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Surface complexation model theory application in NaOL and CTAB collector adsorption differences of diaspore and kaolinite flotation. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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2
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Missana T, Alonso U, García-Gutiérrez M. Evaluation of component additive modelling approach for europium adsorption on 2:1 clays: Experimental, thermodynamic databases, and models. CHEMOSPHERE 2021; 272:129877. [PMID: 33592507 DOI: 10.1016/j.chemosphere.2021.129877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/21/2021] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
This study evaluates the component additive approach for Eu adsorption on mixtures of smectite and illite, which are the most common clays used as barriers for contaminant retention in waste repositories. A thorough set of Eu adsorption data for Na-exchanged smectite and illite that encompasses a wide range of pH values, ionic strengths, and Eu concentrations was provided. This database is likely one of the largest sorption databases available for Eu in 2:1 clays, making it appropriate for sorption model calibration. The main adsorption mechanisms considered were surface complexation, on weak and strong clay edge sites, and cation exchange. Further, the role of principal ions, which are naturally leached from clays, as competitive factors for Eu retention, was evaluated in the modelling calculations. The main uncertainties related to the modelling procedures and the use of different thermodynamic data on sorption modelling were outlined. The reactions and parameters successful in modelling Eu adsorption on individual clays were used without any modification to model Eu adsorption on illite/smectite mixtures, wherein only the relative mineral proportions were considered. The fit of the sorption data in the mixed clay system was satisfactory, indicating that, in 2:1 clays, Eu sorption is an additive process, which stresses the predictive capacity of the component additive approach in these systems. This is an important support for assessing the performance of barrier materials for contaminant migration under different geochemical conditions.
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Affiliation(s)
- Tiziana Missana
- Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Department of Environment, Avenida Complutense 40, 28040, Madrid, Spain.
| | - Ursula Alonso
- Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Department of Environment, Avenida Complutense 40, 28040, Madrid, Spain
| | - Miguel García-Gutiérrez
- Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Department of Environment, Avenida Complutense 40, 28040, Madrid, Spain
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Wu M, Mo L, Bi E. Effects of fulvic acid and montmorillonite colloids at different concentrations on Cd(II) sorption onto nano-hydroxyapatite. CHEMOSPHERE 2020; 248:125992. [PMID: 32006832 DOI: 10.1016/j.chemosphere.2020.125992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 01/13/2020] [Accepted: 01/20/2020] [Indexed: 06/10/2023]
Abstract
Natural colloids can influence the binding mechanisms between nano-hydroxyapatite (nHAP) and Cd(II). In this study, the effects of organic and inorganic natural colloids on Cd(II) sorption onto nHAP were compared. Different experimental approaches combined with the additivity model and the Extended-Derjaguin-Landau-Verwey-Overbeek model were used to quantify the distribution of Cd(II) in the systems of nHAP and natural colloid, and the interaction energy between particles. The results showed that both fulvic acid (FA) and montmorillonite colloid (MONT) had the promotion and inhibition effects on Cd(II) sorption onto nHAP. Coexistence of FA or MONT could stabilize nHAP particles. FA could adsorb onto nHAP particle surface via carboxylic and phenolic groups, which increased nHAP electronegativity and formed steric resistance effect. Coexistence of MONT mainly increased nHAP electronegativity. These effects prevented the reduction of the specific surface area of nHAP particles and increased the Cd(II) sorption onto nHAP. However, the inhibition effect on Cd(II) sorption was enhanced with increasing concentration of FA or MONT because more soluble FA-Cd or suspended MONT-Cd complexes formed in the system. In nHAP-FA-Cd systems, the Cd(II) sorption onto FA was well predicted but that onto solid phase was underestimated by the additivity model. In nHAP-MONT-Cd systems, Cd(II) sorbed onto mixtures of nHAP and MONT was well described by the additive model. The findings of this study can help to understand the fate of Cd(II) in natural water and soil.
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Affiliation(s)
- Mengmeng Wu
- School of Water Resources and Environment, Beijing Key Laboratory of Water Resources and Environmental Engineering, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China.
| | - Limei Mo
- School of Water Resources and Environment, Beijing Key Laboratory of Water Resources and Environmental Engineering, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China.
| | - Erping Bi
- School of Water Resources and Environment, Beijing Key Laboratory of Water Resources and Environmental Engineering, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China.
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Sugiura Y, Tomura T, Ishidera T, Doi R, Francisco PCM, Shiwaku H, Kobayashi T, Matsumura D, Takahashi Y, Tachi Y. Sorption behavior of selenide on montmorillonite. J Radioanal Nucl Chem 2020. [DOI: 10.1007/s10967-020-07092-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Xu L, Huang Y. Kinetics and mechanism of selenite reduction by zero valent iron under anaerobic condition activated and enhanced by dissolved Fe(II). THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 664:698-706. [PMID: 30763850 DOI: 10.1016/j.scitotenv.2019.02.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/26/2018] [Accepted: 02/02/2019] [Indexed: 06/09/2023]
Abstract
Batch test was conducted to investigate Se(IV) removal kinetics and mechanism by zero valent iron (ZVI) in presence of Fe(II) under anaerobic condition. Dissolved Fe(II) activated and enhanced Se(IV) reduction by ZVI, which also determined the removal efficiency, reduction rate, final corrosion products and their structures. Se(IV) was completely removed at initial Fe(II)/Se(IV) ≥ 1.0, and the specific rate constant significantly increased from 0.6 to 3.44 L h-1 m-2 with the augment of ratio from 1.0 to 1.4. At Fe(II)/Se(IV) < 1.0 (take 0.6 as an example), Raman, XPS, SEM-EDS and XRD results suggested that Se(IV) was reduced to amorphous Se(0) in forms of red suspended solids, amorphous FeSe and crystal maghemite (γ-Fe2O3) coated on ZVI surface. At Fe(II)/Se(IV) ≥ 1.0 (take 1.0 and 1.4 as examples), crystal FeSe and magnetite (Fe3O4) deposits formed on ZVI surface with a core-shell structure. Additionally, final pH increased due to Se(IV) reduction. This study suggested that traditional ZVI passivation problem could be overcome through the addition of excess dissolved Fe(II) under anaerobic condition, which also provided an alternative method to produce a reactive ammonia-free Fe3O4/ZVI/Fe(II) system.
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Affiliation(s)
- Lin Xu
- Department of Biological and Agricultural Engineering, Texas A&M University, 2117 TAMU, College Station, TX 77843, USA.
| | - Yongheng Huang
- Department of Biological and Agricultural Engineering, Texas A&M University, 2117 TAMU, College Station, TX 77843, USA.
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Mayordomo N, Foerstendorf H, Lützenkirchen J, Heim K, Weiss S, Alonso U, Missana T, Schmeide K, Jordan N. Selenium(IV) Sorption Onto γ-Al 2O 3: A Consistent Description of the Surface Speciation by Spectroscopy and Thermodynamic Modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:581-588. [PMID: 29231722 DOI: 10.1021/acs.est.7b04546] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The sorption processes of Se(IV) onto γ-Al2O3 were studied by in situ Infrared spectroscopy, batch sorption studies, zeta potential measurements and surface complexation modeling (SCM) in the pH range from 5 to 10. In situ attenuated total reflection fourier-transform infrared (ATR FT-IR) spectroscopy revealed the predominant formation of a single inner-sphere surface species at the alumina surface, supporting previously reported EXAFS results, irrespective of the presence or absence of atmospherically derived carbonate. The adsorption of Se(IV) decreased with increasing pH, and no impact of the ionic strength was observed in the range from 0.01 to 0.1 mol L-1 NaCl. Inner-sphere surface complexation was also suggested from the shift of the isoelectric point of γ-Al2O3 observed during zeta potential measurements when Se(IV) concentration was 10-4 mol L-1. Based on these qualitative findings, the acid-base surface properties of γ-Al2O3 and the Se(IV) adsorption edges were successfully described using a 1-pK CD-MUSIC model, considering one bidentate surface complex based on previous EXAFS results. The results of competitive sorption experiments suggested that the surface affinity of Se(IV) toward γ-Al2O3 is higher than that of dissolved inorganic carbon (DIC). Nevertheless, from the in situ experiments, we suggest that the presence of DIC might transiently impact the migration of Se(IV) by reducing the number of available sorption sites on mineral surfaces. Consequently, this should be taken into account in predicting the environmental fate of Se(IV).
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Affiliation(s)
- Natalia Mayordomo
- CIEMAT , Department of Environment, Avenida Complutense 40, CP 28040, Madrid, Spain
| | - Harald Foerstendorf
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR) , Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Johannes Lützenkirchen
- Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology , Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Karsten Heim
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR) , Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Stephan Weiss
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR) , Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Ursula Alonso
- CIEMAT , Department of Environment, Avenida Complutense 40, CP 28040, Madrid, Spain
| | - Tiziana Missana
- CIEMAT , Department of Environment, Avenida Complutense 40, CP 28040, Madrid, Spain
| | - Katja Schmeide
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR) , Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Norbert Jordan
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR) , Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden, Germany
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