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

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

doi:10.1021/es048856h

Cited by 91 publications

(53 citation statements)

References 66 publications

(142 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several studies have attempted to gain a more mechanistic understanding through the use of advanced spectroscopic techniques (Ö sthols, 1995; Ö sthols et al, 1997), or surface complexation modeling (Reiller et al, 2005). However, little attention is usually given to the choice of background electrolyte.…”

Section: Introductionmentioning

confidence: 99%

“…Many studies are performed in NO 3 À media (Li and Tao, 2002;Guo et al, 2005;Reiller et al, 2005;Sharma et al, 2006Sharma et al, , 2009Zhang et al, 2006;Sheng et al, 2008;Talip et al, 2009), presumably due to its relevance in chemical-separations processes and its ubiquitous presence in groundwater. Studies in ClO 4 À media are also commonly found (Ö sthols, 1995;Ö sthols et al, 1997;Jakobsson, 1999;Reiller et al, 2005;Rojo et al, 2009). Only one study (Jakobsson, 1999) investigated sorption reactions for multiple background electrolytes, namely NaCl and NaClO 4 (in this case on TiO 2 substrates).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of the background electrolyte on Th(IV) sorption to muscovite mica

Schmidt

Hellebrandt

Knope

et al. 2015

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

The adsorption of tetravalent thorium on the muscovite mica (0 0 1) basal plane was studied by X-ray crystal truncation rod (CTR) and resonant anomalous X-ray reflectivity (RAXR) measurements and alpha spectrometry in the presence of perchlorate background electrolytes LiClO 4 , NaClO 4 , and KClO 4 ([Th(IV)] = 0.1 mM, I = 0.1 M or 0.01 M, pH = 3.3 ± 0.3). RAXR data directly reveal a strong influence of the background electrolyte on the actinide sorption. No significant Th adsorption was observed in 0.1 M NaClO 4 , i.e., the Th coverage h(Th), the number of Th per unit cell area of the muscovite surface (A UC = 46.72 Å 2 ), was 60.01 Th/A UC , whereas limited uptake (h(Th) $ 0.04 Th/A UC ) was detected at a lower ionic strength (I = 0.01 M). These results are in stark contrast to the behavior of Th in 0.1 M NaCl which showed a coverage of 0.4 Th/A UC (Schmidt et al., 2012a). Th uptake was also influenced by the electrolyte cation. Weak adsorption was observed in 0.1 M KClO 4 (h(Th) $ 0.07 Th/A UC ) similar to the results in NaClO 4 at lower ionic strength. In contrast, strong adsorption was found in 0.1 M LiClO 4 , with h(Th) = 4.9 Th/A UC , a $10-fold increase compared with that previously reported in NaCl. These differences are confirmed independently by ex situ alpha spectrometry, which shows no measurable Th coverage in 0.1 M NaClO 4 background in contrast to a large coverage of 1.6 Th/A UC in 0.1 M LiClO 4 . Alpha spectrometry cannot be obtained in situ, but sample preparation requires several washing steps that may affect Th(IV) sorption, RAXR, however, is considered to reflect the in situ sorption structure. The CTR/RAXR analyses of Th-LiClO 4 show the sorption structure consisting of Th species that are broadly distributed, centered at heights of 4.1 Å and 29 Å distance from the interface. Neither the very large distribution height of the second species nor the high coverage can be explained with (hydrated) ionic adsorption, suggesting that the enhanced uptake is presumably due to the formation and sorption of Th nanoparticles.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of the background electrolyte on Th(IV) sorption to muscovite mica

Schmidt

Hellebrandt

Knope

et al. 2015

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

show abstract

“…Chen et al [9] reported that the presence of HSs enhanced Th(IV) sorption on -Al 2 O 3 at lower pH scale while inhibited at intermediate and high pH, which may be attributed to the formation of ternary surface complexes, such as  SO-OC-HA-Th and  SO-OC-FA-Th. Moreover, different addition sequences of HSs would lead to the transform of interaction mechanism between metal ions, HSs and sorbents [15,16].…”

Section: Introductionmentioning

confidence: 99%

The sorption mechanisms of Th(IV) on attapulgite

et al. 2011

View full text Add to dashboard Cite

The surface properties of intrinsic and activated attapulgite were studied using potentiometric titration. The sorption mechanisms of Th(IV) on intrinsic and activated attapulgite were investigated by employing surface complexation model and FITEQL 3.2 code. The results indicated that the sorption sites of intrinsic attapulgite involved in the sorption process were main ion exchange site (  XNa/K), strong site (  S s OH) and weak site (  S w OH), while only strong site (  S s OH) and weak site (  S w OH) were predominant for activated attapulgite. At pH < 2.5, the species of Th(IV) was main Th 4+ in aqueous solution; then the hydrolysis species of Th(IV) (i.e., Th(OH) 2 2+ , Th(OH) 3 + and Th(OH) 4 0 ) gradually formed as pH increasing. For the sorption of Th(IV) on intrinsic attapulgite, both ion exchange species (  X 2 Th) and inner-sphere surface complexes (  S s OTh) were dominant, while only inner-sphere surface complexes (i.e.,  S s OThOH and  S w OTh) were observed for Th(IV) sorption to activated attapulgite. In the presence of humic acid (HA), the sorption of Th(IV) on activated attapulgite was obviously enhanced; and both  S s OH-HA-Th and  S s OTh were the predominant speciation. It was also interesting to find that the addition of HA obviously provoked the desorption behavior of Th(IV).attapulgite, Th(IV), HA, sorption, desorption, surface complexation model

show abstract

“…In recent decade years, the sorption of Th(IV) on all kinds of minerals as a function of pH, ionic strength, temperature was studied extensively Fan et aL, 2008;Pan et aL, 2011;Hu and Tan, 2012;Zhang et aL, 2015). Many mechanisms have been postulated for Th(IV) and other actinides of sorption, such as surface complexation, chemi-complexation, chemisorption, cation exchange, surface precipitation, colloid formation at surface and diffusion into the particle micropores (Jakobsson,1999;Reiller et aL, 2005;Wang et aL, 2005a;Wang et aL, 2005b;Wang et aL, 2005c) .…”

Section: Introductionmentioning

confidence: 99%

Natural illite as an Efficient Adsorbent for Thorium Removal

Zhang¹,

Wang²,

Jiang³

et al. 2017

International Journal of Research in Environmental Science

View full text Add to dashboard Cite

In this paper，the natural illite is used as low-cost sorbent for investigating the sorption of Th(IV). ) and are calculated from the temperature-dependent sorption data and the results indicate that the sorption of Th(IV) on natural illite was a spontaneous process. Isotherms of Th(IV) adsorption to natural illite could be described well by Langmuir model. Through the desorption experiments, the adsorption process on natural illite was reversible reaction. The sorption mechnism of Th(IV) on natural illite is ion exchange reaction with its potassium ions that are trapped in its interlayer

show abstract

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

Cited by 91 publications

References 66 publications

Effects of the background electrolyte on Th(IV) sorption to muscovite mica

Effects of the background electrolyte on Th(IV) sorption to muscovite mica

The sorption mechanisms of Th(IV) on attapulgite

Natural illite as an Efficient Adsorbent for Thorium Removal

Contact Info

Product

Resources

About