Simultaneous removal of perchlorate and arsenate by ion-exchange media modified with nanostructured iron (hydr)oxide

J Hazard Mater. 2008 Mar 21;152(1):397-406. doi: 10.1016/j.jhazmat.2007.07.016. Epub 2007 Jul 10.

Abstract

Hybrid ion-exchange (HIX) media for simultaneous removal of arsenate and perchlorate were prepared by impregnation of non-crystalline iron (hydr)oxide nanoparticles onto strong base ion-exchange (IX) resins using two different chemical treatment techniques. In situ precipitation of Fe(III) (M treatment) resulted in the formation of sphere-like clusters of nanomaterials with diameters of approximately 5nm, while KMnO4/Fe(II) treatments yielded rod-like nanomaterials with diameters of 10-50nm inside the pores of the media. The iron content of most HIX media was >10% of dry weight. The HIX media prepared via the M treatment method consistently exhibited greater arsenate adsorption capacity. The fitted Freundlich adsorption intensity parameters (q=K x C(E)(1/n)) for arsenate (1/n<0.6) indicated favorable adsorption trends. The K values ranged between 2.5 and 34.7mgAs/gdry resin and were generally higher for the M treated media in comparison to the permanganate treated media. The separation factors for perchlorate over chloride (alpha(Cl-)(ClO4-)) for the HIX media were lower than its untreated counterparts. The HIX prepared via the M treatment, had higher alpha(Cl-)(ClO4-) than the HIX obtained by the KMnO(4)/Fe(II) treatments suggesting that permanganate may adversely impact the ion-exchange base media. Short bed adsorber (SBA) tests demonstrated that the mass transport kinetics for both ions are adequately rapid to permit simultaneous removal using HIX media in a fixed bed reactor.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adsorption
  • Arsenates / isolation & purification*
  • Ferric Compounds / chemistry*
  • Ion Exchange Resins*
  • Metal Nanoparticles*
  • Microscopy, Electron, Scanning
  • Perchlorates / isolation & purification*

Substances

  • Arsenates
  • Ferric Compounds
  • Ion Exchange Resins
  • Perchlorates
  • ferric oxide
  • arsenic acid
  • perchlorate