Enhanced persulfate activation in confinement ceramic membrane for rapid degradation of pollutants.

Sulfate radical-based advanced oxidation technology is an attractive approach for removing organic pollutants in wastewater. Furthermore, bioinspired nanoconfined catalysis is an important strategy for enhancing catalytic performance. In this study, an advanced oxidation technology functionalized NiAl-LDH@ceramic membrane (LDH@CM) was prepared via an in situ method and used to activate persulfate (PS) for pollutant degradation. The obtained LDH@CM exhibited stability and higher catalytic performance for 100% removal. Trapping experiments and EPR experiments confirmed that O, ·OH, and SO· were the main active species during the degradation process. Meanwhile, the confined environment of the LDH@CM produced a modulating effect on the fluid properties and electron transfer characteristics, which further improved the catalytic performance. Moreover, oxygen vacancies in LDH@CM promoted the redox cycle of Ni(II)/Ni(III) and generated O to maintain catalytic stability. Thus, the mechanistic studies showed that the synergistic effect of the confinement and the surface catalytic reaction sites of the LDH@CM/PS system enhanced the mass transfer process of the reactive substances to the organic compounds and promoted the formation and transformation of the LDH@CM surface reactive substances. The catalytic functionalized ceramic membrane developed in this work provides a new strategy for practical wastewater treatment.