNT College of Engineering

Sponge Chromium

Description: From Introduction: "There follows discussion of the reduction processes suitable for preparing sponge chromium from the chlorides, and finally the question of special methods required to insure the production of a high-purity product is investigated. This order is a natural and chronological one as well as being suited to the needs of presenting an analytic picture of the experimental work and its results and proposals engendered."
Date: 1942
Creator: Maier, C. G.
Partner: UNT Libraries Government Documents Department

Hydrolytic polymerization of chromium (III) hydroxides in the aquatic environment

Description: Products of hydrolytic polymerization of Cr(III) hydroxide were investigated in Milli-Q water and in natural water matrices. Products were first fractionated on Sephadex column using eluents of increasing strength. Ion chromatography (IC) with UV detection at 436 nm was then used to separate the ionic species.
Date: December 1991
Creator: Mbamalu, Godwin E.
Partner: UNT Libraries

Kinetics of sintering chromium carbide

Description: Report presenting an investigation of the sintering of chromium carbide under pressure in order to study the kinetics of grain growth and densification during this process. Densification of a sintered chromium carbide compact was accompanied by grain growth and density and grain size seem to be interdependent during this stage of the sintering process.
Date: August 1951
Creator: Lidman, William G. & Hamjian, H. J.
Partner: UNT Libraries Government Documents Department

Differential isotopic fractionation during Cr(VI) reduction by an aquifer-derived bacterium under arobic versus denitrifying conditions

Description: We studied Cr isotopic fractionation during Cr(VI) reduction by Pseudomonas stutzeri strain RCH2. Despite the fact that strain RCH2 reduces Cr(VI) co-metabolically under both aerobic and denitrifying conditions and at similar specific rates, fractionation was markedly different under these two conditions (ε ~2� aerobically and ~0.4� under denitrifying conditions).
Date: February 1, 2012
Creator: Han, R.; Qin, L.; Brown, S. T.; Christensen, J. N. & Beller, H. R.
Partner: UNT Libraries Government Documents Department

Ion Chromatography of Soluble Cr(III) and Cr(VI)

Description: Ion chromatography coupled with a conductivity detector was used to investigate the analysis of Cr(III) and Cr(VI) in aqueous samples. An IC methodology for Cr(III) was developed using a cation column and an eluent containing tartaric acid, ethylenediamine, and acetonitrile at pH 2.9. The detection limit of this method can reach 0.1 ppm level with good precision. Several operational parameters were evaluated during the regular use of the method. Comparison of the IC method with AA method showed good agreement between the two methods. The anion exchange column was used for Cr(VI) determination. The best results were obtained with an eluent containing sodium gluconate, borate buffer, glycerin, and acetonitrile. The retention time for the Cr207 2 - sample was 11 min. and the calibration curve was linear between 1.0 and 100 ppm.
Date: August 1988
Creator: Huang, Julie Shiong-Jiun
Partner: UNT Libraries

Low-Coordinate Chromium Siloxides: The "Box" [Cr(μ-OSitBu3)]4, Distorted Trigonal [(tBu3SiO)3Cr] [Na(benzene)] and [(tBu3SiO)3Cr] [Na(dibenzo-18-c-6)], and Trigonal (tBu3SiO)3Cr

Description: Article discussing low-coordinate chromium siloxides and the "box" [Cr(μ-Cl)(μ-OSiᵗBu₃)]₄, distorted trigonal [(ᵗBu₃SiO)₃Cr][Na(benzene)] and [(ᵗBu₃SiO)₃Cr][Na(dibenzo-18-c-6)], and trigonal (ᵗBu₃SiO)₃Cr.
Date: March 24, 2005
Creator: Sydora, Orson L.; Wolczanski, Peter T.; Lobkovsky, Emil B.; Buda, Corneliu & Cundari, Thomas R., 1964-
Partner: UNT College of Arts and Sciences

Description of Work for Drilling at the 183-DR Site in Support of the In Situ Gaseous Reduction Test

Description: In Situ Gaseous Reduction is a technology currently being developed by DOE for the remediation of soil waste sites contaminated with hexavalent chromium. Prior work suggests that a candidate for application of this approach is the 183-DR site at Hanford. However, deep vadose zone drilling is needed to verify the presence of a hexavalent chromium source and to determine the concentration levels and spatial distribution of contamination. This document presents the requirements associated with drilling one to two vadose zone boreholes at the 183-DR site to obtain this information. If hexavalent chromium is determined to be present at levels of at least 10 ppm in the vadose zone in one of the initial boreholes, this hole will be completed for gas injection and six additional gas extraction boreholes will be drilled and completed. This network will be used as a flowcell for performing a gas treatment test at the site.
Date: June 26, 2000
Creator: Thornton, Edward C.; Olsen, Khris B. & Schalla, Ronald
Partner: UNT Libraries Government Documents Department

Sampling Instruction: Investigation of Hexavalent Chromium Flux to Groundwater at the 100-C-7:1 Excavation Site

Description: Several types of data are needed to assess the flux of Cr(VI) from the excavation into the groundwater. As described in this plan, these data include (1) temporal Cr(VI) data in the shallow groundwater beneath the pit; (2) hydrologic data to interpret groundwater flow and contaminant transport; (3) hydraulic gradient data; and (4) as a contingency action if necessary, vertical profiling of Cr(VI) concentrations in the shallow aquifer beyond the depth possible with aquifer tubes.
Date: May 1, 2012
Creator: Truex, Michael J. & Vermeul, Vincent R.
Partner: UNT Libraries Government Documents Department

Spin-density-wave antiferromagnetism of Cr in Fe/Cr(001) superlattices

Description: The antiferromagnetic spin-density-wave (SDW) order of Cr layers in Fe/Cr(001) superlattices was investigated by neutron scattering. For Cr thickness 51-190 {Angstrom}, a transverse SDW is formed for all temperatures below Neel temperature with a single wavevector Q normal to the layers. A coherent magnetic structure forms with the nodes of the SDW near the Fe-Cr interfaces. For thinner Cr layers, the magnetic scattering can be described by commensurate antiferromagnetic order.
Date: October 1, 1996
Creator: Fullerton, E.E.; Bader, S.D. & Robertson, J.L.
Partner: UNT Libraries Government Documents Department

Identification of a Hanford Waste Site for Initial Deployment of the In Situ Gaseous Reduction Approach

Description: In Situ Gaseous Reduction is a technology currently being developed by DOE for the remediation of soil waste sites contaminated with hexavalent chromium. This document presents the results of recent characterization activities undertaken at several of the soil waste sites at Hanford that contain significant levels of hexavalent chromium contamination. The objective of this study is to select a site for initial deployment of the technology at the Hanford Site.
Date: November 28, 2000
Creator: Thornton, Edward C; Cantrell, Kirk J; Faurote, James M; Gilmore, Terrance J; Olsen, Khris B & Schalla, Ronald
Partner: UNT Libraries Government Documents Department

Progress Reports - Metallurgical Division: 13. Electrometallurgical Investigations

Description: Report issued by the U.S. Bureau of Mines on the progress made on projects in the Metallurgical Division. Descriptions of progress in the different projects and operations conducted are listed. This report includes tables, graphs, and illustrations.
Date: October 1936
Creator: Koster, J.; Shelton, S. M. & Knickerbocker, R. G.
Partner: UNT Libraries Government Documents Department

Quantitative Analysis Laboratory Experiment: Bilinear Regression Analysis as a Means to Reduce Matrix Effects in Simultaneous Spectrophotometric Determination of Cr(III) and Co(II)

Description: Article on bilinear regression analysis as a means to reduce matrix effects in simultaneous spectrophotometric determination of Cr(III) and Co(II) and a quantitative analysis laboratory experiment.
Date: July 1, 1998
Creator: Pandey, Siddharth; McHale, Mary E. R.; Coym, Karen S. & Acree, William E. (William Eugene)
Partner: UNT College of Arts and Sciences

Chromium isotopes as indicators of hexavalent chromium reduction

Description: This is the final report for a university research project which advanced development of a new technology for identifying chemical reduction of hexavalent chromium contamination in groundwater systems. Reduction renders mobile and toxic hexavalent chromium immobile and less toxic. The new method uses stable isotope ratio measurements, which are made using multicollector ICP-mass spectrometry. The main objectives of this project were completed during the project period and two peer-reviewed articles were published to disseminate the information gained.
Date: March 20, 2012
Creator: Johnson, Thomas M.
Partner: UNT Libraries Government Documents Department

THE ABSOLUTE ABUNDANCE OF THE CHROMIUM ISOTOPES IN SOME SECONDARY MINERALS

Description: Isotopic assays have been made on the Cr in samples from 14 different chrominiferous minerals from different geographic and meteoritic sources. The results of the assays indicate that it is not possible to state unequivocally that variations in isotopic composition have been observed. (auth)
Date: March 14, 1962
Creator: Svec, H.J.; Flesch, G.D. & Capellen, J.
Partner: UNT Libraries Government Documents Department

Immunotoxicity of Chromium Contaminated Soil in the Earthworm, Lumbricus Terrestris

Description: Objective was to assess the toxicity of chromium (Cr) contaminated soil (CS) using the earthworm Lumbricus terrestris. Specific aims were to determine: (1) survival (LC50); .(2) immunotoxicity as indicated by lysozyme activity, coelomocyte counts, secretory (SR) and erythrocyte rosette (ER) formation, and phagocytosis; and (3) compare effects of CS exposure with those of Cr spiked artificial soil (AS) . CS Cr concentration was 8.78 mg/g with 98.2% being Cr^3+ and 1.8% being Cr^6+. Using 14 d AS protocol the LC50 was 6.49% CS: AS mixture. CS concentrations of 0.5, 1.0, 2.5 and 5.0% were sublethal, whereas 6.25, 12.5, 25, 50 and 100% CS were lethal. Sublethal exposure caused no immuno- modulation. Exposure to 50% CS: AS mixture for 5 d caused reduced SR and ER formation. Exposure to AS spiked with 0.27% Cr for 5 d resulted in immunomodulation equivalent to 50% CS: AS mixtures. Results indicated the CS to be acutely toxic.
Date: May 1993
Creator: Mohammadian, Gholamreza
Partner: UNT Libraries

Use of phosphates to reduce slag penetration in Cr2O3-based refractories

Description: A high-chromium refractory material that provides improved resistance to coal slag penetration is presented. The refractory mixture comprises a blend of chromium oxide, aluminum oxide and phosphates. The refractory mixture may be blended with an aggregate and cured. In addition a phosphorous oxide may be blended with chromium oxide and aluminum oxide and additionally an aggregate. The refractory mixture reduces the rate of coal slag penetration into the surface of the cured refractory.
Date: November 9, 2004
Creator: Kwong, Kyei-Sing; Dogan, Cynthia P.; Bennett, James P.; Chinn, Richard E. & Petty, Arthur V.
Partner: UNT Libraries Government Documents Department

Microbial community changes during sustained Cr(VI) reduction at the 100H site in Hanford, WA

Description: Hexavalent Chromium is a widespread contaminant found in soil, sediment, and groundwater. In order to stimulate microbially-mediated reduction of Cr(VI), a poly-lactate compound (HRC) was injected into the Chromium-contaminated aquifer at the Hanford (WA) 100H site in 2004. Cr(VI) concentrations rapidly declined to below the detection limit and remained so for more than three years after injection. Based on the results of the bacterial community composition using high-density DNA 16S rRNA gene microarrays, we observed the community to transition through denitrifying, ironreducing and sulfate-reducing populations. As a result, we specifically focused isolation efforts on three bacterial species that were significant components of the community. Positive enrichments in defined anaerobic media resulted in the isolation of an iron-reducing Geobacter metallireducens-like isolate, a sulfate-reducing Desulfovibrio vukgaris-like strain and a nitrate-reducing Pseudomonas stutzeri-like isolate among several others. All of these isolates were capable of reducing Cr(VI) anoxically and have been submitted for genome sequencing to JGI. To further characterize the microbial, and geochemical mechanisms associated with in situ Cr(VI) reduction at the site, additional HRC was injected in 2008. The goal was to restimulate the indigenous microbial community and to regenerate the reducing conditions necessary for continued Cr(VI) bio-immobilization in the groundwater. Analysis of the microbial populations post-injection revealed that they recovered to a similar density as after the first injection in 2004. In this study, we present the results from our investigation into microbially-mediated Cr(VI) reduction at Hanford, and a comparison of the microbial community development following two HRC injections four years apart.
Date: May 17, 2010
Creator: Chakraborty, Romy; Brodie, Eoin L; Faybishenko, Boris; Piceno, Yvette M; Tom, Lauren; Choudhuri, Swati et al.
Partner: UNT Libraries Government Documents Department

Ductilization of Cr via Oxide Dispersions

Description: Work by Scruggs et al. in the 1960's demonstrated that up to 20% tensile ductility could be achieved at room-temperature in sintered and extruded powder metallurgical Cr alloyed with MgO. During sintering, much of the MgO converts to a MgCr{sub 2}O{sub 4} spinel, which was hypothesized to getter nitrogen from the Cr, rendering it ductile. Recent efforts at Oak Ridge National Laboratory (ORNL) have succeeded in duplicating this original effect. Preliminary results suggest that the ductilization mechanism may be more complicated than the simple nitrogen gettering mechanism proposed by Scruggs, as some ductility was observed at room-temperature in Cr-MgO alloys containing nitride precipitates. Results of microstructural characterization and room-temperature mechanical property studies are presented for Cr-6MgO-(0-2.2)Ti wt.% as a function of hot-pressing and extrusion. Possible mechanisms by which the MgO additions may improve the room-temperature ductility of Cr are discussed.
Date: February 14, 2001
Creator: Brady, M.P.
Partner: UNT Libraries Government Documents Department