Biogenic manganese oxide: An efficient peroxymonosulfate activation catalyst for tetracycline and phenol degradation in water.

Graphical abstract Highlights • BioMnO x had an unprecedented PMS activation efficiency, 3-fold faster than 3D α-Mn 2 O 3. • 100% phenol at 40 min and 99.4% TC at 60 min were degraded in BioMnO x /PMS system. • BioMnO x had a wide pH working range 3.0–9.0 and excellent long-term stability. • 1O 2 was the dominant reactive oxygen species for pollutant degradation over BioMnO x. • Different TC degradation pathway by 1O 2 was proposed vs. by OH radical. Abstract From the view of environment and easy availability, to develop the most efficient manganese oxide for peroxymonosulfate (PMS) activation is of great importance for the degradation of recalcitrant organic pollutants. In this study, biogenic manganese oxide (BioMnO x) exhibited an unprecedented efficiency than the most efficient 3D α-Mn 2 O 3 prepared by chemical method. 100% of phenol degradation at 40 min and 99.4% of tetracycline removal at 60 min were achieved over BioMnO x with PMS, which was 3-fold faster than 3D α-Mn 2 O 3. BioMnO x also has an excellent long-term stability and good performance toward the pollutants degradation at a wide pH range of 3.0–9.0. Most importantly, 1O 2 was identified as the primary reactive species in BioMnO x /PMS system based on the trapping experiment and EPR analysis. The PMS activation over BioMnO x should follow a self-decomposition and energy quenching mechanism instead of electron transfer process as confirmed by the XPS analysis. Finally, the degradation pathways of tetracycline and phenol by 1O 2 over BioMnO x were proposed according to HPLC and HPLC-MS results, which are greatly different from that by OH oxidation in the literature. [ABSTRACT FROM AUTHOR]