Efficient Activation of Peroxymonosulfate by Micro-Nano Bubbles for the Catalytic Degradation of Tetracycline from Wastewater

High-salinity organic wastewater remains difficult to remediate because conventional advanced oxidation processes are often inefficient, and radical pathways are strongly suppressed by matrix effects. Here, we report a micro-nano bubble (MNB)-driven strategy for peroxymonosulfate (PMS) activation, where cavitation-induced localized heating and enhanced gas–liquid mass transfer accelerate PMS activation and generate highly oxidative reactive species for degrading tetracycline hydrochloride (TCH), a representative refractory antibiotic, under saline conditions. Compared with the activation of hydrogen peroxide (H 2 O 2 ) and peroxydisulfate (PDS), MNBs exhibited a markedly higher capability to activate PMS, achieving 99.3% removal of TCH (10 mg L –1 ) within 30 min and significantly outperforming the MNBs-only process. Furthermore, the oxygen source used to generate MNBs substantially improved PMS activation, leading to faster degradation kinetics. Mechanically, it was demonstrated that singlet oxygen ( 1 O 2 ) together with hydroxyl radical (•OH) and sulfate radical (SO 4 •– ) was involved in the activation of PMS enhanced by MNBs. This work provides a robust and efficient route for treating high-salinity organic wastewater via coupling MNB technology with PMS-based oxidation.