Influence of water quality on UV disinfection in two typical reclaimed waters
水质对紫外消毒在两种典型再生水中应用的影响

The effect of water quality on UV disinfection was studied using E. coli as testing bacteria.The result showed that UV could inactivate E. coli effectively and 4.41-lg reduction was achieved at the UV dose of 4 mJ/cm2. Ferric ion and humic acid and dissolved matter in reclaimed waters all had effects on light absorbance degree and UV transmittance of water sample,but no marked effect on inactivation rate of E. coli. At the range of particles concentration (0~200 mg/L), activated sludge particles and kaolin clay particles shielded E. coli to an insignificant degree relative to particle-free control conditions, while the particles present in W1 reclaimed water (2.6 mg/L) provided significant protection, showing a significant tailing. Humic acid enforced the photoreactivation ability of UV-damaged E. coli, but in reclaimed water, the photoreactivation ability reduced to varying degrees according to different water samples.