Migration of membrane fouling with minimal damage to cell integrity by catalytic ceramic membrane systems in low dosages of ozone during algae-laden water treatment

Ultrafiltration coupled with ozonation pretreatment has received more attention in treating algae-laden water, while balance between cell integrity and mitigating membrane fouling remains a significant challenge in implementation. Herein, the objective of this study is to develop a novel ceramic ultrafiltration membrane (TiO2-Mn-Gd-Ce-M) coupled catalytic ozonation pretreatment system for effectively mitigating membrane fouling with minimal damage to cell integrity. Results showed that this coupling system exhibited an impressive algal rejection of 78.70 % and DOC removal of 59.43 % at a low ozone concentration of 0.01 mmol/L. More importantly, membrane fouling could be effectively mitigated through mainly reducing irreversible fouling resistance. Many lines of evidences suggested the main reason responsible for mitigating membrane fouling included: 1) the abundant hydroxyl groups within membrane due to the introduction of TiO2 and Mn3Gd5.5Ce1.5(SiO4)6O1.5 could facilitate the formation of hydrogen bonds with water molecules, which enhanced hydrophilicity and subsequent anti-fouling capability; 2) low concentration ozone exhibited a preference for electrophilic attack during direct oxidation, thereby reducing cellular damage and increasing the electrostatic repulsion between foulants and membrane surfaces. 3) ozone gradient activation from TiO2 on the surface to Mn3Gd5.5Ce1.5(SiO4)6O1.5 in the pores contributed to generating abundant ROSs which effectively mineralized attached organic foulants in membrane and greatly decreased irreversible fouling. In summary, this study not only proposes a viable strategy for the treatment of algae-contaminated water but also offers valuable insights into the migration mechanism of membrane fouling in catalytic ozonation membrane systems. Hence, the TiO2-Mn-Gd-Ce-M catalytic ozonation process demonstrated promising potential for the treatment of algae-contaminated water, effectively mitigating drinking water health risks. © 2024 Elsevier B.V.