The degradation and mineralization of 4-chlorophenol in aqueous solutions by electron beam irradiation in the presence of TiO2 nanoparticles

In this study, the effect of TiO2 nanoparticles on radiation-induced degradation and mineralization of 4-chlorophenol in aqueous solutions was investigated. Solutions of 4-chlorophenol with different contents of TiO2 nanoparticles were irradiated by electron beam with absorbed doses up to 35.2kGy. The changes of absorption spectra, pH, total organic carbon (TOC), 4-chlorophenol and C1- concentrations were examined. The absorbencies of characteristic peaks of 4-chlorophenol decreased distinctly with increasing TiO2 nanoparticle contents at the same absorbed dose. Although the addition of TiO2 nanoparticles changed the initial pH, pH values of the solutions with different contents of TiO2 nanoparticles were almost equal and diminished smoothly with increasing absorbed dose after 3 kGy absorbed dose of irradiation. The TiO2 nanoparticles had little influence on the degradation of 4-chlorophenol but dramatically promoted the mineralization of 4-chlorophenol. It is suggested that TiO2 nanoparticles affect the intermediate degradation products during the decomposition of 4-chlorophenol. (C) 2006 Elsevier Ltd. All rights reserved.