Catalytic ozonation of dimethyl phthalate by Ce-substituted goethite

Abstract

Dimethyl phthalate (DMP) is ubiquitous in aquatic environments due to extensively used as plasticizer, which has received increasing attention in recent years. In this study, the catalytic ozonation of dimethyl phthalate was performed using Ce-substituted goethite as a novel catalyst, which was prepared by isomorphous substitution method. The specific surface area, pHpzc and surface hydroxyl density of the catalyst were determined. The catalyst was characterized using X-ray diffraction, scanning electron microscope and Fourier transform infrared spectroscopy. The removal efficiency of DMP was almost 100% after 30 min, and about 40% DMP was mineralized after 60 min, which was nearly four times higher than single ozonation. During catalytic ozonation process, anions (PO4 3−, SO4 2−, Cl−) affected DMP degradation, indicating that surface hydroxyl groups on the surface of catalyst were main active sites. The electron transfer process by redox reaction between Ce3+/Ce4+, Fe2+/Fe3+ was proposed, and their interaction could also promote the formation of hydroxyl radicals. Ce-substituted goethite was an efficient catalyst for degradation of DMP by catalytic ozonation.