Photocatalytic membrane coated with α-Fe2O3/Fe3O4 for enhanced filtration performance and antifouling property in surface water treatment.

A photocatalytic membrane coated with α-Fe2O3/Fe3O4 nanoparticles has been developed to address the challenges of membrane fouling and organic removal in the treatment of natural surface water. The photocatalytic and filtration properties of the membranes were investigated through a variety of methods. The successful preparation of iron oxide was confirmed by UV-vis diffuse reflectance spectra and X-ray diffractometry, with α-Fe2O3 identified as the primary photocatalytic agent. A commercial ultrafiltration (UF) membrane was employed as a comparison to evaluate the photocatalytic performance and filtration properties of the modified membrane. Results showed that the photocatalytic membrane achieved better removal rates for UV254 (22.0%) and specific fluorescent organic compounds, such as component 2 (19.38%) and component 3 (16.89%), compared to the control group. Furthermore, both irreversible and reversible fouling resistances of the prepared membranes were significantly lower than that of the control group, with reductions of 39.4% and 50.2%, respectively. The membrane coated with α-Fe2O3/Fe3O4 nanoparticles exhibited moderate removal of protein-like and terrestrially derived humic-like fluorescent organics while controlling membrane fouling. Although the α-Fe2O3/Fe3O4 nanoparticles-coated photocatalytic membrane demonstrated good anti-fouling properties, the removals of organic matters were not as effective as anticipated due to the shorter hydraulic retention time. This study provides valuable insights for enhancing pollutant degradation and anti-fouling properties of membranes through the utilization of solar photocatalytic α-Fe2O3/Fe3O4 surface-modified membranes in the treatment of natural surface water.