Effects of Adding UV and H2O2on the Degradation of Pharmaceuticals and Personal Care Products during O3Treatment

Abstract

The degradation of 30 pharmaceuticals and personal care products (PPCPs) subjected to O3, O3/UV, and O3/H2O2 treatments were investigated using semi-batch tests and evaluated by their pseudo-first-order rate constants. The additional application of UV or H 2 O 2 during O3 treatment significantly improved the degradation rate of most of the PPCPs. At the same O 3 feed rate, O3/UV treatment exhibited much higher PPCP degradation efficiency than that of O 3 treatment. This was probably due to degradation of the PPCPs by O3, direct UV photodegradation, and OH radicals that formed from the photodegradation of O3 during O3/UV treatment. PPCP degradation by O 3 was also promoted by adding H 2 O 2 during the O 3 treatment. However, when the initial H 2 O 2 concentration was high during O3 treatment, OH radicals were likely to be scavenged by excess H2O2, leading to low PPCP degradation. Therefore, it is important to determine the appropriate H 2 O 2 dosage during O 3 treatment to improve PPCP degradation when adding H 2 O 2 during O 3 treatment.