Effect of competing anions on arsenate adsorption onto maghemite nanoparticles

T. Tuutijärvi, E. Repo, R. Vahala, M. Sillanpää, Guohua Chen

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39 Citations (Scopus)

Abstract

This paper reports the effect of several competing anions on arsenate adsorption with maghemite nanoparticles. Sulphate (as SO4), nitrate (as NO3-N), phosphate (as PO4-P) ions and silicate (as SiO2) were studied in dual solution with arsenate. Moreover, the combined effect of ions and other water characteristics were examined with a natural groundwater sample which was spiked with a certain amount of arsenate. Arsenate batch adsorption experiments were carried out with two different kinds of maghemite-a commercially available one and a homemade one using the sol-gel process. Sulphate (≤250 mg·L-1) and nitrate (≤12 mg·L-1) had a negligible effect on the arsenate (0.5 mg·L-1) adsorption at pH 3. However, both phosphate (≤2.9 mg·L-1) and silicate (≤50 mg·L-1) had an adverse impact on arsenate (≤3 mg·L-1) adsorption at pH 7. Phosphate (≤1.5 mg·L-1) showed minimal competition with arsenate (0.5 mg·L-1), while silicate (≤10 mg·L-1) inhibition was insignificant for all studied As(V) concentrations at pH 3. The removal of arsenate from the groundwater sample was as efficient as from laboratory water for 0.5 mg·L-1As(V) both at pH 3 and pH 7.
Original languageEnglish
Pages (from-to)505-514
Number of pages10
JournalChinese Journal of Chemical Engineering
Volume20
Issue number3
DOIs
Publication statusPublished - 1 Jun 2012
Externally publishedYes

Keywords

  • anion effect
  • groundwater
  • nitrate
  • phosphate
  • silicate
  • water treatment

ASJC Scopus subject areas

  • Environmental Engineering
  • Biochemistry
  • Chemistry(all)
  • Chemical Engineering(all)

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