Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Cd2+ and Zn2+ sorption on apatite in the presence of EDTA and humic substance
Umeå University, Faculty of Science and Technology, Department of Chemistry.
Umeå University, Faculty of Science and Technology, Department of Chemistry.
2013 (English)In: Proceedings of the 16th International Conference on Heavy Metals in the Environment / [ed] Pirrone, N, EDP Sciences, 2013, article id 01008Conference paper, Published paper (Refereed)
Abstract [en]

The sorption of Cd2+ and Zn2+ on hydroxyapatite [HAP-Ca-10(PO4)(6)(OH)(2)] and fluorapatite [FAP-Ca-10(PO4)(6)(F)(2)] with different specific surface area and stoichiometry was investigated in batch experiments in the pH range 4 to 11 (25 degrees C; 0.1 M KNO3). The impact of different conditions was concerned: solution pH, the presence of complexing ligands (EDTA and humic substance) and competing metal ions, as well as reaction kinetic and equilibrium conditions. To evaluate the reversibility of Cd2+ sorption onto HAP, desorption characteristics in water, Ca, EDTA, and HUM-solutions were determined. Additionally to solution analysis the surface composition of solid phases was analysed by X-Ray Photoelectron Spectroscopy (XPS). The information from the chemical analyses was used to design an equilibration model that takes into account dissolution, surface potential, solution and surface complexation, as well as possible phase transformations. It was revealed that apatites effectively sorb Cd2+ and Zn2+ by ion exchange reactions on surface by formation of new surface phases. Using XPS the formation of a Me-enriched HAP surface was found, which was interpreted as the formation of a solid solution with the general formula: Ca8.4-xMex(HPO4)(1.6)(PO4)(4.4)(OH)(0.4). In a binary solution (Cd+ Zn) the competition of metals reduced individual sorbed amount compared with the single component solutions but the total adsorption maximum was approximately constant. The presence of EDTA reduces the metal sorption on apatite due to [CdEDTA](2)- and [ZnEDTA] 2-complexes and increases apatite solubility due to [CaEDTA](2)-complex formation. The dissolved humic substance was bound on apatite in suspensions but the amount of Cd2+ bound was not changed. The results showed that the solution pH and the presence of complexing ligands have a significant effect on heavy metal sorption on apatite and must be considered if apatites are used as remediation agent. The proposed model can be used to predict apatite dissolution and surface phase transformations in the presence of metal ions and EDTA.

Place, publisher, year, edition, pages
EDP Sciences, 2013. article id 01008
Series
E3S Web of Conferences, ISSN 2267-1242 ; 1
Keyword [en]
apatite, heavy metals, sorption, complexing ligands, XPS, modelling
National Category
Geochemistry
Identifiers
URN: urn:nbn:se:umu:diva-142777DOI: 10.1051/e3sconf/20130101008ISI: 000326475400008OAI: oai:DiVA.org:umu-142777DiVA, id: diva2:1167261
Conference
16th International Conference on Heavy Metals in the Environment (ICHMET), SEP 23-27, 2012, Rome, ITALY
Available from: 2017-12-18 Created: 2017-12-18 Last updated: 2017-12-18Bibliographically approved

Open Access in DiVA

fulltext(534 kB)8 downloads
File information
File name FULLTEXT01.pdfFile size 534 kBChecksum SHA-512
ce91bf3a3eafeadb4e78e2df52a57927c92ff462a6b7107b18500a23be9aa67a0998f36c607a9a11b4b60431231d2c81f83e2f6c9c3799fa8a72e3f812e722d3
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Shchukarev, Andrey
By organisation
Department of Chemistry
Geochemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 8 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 16 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf