SO4•--based catalytic ceramic UF membrane for organics removal and flux restoration

Catalytic membranes have gained increasing interest in water treatment due to their improved performance on contaminants removal, fouling mitigation, and cleaning efficiency. The reactive species generated in the catalytic membrane system play a critical role in the process. However, the performance of SO4 center dot--based catalytic membrane has been considerably less studied. The current research investigated the performance of a novel SO4 center dot--based ceramic ultrafiltration membrane on organics removal, fouling mitigation, and cleaning efficiency. The catalytic membrane was prepared through the filtration of a MnO2-Co3O4 nanoparticle solution, followed by sintering and sonication. Characterization results demonstrated the successful deposition of nanoparticles onto the membrane surface. Besides, the influence of 0.06 mg/cm(2) of coating on membrane permeability was negligible. The production of SO4 center dot- (i.e., with the presence of peroxymonosulfate (PMS)) as predominant radical species was confirmed using para-chlorobenzoic acid (pCBA) and nitrobenzene (NB) as probe compounds. Due to the reaction with SO4 center dot-, a higher NOM removal rate was observed with the coated membrane as compared to the pristine membrane. However, the permeate flux of the coated membrane was only slightly increased in the presence of PMS (i.e., 8% increase in normalized flux), possibly due to the formation of small molecules leading to internal pore fouling. Contrariwise, the PMS cleaning efficiency with the coated membrane was remarkably higher than the pristine membrane and stable within three cycles of membrane filtration. The results of this study would significantly assist in the optimization of SO4 center dot--based catalytic membrane processes for future successful industrial implementation.