Activation of peroxymonosulfate by microwave irradiation for degradation of organic contaminants

In this study, peroxymonosulfate (PMS) activation was successfully achieved by microwave (MW) irradiation directly and subsequently applied for the degradation of bisphenol A (BPA, an endocrine disrupting chemical frequently detected in the environment), especially at temperatures above 60(circle)C. The experiment results showed that a higher reaction temperature, MW power level, initial PMS dose, and initial solution pH had positive effects on the degradation efficiency of BPA. The degradation efficiency of BPA was slightly enhanced in real water compared to that in ultrapure water. The result of radical scavenger experiments indicated that both sulfate radical and hydroxyl radical were the dominant reactive oxygen species. Based on the results of high performance liquid chromatography and gas chromatography-mass spectrometry, several transformation pathways, including beta-scission, hydroxylation, dehydration, oxidative skeletal rearrangement, and ring opening, were proposed. The complete degradation of several typical organic contaminants was also achieved using the MW/PMS process. This work would broaden the selection of PMS activation methods and provide an option for wastewater treatment. (C) 2017 Elsevier B.V. All rights reserved.