Title: Photocatalytic Inactivation of Microbial Pathogens in Water
Author: Peter Kerr
Date: April 2008
Abstract
The inactivation of pathogens in drinking water has, for the last hundred years, been a major contributor to public health and well being. Chlorination of drinking water, introduced in the early nineteenth century, has contributed to the reduction of microbial pathogens in drinking water and numbers of those reporting illnesses associated with contaminated water.
Chlorination, however, has its own drawbacks, including the formation of trihalomethanes, and the fact that research suggests that it may be ineffective against protozoan, viral or biofilm forming organisms.
Over the last twenty years a new technology has been developed which has been shown to address the above concerns. Semiconductor photocatalysis is a process which requires no addition of chemicals to the water and therefore leaves no residual toxic by products.
This study involves the experimental assessment of the disinfection efficiency of a point of use photocatalytic system for the domestic market. Experiments were carried out using E.coli in deionised water and tap water, with a reactor coated with titanium dioxide, over a period of several weeks.
The results, while inconclusive, did indicate that the process has merits. On each occasion, the bacterial count was reduced substantially although the reduction was not as pronounced as other studies have demonstrated it to be.
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