Industrial NSERC Chair on Drinking Water, Ecole Polytechnique de Montreal, Department of Civil, Geological, and Mining Engineering. P.O. Box 6079, Downtown Station, Montreal, Quebec, Canada H3C 3A7.
Water Sci Technol. 2011;63(9):1823-31. doi: 10.2166/wst.2011.385.
In this comparative study, the impact of two microbial protective mechanisms against simulated UVA disinfection was assessed by using protocols previously developed for UVC disinfection assays. (i) The impact of natural microorganism aggregation and attachment to particles was assessed by targeting total coliform bacteria in natural surface water samples. (ii) The impact of bacteria internalisation by zooplankton was assessed by using C. elegans nematodes as a model host and E. coli as a bacterial target for UVA inactivation. Dispersion of natural aggregates by blending prior to UVA exposure was shown to enhance the inactivation rate of total coliforms as compared to untreated raw water. Removal of particles by an 8-microm membrane filtration did not improve UVA disinfection efficiency. Twenty-four per cent of the highest applied UVA fluence was found to reach internalised E. coli in nematodes. Both aggregation and internalisation showed similar impact as protective mechanisms against UVA and UVC bacterial inactivation.
在这项对比研究中，我们使用先前开发的用于 UVC 消毒检测的方案，评估了两种微生物保护机制对模拟 UVA 消毒的影响。(i)通过检测天然地表水样本中的总大肠菌群，评估了微生物自然聚集和附着到颗粒上的影响。(ii)利用秀丽隐杆线虫作为模式宿主和大肠杆菌作为 UVA 失活动物的细菌靶标，评估了浮游动物内吞细菌的影响。与未经处理的原水相比，在暴露于 UVA 之前通过混合分散天然聚集体，提高了总大肠菌群的失活率。通过 8 微米膜过滤去除颗粒并不能提高 UVA 消毒效率。发现 24%的最高应用 UVA 剂量能够到达线虫内的内吞大肠杆菌。聚集和内吞作用均显示出对 UVA 和 UVC 细菌失活的类似保护机制的影响。
