Effects of Adding UV and H_2O_2 on the Degradation of Pharmaceuticals and Personal Care Products during O_3 Treatment

摘要

The degradation of 30 pharmaceuticals and personal care products (PPCPs) subjected to O_3, O_3/UV, and O_3/H_2O_2 treatments were investigated using semi-batch tests and evaluated by their pseudo-first-order rate constants. The additional application of UV or H_2O_2 during O_3 treatment significantly improved the degradation rate of most of the PPCPs. At the same O_3 feed rate, 03/UV treatment exhibited much higher PPCP degradation efficiency than that of O_3 treatment. This was probably due to degradation of the PPCPs by O_3, direct UV photodegradation, and OH radicals that formed from the photodegradation of O_3 during 03/UV treatment. PPCP degradation by O_3 was also promoted by adding H_2O_2 during the O_3 treatment. However, when the initial H_2O_2 concentration was high during O_3 treatment, OH radicals were likely to be scavenged by excess H_2O_2, leading to low PPCP degradation. Therefore, it is important to determine the appropriate H_2O_2 dosage during O_3 treatment to improve PPCP degradation when adding H_2O_2 during O_3 treatment.