Activation of Peroxymonosulfate by Co–Al-LDH@PU Membrane for Efficient Removal of Tetracycline Hydrochloride

Immobilizing the activator on the carrier is an effective strategy to solve the difficult recovery and secondary pollution of activator in advanced oxidation process. In this study, cobalt–aluminum-layered double hydroxide (activator) was immobilized on a PU membrane carrier (Co–Al-LDH@PU membrane) by a hydrothermal in situ growth technique to form a recyclable peroxymonosulfate (PMS) activator. The as-prepared Co–Al-LDH@PU membrane exhibited an excellent ability to activate PMS for the removal of tetracycline hydrochloride (TC). 97.20% of TC (30 mg L −1 ) was eliminated with Co–Al-LDH@PU membrane (3 × 3 cm 2 ) and 1.6 mM PMS at pH 5.5 in 30 min. Singlet oxygen ( 1 O 2 ) was verified as dominant reactive oxygen species responsible for TC removal via quenching tests. Mechanism investigation suggested that the redox cycle of Co 2+ /Co 3+ on the surface of Co–Al-LDH@PU membrane was crucial for PMS activation. Meanwhile, Co–Al-LDH@PU membrane displayed the ideal reusability and versatility.