Degradation of n-butyl benzyl phthalate using TiO 2/UV

Abstract

n-Butyl benzyl phthalate (BBP) has been classified as endocrine disrupting compound and priority pollutant. Effects of TiO 2 dosage, pH, initial BBP concentration and co-existing substances on the degradation of BBP by TiO 2/UV process were investigated. The optimal TiO 2 dosage and pH value for the BBP degradation were 2.0 g L −1 and 7.0, respectively. The degradation rate of BBP by TiO 2/UV process could be fitted pseudo-first-order kinetics. The effects of co-existing substances on the degradation rate of BBP revealed that some anions (such as BrO 3 −, ClO 4 − and Cr 2O 7 2−) could enhance BBP degradation, and other anions would restrain BBP degradation. The sequence of inhibition was PO 4 3− > CO 3 2− > NO 3 − > SO 4 2− > Cl −. The cations K +, Na +, Mg 2+ and Ca 2+ had the restrained effect on the BBP degradation, and the effect of Ca 2+ was the strongest among four cations tested. The organic compounds acetone and methanol decreased the degradation rate of BBP. The major intermediates of BBP degradation were identified as mono-butyl phthalate, mono-benzyl phthalate and phthalic acid, and a primary degradation mechanism was proposed.