Photocatalytic removal of Cr(VI) and Ni(II) by UV/TiO2: Kinetic study

Abstract

In this study, photocatalytic removal of Cr(VI) and Ni(II) by illuminated TiO2 was investigated with variation of solution pH, contact time, TiO2 dosage and initial Cr(VI) and Ni(II) concentration. From the photocatalytic reaction, near complete elimination of Cr(VI) and Ni(II) occurred from the adsorption of Cr(VI) and Ni(II) on the surface of TiO2 as well as reduction of Cr(VI) and Ni(II) to Cr(III) and Ni(0), respectively. Reduction was recognized as a significant elimination process for the treatment Cr(VI) and Ni(II) from wastewater. Removal of Cr(VI) decreased with increasing pH while removal of Ni(II) increased with increasing pH. TiO2 dosage was also an important parameter for the removal of Cr(VI). As the TiO2 dosage increased up to 1 g l-1, removal of Cr(VI) and Ni(II) was continuously enhanced. © 2012 Desalination Publications. All rights reserved.