Decomposition of 2-chlorophenol in aqueous solution by UV irradiation with the presence of titanium dioxide

Abstract

The decomposition of 2-chlorophenol in aqueous solution by UV TiO 2 oxidation process was studied under various solution pH values, light intensities and types of TiO 2. The removal of 2-chlorophenol and organic intermediates was found to be more effective for acidic solutions. The decomposition of 2-chlorophenol can be fitted well by a pseudo first-order kinetics. Experimental results indicated that the distribution of non-chlorinated and chlorinated intermediates on the photocatalytic decomposition rate of 2-chlorophenol were highly dependent on solution pH. At the same light intensity, the adequate dosage of TiO 2 was found to be less for alkaline solutions than that for acidic solutions. Increasing the light intensity would significantly increase the decomposition rate of 2-chlorophenol at pH 3, but not at pH 11. Both rutile and anatase forms of TiO 2 were used in this study. The destruction rate of 2-chlorophenol of unit weight of rutile was less than that of anatase. However, the decomposition rates of 2-chlorophenol of unit surface area for both were almost the same in this research. Thus, the difference of the decomposition rates of 2-chlorophenol might be attributed to the difference of the surface area of various forms of TiO 2, not to the difference of the crystal properties.