Improved separation performance of carbon nanotube hollow fiber membrane by peroxydisulfate activation

Abstract

• A CNT hollow fiber membrane was fabricated via wet-spinning method. • An excellent phenol removal rate could be achieved by integrating the CNT hollow fiber membrane with PDS activation. • The electro-transfer, and 1 O 2 are predominant reaction radicals for phenol oxidation. • The CNT hollow fiber membrane has good reusability after the pyrolysis process. Membrane separation has been widely used to address the global water crisis, but is limited by the permselectivity trade-off. Herein, an effective strategy was adopted to overcome this drawback by integrating membrane separation with peroxydisulfate (PDS) activation on a carbon nanotube (CNT) hollow fiber membrane. During the phenolic wastewater treatment, the CNT hollow fiber membrane not only performed as the separation barrier, but also as the catalyst to activate PDS to degrade the micro-size phenol timely. Compared to the sole filtration (33%), the advanced oxidation functions (AOFs)-based membrane has a higher phenol removal rate (97%) under the optimal conditions: neutral condition (pH = 6), 0.5 mM PDS, and hydraulic retention time (HRT) of 39.6 s. The separation mechanism was confirmed to be the non-radical reaction pathways (electro-transfer, and 1 O 2 ) through radical quenching, electron paramagnetic resonance (EPR), linear sweep voltammetry (LSV), and open circuit potential model. Such results suggested this work exhibited a high promising prospect for the remediation of organic pollution by a CNT hollow fiber membrane with AOFs.