Ag–TiO₂/HAP/Al₂O₃ bioceramic composite membrane: Fabrication, characterization and bactericidal activity

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• 作者：Ning Ma ; Xinfei Fan ; Xie Quan ; Yaobin Zhang
• 关键词：Composite membrane ; Ag– ; TiO₂ ; Hydroxyapatite ; E. coli ; Inactivation
• 刊名：Journal of Membrane Science
• 出版年：2009
• 出版时间：1 July 2009
• 年：2009
• 卷：336
• 期：1-2
• 页码：109-117
• 全文大小：1711 K

文摘

Ag–TiO₂/hydroxyapatite (HAP, Ca₁₀(PO₄)₆(OH)₂)/Al₂O₃ bioceramic composite membrane was fabricated to integrate membrane separation and photocatalytic bacterial inactivation by a facile two-step approach involving sol–gel method followed by calcination. The as-prepared composite membrane was characterized as a microporous membrane structure with average 0.8 μm pore size, which comprised of Ag–TiO₂/HAP composite layer with a thickness of 10 μm overlaid on α-Al₂O₃ disk support. Detailed morphology of Ag–TiO₂/HAP composite layer revealed a thickness of 10–30 nm Ag–TiO₂ photocatalytic layer partially covered over HAP particles. Surface photovoltage measurement revealed a superior ability of promoted interfacial charge-transfer reactions in the case of 1 wt. % Ag–TiO₂ composite. A rapid crossflow membrane system was designed to evaluate the roles of the HAP layer and Ag–TiO₂ photocatalyst in the inactivation of Escherichia coli (E. coli) in suspension. HAP acted as a high efficient bacterial adsorbent while Ag–TiO₂ provided powerful photocatalytic attack toward E. coli strains. The removal of E. coli within 60 min with as-prepared membrane was approximately 6 and 4 log units under UV illumination (a weak light intensity of 0.3 mW/cm²) and in dark, respectively. The permeate flux of outlet was evidently improved by 71.7 % after 1 h under UV illumination, compared with that in dark. These results showed that this novel membrane of anti-fouling property might integrate multifunction of membrane separation, bacterial adsorption and photocatalytic inactivation, which suggested great potential for antibacterial treatment of groundwater and drinking water.