Photocatalytic Inactivation of Escherichia coli with LbL Fabricated Immobilized TiO2 Thin Films

Sontakke, Sharad and Modak, Jayant and Madras, Giridhar (2011) Photocatalytic Inactivation of Escherichia coli with LbL Fabricated Immobilized TiO2 Thin Films. In: Journal of Advanced Oxidation Technologies, 14 (1). pp. 86-92.

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Abstract

Photocatalysis using semiconductor catalyst such as TiO2, in presence of UV light, is a promising technique for the inactivation of various microorganisms present in water. In the current study, the photocatalytic inactivation of Escherichia coli bacteria was studied with commercial Degussa Aeroxide TiO2 P25 (Aeroxide) and combustion synthesized TiO2 (CS TiO2) catalysts immobilized on glass slides in presence of UV irradiation. Thin films of the catalyst and polyelectrolytes, poly(allyl amine hydrochloride) and poly(styrene sulfonate sodium salt), were deposited on glass slides by layer by layer (LbL) deposition method and characterized by SEM and AFM imaging. The effect of various parameters, namely, catalyst concentration, surface area and number of bilayers, on inactivation was studied. Maximum inactivation of 8-log reduction in the viable count was observed with 1.227 mg/cm(2) of catalyst loaded slides. With this loading, complete inactivation was observed within 90 min and 75 min of irradiation, for Aeroxide and CS TiO2, respectively. Further increase in the catalyst concentration or increasing number of bilayers had no significant effect on inactivation. The effect of surface area on the inactivation was studied by increasing the number of slides and the inactivation was observed to increase with increasing surface area. It was also observed that the immobilized catalyst slides can be used for several cycles leading to an economic process. The study shows potential application of TiO2, for the inactivation of bacteria, in its fixed form by a simple immobilization technique.

Item Type:	Journal Article
Publication:	Journal of Advanced Oxidation Technologies
Publisher:	Science & Technology Network Inc
Additional Information:	Copyright of this article belongs to Science & Technology Network Inc.
Keywords:	Photocatalytic inactivation; immobilized TiO2; Escherichia coli
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	31 Mar 2011 06:46
Last Modified:	31 Mar 2011 07:23
URI:	http://eprints.iisc.ac.in/id/eprint/36355

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