Fe-glycerate microspheres as a heterogeneous catalyst to activate peroxymonosulfate for efficient degradation of methylene blue

Sulfate radical-based advanced oxidation processes (SR-AOPs) have emerged as an attractive technology in organic dye wastewater treatment. In this study, hydrothermally synthesized Fe-glycerate microspheres is successfully applied as a heterogeneous catalyst to degrade methylene blue (MB) via activating peroxymonosulfate (PMS). The experimental results suggest that MB degradation efficiency and total organic carbon (TOC) removal can arrive at 99.7% and 37.1% in 60 min by the Fe-glycerate/PMS system, indicating that Fe-glycerate microspheres has an excellent catalytic degradation performance. In addition, the effects of PMS concentration, catalyst dosage, initial pH and coexisting ions on MB degradation efficiency were studied. Radical quenching and electron paramagnetic resonance (EPR) tests confirm that the major active species are sulfate radical (SO4·–) and singlet oxygen (1O2) for MB degradation, followed by superoxide radical (O2·–) and hydroxyl radical (·OH). Furthermore, the possible mechanism of MB degradation by Fe-glycerate/PMS system was inferred. This work shows Fe-glycerate microspheres can be considered as a new and promising pathway to activate PMS for treating organic dye wastewater.