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Structures and stabilities of Cd(II) and Cd(II)-phthalate complexes at the goethite/water interface

Boily, J. F.; Sjoberg, S. and Persson, Per LU (2005) In Geochimica et Cosmochimica Acta 69. p.3219-3235
Abstract
The complexation of Cd(II) and Cd(II)-phthalate at the goethite/water interface were investigated by EXAFS and IR spectroscopy, by batch adsorption experiments and by potentiometric titrations at 298.15 K. The EXAFS spectra showed Cd(IT) to form only inner-sphere corner-sharing complexes with the goethite surface sites in the presence and absence of phthalate. EXAFS spectra also showed the presence of Cd(II)-chloride complexes in 0.1 mol/L NaCl. IR spectra also showed phthalate to form (1) an inner-sphere complex with adsorbed corner-sharing Cd(II) surface complexes in the pH 3.5 to 9.5 and (2) an outer-sphere complex with the same type of corner-sharing Cd(II) complex however at pH > 6, in addition to the inner- and outer-sphere... (More)
The complexation of Cd(II) and Cd(II)-phthalate at the goethite/water interface were investigated by EXAFS and IR spectroscopy, by batch adsorption experiments and by potentiometric titrations at 298.15 K. The EXAFS spectra showed Cd(IT) to form only inner-sphere corner-sharing complexes with the goethite surface sites in the presence and absence of phthalate. EXAFS spectra also showed the presence of Cd(II)-chloride complexes in 0.1 mol/L NaCl. IR spectra also showed phthalate to form (1) an inner-sphere complex with adsorbed corner-sharing Cd(II) surface complexes in the pH 3.5 to 9.5 and (2) an outer-sphere complex with the same type of corner-sharing Cd(II) complex however at pH > 6, in addition to the inner- and outer-sphere complexes of phthalate reported in a previous study. The potentiometric fitration and the batch adsorption data were used to constrain the formation constants of the different Cd(II)-phthalate surface complexes on the dominant {110} and the {001} planes of the goethite. The models were carried out with the Charge Distribution Multisite Complexation model coupled to the Three Plane Model and can predict the molecular-scale speciation of cadmium and phthalate in the presence of goethite. Cd(II) adsorption models calibrated on a 90 m(2)/g goethite also could accurately predict experimental data for a 37 m(2)/g goethite of slightly different basic charging properties. Copyright (C) 2005 Elsevier Ltd. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Geochimica et Cosmochimica Acta
volume
69
pages
3219 - 3235
publisher
Elsevier
external identifiers
  • scopus:21644474912
ISSN
0016-7037
DOI
10.1016/j.gca.2004.12.013
language
English
LU publication?
no
id
76dc1ec3-c01b-4dfc-a5c9-4e82c4b0a5aa (old id 4332527)
date added to LUP
2014-03-04 09:41:25
date last changed
2017-10-29 03:42:25
@article{76dc1ec3-c01b-4dfc-a5c9-4e82c4b0a5aa,
  abstract     = {The complexation of Cd(II) and Cd(II)-phthalate at the goethite/water interface were investigated by EXAFS and IR spectroscopy, by batch adsorption experiments and by potentiometric titrations at 298.15 K. The EXAFS spectra showed Cd(IT) to form only inner-sphere corner-sharing complexes with the goethite surface sites in the presence and absence of phthalate. EXAFS spectra also showed the presence of Cd(II)-chloride complexes in 0.1 mol/L NaCl. IR spectra also showed phthalate to form (1) an inner-sphere complex with adsorbed corner-sharing Cd(II) surface complexes in the pH 3.5 to 9.5 and (2) an outer-sphere complex with the same type of corner-sharing Cd(II) complex however at pH > 6, in addition to the inner- and outer-sphere complexes of phthalate reported in a previous study. The potentiometric fitration and the batch adsorption data were used to constrain the formation constants of the different Cd(II)-phthalate surface complexes on the dominant {110} and the {001} planes of the goethite. The models were carried out with the Charge Distribution Multisite Complexation model coupled to the Three Plane Model and can predict the molecular-scale speciation of cadmium and phthalate in the presence of goethite. Cd(II) adsorption models calibrated on a 90 m(2)/g goethite also could accurately predict experimental data for a 37 m(2)/g goethite of slightly different basic charging properties. Copyright (C) 2005 Elsevier Ltd.},
  author       = {Boily, J. F. and Sjoberg, S. and Persson, Per},
  issn         = {0016-7037},
  language     = {eng},
  pages        = {3219--3235},
  publisher    = {Elsevier},
  series       = {Geochimica et Cosmochimica Acta},
  title        = {Structures and stabilities of Cd(II) and Cd(II)-phthalate complexes at the goethite/water interface},
  url          = {http://dx.doi.org/10.1016/j.gca.2004.12.013},
  volume       = {69},
  year         = {2005},
}