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Wei W, Han X, Shao Y, Xie W, Zhang Y, Yao Y, Zhao W, Han R, Li S, Zhang Y, Zheng C. Comparing the effects of humic acid and oxalic acid on Pb(II) immobilization by a green synthesized nanocrystalline hydroxyapatite. CHEMOSPHERE 2021; 285:131411. [PMID: 34246936 DOI: 10.1016/j.chemosphere.2021.131411] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/20/2021] [Accepted: 06/26/2021] [Indexed: 06/13/2023]
Abstract
Dissolved organic matter (DOM) is one of the most significant parameters to affect the remediation efficiency of Pb(II) by apatites. Numerous studies chose humic substances as a surrogate of DOM to investigate its influence on Pb(II) immobilization. However, the effect of low-molecular-weight organic acids such as oxalic acid (OA), which is ubiquitous in the environment and a primary component of DOM, in immobilizing Pb(II) was still not fully understood. Herein, humic acid (HA) and OA were examined to distinguish their influence on Pb(II) immobilization by a green synthesized nanocrystalline hydroxyapatite (nHAP). Various parameters were considered to evaluate the removal performance of nHAP towards Pb(II) as affected by HA/OA. Results indicated that Pb(II) immobilization was significantly promoted in the coexistence of OA owing to the precipitation of hydroxypyromorphite (HPY) as well as PbC2O4, but was independent on the addition sequence and slightly hindered by HA, disclosing that Pb(II) preferred to bind directly with nHAP instead of via HA. Characterization of the Pb(II) loaded solids by multiple technologies revealed that HPY was the predominant precipitate both in the absence and presence of HA, while the formation of PbC2O4 was preferred over that of HPY in the existence of OA. X-ray photoelectron spectroscopy indicated that PbC2O4 was the prevalent solid phase with the ratio of 62.97% after Pb(II) immobilization by nHAP in the presence of OA. These findings implied that the transformation efficiency of Pb(II) to HPY by apatites can be overestimated in the presence of OA due to the precipitation of PbC2O4.
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Affiliation(s)
- Wei Wei
- School of Environment, Nanjing Normal University, Nanjing, 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, 210023, China; Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Shenzhen, 518055, China.
| | - Xuan Han
- School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Yi Shao
- School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Wenming Xie
- School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Yong Zhang
- School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Yijun Yao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wei Zhao
- School of Materials Engineering, Changshu Institute of Technology, Changshu, 215500, China
| | - Ruiming Han
- School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Shiyin Li
- School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Yong Zhang
- Department of Geological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA.
| | - Chunmiao Zheng
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Shenzhen, 518055, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
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Verma PK, Mohapatra PK. Luminescence spectroscopic investigations of europium complexes formed in the kaolinite-humic acid/citric acid systems. RADIOCHIM ACTA 2020. [DOI: 10.1515/ract-2019-3148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In the present study, the nature of Eu(III) complexes (Eu(III) was used as a surrogate for Am(III)) formed in kaolinite–humic acid (HA)/citric acid (CA) system was investigated by luminescence spectroscopy. In addition to the ternary system (kaolinite + Eu + L(CA/HA)), the binary system (Eu-L) was also looked at for a better understanding of the complexes formed at the kaolinite surface. The lifetime and emission spectra of Eu-L complexes on the kaolinite surface differ considerably as compared to the same in the aqueous phase. The Eu-HA aqueous complexation shows differences in the excitation spectra with similar decay lifetimes with increasing aqueous HA concentrations. The ligand-to-metal charger transfer (LMCT) in the Eu-HA excitation spectra suggests the complexation of Eu(III) with HA at pH ∼ 4. Although the mode of Eu(III) binding to the kaolinite surface in the presence of CA/HA was the same i.e. metal-bridged ternary complex formation, the local surroundings around the sorbed Eu(III) differ in the two cases. The loading of HA in the Eu-HA-kaolinite system does not have a large effect on the local structure around the sorbed Eu(III) ion, but enhances the percentage of Eu(III) uptake onto the kaolinite surface. The number of H2O molecules in the primary hydration sphere of sorbed Eu(III) differs in the Eu-HA-kaolinite and Eu-CA-kaolinite systems. In addition, Eu(III) assisted precipitation of HA was also seen using a radiometric method.
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Affiliation(s)
- Parveen Kumar Verma
- Radiochemistry Division, Bhabha Atomic Research Centre , Trombay , Mumbai , 400085 , India
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3
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Patel MA, Kar AS, Raut VV, Jeyakumar S, Singal R, Tomar BS. Delineating the influence of picolinic acid on Eu(iii) sorption by γ-alumina. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:329-339. [PMID: 31909405 DOI: 10.1039/c9em00287a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The present study aims at understanding the sorption mechanism of Eu(iii) by γ-alumina in the presence of picolinic acid (PA), a decontaminating agent used in the nuclear industry, through batch sorption studies, spectroscopy and surface complexation modeling. PA is weakly sorbed by γ-alumina, with the sorption increasing with pH up to 4.5 and decreasing with further increase in pH. Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) measurements indicate that PA forms an inner sphere surface complex on γ-alumina. The presence of PA does not affect Eu(iii) sorption by γ-alumina at low [Eu(iii)], while it drastically reduces Eu(iii) sorption at high [Eu(iii)]. Similar Eu(iii) sorption profiles with different addition sequences of Eu(iii) and PA suggest identical Eu(iii) surface species for Eu(iii) sorption on γ-alumina in the presence of PA which has been validated by time resolved fluorescence spectroscopy (TRFS). TRFS measurements of Eu(iii) sorbed on γ-alumina in the absence (binary systems) and presence of PA (ternary systems) exhibited two components 1 & 2. The lifetime value of component 1 in ternary systems is enhanced compared to that in binary systems signifying the formation of new surface species containing Eu(iii), PA and the γ-alumina surface whereas the similarity of component 2 in both the binary and ternary systems reveals an almost identical coordination environment of Eu(iii) in the two types of system. Using the spectroscopic information obtained from TRFS, Eu(iii) sorption, at high [Eu(iii)], in ternary systems has been successfully modeled by considering Eu(iii) bridged PA surface species at both low and high affinity sites of γ-alumina. At low [Eu(iii)] both PA and Eu(iii) bridged ternary surface complexes only at high affinity sites of γ-alumina could describe the Eu(iii) sorption adequately.
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Affiliation(s)
- Madhuri A Patel
- Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, India.
| | | | - Vaibhavi V Raut
- Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, India.
| | - S Jeyakumar
- Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, India.
| | | | - B S Tomar
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
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4
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Mutual effects behind the simultaneous U(VI) and humic acid adsorption by hierarchical MWCNT/ZIF-8 composites. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.110971] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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5
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Chen L, Yu X, Zhao Z, Dong Y. The Sorption of Th(IV) Ions onto Montmorillonite: The Effect of pH, Ionic Strength and Fulvic Acid. ADSORPT SCI TECHNOL 2016. [DOI: 10.1260/026361706779319616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Lei Chen
- School of Chemical Engineering, Shandong University of Technology, 255049, Zibo, Shandong, P. R. China
| | - Xianjin Yu
- School of Chemical Engineering, Shandong University of Technology, 255049, Zibo, Shandong, P. R. China
| | - Zengdian Zhao
- School of Chemical Engineering, Shandong University of Technology, 255049, Zibo, Shandong, P. R. China
| | - Yunhui Dong
- School of Chemical Engineering, Shandong University of Technology, 255049, Zibo, Shandong, P. R. China
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6
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Li S, Wang X, Huang Z, Du L, Zhang D, Tan Z, Fu Y, Wang X. Sorption–desorption hysteresis of uranium(VI) on/from GMZ bentonite. J Radioanal Nucl Chem 2016. [DOI: 10.1007/s10967-016-4831-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Macroscopic and spectroscopic investigations on Eu(III) and Cm(III) sorption onto bayerite (β-Al(OH)3) and corundum (α-Al2O3). J Colloid Interface Sci 2016; 461:215-224. [DOI: 10.1016/j.jcis.2015.09.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/04/2015] [Accepted: 09/08/2015] [Indexed: 11/19/2022]
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8
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Cai Y, Ren X, Lang Y, Liu Z, Zong P, Wang X, Yang S. Sequestration and speciation of Eu(iii) on gamma alumina: role of temperature and contact order. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2015; 17:1904-1914. [PMID: 26428412 DOI: 10.1039/c5em00412h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The speciation, migration and transport of radionuclides in the environment are significantly influenced by their interactions with the natural minerals and humic substances therein. In view of this, the effect of temperature and contact order on the sorption behaviors of trivalent Eu(iii) in the γ-Al2O3/Eu(iii) and γ-Al2O3/HA/Eu(iii) systems was studied using batch experiments and the extended X-ray absorption fine structure spectroscopy (EXAFS) technique. The endothermic sorption behavior of Eu(iii) in the γ-Al2O3/Eu(iii) systems was induced by the hydrolysis reaction of Eu(iii) in solution and the complexation of Eu(iii) with the γ-Al2O3 surface sites. The endothermic sorption of Eu(iii) in the γ-Al2O3/HA/Eu(iii) systems was attributed to the endothermic binding of HA on γ-Al2O3 and the endothermic complexation between Eu(iii) and HA. EXAFS analysis suggested the formation of type B ternary complexes and their thermodynamic stability improves with rising temperature. The different sorption percentages under various contact orders were closely related to the binding mode of Eu(iii) on the exposed γ-Al2O3 surfaces or the γ-Al2O3/HA colloids. The findings obtained herein are important to evaluate the security of the radioactive waste repository and predict the fate of trivalent actinides (e.g., Am(iii), Cm(iii), Pu(iii), etc.) near the geological repository.
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Affiliation(s)
- Yawen Cai
- School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, P. R. China. and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Xuemei Ren
- Institute of Plasma Physics, Chinese Academy of Sciences, P. O. Box 1126, 230031 Hefei, P. R. China
| | - Yue Lang
- School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, P. R. China. and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Zhiyong Liu
- School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, P. R. China. and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Pengfei Zong
- Reactor Operation and Application Division, Nuclear Power Institute of China, 610005 Chengdu, P. R. China
| | - Xiangke Wang
- School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, P. R. China. and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Shitong Yang
- School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, P. R. China. and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
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9
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Chen X, Wang J, Wang S, Ma F, Chen X, Li J. Effect of solution properties on the interaction of 90Sr(II) with GMZ bentonite. KOREAN J CHEM ENG 2015. [DOI: 10.1007/s11814-015-0045-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Sorption behavior of Np(V) on illite, shale and MX-80 in high ionic strength solutions. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-4332-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Tan X, Ren X, Chen C, Wang X. Analytical approaches to the speciation of lanthanides at solid-water interfaces. Trends Analyt Chem 2014. [DOI: 10.1016/j.trac.2014.06.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Kouraim MN, Sheta MES, Abd Elaal MM. Investigation of uranium sorption from acidic sulfate solution using organosilicate compound and Amberlite IRA 402. EUROPEAN JOURNAL OF CHEMISTRY 2014; 5:446-450. [DOI: 10.5155/eurjchem.5.3.446-450.1026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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13
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Chen X, Peng S, Wang J. Retention profile and kinetics characteristics of the radionuclide 90-Sr(II) onto kaolinite. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3458-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Bauer N, Fröhlich DR, Panak PJ. Interaction of Cm(iii) and Am(iii) with human serum transferrin studied by time-resolved laser fluorescence and EXAFS spectroscopy. Dalton Trans 2014; 43:6689-700. [DOI: 10.1039/c3dt53371a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Xiao J, Zhao L, Zhang W, Liu X, Chen Y. Effect of pH, ionic strength, foreign ions, humic acid and temperature on Zn(II) sorption onto γ-Al2O3. KOREAN J CHEM ENG 2013. [DOI: 10.1007/s11814-013-0207-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Sorption of Eu(III) by amorphous titania, anatase and rutile: Denticity difference in surface complexes. Colloids Surf A Physicochem Eng Asp 2013. [DOI: 10.1016/j.colsurfa.2013.05.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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17
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Sturzbecher-Hoehne M, Goujon C, Deblonde GJP, Mason AB, Abergel RJ. Sensitizing curium luminescence through an antenna protein to investigate biological actinide transport mechanisms. J Am Chem Soc 2013; 135:2676-83. [PMID: 23363005 DOI: 10.1021/ja310957f] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Worldwide stocks of actinides and lanthanide fission products produced through conventional nuclear spent fuel are increasing continuously, resulting in a growing risk of environmental and human exposure to these toxic radioactive metal ions. Understanding the biomolecular pathways involved in mammalian uptake, transport and storage of these f-elements is crucial to the development of new decontamination strategies and could also be beneficial to the design of new containment and separation processes. To start unraveling these pathways, our approach takes advantage of the unique spectroscopic properties of trivalent curium. We clearly show that the human iron transporter transferrin acts as an antenna that sensitizes curium luminescence through intramolecular energy transfer. This behavior has been used to describe the coordination of curium within the two binding sites of the protein and to investigate the recognition of curium-transferrin complexes by the cognate transferrin receptor. In addition to providing the first protein-curium spectroscopic characterization, these studies prove that transferrin receptor-mediated endocytosis is a viable mechanism of intracellular entry for trivalent actinides such as curium and provide a new tool utilizing the specific luminescence of curium for the determination of other biological actinide transport mechanisms.
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Affiliation(s)
- Manuel Sturzbecher-Hoehne
- Chemical Sciences Division, The Glenn T. Seaborg Center, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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18
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Geckeis H, Lützenkirchen J, Polly R, Rabung T, Schmidt M. Mineral–Water Interface Reactions of Actinides. Chem Rev 2013; 113:1016-62. [DOI: 10.1021/cr300370h] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Horst Geckeis
- Karlsruhe Institute of Technology (KIT), Institute for Nuclear Waste Disposal
(INE), Karlsruhe, P.O.Box 3640, D-76021 Karlsruhe, Germany
| | - Johannes Lützenkirchen
- Karlsruhe Institute of Technology (KIT), Institute for Nuclear Waste Disposal
(INE), Karlsruhe, P.O.Box 3640, D-76021 Karlsruhe, Germany
| | - Robert Polly
- Karlsruhe Institute of Technology (KIT), Institute for Nuclear Waste Disposal
(INE), Karlsruhe, P.O.Box 3640, D-76021 Karlsruhe, Germany
| | - Thomas Rabung
- Karlsruhe Institute of Technology (KIT), Institute for Nuclear Waste Disposal
(INE), Karlsruhe, P.O.Box 3640, D-76021 Karlsruhe, Germany
| | - Moritz Schmidt
- Karlsruhe Institute of Technology (KIT), Institute for Nuclear Waste Disposal
(INE), Karlsruhe, P.O.Box 3640, D-76021 Karlsruhe, Germany
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Sorption of Th(IV) from aqueous solution to GMZ bentonite: effect of pH, ionic strength, fulvic acid and electrolyte ions. J Radioanal Nucl Chem 2012. [DOI: 10.1007/s10967-012-1991-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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21
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Schott J, Acker M, Barkleit A, Brendler V, Taut S, Bernhard G. The influence of temperature and small organic ligands on the sorption of Eu(III) on Opalinus Clay. RADIOCHIM ACTA 2012. [DOI: 10.1524/ract.2012.1921] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The influence of temperature up to 50 ºC and small organic ligands (citrate, tartrate) on the sorption of Eu(III) on the natural clay rock Opalinus Clay (OPA) under aerobic (p
CO2
= 10−3.5 atm) synthetic OPA pore water conditions (pH 7.6, I = 0.4 mol L−1) was investigated. Batch sorption experiments and time-resolved laser-induced fluorescence spectroscopy (TRLFS) were used to study these influencing factors on the Eu(III) sorption.
Sorption isotherms and distribution coefficients R
d (15 ºC: log R
d = 4.50 ± 0.05...50 ºC: log R
d = 5.54 ± 0.06) at 2 × 10−9 mol L−1 Eu(III) as a function of the solid-to-liquid ratio (up to 3 g L−1) and temperature were determined. A significant temperature dependency of the Eu(III) sorption was observed. With rising temperature the Eu(III) sorption increases. The surface reaction is endothermic (Δ H
sorb ∼ 50 kJ mol−1). Using TRLFS, a surface species with a luminescence emission lifetime of 201 ± 9 μs was identified.
In the presence of tartrate or citrate the Eu(III) sorption decreases with increasing ligand concentration due to a complex formation of Eu(III) in solution, with citrate having a more pronounced influence on the sorption than tartrate. With the batch sorption experiments it can be shown that at a citrate concentration larger than 10−5 mol L−1 and at a tartrate concentration larger than 10−4 mol L−1 an increasing Eu(III) desorption occurs. This result is supported by TRLFS measurements, which show the correlation between the complexation of Eu(III) by citrate or tartrate in solution and the Eu(III) desorption process. Possible Eu(III) citrate or Eu(III) tartrate surface species on OPA could not be detected using TRLFS.
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Affiliation(s)
| | - M. Acker
- Dresden University of Technology, Central Radionuclide Laboratory, Dresden, Deutschland
| | - A. Barkleit
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiochemistry, Dresden, Deutschland
| | - V. Brendler
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Radiochemistry, Dresden, Deutschland
| | - S. Taut
- Dresden University of Technology, Central Radionuclide Laboratory, Dresden, Deutschland
| | - G. Bernhard
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiochemistry, Dresden, Deutschland
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Effect of pH, ionic strength, foreign ions, humic acid and temperature on sorption of radionuclide 60Co(II) on illite. J Radioanal Nucl Chem 2012. [DOI: 10.1007/s10967-012-1618-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Complexation and sorption studies of Co(II) with γ-alumina-bound fulvic acid: effect of pH, ionic strength, fulvic acid and alumina concentration. J Radioanal Nucl Chem 2011. [DOI: 10.1007/s10967-011-1567-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Zhang L, Zhang H, Yu X. Investigation of solution chemistry effects on sorption behavior of Cu(II) on ZSM-5 zeolite. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2011; 83:2170-2177. [PMID: 22368959 DOI: 10.2175/106143011x12989211841250] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The sorption of Cu(II) from an aqueous solution using ZSM-5 zeolite was investigated by batch technique under ambient conditions. Sorption was investigated as a function of pH, ionic strength, foreign ions, humic substances, and temperature. The results indicate that the sorption of Cu(II) on ZSM-5 zeolite is strongly dependent on pH. Sorption is dependent on ionic strength at low pH, but independent of ionic strength at high pH values. The presence of humic/fluvic acid (HA/FA) enhances the sorption of Cu(II) on ZSM-5 zeolite at low pH values, and reduces Cu(II) sorption at high pH values. Sorption isotherms were well simulated by the Langmuir model. Thermodynamic parameters (i.e., deltaH0, deltaS0 and deltaG0) for the sorption of Cu(II) were determined from temperature-dependent sorption isotherms at 293.15, 313.15, and 333.15 K, respectively. Results indicate that the sorption process of Cu(II) on ZSM-5 zeolite is spontaneous and endothermic.
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Affiliation(s)
- Lipeng Zhang
- School of Chemical Engineering, Shandong University of Technology, Zibo, China
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Dong Y, Liu Z, Li Y, Chen L, Zhang Z. Effect of pH, ionic strength, foreign ions, fulvic acid and temperature on 109Cd(II) sorption to γ-Al2O3. J Radioanal Nucl Chem 2011. [DOI: 10.1007/s10967-011-1456-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Yan L, Qiaohui F, Wangsuo W. Sorption of Th(IV) on goethite: effects of pH, ionic strength, FA and phosphate. J Radioanal Nucl Chem 2011. [DOI: 10.1007/s10967-011-1166-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Liu Z, Chen L, Dong Y, Zhang Z. Impact of environmental conditions on the sorption behavior of Co(II) on Na-rectorite studied by batch experiments. J Radioanal Nucl Chem 2011. [DOI: 10.1007/s10967-011-1150-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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29
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Geckeis H. Research in actinide geochemistry: Do we need speciation information at the molecular level? ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-932-22.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTRadionuclide sorption to rock or sediment surfaces in the vicinity of a nuclear waste reposi-tory contributes significantly to the overall safety performance of a given disposal concept. State-of-the-artspeciation techniques as laser - and X-ray spectroscopy are becoming more and more involved into the elucidation of sorption mechanisms and to the quantification of surface speciation. They are extremely valuable tools to gain fundamental understanding as a basis for the development of geochemical sorption models which in turn are needed to predict ra-dionuclide behaviour in the environment.
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Kar AS, Kumar S, Tomar BS, Manchanda VK. Sorption of curium by silica colloids: effect of humic acid. JOURNAL OF HAZARDOUS MATERIALS 2011; 186:1961-1965. [PMID: 21236572 DOI: 10.1016/j.jhazmat.2010.12.092] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 12/20/2010] [Accepted: 12/20/2010] [Indexed: 05/30/2023]
Abstract
Sorption of curium by silica colloids has been studied as a function of pH and ionic strength using (244)Cm as a tracer. The sorption was found to increase with increasing pH and reach a saturation value of ∼95% at pH beyond 5.3. The effect of humic acid on the sorption of (244)Cm onto silica was studied by changing the order of addition of the metal ion and humic acid. In general, in the presence of humic acid (2 mg/L), the sorption increased at lower pH (<5) while it decreased in the pH range 6.5-8 and above pH 8, the sorption was found to increase again. As curium forms strong complex with humic acid, its presence results in the enhancement of curium sorption at lower pH. At higher pH the humic acid present in the solution competes with the surface sites for curium thus decreasing the sorption. The decrease in the Cm sorption in presence of humic acid was found to be less when humic acid was added after the addition of curium. Linear additive model qualitatively reproduced the profile of the Cm(III) sorption by silica in presence of humic acid at least in the lower pH region, however it failed to yield quantitative agreement with the experimental results. The results of the present study evidenced the incorporation of Cm into the silica matrix.
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Sorption speciation of lanthanides/actinides on minerals by TRLFS, EXAFS and DFT studies: a review. Molecules 2010; 15:8431-68. [PMID: 21085087 PMCID: PMC6259111 DOI: 10.3390/molecules15118431] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 11/09/2010] [Accepted: 11/15/2010] [Indexed: 11/17/2022] Open
Abstract
Lanthanides/actinides sorption speciation on minerals and oxides by means of time resolved laser fluorescence spectroscopy (TRLFS), extended X-ray absorption fine structure spectroscopy (EXAFS) and density functional theory (DFT) is reviewed in the field of nuclear disposal safety research. The theoretical aspects of the methods are concisely presented. Examples of recent research results of lanthanide/actinide speciation and local atomic structures using TRLFS, EXAFS and DFT are discussed. The interaction of lanthanides/actinides with oxides and minerals as well as their uptake are also of common interest in radionuclide chemistry. Especially the sorption and inclusion of radionuclides into several minerals lead to an improvement in knowledge of minor components in solids. In the solid-liquid interface, the speciation and local atomic structures of Eu(III), Cm(III), U(VI), and Np(IV/VI) in several natural and synthetic minerals and oxides are also reviewed and discussed. The review is important to understand the physicochemical behavior of lanthanides/actinides at a molecular level in the natural environment.
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Xu D, Wang XK, Chen CL, Zhou X, Tan XL. Influence of soil humic acid and fulvic acid on sorption of thorium(IV) on MX-80 bentonite. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.2006.94.8.429] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
SummaryTh(IV) is considered herein as a chemical analogue of other actinides (IV). Effect of pH, ionic strength and humic acid/fulvic acid concentrations on the sorption of thorium(IV) to MX-80 bentonite was studied by batch technique. The sorption isotherms were acquired by varying pH in the range of 0.5–12 and FA/HA concentration in the range of 2–20 mg/L. The results indicate that soil fulvic acid has higher carboxylic content than humic acid, and has stronger positive influence on the sorption of Th(IV) on bentonite at low pH values than humic acid. The increase of FA/HA concentration results in a slight increase of Th(IV) sorption on FA/HA coated bentonite. The results of no drastic effect of different addition sequences of FA/HA and Th(IV) to bentonite suspension on Th(IV) sorption in the ternary system HA/FA-Th(IV)-bentonite indicate that both the Th(IV)-HA/FA complexation and HA/FA-bentonite sorption do not affect the sorption of Th(IV) on HA/FA coated bentonite obviously. The samples were also measured by SEM method and the results show that the surface properties of different samples are different.
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Xu D, Shao D, Chen C, Ren A, Wang X. Effect of pH and fulvic acid on sorption and complexation of cobalt onto bare and FA bound MX-80 bentonite. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.2006.94.2.97] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
SummaryBentonite has attracted great interest in nuclear waste management because of its outstanding properties. Herein, the sorption and complexation of cobalt on bare bentonite and fulvic acid (FA) coated bentonite are studied, respectively, under ambient conditions. The experiments are carried out atT= 25 ± 2 °C in 0.01 M KNO3solutions. Effect of pH, bentonite concentration, fulvic acid and cobalt solution concentration on cobalt sorption to bentonite is also investigated. The results show that cobalt sorption is strongly pH dependent and weakly bentonite content dependent. The presence of fulvic acid enhances Co2+sorption at low pH values and reduces the sorption of Co2+at high pH values. Effect of addition sequences of Co2+and FA to bentonite suspension on cobalt sorption to FA-bentonite colloids is also studied and the results indicate that the sorption of cobalt on FA coated bentonite is dependent on the addition sequences. The mechanism is discussed by the relative strength between both complexes of Co(II) with sorbed and soluble FA and with bentonite.
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Adsorption and kinetic desorption study of 152+154Eu(III) on multiwall carbon nanotubes from aqueous solution by using chelating resin and XPS methods. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.2008.1457] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Multiwall carbon nanotubes (MWCNTs) have been pretreated with HNO3 and used for the adsorption of radionuclide 152+154Eu(III) from aqueous solutions. The effects of pH (2–12), ionic strength (0.01 M and 0.1 M NaClO4) and radionuclide 152+154Eu(III) solution concentrations (10-8–10-5 mol/L) on the adsorption of 152+154Eu(III) on MWCNTs were investigated. The experiments were carried out at 25±2 °C and under atmosphere conditions. Adsorption of 152+154Eu(III) on MWCNTs increases significantly with increasing pH at pH <6, and over 96% 152+154Eu(III) are adsorbed on MWCNTs at pH >6. Strong surface complexation and/or chemisorptions are considered as the main adsorption mechanism. The sorption was also characterized by using high resolution XPS spectra. The results show that MWCNTs can be a promising candidate of adsorbent for preconcentration of lanthanides from large volumes in radioactive nuclear waste management.
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Cm(III) sorption onto γ-Al2O3: New insight into sorption mechanisms by time-resolved laser fluorescence spectroscopy and extended X-ray absorption fine structure. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.2006.94.9-11.609] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Sorption of trivalent Cm onto γ-Al2O3is investigated by time-resolved laser fluorescence spectroscopy (TRLFS). The pH dependent sorption of Cm(III) is followed at constant ionic strength of 0.1 M NaClO4under argon atmosphere in the pH range between 3.5 and 13.2 at a total Cm(III) concentration of 2.5×10-7mol/L. Three different surface-sorbed Cm(III) species appearing at different pH are identified by their emission spectra with peak maxima at 600.6 nm, 602.5 nm, and 605.7 nm using an excitation wavelength of λex=396.6 nm. No variation of the emission decay is observed for the three sorbed species (constant lifetimes of 110 μs). The pH dependent species distribution obtained from peak deconvolution of emission spectra is in agreement with earlier Eu/Cm sorption studies and sorbed species are assigned to >Al−O−Cm(OH)x(2-x)(H2O)5-xinner-sphere complexes. Indirect Cm excitationviaenergy transfer from the solid to the metal ion at λex=355 nm yields emission bands significantly shifted compared to spectra obtained at λex=396.6 nm. We interpret this observation as a hint for the existence of Cm inner-sphere complexes bound to different γ-Al2O3surface sites. The exact nature of those species is presently not known, but they likely involve Cm interaction with Al(OH)3phases at the solid surface which may even dominate the solid surface chemistry. Complementary EXAFS measurements are performed with Lu and Gd, taken as chemical homologues of the trivalent actinides. EXAFS for Gd/Lu(III) sorbed onto γ-Al2O3at pH=6 identifies a single oxygen coordination shell with a high degree of disorder. For Gd this shell consists of 9±1.5 atoms at a 2.45±0.02 Å distance. A coordination number of 7±1.5 and a Lu−O distance of 2.28±0.02 Å is found in the Lu-samples. Those values are quite close to what is known for the respective aquo ions. The large asymmetry in the coordination shell, however, suggests inner-sphere complexation. This is in agreement with TRLFS results showing clearly the existence of inner-sphere surface complexes where the first coordination shell of the trivalent metal ions consists of 5H2O/OH-entities. Together with EXAFS data, a metal ion coordination to four oxygen atoms belonging to the γ-alumina surface is concluded. Both spectroscopic studies indicate a certain variability of surface binding sites for trivalent metal ions.
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Pathak P, Choppin GR. Sorption behavior of curium(III) on hydrous silica: a kinetic and thermodynamic study. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.2007.95.3.137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Sorption of tracer curium, Cm3+, on SiO2· H2O (silica gel) was investigated under different experimental conditions such as time of equilibration, concentration of Sm3+, pcH, and temperature. Sm3+was used as a carrier for Cm3+ions in this study. From the sorption kinetics data, the diffusion coefficient of Cm3+ion was calculated to be 1.20(±0.05)×10-11m2s-1under particle diffusion-controlled conditions. The sorption rate was determined to be 3.47(±0.19)×10-3s-1at 298 K, pcH 5.25(±0.03) in 0.20 M (NaClO4). The sorption data were fitted in Freundlich, Langmuir and Dubinin–Radushkevich (D–R) isotherms. A synergistic enhancement in the sorption of Cm3+(Sm3+)-ligand (e.g., CO32-, F-, H2PO4-and C2O42-) complexes on silica gel was observed. The presence of these anions increase the sorption of Cm3+(Sm3+) in the following order: CO32-< F-< C2O42-< H2PO4-. Temperature variation experiments gave enhanced sorption with increased temperature for Cm3+indicating an endothermic enthalpy.
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Yang S, Li J, Lu Y, Chen Y, Wang X. Sorption of Ni(II) on GMZ bentonite: Effects of pH, ionic strength, foreign ions, humic acid and temperature. Appl Radiat Isot 2009; 67:1600-8. [DOI: 10.1016/j.apradiso.2009.03.118] [Citation(s) in RCA: 184] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 01/19/2009] [Accepted: 03/10/2009] [Indexed: 11/25/2022]
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Characterization of MX-80 bentonite and its sorption of radionickel in the presence of humic and fulvic acids. J Radioanal Nucl Chem 2009. [DOI: 10.1007/s10967-007-7252-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Rabung T, Geckeis H. Influence of pH and metal ion loading on the Cm(III) humate complexation: a time resolved laser fluorescence spectroscopy study. RADIOCHIM ACTA 2009. [DOI: 10.1524/ract.2009.1609] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Effect of humic acid, pH and ionic strength on the sorption of Eu(III) on red earth and its solid component. J Radioanal Nucl Chem 2008. [DOI: 10.1007/s10967-006-6814-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tan XL, Wang XK, Geckeis H, Rabung T. Sorption of Eu(III) on humic acid or fulvic acid bound to hydrous alumina studied by SEM-EDS, XPS, TRLFS, and batch techniques. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:6532-6537. [PMID: 18800526 DOI: 10.1021/es8007062] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
To identify the effect of humic acid (HA) and fulvic acid (FA) on the sorption mechanism of Eu(III) on organic--inorganic colloids in the environment at a molecular level, surface adsorbed/ complexed Eu(III) on hydrous alumina, HA-, and FA-hydrous alumina hybrids were characterized by using X-ray photoelectron spectroscopy (XPS) and time-resolved laser fluorescence spectroscopy (TRLFS). The experiments were performed in 0.1 mol/L KNO3 or 0.1 mol/L NaClO4 under ambient conditions. The pH values were varied between 2 and 11 at a fixed Eu(III) concentration of 6.0 x 10(-7) mol/L and 4.3 x 10(-5) mol/L. The different Eu(III)/FA(HA)/hydrous alumina complexes were characterized by their fluorescence emission spectra ((5D0-F1)/ (5D0 --> 7F2)) and binding energy of Eu(III). Inner-sphere surface complexation may contribute mainly to Eu(III) sorption on hydrous alumina, and a ternary surface complex is formed at the HA/ FA-hydrous alumina hybrid surfaces. The sorption and species of Eu(III) in ternary Eu-HA/FA-hydrous alumina systems are not dominated by either HA/FA or hydrous alumina, but are dominated by both HA/FA and hydrous alumina. The results are important for understanding the sorption mechanisms and the nature of surface adsorbed Eu(III) species and trivalent chemical homologues of Eu(III) in the natural environment.
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Affiliation(s)
- X L Tan
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O.Box 1126, 230031, Hefei, PR China
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Moll H, Glorius M, Bernhard G. Curium(III) Complexation with Desferrioxamine B (DFO) Investigated Using Fluorescence Spectroscopy. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2008. [DOI: 10.1246/bcsj.81.857] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Glorius M, Moll H, Bernhard G. Complexation of curium(III) with hydroxamic acids investigated by time-resolved laser-induced fluorescence spectroscopy. Polyhedron 2008. [DOI: 10.1016/j.poly.2008.04.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chen L, Lu S. Sorption and desorption of radiocobalt on montmorillonite—Effects of pH, ionic strength and fulvic acid. Appl Radiat Isot 2008; 66:288-94. [PMID: 17897834 DOI: 10.1016/j.apradiso.2007.07.031] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 06/13/2007] [Accepted: 07/23/2007] [Indexed: 11/29/2022]
Abstract
Humic substances and clay minerals have been studied extensively in radioactive waste management. In our research, the sorption and desorption of radiocobalt on montmorillonite in the presence and absence of fulvic acid as a function of pH and ionic strength were investigated under ambient conditions by using batch techniques. The results indicate that the sorption of cobalt is strongly dependent on pH values and independent of ionic strength. Surface complexation rather than cation exchange is considered as the main mechanism of cobalt sorption to montmorillonite. The presence of fulvic acid enhances cobalt sorption obviously at pH values<8. The desorption behavior changes of surface-sorbed cobalt from montmorillonite were studied by decreasing pH values and the solution cobalt concentrations independently. The results indicated that the sorption of cobalt on montmorillonite is irreversible.
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Affiliation(s)
- Lei Chen
- School of Chemical Engineering, Shandong University of Technology, 255049 Zibo, Shandong, PR China.
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Fan QH, Wu WS, Song XP, Xu JZ, Hu J, Niu ZW. Effect of humic acid, fulvic acid, pH and temperature on the sorption-desorption of Th(IV) on attapulgite. RADIOCHIM ACTA 2008. [DOI: 10.1524/ract.2008.1475] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Wu W, Fan Q, Xu J, Niu Z, Lu S. Sorption–desorption of Th(IV) on attapulgite: Effects of pH, ionic strength and temperature. Appl Radiat Isot 2007; 65:1108-14. [PMID: 17604176 DOI: 10.1016/j.apradiso.2007.05.009] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 04/02/2007] [Accepted: 05/14/2007] [Indexed: 10/23/2022]
Abstract
The sorption of Th(IV) on attapulgite was studied as a function of pH, ionic strength, temperature, attapulgite contents and Th(IV) concentrations under ambient conditions using a batch technique. The results indicated that sorption of Th(IV) on attapulgite was strongly affected by pH values, and weakly dependent on ionic strength. Sorption of Th(IV) was dominated by surface complexation, although ion exchange also contributed to this sorption. Sorption of Th(IV) increased with increasing temperature of the system. Enthalpy (DeltaH(0)), entropy (DeltaS(0)) and Gibbs free energy (DeltaG(0)) were calculated from the temperature-dependent sorption data; the results indicated that the sorption of Th(IV) on attapulgite was a spontaneous process. Sorption-desorption hysteresis indicated that the sorption of Th(IV) was irreversible, and that the Th(VI) adsorbed on attapulgite was difficult to be desorbed from solid to liquid phases.
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Affiliation(s)
- Wangsuo Wu
- Radiochemistry Laboratory, Lanzhou University, Lanzhou, 730000 Gansu, PR China
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Chen L, Yu X, Zhao Z, Pan J. Sorption and desorption of Co(II) on montmorillonite in presence and absence of fulvic acid. J Radioanal Nucl Chem 2007. [DOI: 10.1007/s10967-007-6990-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Miró C, Baeza A, Salas A, Pastor-Valle JF, Pastor-Villegas J. Adsorption of 241Am and 226Ra from natural water by wood charcoal. Appl Radiat Isot 2007; 66:95-102. [PMID: 17900915 DOI: 10.1016/j.apradiso.2007.07.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 07/25/2007] [Accepted: 07/28/2007] [Indexed: 11/18/2022]
Abstract
The adsorption of (241)Am and (226)Ra from natural water by a granulated wood charcoal was investigated as a function of the solution pH, in the range 4-10, and of the water flow, in the range 3.5-42 cm(3)/min. The percentage adsorption of (241)Am (fairly constant at >80% for all pHs) was greater than that of (226)Ra (which increased with increasing pH from approximately 40% up to >80%). The results are explained by considering the different species of each radionuclide present at the pH values of the solution at the end of the adsorbent column, and the pH of the point of zero charge of the adsorbent. At pH 6, the elimination of (241)Am from natural water was independent of the water flow, while the elimination of (226)Ra declined linearly as the flow rate was increased.
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Affiliation(s)
- C Miró
- Departamento de Física Aplicada, Facultad de Veterinaria, Universidad de Extremadura, Avda. de la Universidad s/n, 10071 Cáceres, Spain.
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Moll H, Johnsson A, Schäfer M, Pedersen K, Budzikiewicz H, Bernhard G. Curium(III) complexation with pyoverdins secreted by a groundwater strain of Pseudomonas fluorescens. Biometals 2007; 21:219-28. [PMID: 17653625 DOI: 10.1007/s10534-007-9111-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Accepted: 07/13/2007] [Indexed: 10/23/2022]
Abstract
Pyoverdins, bacterial siderophores produced by ubiquitous fluorescent Pseudomonas species, have great potential to bind and thus transport actinides in the environment. Therefore, the influence of pyoverdins secreted by microbes on the migration processes of actinides must be taken into account in strategies for the risk assessment of potential nuclear waste disposal sites. The unknown interaction between curium(III) and the pyoverdins released by Pseudomonas fluorescens (CCUG 32456) isolated from the granitic rock aquifers at the Aspö Hard Rock Laboratory (Aspö HRL), Sweden, is the subject of this paper. The interaction between soluble species of curium(III) and pyoverdins was studied at trace curium(III) concentrations (3 x 10(-7)M) using time-resolved laser-induced fluorescence spectroscopy (TRLFS). Three Cm(3+)-P. fluorescens (CCUG 32456) pyoverdin species, M(p)H(q)L(r), could be identified from the fluorescence emission spectra, CmH(2)L(+), CmHL, and CmL(-), having peak maxima at 601, 607, and 611 nm, respectively. The large formation constants, log beta(121 )= 32.50 +/- 0.06, log beta(111) = 27.40 +/- 0.11, and log beta(101) = 19.30 +/- 0.17, compared to those of other chelating agents illustrate the unique complexation properties of pyoverdin-type siderophores. An indirect excitation mechanism for the curium(III) fluorescence was observed in the presence of the pyoverdin molecules.
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Affiliation(s)
- Henry Moll
- Institute of Radiochemistry, Forschungszentrum Dresden-Rossendorf, Dresden, Germany.
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