UV-TiO₂ photocatalytic disinfection and photoreactivation of pathogenic bacterium in municipal wastewater

【摘要】 The disinfected bacteria will be a photoreactivation under the irradiation of the sunlight,and the light intensity plays an important role in the bacteria resurrection.The effect of light intensity on photoreactivation of Escherichia coli（E.coli） and Enterococcus faecalis（E.faecalis） in secondary effluents which were disinfected respectively by pure UV and UV-TiO₂ was investigated.The results show that the disinfection efficiency of UV-TiO₂ is much higher than that of the pure UV disinfection.The photoreactivation rate of E.coli is much higher in pure UV disinfection than in UV-TiO₂ photocatalytic disinfection.Under high light intensity in UV-TiO₂ disinfection,high resurrection rate can be induced.However,a higher resurrection rate can be introduced even under low light intensity in pure UV disinfection alone.Meanwhile,UV-TiO₂ disinfection has a strong inhibition effect on E.faecalis photoreactivation.When the light intensity is lower than 21 μW/cm²,nearly no resurrection of E.faecalis occurs after 72 h resurrection irradiation,and a little resurrection rate is observed only under a strong photoreactivating light intensity.更多还原

【Abstract】 The disinfected bacteria will be a photoreactivation under the irradiation of the sunlight,and the light intensity plays an important role in the bacteria resurrection.The effect of light intensity on photoreactivation of Escherichia coli（E.coli） and Enterococcus faecalis（E.faecalis） in secondary effluents which were disinfected respectively by pure UV and UV-TiO₂ was investigated.The results show that the disinfection efficiency of UV-TiO₂ is much higher than that of the pure UV disinfection.The photoreactivation rate of E.coli is much higher in pure UV disinfection than in UV-TiO₂ photocatalytic disinfection.Under high light intensity in UV-TiO₂ disinfection,high resurrection rate can be induced.However,a higher resurrection rate can be introduced even under low light intensity in pure UV disinfection alone.Meanwhile,UV-TiO₂ disinfection has a strong inhibition effect on E.faecalis photoreactivation.When the light intensity is lower than 21 μW/cm²,nearly no resurrection of E.faecalis occurs after 72 h resurrection irradiation,and a little resurrection rate is observed only under a strong photoreactivating light intensity.更多还原