Retention behaviour of humic substances onto mineral surfaces and consequences upon thorium (IV) mobility: case of iron oxides

Reiller, Pascal E.; Moulin, Valérie; Casanova, F.; Dautel, Christian

doi:10.1016/s0883-2927(02)00045-8

Cited by 89 publications

(83 citation statements)

References 62 publications

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“…Similarly, ionic strength had no or very weak influence on HA retention onto this substrate as evidenced in the previous study (17). As a matter of fact, the actual colloidal state of this α-Fe 2 O 3 sample limits the effect of ionic strength (50,60).…”

Section: Resultssupporting

confidence: 56%

“…In figure 1 are reported pH isotherms obtained in The results of HA retention in the systems were reported earlier (17). The decrease in metal retention when HA is pre-equilibrated with the solid is a classical observation (18-21, 57).…”

Section: Resultsmentioning

confidence: 65%

“…HA added first, From reference (17) This value is lower than the one used in this study ( (66) could be compared to our results apart from the lack of site density determination and the difference in specific surface area (7.41 m²/g).…”

Section: Pre-equilibration Of Hematite and Th(iv)mentioning

confidence: 56%

“…(17) from ref. (17) complexation by surface sites increases up to 50%. Hence in this system, where hematite is pre-equilibrated with HA, organic matter controls Th(IV) behaviour.…”

Section: Resultsmentioning

confidence: 98%

“…Therefore, in order to illustrate the different cases we have studied the following pre-equilibrated systems: (i) hematite and HA equilibrated before any addition of Th(IV); (ii) hematite and Th(IV) equilibrated before any addition of HA, (iii) Th(IV) and HA pre-equilibrated before any addition of hematite Experimental Materials. The colloidal hematite suspension and humic acids were the same as the one used in previous studies (17,50,51). Briefly, hematite was obtained from AEA Harwell and Different modus operandi were used depending on the order of addition of the constituents.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Addition Order and Contact Time on Thorium(IV) Retention by Hematite in the Presence of Humic Acids

Reiller¹,

Casanova²,

Moulin

2005

Environ. Sci. Technol.

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The influence of addition order and contact time in the system hematite (α-Fe 2 O 3 ) -humic acid (HA) -thorium (IV) was studied in batch experiments. Thorium (IV) is considered here as a chemical analogue of other actinides (IV). The sorption isotherms were acquired varying pH in the range 2-10, and HA concentration in the range 1-100 mg/L. As already observed by numerous authors, thorium (IV) retention was hindered when HA and hematite were equilibrated beforehand during 24 hours. As it has been observed in a previous study, this 2 effect was drastic when the ratio between humic and surface (iron oxide) sites exceeds a critical value. However, when HA were added after a 24 hours equilibration of the hematitethorium (IV) system, thorium (IV) was barely desorbed from the iron oxide surface.Furthermore, no drastic effect of the ratio between humic and surface sites could be evidenced, as the increase of HA concentration only results in a slight monotonic decrease in Th(IV) retention. Increasing contact time between components of the systems only indicated slight Th(IV) retention variation. This was interpreted as a consequence of slow kinetic controls of both the Th(IV)-HA complexation and HA-hematite sorption.

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Section: Resultssupporting

confidence: 56%

Section: Resultsmentioning

confidence: 65%

Section: Pre-equilibration Of Hematite and Th(iv)mentioning

confidence: 56%

“…(17) from ref. (17) complexation by surface sites increases up to 50%. Hence in this system, where hematite is pre-equilibrated with HA, organic matter controls Th(IV) behaviour.…”

Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Influence of Addition Order and Contact Time on Thorium(IV) Retention by Hematite in the Presence of Humic Acids

Reiller¹,

Casanova²,

Moulin

2005

Environ. Sci. Technol.

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Copper and nickel partitioning with nanoscale goethite under variable aquatic conditions

Danner¹,

Hammerschmidt²,

Costello³

et al. 2015

Enviro Toxic and Chemistry

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Metal contaminated sediments can be toxic to aquatic organisms and are common in human-dominated ecosystems, which results in metals being a leading cause of ecosystem impairment. Bioavailability of metals is influenced by their affinity for dissolved and solid-phase ligands, including iron (Fe) oxyhydroxides, which have been hypothesized to reduce metal toxicity in sediments. The authors examined the adsorption kinetics of copper (Cu) and nickel (Ni) with goethite (α-FeOOH) and characterized the influences of solute metal concentration, pH, ionic strength, and humate concentration on steady-state partitioning of the metals with goethite under conditions representative of natural aquatic environments. Copper and Ni readily adsorbed to goethite, and steady-state partitioning was achieved within 2 h. Although ionic strength had no effect on metal partitioning, adsorption of Cu and Ni to goethite was enhanced by alkaline pH and reduced by competition with humate. Because distribution coefficient (KD ) values for Cu and Ni from the present study are comparable to values measured in natural systems, the authors hypothesize that goethite may contribute significantly to the adsorption of both Ni and Cu to particles in the environment. The authors suggest that incorporating binding by Fe oxides in metal bioavailability models should be a priority for improving risk assessment of metal-contaminated oxic sediments.

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Complexation of Radionuclides with Humic Substances

Moulin

NATO Science Series

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Humic substances are ubiquitous compounds presenting specific properties with respect to complexation, sorption and transport. Because they may enhance metal solubilities due to their strong complexing properties, as well as increase or decrease metal retention on mineral surfaces due to their affinity for mineral substrates and their scavenging properties, humic substances may impact metal speciation in the environment, and in particular radionuclides speciation. Various examples based on actinides, lanthanides or iodine will be presented to illustrate the complexation properties as well as speciation calculations with emphasis on the thermodynamic constants used and the techniques used to obtain them.

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Retention behaviour of humic substances onto mineral surfaces and consequences upon thorium (IV) mobility: case of iron oxides

Cited by 89 publications

References 62 publications

Influence of Addition Order and Contact Time on Thorium(IV) Retention by Hematite in the Presence of Humic Acids

Influence of Addition Order and Contact Time on Thorium(IV) Retention by Hematite in the Presence of Humic Acids

Copper and nickel partitioning with nanoscale goethite under variable aquatic conditions

Complexation of Radionuclides with Humic Substances

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