Actinide and Technetium Sorption on Iron-Silicate and Dispersed Clay Colloids

Shade, J.W.; Ames, L.L.; McGarrah, J.E.

doi:10.1021/bk-1984-0246.ch004

Cited by 6 publications

(5 citation statements)

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“…These higher values under reducing conditions can be attributed principally to reduction of Tc(VII) and subsequent precipitation of Tc(IV) and not due to adsorption reactions. Tests conducted by Shade et al (1984) on two silicate minerals in a groundwater matrix indicated K d values of ~130 -2270 ml/g for a sample of Na-bentonite, whereas, the synthetic Fe-silicate did not adsorb any Tc. Comparatively, studies conducted by Nowak (1980b) on samples of bentonite and hectorite in 5M sodium chloride brine (reflecting the Yucca Mountain repository environment) showed very low affinity for Tc (K d : 0-1 ml/g).…”

Section: Oxides and Hydroxide Mineralsmentioning

confidence: 94%

Selection and Testing of "Getters" for Adsorption of Iodine-129 and Technetium-99: A Review

Mattigod¹,

Serne²,

Fryxell³

2003

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Section: Oxides and Hydroxide Mineralsmentioning

confidence: 94%

Selection and Testing of "Getters" for Adsorption of Iodine-129 and Technetium-99: A Review

Mattigod¹,

Serne²,

Fryxell³

2003

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“…Laboratory tests show that aluminum and iron colloids are formed during glass corrosion [167], and that these may sorb radionuclides [67,266]. Depending on the colloid size, solution chemistry, groundwater flow and the characteristics of the surrounding geology, these colloids may or may not be transportable, and their transportability may change over time.…”

Section: 3mentioning

confidence: 99%

The effects of the glass surface area/solution volume ratio on glass corrosion: A critical review

Ebert

1995

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Argonne National Lahoratory. wi1th facilitie, in the states of liiinois and Idaho. is owned by the united States govern lent, and operated by The Un diversity of Chicago under the provisions of a contract with thie department of Enery. DISCLAIM ER THE FFFECTS OF THE GLASS SURFACE AREA/SOLUTION VOLUME RATIO ON GLASS CORROSION: A CRITICAL REVIEW William L. Ebert ABSTRACTThis report reviews and summarizes the present state of knowledge regarding the effects of the glass surface area/solution volume (SA/V) ratio on the corrosion behavior of borosilicate waste glasses. The SA/V ratio affects the rate of glass corrosion through the extent of dilution ok corrosion products released from the glass into the leachate solution: glass corrosion products are diluted more in tests conducted at low SA/V ratios than they are in tests conducted at high SAN ratios. Differences in the solution chemistries generated in tests conducted at different SA/V ratios then affect the observed glass corrosion behavior. Corrosion of borosilicate waste glasses results in the dissolution of soluble components and the accumulation of sparingly soluble components in a layer on the surface of the corroding glass. Laboratory tests performed to distinguish the effects of the solution chemistry and the surface layer on the glass corrosion rate have shown the rate to be controlled primarily by the solution chemistry. Therefore, any testing parameter that affects the solution chemistry will also affect the glass corrosion rate. The results of static leach tests conducted to assess the effects of the SAN are discussed with regard to the effects of SAN on the solution chemistry. The effects of the SA/V ratio observed in static tests can be understood based on the effects of the solution chemistry on glass corrosion behavior. Test results show several remaining issues with regard to the long-term glass corrosion behavior: Can the SAN ratio be used as an accelerating parameter to characterize the advanced stages of glass corrosion relevant to long disposal times? Is the alteration of the glass surface the same in tests conducted at different SAN, and in tests conducted with monolithic and crushed glass samples? What are the effects of the SAN and the extent of glass corrosion on the disposition of released radionuclides? These issues will bear on the prediction of the long-term performance of waste glasses during storage. The results of an experimental program conducted at ANL to address these and other remaining issues regarding the effects of SA/V on glass corrosion are described. I 2 SUMMARYThis report reviews and summarizes the present state of knowledge regarding the effects of the glass surface area/solution volume ratio (SA/V) on the corrosion behavior of borosilicate waste glasses. The effects of the SA/ occur through dilution of corrosion products and through the effects of the corrosion products on the glass corrosion mechanism and rate. Therefore, the effects of the SA/V on glass corrosion are discussed in terms of the various effects of t...

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“…Laboratory experiments by Vandegrift et al [1984] found significant bentonite retention in basalt fissures. Shade et al [1984] discussed preliminary experiments on the adsorption of radionuclides to silica rich colloids released from glass waste containers. These colloids were not destabilized by the natural groundwater considered, although the authors did not attempt a complete characterization of colloids.…”

Section: Sealants and Barriersmentioning

confidence: 99%

Particle transport through porous media

McDowell-Boyer¹,

Hunt²,

Sitar³

1986

Water Resources Research

784

456

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The authors are to be commended for their thorough and timely review [McDowell-Boyer et al., 1986] on the subject of particle transport through porous media. It was felt, however, that they have not followed far enough their own streams of thoughts. Despite the detailed descriptions of current perceptions how particles get separated from the carrying liquid and how they interact with the porous media, little attention was paid to the fact why they can be transported over hundreds of meters. The authors mentioned the studies by Smith et el.[1985], who reported microbial breakthrough at the 0.3-m depth of undisturbed soil columns within 17-50 min. Gerba and Goyal's [1985] study is also cited according to which bacteria had moved over distances of more than 800 m. However, no discussion is offered about the discrepancy between these and many other reported observations on fast and farreaching particle transport in porous media and the lack of models dealing with this kind of transport. Corapcioglu and Haridas [1985], for instance, presented an approach to the transport of microorganisms through porous media. No matter how these authors stressed the flow parameters (they went to the permissible limits), their model strongly indicated that bacteria cannot be transported over distances exceeding 0.2 m under the commonly accepted constrains of the model.The reasons for these deficiencies in the perception of particle transport through porous media, as they are well represented in this review article, can be traced back to the early beginnings of groundwater hydrology. It was Darcy's [1856] cracks. Voids which support particle transport have diameters at least an order of magnitude greater than the particles that move. This movement results in readily recognizable accumulations of silt (siltants) or clay (argilans) coatings on the surfaces of the voids, eventually plugging them. Filter theory conceptualizes the porous media as homogenous, whereas microscopists conceptualize the same media as inhomogeneous [Jeans, 1986; Bullock et al., 1985]. Thus surface accumulation is, indeed, observed but at much smaller scales. Pores only 50/•m wide are often distinctly lined with clay particles. Apparently, water carrying them through those pores lost its dragging power due to loss of momentum. This 10ss can be caused by decreasing flow velocity, by the reduction of mass flow due to water sorption into the finer pores surrounding the flow paths, or by any combination of the two. Gerba and Biton [1984], for instance, reported from groundwater flow studies that the bulk of larger Escherichia coil appeared about 1 hour earlier in an observation well 160 m downstream from an injection well than the bulk of the much smaller coliphage f2. Likewise, Harvey et al. [1986] reported that the peak abundance during fractional breakthrough of carboxylated microspheres at 1.5 m from the point of injection was highest for the 1.2-/•m diameter size class, followed by the 0.7-and 0.2-#m microspheres. This indicates that some of the larger partic...

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Actinide and Technetium Sorption on Iron-Silicate and Dispersed Clay Colloids

Cited by 6 publications

References 0 publications

Selection and Testing of "Getters" for Adsorption of Iodine-129 and Technetium-99: A Review

Selection and Testing of "Getters" for Adsorption of Iodine-129 and Technetium-99: A Review

The effects of the glass surface area/solution volume ratio on glass corrosion: A critical review

Particle transport through porous media

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