Photocatalytic Elimination of Cr(VI) in Aqueous Solution by Using ZSM-5 Zeolite as Catalyst and Urea as Coexisting Organic Contaminants
Abstract
The photocatalytic reduction of Cr(VI) to Cr(III) in aqueous solutions without or with urea (a model organic contaminant) using ZSM-5 zeolite as catalyst under UV illumination was studied. The used ZSM-5 zeolite has the characteristics of pure ZSM-5 zeolite crystalline structure, with the point of zero charge (pHPZC) value of pH = 3.7–3.9. The effects of illumination time, mass content of ZSM-5 zeolite, urea concentrations, Cr(VI) initial concentrations and ionic strength on the photocatalytic reduction of Cr(VI) to Cr(III) were investigated. The results indicated that both the increase of urea concentration and the mass content of ZSM-5 zeolite can improve the photocatalytic reduction of Cr(VI) to Cr(III) under UV illumination. The results are important to understand the photocatalytic reduction of Cr(VI) to Cr(III) in natural environment with organic contaminant.
