Targeted capture of active aluminum species by yttrium-doped zirconia membrane for synergistic antifouling in nutrient-enriched algal systems

Eutrophication driven by excessive phosphorus discharge triggers algal blooms, endangering both aquatic ecosystems and public water sources. While ceramic membranes can efficiently treat algae-laden water, they struggle with the dual challenges of inefficient phosphorus capture and membrane fouling. Herein, we designed a yttrium-doped zirconia ceramic membrane (ZRCM) that addressed these issues through actively sequestering the active aluminum species (Alb) from polyaluminum chloride (PACl) hydrolysis. Yttrium-induced modulation of the ZrO₂ electronic structure enhanced the coordinating reactivity of surface hydroxyls, enabling them to selectively and stably bind Alb via Zr-O-Al bonds for interfacial enrichment. Additionally, the anchored Alb facilitated efficient phosphorus capture by forming Zr-O-P/P=O multilevel bridges, thereby functioning as a secondary adsorption platform. Besides, the in-situ Alb active layer alleviated membrane fouling by strengthening interfacial charge repulsion and creating a hydration barrier, achieving reductions of 67.12% and 43.62% in reversible and irreversible fouling resistance, respectively. The ZRCM developed a loose, porous surface structure, replacing the dense cake layer of the unmodified ceramic membranes and shifting the primary fouling mechanism from intermediate blocking/cake filtration to standard blocking. This work elucidated a molecular-level interfacial antifouling mechanism, offering a promising strategy for advanced treatment of algae-laden water based on ceramic membrane technology.