Inactivation of Waterborne Pathogens Using Solar Photocatalysis

Abstract

AbstractCryptosporidium parvum oocysts and helminth eggs are among the waterborne pathogens that resist the most to traditional chemical disinfection processes. Since the application of high doses of chlorine, ozone or other chemical disinfectant is not possible in practice because of the subsequent formation of disinfection byproducts, alternative processes for water disinfection have been investigated. This study investigated the potential of catalyzed-solar radiation to control the occurrence of C. parvum oocysts and helminth eggs in drinking water and wastewater, respectively. Bacillus subtilis spores were used as surrogate microorganisms for C. parvum oocysts. Experimental results indicate that 1.5 hours of exposure to ~1 sun-intensity solar radiation, in the presence of 5 mM ferrous ion and 70 mM hydrogen peroxide, decrease egg and spore viability by 49 and 96 percent, respectively. These results suggest that solar photocatalysis may represent an effective and economic alternative for water disinfection in rural communities and for developing countries.