AWWA PATH50780

Outbreaks of waterborne cryptosporidosis in the past decade have resulted in an increase in research into new disinfection technologies. The current bacterial indicators do not correlate well with the occurrence of protozonal and viral disease causing organisms. Clostridium perfringens spores have been suggested as a treatment efficiency indicator for the removal of Cryptosporidium parvum oocysts from drinking water sources. Micro-porous nanocrystalline films of titanium dioxide were prepared on Ti alloy and indium tin oxide coated glass by electrophoretic immobilization, followed by heat treatment. These films were used for the photocatalytic disinfection of water containing Clostridium perfringens spores. This study showed >96% spore inactivation in under 120 minutes UVA illumination of the TiO[2] films. Chick's Law was applied to the data and first order rate constants for the inactivation of spores determined. TiO[2] films on the Ti alloy were more effective for inactivation of C. perfringens than the ITO glass films. Front face illumination of the TiO[2]/ITO glass was more efficient than back face illumination. Electrochemically assisted photocatalysis was also used to inactivate C. perfringens spores. The disinfection rate constant increases significantly upon the application of a positive potential of 1000 mV vs Ag/AgCl. Includes 36 references, tables, figures.