Photocatalytic ozonation of dimethyl phthalate with TiO2 prepared by a hydrothermal method.

TiO(2) was prepared by a hydrothermal method at a low temperature and used to degrade and mineralize dimethyl phthalate (DMP). TiO(2) was characterized by XRD, TEM, BET and UV-vis techniques. The characteristics of TiO(2) prepared by a hydrothermal method (h-t TiO(2)) included a good crystalline anatase phase, greater surface area, stronger absorption to UV light wavelength and lower agglomeration than TiO(2) prepared by a classic sol-gel method (s-g TiO(2)). The photocatalytic activity of h-t TiO(2) prepared under optimal hydrothermal condition (180°C for 10h) was 2.5 times higher than that of s-g TiO(2) in degrading DMP. The process of photocatalysis combined with UV irradiation and ozonation (TiO(2)/UV/O(3)) considerably improved the mineralization and degradation of DMP compared to photocatalysis combined with UV irradiation (TiO(2)/UV), ozonation combined with UV irradiation (UV/O(3)), and ozonation alone (O(3)). A kinetic study showed the mineralization in TiO(2)/UV/O(3) followed the Langmuir-Hinshelwood model.