Tc(IV) and Tc(VII) interactions with iron oxyhdroxides

Walton, Frank B.; Paquette, Jean; Ross, J.P.M.; Lawrence, W.E.

doi:10.1016/0191-815x(86)90049-5

Cited by 30 publications

(24 citation statements)

References 10 publications

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“…A plausible explanation for this behavior is the sorption of TcO 4 − on the oxidized surface of FeS, reported to be iron oxyhydroxide [28]. The hydrous iron oxyhydroxide has the potential to form surface complexes with anions [75] and was reported to have little sorption of TcO 4 − over short time periods (0.24% in 4 h) [76]. However, it is possible that the iron oxyhydroxide sorbed TcO 4 − over a longer period of time, resulting in the decrease of TcO 4 − observed.…”

Section: Product Stabilitymentioning

confidence: 99%

Pertechnetate immobilization with amorphous iron sulfide

Liu

Terry

Jurisson³

2008

Radiochimica Acta

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Section: Product Stabilitymentioning

confidence: 99%

Pertechnetate immobilization with amorphous iron sulfide

Liu

Terry

Jurisson³

2008

Radiochimica Acta

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“…Korte et al (1997) also reported effective removal of 99 Tc from groundwater by zero-valent iron, but concluded that reductive precipitation was the primary removal mechanism. In F-Area groundwater the concentrations of 99 Tc are below the solubility of TcO 2 ·1.6H 2 O, so the removal mechanism would have to be sorption onto iron hydroxides in the soil or coating the iron particles (Walton et al, 1986;Lieser and Bauscher, 1987).…”

Section: Summary Of Methodsmentioning

confidence: 99%

“…Thus, reduction of technetium will not cause precipitation of TcO 2 ·1.6H 2 O and is unlikely to result in precipitation of the less soluble TcO 2 . Nevertheless, 99 Tc concentrations may decrease upon reduction to Tc(IV) because of enhanced sorption of the aqueous species TcO(OH) + and TcO(OH) 2 o (Walton et al, 1986;Lieser and Bauscher, 1987;Liang et al, 1996).…”

Section: Any Decrease In 99mentioning

confidence: 99%

Potential In Situ Remediation of 129-I and 99-Tc in Groundwater Associated with the F-Area Seepage Basins

Denham¹

2003

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“…In Figure 13 (Walton et al, 1986;Lieser and Bauscher, 1987;Liang et al, 1996). Another reduction option is to reduce Tc(VII) to sparingly soluble Tc metal.…”

Section: Any Decrease Inmentioning

confidence: 99%

Recommended Amendment Mixture for in Situ Treatment of Water Management Unit Groundwater, Ashtabula Closure Project

Denham¹

2004

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Executive SummaryThis document provides recommendations for the composition of a mixture of peat, hydroxyapatite, and sand to treat dissolved TCE, uranium, and technetium-99 in groundwater at the Waste Management Unit (WMU) of the Ashtabula Closure Project. One option for treatment presented by the Department of Energy Office of Environmental Management sponsored technical assistance team was to remove the most contaminated soil and fill the engineered excavation with amendments for in situ clean up of the groundwater.A mixture of peat and hydroxyapatite will produce conditions necessary for stabilization of uranium and technetium-99, as well as anaerobic degradation of TCE. There is an ample body of literature supporting the use of peat to maintain the methanogenic conditions required for reductive dechlorination of TCE. Likewise, peat has been used to remediate uranium in groundwater. Furthermore, reducing conditions that stabilize uranium will also stabilize technetium-99. Addition of hydroxyapatite, a natural phosphate mineral, will enhance stabilization of uranium by precipitation of low solubility phosphate phases. Hydroxyapatite will also provide phosphate, a critical nutrient, to promote microbial degradation of the peat required to maintain methanogenic conditions. This is based on the composition of WMU groundwater, the groundwater flow rate, and an assumed 30-year lifetime for the outermost meter of the treatment zone. The lifetime of the treatment system as a whole depends on the size of the treatment zone. It is recommended that laboratory treatability studies be conducted prior to any implementation of this system. The studies should focus on effectiveness and longevity. Two specific issues that may affect these are replacement of hydroxyapatite by fluorapatite and precipitation of calcite within the system. 3Denham et al

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Tc(IV) and Tc(VII) interactions with iron oxyhdroxides

Cited by 30 publications

References 10 publications

Pertechnetate immobilization with amorphous iron sulfide

Pertechnetate immobilization with amorphous iron sulfide

Potential In Situ Remediation of 129-I and 99-Tc in Groundwater Associated with the F-Area Seepage Basins

Recommended Amendment Mixture for in Situ Treatment of Water Management Unit Groundwater, Ashtabula Closure Project

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