Analogies and differences between photocatalytic oxidation of chemicals and photocatalytic inactivation of microorganisms

WATER RESEARCH

卷:44

Article

Marugan, Javier¹  van Grieken, Rafael¹  Pablos, Cristina¹  Sordo, Carlos¹ 

[1] Univ Rey Juan Carlos, Dept Chem & Environm Technol, ESCET, Madrid 28933, Spain

关键词: Photocatalysis;    Disinfection;    E. coli;    Methylene blue;    Water composition;    Immobilized TiO2;   

DOI  :  10.1016/j.watres.2009.10.022

来源: Elsevier

【 摘 要 】

This study reports the analogies and differences found when comparing TiO2 photocatalytic treatment for chemical oxidation and microorganisms inactivation, using methylene blue and Escherichia coli as references, respectively. In both processes the activation is based on the same physicochemical phenomena and consequently a good correlation between them is observed when analyzing the effect of operational variables such as catalyst concentration or incident radiation flux, both factors influencing common stages such radiation absorption and generation of reactive oxygen species. However, different microbiological aspects (osmotic stress, repairing mechanism, regrowth, bacterial adhesion to the titania surface, etc) makes disinfection kinetics significantly more complex than the first-order profiles usually observed for the oxidation of chemical pollutants. Moreover, bacterial inactivation reactions are found to be extremely sensitive to the composition of water and modifications of the catalysts in comparison with the decolorization of the dye solutions, showing opposite behaviors to the presence of chlorides, incorporation of silver to the catalysts or the use of different types of immobilized TiO2 systems. Therefore, the activity observed for the photocatalytic oxidation of organics can not be always extrapolated to photocatalytic disinfection processes. (c) 2009 Elsevier Ltd. All rights reserved.

【 授权许可】

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