An XPS study for mechanisms of arsenate adsorption onto a magnetite-doped activated carbon fiber

Shujuan Zhang; Xiao-yan Li; J Paul Chen

doi:10.1016/j.jcis.2009.11.001

An XPS study for mechanisms of arsenate adsorption onto a magnetite-doped activated carbon fiber

J Colloid Interface Sci. 2010 Mar 1;343(1):232-8. doi: 10.1016/j.jcis.2009.11.001. Epub 2009 Nov 5.

Authors

Shujuan Zhang¹, Xiao-yan Li, J Paul Chen

Affiliation

¹ Environmental Engineering Research Centre, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.

PMID: 20018292
DOI: 10.1016/j.jcis.2009.11.001

Abstract

The surface and bulk structures of a newly developed carbon-based iron-containing adsorbent for As(V) adsorption were investigated by using X-ray diffraction (XRD), field emission scanning electronic microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS). XRD patterns of the adsorbents indicated that the modified activated carbon fiber (MACF) was a simple mixture of the raw activated carbon fiber (RACF) and magnetite. After modification, a porous film was formed on the surface of the MACF with nano-sized magnetite on it. The As(V) uptake on the MACF was highly pH dependent and was facilitated in acidic solutions. XPS studies demonstrated that the surface oxygen-containing functional groups were involved in the adsorption and that magnetite played a key role in As(V) uptake. The dominance of HAsO(4)(2-) in surface complexes and the pH effect on As(V) uptake demonstrated that the monoprotonated bidentate complexes were dominant on the surface of the MACF. No reduction of As(V) was observed on the surface of the ACFs.