Effect of advanced photocatalysis on pathogen reactivation rates after UV disinfection in water

摘要

Advanced photocatalytic processes generate highly reactive species in water which enables the mineralization of cellular organic compounds. Titanium dioxide (TiO^ is the most widely studied photocatalyst in water disinfection. Reactivation potentialsof an indicator waterborne pathogen, E. coli (ATCC10798), after photocatalytic treatment of water was evaluated. Dark repair studies were conducted in 200 mL water samples irradiated under low pressure ultra violet (UV) light (with or without Ti02). Three different Ti02 concentrations were used to determine the optimal concentration which provides higher rate of deactivation of cellular organic compounds and lower rate of repair after treatment. Cultured based method was used for bacteria enumeration. It was found that 1 g/L Ti02 has lowered the rate of E. coli dark repair in water after UV disinfection in contrast to UV treatment alone, which is most common disinfection method in water treatment plants.