摘要
γ-Al 2 O 3 ceramic nanofiltration (NF) membranes are promising for water treatment owing to their excellent thermal and chemical durability; however, their widespread application is restricted by low water permeance, severe membrane fouling, and insufficient stability under acidic conditions. Herein, hydrophilic TiO 2 @Al 2 O 3 NF membranes were fabricated via a controlled sol deposition strategy, in which polyvinyl alcohol (PVA) regulated sol penetration into the porous support to construct a defect-free separation layer with reduced transport resistance. Simultaneously, TiO 2 incorporation into the boehmite-derived network induced the formation of Ti–O–Al linkages, leading to enhanced membrane hydrophilicity and structural integrity. As a result, the optimized membrane exhibited a pure water permeance of 23.71 L m −2 h −1 ·bar −1 , corresponding to a 36.13% increase over the pristine Al 2 O 3 membrane, while maintaining high rejections of 91.50% for MgCl 2 and 88.28% for CaCl 2 via the synergistic effects of size sieving and Donnan exclusion. The membrane sustained MgCl 2 rejection above 90% over 48 h of continuous filtration at pH 4, demonstrating enhanced stability under moderately acidic conditions. Significantly improved antifouling performance was achieved, with approximately 1.6-fold higher flux recovery than the pristine membrane after 8 h of tetracycline fouling tests. The enhanced separation performance is attributed to the synergistic effects of reduced transport resistance, Ti–O–Al-mediated structural reinforcement, and the formation of a stable hydration layer that mitigates foulant adhesion. This work presents an effective strategy for engineering ceramic NF membranes with simultaneously enhanced permeance, antifouling capability, and operational stability under moderately acidic conditions, providing new insights into membrane design for water treatment.
危险品化学品经营许可证（带存储）