0
Research Papers

Disinfection of Natural Water by Solar Photocatalysis Using Immobilized TiO2 Devices: Efficiency in Eliminating Indicator Bacteria and Operating Life of the System

[+] Author and Article Information
Asunción Acevedo

 Environmental Technologies Department, Faculty of Environmental Sciences, Cadiz University, Avda. Republica Saharaui S/N, 11510-Puerto Real, Cádiz, Spain

Edward A. Carpio

 Faculty of Sciences, National University of Engineering, P.O. Box 31-139, Av. Tupac Amaru 210, Lima, Peru

Juan Rodríguez

 University of Tarapaca, Av. General Velazquez 1775, Arica, Chile; Faculty of Sciences, National University of Engineering, P.O. Box 31-139, Av. Tupac Amaru 210, Lima, Peru

Manuel A. Manzano

 Environmental Technologies Department, Faculty of Environmental Sciences, Cadiz University, Avda. Republica Saharaui S/N, 11510-Puerto Real, Cádiz, Spainmanuel.manzano@uca.es

J. Sol. Energy Eng 134(1), 011008 (Nov 29, 2011) (10 pages) doi:10.1115/1.4005338 History: Received April 14, 2011; Revised October 07, 2011; Published November 29, 2011

Natural water has been disinfected using TiO2 as the fixed catalyst incorporated in a homemade photoreactor, in which the dimensions and the design parameters are representative of devices that are currently employed at larger scale. The catalyst was immobilized on the external surface of a cylinder of frosted glass situated in the longitudinal axis of a tubular glass reactor. Two alternative methods of immobilizing the catalyst on glass were studied: in the first, a commercial titanium oxide powder (Aeroxide® TiO2 P25) was mounted on a polymeric support; and in the second, it was applied by sol-gel deposition. Illumination was effected by installing the glass reactor in the irradiation chamber of a solar simulator. Under laboratory conditions, groundwater contaminated with cultured and wild bacteria was treated photocatalytically, and the influence of the photolysis, the pumping, and the catalysts was studied. The results obtained have demonstrated that the catalyst immobilized in the interior of the photoreactor presents similar results, in the disinfection of E. coli, as 0.5 g/l of TiO2 P25; and that, in 1.5 h approximately of simulated solar illumination (167 kWUVA s/m2 ) on the sol-gel deposit of TiO2 , it is possible to eliminate 100% of the bacteria covered by international regulations in respect of water for human consumption. With regard to the aging assay of the system, it was observed at 250 h of operation a reduction in the effectiveness of the disinfection process. At 0 and 250 h of operation, the percentages of elimination of E. coli after 50 min of illumination were 100% and 99.5%, respectively. This reduction in the effectiveness of the process was due to the formation of a film of calcium carbonate adhering to the internal glass wall of the photoreactor, which is in contact with the liquid being treated, and to the presence of calcium carbonate precipitates on catalyst surface.

FIGURES IN THIS ARTICLE
<>
Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Experimental device employed in the disinfection experiments

Grahic Jump Location
Figure 2

Results of the disinfection assays with the strain E. coli ATCC® 11229™

Grahic Jump Location
Figure 3

Results of the disinfection assays with wild strains of E. coli, total coliform bacteria, intestinal enterococci and C. perfringens

Grahic Jump Location
Figure 4

Percentages of disinfection of E. coli after 10 and 50 min of illumination, in function of the operating time of the equipment

Grahic Jump Location
Figure 5

Deposit on the internal glass wall of the photo-reactor. (a) SEM micrograph of the deposit after being scraped off the glass; (b) general spectrum.

Grahic Jump Location
Figure 6

(a) and (c) SEM micrographs and (b) and (d) EDX elemental composition obtained by SEM of the ground glass used as support for the catalyst (1), and of this same support after the TiO2 has been fixed by deposition using the sol-gel procedure, before the test of operating life

Grahic Jump Location
Figure 7

STEM Micrograph (a) and DRX diffractogram (b) of a fragment of the TiO2 deposited on the surface of the catalyst

Grahic Jump Location
Figure 8

SEM micrographs (a) and EDX elemental composition (b) obtained by SEM of the catalyst supported on ground glass after the operating life test

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In