Removal of ciprofloxacin-humic acid pollutant residue in wastewater through a hybrid treatment system consisting of pre-treatment with ozonation-AC/TiO2/CeO2 adsorption and degradation using PVDF/Ni-CeO2@SiO2 photocatalytic membrane

Abstract

Photocatalytic membranes (PMs) provide an excellent removal efficiency for emerging pollutants (EPs) through simultaneous photocatalytic degradation and molecular separation. However, the fabrication of PMs from conventional photocatalytic nanoparticle suffers from low membrane performance, especially due to chemical incompatibility and maldistribution of the photocatalytic nanoparticles, and low photocatalytic caused by rapid recombination of e-/h+ pair. Prior to the preparation of PVDF/Ni-CeO2@SiO2 membrane (NCSM), nanocomposite photocatalyst of Ni-CeO2@SiO2 was firstly prepared according to the sol-gel method. The CeO2 photocatalyst was doped by Ni atom to improve its optical properties and followed by impregnation into SiO2 support to amplify the photocatalyst distribution. Then, the NCSM was further coated using polydopamine (PDA) to enhance permeate water flux. The NCSM exhibited significant structural porosity enhancement to ease water molecule penetration. The PDA coated NCSM demonstrated 1.2 times higher photocatalytic activity than the uncoated one. Indeed, the membrane has considerably high permeate flux up to ∼70.9 L.m−2.h−1 with ciprofloxacin and humic acid removal up to 99.9% and 98%, respectively. In addition, the NCSM also showed excellent antifouling properties that develop remarkable stability of 98% flux recovery after 3 cycles. Therefore, this study promotes a great potential of PMs for highly effective antibiotic eradication in wastewater.