Degradation of Dibutyl Phthalate in Aqueous Solution by a Combined Ferrate and Photocatalytic Oxidation Process

Abstract

The aim of the present work was to study the interaction of ferrate oxidation and photocatalytic oxidation in terms of dibutyl phthalate (DBP) degradation in aqueous solution, in which three sets of experiments were carried out, including (1) ferrate oxidation alone, (2) photocatalytic oxidation alone, and (3) the combination of ferrate oxidation and photocatalytic oxidation. Laboratory experiments demonstrated that ferrate oxidation and phtotocatalytic oxidation of DBP in aqueous solution are relatively slow processes. However, the presence of TiO 2 and ferrate together under UV illumination accelerated the DBP degradation significantly. Since ferrate was reduced quickly due to the presence of TiO 2 and UV irradiation, the DBP degradation reaction can be divided into two phases. During the first 30 min (Phase 1) the DBP was degraded by both photocatalytic oxidation and ferrate oxidation, and by interactive reactions. After 30 min (Phase 2), the ferrate residual had declined to a very low level and the photocatalytic reaction was the dominant mechanism of further DBP degradation. The influence of three main factors, ferrate dosage, TiO 2 dosage and pH, on the DBP degradation were investigated in order to understand the reaction mechanism and kinetics.