Polyacrylonitrile (PAN)-induced carbon membrane with in-situ encapsulated cobalt crystal for hybrid peroxymonosulfate oxidation-filtration process: Preparation, characterization and performance evaluation

A novel polyacrylonitrile (PAN)-induced carbon membrane with in-situ encapsulated cobalt crystal was developed via a one-step carbonization method and applied for peroxymonosulfate (PMS) activation. The dual-function of cobalt in tuning carbon formation and activating PMS was explored. The growth mechanism of the functionalized membrane was investigated via TGA-DSC, FTIR, XRD, Raman and XPS. Results indicated that the addition of cobalt could tune the formation of C and N containing functional groups in the carbon membrane. The membrane morphologies and surface properties were further characterized by FESEM and AFM. Batch studies revealed that more than 90% of sulfamethoxazole (SMX) could be degraded after 60 min of membranes exposure in the presence of PMS. Electron paramagnetic resonance (EPR) results verified the generation of sulfate radical in this process. The removal of humic acid (HA) in a dead-end membrane filtration mode could be maintained at ∼100% with an inconspicuous sacrifice of permeate flux over 450 min. The permeate flux achieved with PMS was higher as compared to the case without PMS addition, which could be ascribed to the catalytic oxidation of organic molecules accumulated on the membrane surface. The catalytic property imports an intrinsic antifouling property of the carbon membrane in the hybrid catalytic membrane filtration process.