The degradation and mineralization of 4-chlorophenol in aqueous solutions by electron beam irradiation in the presence of TiO 2 nanoparticles

Abstract

In this study, the effect of TiO 2 nanoparticles on radiation-induced degradation and mineralization of 4-chlorophenol in aqueous solutions was investigated. Solutions of 4-chlorophenol with different contents of TiO 2 nanoparticles were irradiated by electron beam with absorbed doses up to 35.2 kGy. The changes of absorption spectra, pH, total organic carbon (TOC), 4-chlorophenol and Cl − concentrations were examined. The absorbencies of characteristic peaks of 4-chlorophenol decreased distinctly with increasing TiO 2 nanoparticle contents at the same absorbed dose. Although the addition of TiO 2 nanoparticles changed the initial pH, pH values of the solutions with different contents of TiO 2 nanoparticles were almost equal and diminished smoothly with increasing absorbed dose after 3 kGy absorbed dose of irradiation. The TiO 2 nanoparticles had little influence on the degradation of 4-chlorophenol but dramatically promoted the mineralization of 4-chlorophenol. It is suggested that TiO 2 nanoparticles affect the intermediate degradation products during the decomposition of 4-chlorophenol.