Emerging PMS-Based LMO–COF Membrane with Improved Stability for the Mineralization of Micropollutants and Rejection of Nanoplastics from Wastewater

Abstract

This study developed a novel layered metal oxide–covalent organic framework (LMO–COF) membrane for the simultaneous removal of pharmaceutical micropollutants and nanoplastics from wastewater. The membrane was integrated with peroxymonosulfate (PMS) as an oxidant, achieving optimal performance at 20% COF (0.025 M) relative to the total LMO content. Under these conditions, complete removal of ranitidine (0.1 mM PMS) and 100% rejection of the nanoplastics were achieved. The membrane delivered a high water flux of 1300 L/m²/h/bar, ensuring efficient micropollutant mineralization even at low PMS levels. Stability tests confirmed consistent performance over 10 operational cycles with a 96% flux recovery ratio. Removal efficiency was sustained across a wide pH range (3–11) and in the presence of various anions, while cobalt leaching remained minimal (0.03–0.1 μg/L). These findings highlight the membrane’s robustness, durability, and potential for large-scale application in wastewater treatment plants.