Characterization of Sediments from the Soil Desiccation Pilot Test (SDPT) Site in the BC Cribs and Trenches Area (open access)

Characterization of Sediments from the Soil Desiccation Pilot Test (SDPT) Site in the BC Cribs and Trenches Area

This technical report documents the results of laboratory geochemical and hydrologic measurements of sediments collected from new borehole 299-E13-65 (C7047) and comparison of the results with those of nearby borehole 299-13E-62 (C5923) both drilled in the BC Cribs and Trenches Area. The total and water-leachable concentrations of key contaminants will be used to update contaminant-distribution conceptual models and to provide more data for improving baseline risk predictions and remedial alternative selections. Improved understanding of subsurface conditions and methods to remediate these principal contaminants can be also used to evaluate the application of specific technologies to other contaminants across the Hanford Site.
Date: September 25, 2009
Creator: Um, Wooyong; Truex, Michael J.; Valenta, Michelle M.; Iovin, Cristian; Kutnyakov, Igor V.; Chang, Hyun-shik et al.
System: The UNT Digital Library
TANK 12 SLUDGE CHARACTERIZATION AND ALUMINUM DISSOLUTION DEMONSTRATION (open access)

TANK 12 SLUDGE CHARACTERIZATION AND ALUMINUM DISSOLUTION DEMONSTRATION

A 3-L sludge slurry sample from Tank 12 was characterized and then processed through an aluminum dissolution demonstration. The dominant constituent of the sludge was found to be aluminum in the form of boehmite. The iron content was minor, about one-tenth that of the aluminum. The salt content of the supernatant was relatively high, with a sodium concentration of {approx}7 M. Due to these characteristics, the yield stress and plastic viscosity of the unprocessed slurry were relatively high (19 Pa and 27 cP), and the settling rate of the sludge was relatively low ({approx}20% settling over a two and a half week period). Prior to performing aluminum dissolution, plutonium and gadolinium were added to the slurry to simulate receipt of plutonium waste from H-Canyon. Aluminum dissolution was performed over a 26 day period at a temperature of 65 C. Approximately 60% of the insoluble aluminum dissolved during the demonstration, with the rate of dissolution slowing significantly by the end of the demonstration period. In contrast, approximately 20% of the plutonium and less than 1% of the gadolinium partitioned to the liquid phase. However, about a third of the liquid phase plutonium became solubilized prior to the dissolution period, when the …
Date: March 25, 2009
Creator: Reboul, S; Michael Hay, M; Kristine Zeigler, K & Michael Stone, M
System: The UNT Digital Library
Biofuels: Potential Effects and Challenges of Required Increases in Production and Use (open access)

Biofuels: Potential Effects and Challenges of Required Increases in Production and Use

A chapter report issued by the Government Accountability Office with an abstract that begins "In December 2007, the Congress expanded the renewable fuel standard (RFS), which requires rising use of ethanol and other biofuels, from 9 billion gallons in 2008 to 36 billion gallons in 2022. To meet the RFS, the Departments of Agriculture (USDA) and Energy (DOE) are developing advanced biofuels that use cellulosic feedstocks, such as corn stover and switchgrass. The Environmental Protection Agency (EPA) administers the RFS. This report examines, among other things, (1) the effects of increased biofuels production on U.S. agriculture, environment, and greenhouse gas emissions; (2) federal support for domestic biofuels production; and (3) key challenges in meeting the RFS. GAO extensively reviewed scientific studies, interviewed experts and agency officials, and visited five DOE and USDA laboratories."
Date: August 25, 2009
Creator: United States. Government Accountability Office.
System: The UNT Digital Library