The influence of humic acid on europium–mineral interactions

Fairhurst, Andrew J.; Warwick, Peter

doi:10.1016/s0927-7757(98)00662-1

Cited by 49 publications

(28 citation statements)

References 11 publications

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“…Europium-Siderophore Interactions. The close correspondence between the Eu(III) adsorption edges on goethite ( Figure 2) and boehmite (Figure 3) in the absence of ligands is consistent with previous observations (49). It is most likely a result of the similar pznc values for the two oxide minerals (37).…”

Section: Resultssupporting

confidence: 89%

“…Comparing lead adsorption in the absence (Figure 4) and in the presence of 150 µM DFOMTA (Figure 7), we infer that DFOMTA adsorption at pH < 5 induces Pb(II) adsorption in excess of what occurs in the absence of ligands, whereas at pH > 5, decreasing adsorption of DFOMTA and the strong affinity of the ligand for Pb(II) act to diminish Pb(II) adsorption. Similar observations of enhanced sorption of Eu(III) on goethite and boehmite at below pH 50 and reduced adsorption above pH50 in the presence of humic acid have been reported in the literature (49). These findings accord with the conceptual scheme of Murphy and Zachara (28), who proposed that anionic organic ligands will enhance trace metal adsorption at pH values below the intersection of the ligand adsorption envelope with the free-metal adsorption edge (just above pH 5 in the present experiments), whereas they will diminish trace metal adsorption above this pH value.…”

Section: Resultssupporting

confidence: 89%

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Adsorption of Pb(II) and Eu(III) by Oxide Minerals in the Presence of Natural and Synthetic Hydroxamate Siderophores

Kraemer

Raymond

et al. 2002

Environ. Sci. Technol.

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Trihydroxamate siderophores have been proposed for use as mediators of actinide and heavy metal mobility in contaminated subsurface zones. These microbially produced ligands, common in terrestrial and marine environments, recently have been derivatized synthetically to enhance their affinity for transuranic metal cations. However, the interactions between these synthetic derivative and adsorbed trace metals have not been characterized. In this paper we compare a natural siderophore, desferrioxamine-B (DFO-B), with its actinide-specific catecholate derivative, N-(2,3-dihydroxy-4-(methylamido)benzoyl)-desferrioxamine-B (DFOMTA), as to their effect on the adsorption of Pb(II) and Eu(III) by goethite and boehmite. In the presence of 240 µM DFO-B, a strongly depleting effect on Eu(III) adsorption by goethite and boehmite occurred above pH 6. By contrast, almost total removal of Eu(III) from solution in the neutral to slightly acidic pH range was observed in the presence of either 10 or 100 µM DFOMTA, due primarily to the formation of metal-DFOMTA precipitates. Addition of DFOMTA caused an increase in Pb(II) adsorption by goethite below pH 5, but a decrease above pH 5, such that the Pb(II) adsorption edge in the presence of DFOMTA strongly resembled the DFOMTA adsorption envelope, which showed a maximum near pH 5 and decreasing adsorption toward lower and higher pH.

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Section: Resultssupporting

confidence: 89%

Section: Resultssupporting

confidence: 89%

Adsorption of Pb(II) and Eu(III) by Oxide Minerals in the Presence of Natural and Synthetic Hydroxamate Siderophores

Kraemer

Raymond

et al. 2002

Environ. Sci. Technol.

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“…The main species of Eu(III) is Eu-HA at pH\6; Eu-HA, Eu(OH)-HA and Eu(CO 3 )-HA were the dominant species over the pH range of 6.0-10.0; whereas Eu(CO 3 Þ À 2 became the prevalent species at pH [10.0. At low pH, the adsorption of HA on FeNi-RGO surface could decrease the surface potential, and improved the electrostatic forces, thus enhanced the adsorption of Eu(III) on [4] also reported that the Eu-HA complexes formed at low pH which were adsorbed by mineral to the same extent as HA, leading to the enhanced Eu(III) adsorption. It was also reported that the decrease of HA sorption with increasing pH was due to electrostatic repulsion effects and surface complexation reactions [6].…”

Section: Effects Of Anions and Cationsmentioning

confidence: 84%

“…Eu(III) is a trivalent lanthanide and a chemical homologue to trivalent actinides, therefore, Eu(III) is usually used to assess the performance and safety of geological repository to long-life and high level radioactive waste [1][2][3][4]. Wang et al [5] researched the influences of pH, ionic strength and humic acid (HA) on Eu(III) sorption on c-Al 2 O 3 through batch approach.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Eu(III) on defective magnetic FeNi/RGO composites: effect of pH, ion strength, ions and humic acid

Tian

Liu

et al. 2014

J Radioanal Nucl Chem

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The defective magnetic iron-nickel-graphene (FeNi-RGO) complexes were synthesized for investigating the adsorption of Eu(III) ions from aqueous solutions as a function of pH, solid-to-liquid ratio, ion strength, anions, cations and humic acid (HA). The adsorption of Eu(III) on FeNi-RGO was significantly dependent on pH and weakly dependent on ionic strength, anions and cations. HA could promote the adsorption of Eu(III) on FeNi-RGO at low pH while inhibited that at high pH with depending on the HA concentration. The results of this work were helpful for extraction and separation useful radionuclides from radioactive wastewater.

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“…Because it strongly binds cationic species, NOM, when solid, can retard the transport of metal ions or, conversely, when dissolved, can enhance the mobility of these ions [1,2,3,4,5,6,7,8,9,10]. The ability to predict speciation of metal ions in soils first requires evaluation of the binding capacities of both the minerals and the organic matter for the metal ions studied.…”

Section: Introductionmentioning

confidence: 99%

Fluorescence spectrometry for quantitative characterization of cobalt(II) complexation by Leonardite humic acid

Monteil-Rivera

Dumonceau

2002

Analytical and Bioanalytical Chemistry

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Quenching of the fluorescence of a Leonardite humic acid by Co(II) has been studied at different pH. The interaction was monitored by emission fluorescence and by synchronous fluorescence with two different offsets (deltalambda=20 and 80 nm). It was found that synchronous fluorescence performed with the smaller offset resolves the individual components of the heterogeneous material better than emission or synchronous fluorescence performed with the larger offset. Enhancement of the signal induced by Cobalt(II) complexation resulted in more complex behavior for measurements performed by synchronous fluorescence with an offset of 20 nm, however. The quenching profiles obtained for pH 5.0, 6.0, and 7.0 ([KNO(3)]=0.1 mol L(-1); [LHA]=3.3 mg(C) L(-1); [Co(II)]=1.0 x 10(-6)-1.6 x 10 (-3) mol L(-1)) by emission and synchronous (deltalambda=80 nm) fluorescence were analyzed by two methods: 1. a non-linear least-squares procedure that leads to conditional constants; and 2. a pH-dependent discrete logK spectrum model that leads to stability constants. The first method resulted in poor fitting and unreasonable values for maximum capacities. The second procedure resulted in smooth fitting that accounted well for the pH changes when results for pH 6.0 and 5.0 were predicted by use of the four values of logK(Co)(i) (4.31, 3.76, 7.32, and 7.67 corresponding to the four sites (i) of the respective pKa(i) values 4, 6, 8, and 10) calculated at pH 7.0 for the equilibrium

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The influence of humic acid on europium–mineral interactions

Cited by 49 publications

References 11 publications

Adsorption of Pb(II) and Eu(III) by Oxide Minerals in the Presence of Natural and Synthetic Hydroxamate Siderophores

Adsorption of Pb(II) and Eu(III) by Oxide Minerals in the Presence of Natural and Synthetic Hydroxamate Siderophores

Adsorption of Eu(III) on defective magnetic FeNi/RGO composites: effect of pH, ion strength, ions and humic acid

Fluorescence spectrometry for quantitative characterization of cobalt(II) complexation by Leonardite humic acid

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