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Adsorption, desorption, and surface-promoted hydrolysis of glucose-1-phosphate in aqueous goethite (alpha-feooh) suspensions

Olsson, R.; Giesler, R.; Loring, J. S. and Persson, Per LU (2010) In Langmuir 26. p.18760-18770
Abstract
Adsorption, desorption, and precipitation reactions at environmental interfaces govern the fate of phosphorus in terrestrial and aquatic environments. Typically, a substantial part of the total pool of phosphorus consists of organophosphate, and in this study we have focused on the interactions between glucose-I-phosphate (G I P) and goethite (alpha-FeOOH) particles. The adsorption and surface-promoted hydrolysis reactions have been studied at room temperature as a function of pH, time, and total concentration of GIP by means of quantitative batch experiments in combination with infrared spectroscopy. A novel simultaneous infrared and potentiometric titration (SI PT) technique has also been used to study the rates and mechanisms of... (More)
Adsorption, desorption, and precipitation reactions at environmental interfaces govern the fate of phosphorus in terrestrial and aquatic environments. Typically, a substantial part of the total pool of phosphorus consists of organophosphate, and in this study we have focused on the interactions between glucose-I-phosphate (G I P) and goethite (alpha-FeOOH) particles. The adsorption and surface-promoted hydrolysis reactions have been studied at room temperature as a function of pH, time, and total concentration of GIP by means of quantitative batch experiments in combination with infrared spectroscopy. A novel simultaneous infrared and potentiometric titration (SI PT) technique has also been used to study the rates and mechanisms of desorption of the surface complexes. The results have shown that GIP adsorption occurs over a wide pH interval and at pH values above the isoelectric point of goethite (IEPgoethite = 9.4), indicating a comparatively strong interaction with the particle surfaces. As evidenced by IR spectroscopy, GIP formed pH-dependent surface complexes on goethite, and investigations of both adsorption and desorption processes were consistent with a model including three types of surface complexes. These complexes interact monodentately with surface Fe but differ in hydrogen bonding interactions via the auxiliary oxygens of the phosphate group. The apparent desorption rates were shown to be influenced by reaction pathways that include interconversion of surface species, which highlights the difficulty in determining the intrinsic desorption rates of individual surface complexes. Desorption results have also indicated that the molecular structures of surface complexes and the surface charge are two important determinants of GIP desorption rates. Finally, this study has shown that surface-promoted hydrolysis of GIP by goethite is base-catalyzed but that the extent of hydrolysis was small. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
inositol hexaphosphate, myoinositol hexaphosphate, organic phosphorus, soil, interface, arsenate, complexation, spectroscopy, mechanisms, phosphate
in
Langmuir
volume
26
pages
18760 - 18770
publisher
The American Chemical Society
external identifiers
  • scopus:78650197435
ISSN
0743-7463
DOI
10.1021/la1026152
language
English
LU publication?
no
id
49cbcf7d-aa51-4751-867d-3804a822a8ff (old id 4332328)
date added to LUP
2014-03-04 09:39:44
date last changed
2018-05-29 10:31:09
@article{49cbcf7d-aa51-4751-867d-3804a822a8ff,
  abstract     = {Adsorption, desorption, and precipitation reactions at environmental interfaces govern the fate of phosphorus in terrestrial and aquatic environments. Typically, a substantial part of the total pool of phosphorus consists of organophosphate, and in this study we have focused on the interactions between glucose-I-phosphate (G I P) and goethite (alpha-FeOOH) particles. The adsorption and surface-promoted hydrolysis reactions have been studied at room temperature as a function of pH, time, and total concentration of GIP by means of quantitative batch experiments in combination with infrared spectroscopy. A novel simultaneous infrared and potentiometric titration (SI PT) technique has also been used to study the rates and mechanisms of desorption of the surface complexes. The results have shown that GIP adsorption occurs over a wide pH interval and at pH values above the isoelectric point of goethite (IEPgoethite = 9.4), indicating a comparatively strong interaction with the particle surfaces. As evidenced by IR spectroscopy, GIP formed pH-dependent surface complexes on goethite, and investigations of both adsorption and desorption processes were consistent with a model including three types of surface complexes. These complexes interact monodentately with surface Fe but differ in hydrogen bonding interactions via the auxiliary oxygens of the phosphate group. The apparent desorption rates were shown to be influenced by reaction pathways that include interconversion of surface species, which highlights the difficulty in determining the intrinsic desorption rates of individual surface complexes. Desorption results have also indicated that the molecular structures of surface complexes and the surface charge are two important determinants of GIP desorption rates. Finally, this study has shown that surface-promoted hydrolysis of GIP by goethite is base-catalyzed but that the extent of hydrolysis was small.},
  author       = {Olsson, R. and Giesler, R. and Loring, J. S. and Persson, Per},
  issn         = {0743-7463},
  keyword      = {inositol hexaphosphate,myoinositol hexaphosphate,organic phosphorus,soil,interface,arsenate,complexation,spectroscopy,mechanisms,phosphate},
  language     = {eng},
  pages        = {18760--18770},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Adsorption, desorption, and surface-promoted hydrolysis of glucose-1-phosphate in aqueous goethite (alpha-feooh) suspensions},
  url          = {http://dx.doi.org/10.1021/la1026152},
  volume       = {26},
  year         = {2010},
}