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SUPPLEMENTAL COLUMBIA RIVER PROTECTION ACTIVITIES AT THE DEPARTMENT OF ENERGY HANFORD SITE 2008 TECHNICAL REVIEW
Beginning in 2006, the US Department of Energy (DOE) supported nine applied research projects to improve the protection of the Columbia River and mitigate the impacts of Hanford Site groundwater. These projects were funded through a supplemental Congressional budget allocation, and are now in various stages of completion in accordance with the research plans. The DOE Office of Environmental Management Groundwater and Soil Cleanup Technologies (EM-22) sponsored a technical peer review meeting for these projects in Richland WA, July 28-31, 2008. The overall objective of the peer review is to provide information to support DOE decisions about the status and potential future application of the various technologies. The charge for the peer review panel was to develop recommendations for each of the nine 'technologies'. Team members for the July 2008 review were Brian Looney, Gene LeBoeuf, Dawn Kaback, Karen Skubal, Joe Rossabi, Paul Deutsch, and David Cocke. Previous project reviews were held in May 2007 and March-May of 2006. The team used the following four rating categories for projects: (a) Incorporate the technology/strategy in ongoing and future EM activities; (b) Finish existing scope of applied research and determine potential for EM activities when research program is finished; (c) Discontinue current development activities and do not incorporate technology/strategy into ongoing and future EM activities unless a significant and compelling change in potential viability is documented; and (d) Supplement original funded work to obtain the data needed to support a DOE decision to incorporate the technology into ongoing and future EM activities. The supplemental funding portfolio included two projects that addressed strontium, five projects that addressed chromium, one project that addressed uranium and one project that addressed carbon tetrachloride. The projects ranged from in situ treatment methods for immobilizing contaminants using chemical-based methods such as phosphate addition, to innovative surface treatment technologies such as electrocoagulation. Total funding for the nine projects was 2,000,000 in FY 2007. At the Richland meeting, the peer reviewers provided a generally neutral assessment of the projects and overall progress, and a generally positive assessment with regard to the principal investigators meeting their stated research objectives and performing the planned laboratory research and limited field work. Only one project, the Electrocoagulation Treatability Test, received a rating of 'discontinue' from the team because the project goals had not been met. Because this particular project has already ended, no action with respect to funding withdrawal is necessary. All other projects were recommended to be finished and/or incorporated into field efforts at Hanford. Specific technical comments and recommendations were provided by the team for each project
Effects of iron oxide nanoparticles on polyvinyl alcohol: Interfacial layer and bulk nanocomposites thin film
Iron oxide (α-phase) nanoparticles with coercivity larger than 300 Oe have been fabricated at a mild temperature by an environmentally benign method. The economic sodium chloride has been found to effectively serve as a solid spacer to disperse the iron precursor and to prevent the nanoparticles from agglomeration. Higher ratios of sodium chloride to iron nitrate result in smaller nanoparticles (19 nm for 20:1 and 14 nm for 50:1). The presence of polyvinyl alcohol (PVA) limits the particle growth (15 nm for 20:1 and 13 nm for 50:1) and favors nanoparticle dispersion in polymer matrices. Obvious physicochemical property changes have been observed with PVA attached to the nanoparticle surface. With PVA attached to the nanoparticle surface, the nanoparticles are found not only to increase the PVA cross-linking with an increase in melting temperature but also to enhance the thermal stability of the PVA. The nanoparticles are observed to be uniformly dispersed in the polymer matrix. Scanning electron microscopy (SEM) microstructure also shows an intermediate phase with a strong interaction between the nanoparticles and the polymer matrices, arising from the hydrogen bonding between the PVA and hydroxyl groups on the nanoparticle surface. The addition of nanoparticles favors the cross-linkage of the bulk PVA matrices, resulting in a higher melting temperature, and an enhanced thermal stability of the polymer matrix. © Springer Science+Business Media B.V. 2009