Oxidative degradation of dimethyl phthalate (DMP) by UV/H 2O 2 process

Abstract

The photochemical degradation of dimethyl phthalate (DMP) in UV/H 2O 2 advanced oxidation process was studied and a kinetic model based on the elementary reactions involved was developed in this paper. Relatively slow DMP degradation was observed during UV radiation, while DMP was not oxidized by H 2O 2 alone. In contrast, the combined UV/H 2O 2 process could effectively degraded DMP, which is attributed to the strong oxidation strength of hydroxyl radical produced. Results show that DMP degradation rate was affected by H 2O 2 concentration, intensity of UV radiation, initial DMP concentration, and solution pH. A kinetic model without the pseudo-steady state assumption was established according to the generally accepted elementary reactions in UV/H 2O 2 advanced oxidation process. The rate constant for the reaction between DMP and hydroxyl radical was found to be 4.0 × 10 9 M −1 s −1 through fitting the experimental data to this model. The kinetic model could adequately describe the influence of key factors on DMP degradation rate in UV/H 2O 2 advanced oxidation process, and could serve as a guide in designing treatment systems for DMP removal.