Cyanobacterial biochar modified ceramic membrane for in situ filtration and peroxymonosulfate activation: focusing on interface adjustment and enhanced anti-fouling†

In this study, a novel catalytic ceramic membrane (ITC-2-800@CM) was modified with Fe/N/S doped cyanobacterial biochar catalysts to adjust its surface morphology and properties to significantly enhance its organic pollutant removal performance and membrane anti-fouling ability. Specifically, the biochar modification further increased the roughness and hydrophobicity of the pristine ceramic membrane, apparently improving the adsorption capacity of hydroxychloroquine (HCQ) causing membrane fouling. Although sacrificing partial membrane permeability, based on the strong peroxymonosulfate (PMS) activation performance of cyanobacterial biochar, abundant reactive oxygen species were generated and degraded the organic pollutants adsorbed on the surface and pore of ITC-2-800@CM. Hence, the efficient synergistic effect between in situ adsorption, filtration and PMS activation further enhanced hydroxychloroquine removal and membrane anti-fouling performance, especially under a long operation. The actual lake water treatment experiments demonstrated that the ITC-2-800@CM–PMS system could stably remove more than 90% of HCQ and reduce the reversible and irreversible membrane fouling resistance by 81.57% and 60.68% as compared to the pristine CM/PMS system. Furthermore, the treated effluent showed significant reduction in total nitrogen, dissolved organic carbon and UV₂₅₄ concentrations, highlighting the high applicability of the ITC-2-800@CM–PMS system in practical polluted water treatment. This improvement can decrease the need for frequent membrane cleaning during water treatment, thereby reducing operational costs. This research not only provided an easy method for ceramic membrane modification to extend its operational lifespan, but also offered deeper insights into the synergistic effect between in situ filtration and advanced oxidation.