Photocatalytical removal of inorganic and organic arsenic species from aqueous solution using zinc oxide semiconductor

Photochem Photobiol Sci. 2013 Apr;12(4):653-9. doi: 10.1039/c2pp25231g.

Abstract

The photocatalytic removal of arsenite [As(III)] and monomethylarsonic acid [MMA(V)] was investigated in the presence of UV light (350 nm) and aqueous suspensions of ZnO synthesized by the sol-gel technique. Photocatalytic removal of these potent arsenic compounds results in the effective and rapid mineralization to less toxic inorganic arsenate [As(V)]. The effect of ZnO loading and solution pH on the treatment efficiency of the UV/ZnO photocatalytic process was evaluated. The optimal conditions for the removal of 5 mg L(-1) [As(III)] and [MMA(V)] aqueous solutions were observed at catalyst loadings of 0.25 and 0.50 g L(-1) with solution pH values of 7 and 8, respectively. Under these conditions, the activity of photocatalyst sol-gel ZnO was compared with TiO2 Degussa P25 and commercial ZnO catalyst. The results demonstrate that the high adsorption capacity of ZnO synthesized by sol-gel gives enhanced removal of arsenic species from water samples, indicating that this catalyst is a promising material for treatment of arsenic contaminated groundwater.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Arsenicals / chemistry*
  • Arsenites / chemistry*
  • Arsenites / isolation & purification
  • Catalysis
  • Gels / chemistry
  • Hydrogen-Ion Concentration
  • Semiconductors
  • Titanium / chemistry
  • Ultraviolet Rays*
  • Water Pollutants, Chemical / chemistry*
  • Water Pollutants, Chemical / isolation & purification
  • Water Purification
  • Zinc Oxide / chemistry*

Substances

  • Arsenicals
  • Arsenites
  • Gels
  • Water Pollutants, Chemical
  • titanium dioxide
  • Titanium
  • monomethylarsonic acid
  • arsenite
  • Zinc Oxide