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Indexed by:期刊论文

Date of Publication:2009-07-01

Journal:JOURNAL OF MEMBRANE SCIENCE

Included Journals:SCIE、EI

Volume:336

Issue:1-2

Page Number:109-117

ISSN No.:0376-7388

Key Words:Composite membrane; Ag-TiO2; Hydroxyapatite; E. coli; Inactivation

Abstract:Ag-TiO2/hydroxyapatite (HAP, Ca-10(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 mu m pore size, which comprised of Ag-TiO2/HAP composite layer with a thickness of 10 mu m overlaid on alpha-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 cross-flow 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/cm(2)) and in dark, respectively. The permeate flux of outlet was evidently improved by 71.7% after 1h 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. (C) 2009 Elsevier B.V. All rights reserved.