UV-TiO2 Photocatalytic Disinfection and its Influence on Drinking Water Biological Stability

UV-TiO2 photocatalysis have the characteristics of non-toxic and broad-spectrum sterilizing ability, its application in drinking water disinfection has taken much emphasis. This research was conducted in S waterworks which located in Nanjing and take Yangtze river as its source water. UV-TiO2 photocatalytic disinfection experiments were conducted in a self made photocatalysis reactor. Result showed that a 2-log disinfection efficiency can be achieved under UV dose of 19 mJ/cm2. The orthophosphate concentration in water increased under UV dose higher than 198 mJ/cm2, the biodegradable dissolved organic carbon (BDOC) and bacterial regrowth potential(BGP) concentration in water increased significantly under UV dose higher than 396 mJ/cm2. When UV dose increased from 0 mJ/cm2 to 11880 mJ/cm2, the orthophosphate, BDOC, BGP concentration in water increased 47.09%, 265 % and 49.16% respectively. Nevertheless, under low UV dose for drinking water disinfection, there were no significant increase of orthophosphate concentration and BGP, this indicated that UV-TiO2 photocatalysis is a promising disinfection technology; it can effectively kill the bacteria in drinking water and won´t induce biological instability.