Cyclodextrin-Modified Amorphous Manganese Oxides to Pms Activation for the High-Efficiency Bisphenol a Degradation

Abstract

Advanced oxidation technology of manganese oxide activated persulfate is one of the ideal methods to remove emerging contaminants (ECs). In this work, β-CD modified amorphous manganese oxide (CD-AM) catalyst was prepared under the condition of 80℃ oil bath. The introduction of CD greatly enhances the properties and activity of amorphous manganese oxides. The degradation efficiency is increased from 33.1% to 99.4%, the kinetic constant increased to 14.9 times. The quenching experiments showed that 1 O 2 and ·OH were the main ROS to degrade BPA in the CD-AM/PMS system. O 2 ·-   only appeared in the CD-AM/PMS system, indicating that the addition of CD interfered with the original AM formation process, and promoted the conversion of O 2 ·- to 1 O 2 and Mn (III)/ Mn (IV) cycle. In addition, after the CD-AM was transformed into a supported membrane (AMSM), the performance was further improved and the Mn leaching concentration was effectively reduced, the Mn ion concentration in the filtrate after the first membrane filtration was about 1.2 mg/L, which was only 37% of the Mn concentration in the first leaching of CD-AM. After 4 cycles, the BPA degradation efficiency was 96.9%. When the AMSM/PMS system treated BPA in the river water, the final degradation efficiency reached 94.8%. Therefore, CD-AM as a catalyst for activating PMS shows great application potential in actual water body.

Keywords: Bisphenol A, Peroxymonosulfate, Manganese oxides, Cyclodextrin