Photocatalytic inactivation of E. coli in natural water sources using a microwave-treated TiO2 catalyst

CATL 35

SM Ede, s.ede@qut.edu.au1, LM Hafner2, and GD Will1. (1) School of Physical and Chemical Sciences, Queensland University of Technology, 2 George St, Brisbane, Australia, (2) School of Life Sciences, and Institute of Health and Biomedical Innovation, Queensland University of Technology, 2 George St, Brisbane, Australia
Photocatalysis of E. coli was observed using immobilised films of TiO2 colloids prepared via a post-synthetic microwave-modification process, Degussa P25, and convection hydrothermally-treated TiO2. As E. coli inactivation was observed using distilled water, photocatalysis in natural river water was trialled. Natural water required the pH to be lowered from 7.5 to 5.0 and with an initial cell concentration of 1 x 103 colony forming units per cm3 or less, inactivation was observed during a five hour treatment period. Differences were observed in the UVA absorbance and the photocatalytic properties of the three types of TiO2 colloids tested and were attributed to the crystal structures of the colloids and the variation in particle size. Experiments were devised to evaluate the effect of unabsorbed UV irradiation within the system. Small colony variants were also identified after photocatalytic and UV treatment, and may present a potential threat to public health for this mode of treatment.
 

Photocatalysis
1:30 PM-4:50 PM, Tuesday, August 21, 2007 BCEC -- 261, Oral

Catalysis & Surface Science Secretariat

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007