Synergistic electro-catalytic oxidation of ibuprofen in electro-peroxone system with flow-through carbon nanotube membrane cathode

A novel electro-peroxone membrane filtration (EPMF) system was constructed based on catalytic •OH production and enhanced mass transport with a flow-through, carbon nanotube (CNT) membrane cathode. Scanning electron microscopic and conductive atomic force microscopic characterization affirmed that the CNT membrane possessed a compact nano-porous structure with high electrical conductivity and large catalytic area. The EPMF system removed ibuprofen, a typical ozone-resistant pharmaceutical and personal care product, by 95.75 ± 1.12%, which was 3.72, 1.97 and 1.60 folds greater than those obtained in separate electrochemical filtration, and ozonation/peroxone-coupled filtration, respectively. Moreover, electron spin resonance in conjunction of quantitative •OH measurements showed that IBU degradation was mainly associated with advanced oxidation by in-situ produced •OH. The CNT cathode played a critical role in catalyzing H 2 O 2 and O 3 decomposition, which synergistically promoted •OH formation during the EPMF process. These findings provided new insights into the applicability and mechanisms of EPMF for advanced drinking water treatment.