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Competitive adsorption involving phosphate and benzenecarboxylic acids on goethite-Effects of molecular structures

Lindegren, Malin and Persson, Per LU (2010) In Journal of Colloid and Interface Science 343. p.263-270
Abstract
The competitive adsorption between phosphate and either one of seven benzenecarboxylates (benzoate, phthalate, trimellitate, trimesoate, hemimellitate, pyromellitate, and mellitate) on the surfaces of fine-particulate goethite (alpha-FeOOH) was investigated as a function of pH. The series of ligands contained Molecules with an increasing number of functional groups as well as three structural isomers of the tricarboxylates. Thus, the effects of both the number of carboxylate groups and the relative positions of these groups on the competitive efficiency toward phosphate were probed ill this Study. Quantitative adsorption experiments in batch mode and infrared spectroscopy were collectively Used to evaluate the competitive adsorption... (More)
The competitive adsorption between phosphate and either one of seven benzenecarboxylates (benzoate, phthalate, trimellitate, trimesoate, hemimellitate, pyromellitate, and mellitate) on the surfaces of fine-particulate goethite (alpha-FeOOH) was investigated as a function of pH. The series of ligands contained Molecules with an increasing number of functional groups as well as three structural isomers of the tricarboxylates. Thus, the effects of both the number of carboxylate groups and the relative positions of these groups on the competitive efficiency toward phosphate were probed ill this Study. Quantitative adsorption experiments in batch mode and infrared spectroscopy were collectively Used to evaluate the competitive adsorption reactions. Under the conditions probed, mono- and dicarboxylates had no detectable effect on phosphate adsorption whereas the ligands containing three or more carboxylate groups were able to partially outcompete phosphate. However, the pH dependency and the extent of these competitive effects were strongly dependent on (lie structure and composition of the benzenecarboxylate. The collective results showed that it was the competition for hydrogen-bonding surface sites rather than inner sphere Surface sites that primarily determined the outcome of the competitive adsorption experiments,and it was the ability of the organic ligand to act as hydrogen-bonding acceptor and/or donor in various parts of the pH range that also determined the competitive pH dependency. The importance of H-bonding for the competitive adsorption between phosphate and benzenecarboxylic acids suggested that H-bonding interactions contributed substantially to the stabilities of both the adsorbed benzenecarboxylates and the phosphate ions and that these interactions were structurally specific: i.e., they were sensitive to the locations and the directional properties of the H-acceptor and H-donor surface sites. (c) 2009 Elsevier Inc. All rights reserved. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Colloid and Interface Science
volume
343
pages
263 - 270
publisher
Elsevier
external identifiers
  • scopus:74449084196
ISSN
1095-7103
DOI
10.1016/j.jcis.2009.11.040
language
English
LU publication?
no
id
db608b6b-4bb9-45fb-b7a4-8b96aea0fd34 (old id 4332339)
date added to LUP
2014-03-04 09:46:27
date last changed
2018-05-29 10:29:45
@article{db608b6b-4bb9-45fb-b7a4-8b96aea0fd34,
  abstract     = {The competitive adsorption between phosphate and either one of seven benzenecarboxylates (benzoate, phthalate, trimellitate, trimesoate, hemimellitate, pyromellitate, and mellitate) on the surfaces of fine-particulate goethite (alpha-FeOOH) was investigated as a function of pH. The series of ligands contained Molecules with an increasing number of functional groups as well as three structural isomers of the tricarboxylates. Thus, the effects of both the number of carboxylate groups and the relative positions of these groups on the competitive efficiency toward phosphate were probed ill this Study. Quantitative adsorption experiments in batch mode and infrared spectroscopy were collectively Used to evaluate the competitive adsorption reactions. Under the conditions probed, mono- and dicarboxylates had no detectable effect on phosphate adsorption whereas the ligands containing three or more carboxylate groups were able to partially outcompete phosphate. However, the pH dependency and the extent of these competitive effects were strongly dependent on (lie structure and composition of the benzenecarboxylate. The collective results showed that it was the competition for hydrogen-bonding surface sites rather than inner sphere Surface sites that primarily determined the outcome of the competitive adsorption experiments,and it was the ability of the organic ligand to act as hydrogen-bonding acceptor and/or donor in various parts of the pH range that also determined the competitive pH dependency. The importance of H-bonding for the competitive adsorption between phosphate and benzenecarboxylic acids suggested that H-bonding interactions contributed substantially to the stabilities of both the adsorbed benzenecarboxylates and the phosphate ions and that these interactions were structurally specific: i.e., they were sensitive to the locations and the directional properties of the H-acceptor and H-donor surface sites. (c) 2009 Elsevier Inc. All rights reserved.},
  author       = {Lindegren, Malin and Persson, Per},
  issn         = {1095-7103},
  language     = {eng},
  pages        = {263--270},
  publisher    = {Elsevier},
  series       = {Journal of Colloid and Interface Science},
  title        = {Competitive adsorption involving phosphate and benzenecarboxylic acids on goethite-Effects of molecular structures},
  url          = {http://dx.doi.org/10.1016/j.jcis.2009.11.040},
  volume       = {343},
  year         = {2010},
}