Complexation of Radionuclides with Humic Substances

Moulin, Valérie

doi:10.1007/1-4020-3252-8_7

Cited by 5 publications

(3 citation statements)

References 42 publications

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“…At such low pH, the solubility of Al, Th, and U is favoured and the release of a series of elements is expected to increase (Hindar and Nordstrom, 2015;Landa, 2007), whereas scavenging by Fe (oxy)hydroxides will be minimal (Jeng, 1992;Singer and Stumm, 1970). Furthermore, the presence of organic matter can play an important role in changing the speciation, and thus mobility, of elements with high affinity for humic substances, such as Ni, Zn, Cu, Cd, Pb and U (Moulin et al, 2004). Therefore, the weathering of and leaching from alum shale will depend on the storage conditions.…”

Section: Introductionmentioning

confidence: 99%

Limited Access to Oxygen Reduces the Release of Harmful Trace Elements from Submerged Alum Shale Debris

Wærsted¹,

Reinoso-Maset²,

Salbu

et al. 2023

Preprint

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Section: Introductionmentioning

confidence: 99%

Limited Access to Oxygen Reduces the Release of Harmful Trace Elements from Submerged Alum Shale Debris

Wærsted¹,

Reinoso-Maset²,

Salbu

et al. 2023

Preprint

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“…The colloid-facilitated transport of actinides has attracted considerable attention following the pioneering work of McCarthy and Zachara . And since then extensive evidence finds for colloid facilitated mobilization of actinides, both in field studies , and in laboratory experiments. ,, On the other hand, a retarded transport of actinides in porous media, such as soils and sediments, has been reported as well. − The direct correlations between accumulation of Pu and the content of total organic carbon (TOC) in soils and sediments were observed. , It was also reported that the migration rate of Pu can be reduced substantially with an increase in the soil’s organic content. , …”

Section: Introductionmentioning

confidence: 99%

“…These above cited studies have motivated numerous investigations regarding the impact of humic substances (HS) on actinide transport in aquatic systems and soils. ,− HS comprise of 50–80% of natural organic matter (NOM), and their molecular structures include reducing and complexing units, which provide for both redox and complexing interactions with plutonium and other actinides. ,, Comparable interactions with plutonium are characteristic of bacterial exopolymers as recently reported in the literature. , Given that these humic materials occur throughout the environment both in mobile colloidal and immobile organo-inorganic states they can be considered as important matricies for manipulating and controlling actinide migration.…”

Section: Introductionmentioning

confidence: 99%

Nonreversible Immobilization of Water-Borne Plutonium onto Self-Assembled Adlayers of Silanized Humic Materials

Shcherbina

Kalmykov²,

Karpiouk³

et al. 2014

Environ. Sci. Technol.

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The objective was to study plutonium partitioning between immobile and mobile humic materials at the water-solid interfaces. Immobilization of the humic materials on solid supports was performed in situ using self-adhesive silanized humic derivatives. The presence of the humic adlayers on solid supports was shown to significantly enhance Pu sorption and its retention under both steady state and dynamic conditions. While plutonium may exist in multiple oxidations states plus colloidal forms, the major thrust in this work was to study the behavior of most mobile--the PuO2(+) form in dilute solutions. The values of the plutonium partition coefficients (Kd) between water and humics-coated silica gels after 10 days exposure reached 1.6 × 10(4) L · kg(-1) at pH 7.5 under anaerobic conditions with a total plutonium concentration of 1.2 × 10(-8) M exceeding those for the uncoated SiO2 (6.3 × 10(2) L · kg(-1)). Column tests showed substantial sequestration of water-borne plutonium (up to 73%) on the humics-coated silica gels. Remobilization experiments conducted under batch conditions at different pH values (3.5, 4.5, 7.5) showed that no more than 3% of the sequestered Pu was remobilized from the humics-coated silica gels by treatment with dissolved humic materials at environmentally relevant pH of 7.5. Consequently, silanized humic materialas can be seen as both molecular probes and as potent candidate materials for scavenging mobile Pu from an aqueous phase.

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Effect of organic acids on sorption of uranyl ions in solution onto ZrP2O7

García-González

Ordóñez-Regil

Simoni

et al. 2009

J Radioanal Nucl Chem

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Hydration of zirconium diphosphate (ZrP2O7) conduced to formation of active sites in solid/liquid interface. In ZrP2O7/NaClO4 0.5 M suspensions, active sites and their acidity constants are quite determined but the presence of some impurities is now studied. This work was conducted to determine the surface properties changes produced by oxalic and citric acid during the hydration process. Moreover the presence of organic acids with ZrP2O7 modified reveals an increase in uranium sorption constants. The zirconium diphosphate has been characterized using X-ray powder diffraction (XRD), Scanning electron microscopy (SEM) and Particle induced X-ray emission and Neutron (PIXE). Furthermore, the specific surface area, measured by the BET method, was 3.5 m2/g. The pH corresponding to the isoelectric point, determined by Zeta Potential measurements and mass titration was 3.6. The sites density calculated using titration curves was around of 5.37 s/nm2 for NaClO4 0.5 M, 13.71 s/nm2 for NaClO4 0.5 M/citric acid 0.1 M and 7.33 s/nm2 NaClO4 0.5 M/oxalic acid 0.1 M. The surface acidity constants and species distribution in surface were calculated by means of simulation of the titration curves with the FITEQL code (constant capacitance model), for ZrO and PO amphoteric sites of ZrP2O7. The uranyl sorption edge was determined for NaClO4 0.5 M. It spreads between pH 3 and 4.5 for complete sorption according to the previously published results. In the ZrP2O7–citrate modified surface, the uranyl sorption edge begin at pH 2 and was almost complete at pH 3.2 while ZrP2O7–oxalate modified surface edge started at 50% of sorption at pH of 1.5 and was complete at pH 3

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Complexation of Radionuclides with Humic Substances

Cited by 5 publications

References 42 publications

Limited Access to Oxygen Reduces the Release of Harmful Trace Elements from Submerged Alum Shale Debris

Limited Access to Oxygen Reduces the Release of Harmful Trace Elements from Submerged Alum Shale Debris

Nonreversible Immobilization of Water-Borne Plutonium onto Self-Assembled Adlayers of Silanized Humic Materials

Effect of organic acids on sorption of uranyl ions in solution onto ZrP2O7

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