Impact of Particle Aggregated Microbes on UV Disinfection. II: Proper Absorbance Measurement for UV Fluence
Impact of Particle Aggregated Microbes on UV Disinfection. II: Proper Absorbance Measurement for UV Fluence
复制标题
颗粒聚集微生物对紫外线消毒的影响。
DOI：
10.1061/(asce)0733-9372(2006)132:6(607
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发表时间：
2006
影响因子：
2.2
通讯作者：
K. Linden
中科院分区：
文献类型：
--
作者：
H. Mamane;K. Linden
当存在散射光的颗粒或聚集体时，使用标准分光光度计测量紫外线的吸光度会有很大的误差。对于高度浑浊的水，应使用积分球IS分光光度法测量高混浊水的真实紫外线吸光度，该分光光度法允许同时收集反射和透射辐射。当散射影响紫外线消毒时，这一点尤其重要--例如在存在聚集体的情况下。通过比较标准分光光度计法和积分球吸光度测量法测定紫外线通量，评价聚集态微生物光散射对紫外线消毒的影响。以明矾为絮凝剂，诱导模拟饮用水中的孢子团聚体和含有天然颗粒的原水中的孢子团聚体。与非混凝系统相比，混凝系统显著降低了紫外线灭活效果，对天然原水的影响更为明显。在计算通量时，使用标准分光光度法测量悬浮液和聚集体的吸光度会导致过量使用，而使用IS光谱分析则不会。结果表明，聚集保护孢子免受紫外线消毒，使用适当的吸光度测量技术，考虑到颗粒散射，对于正确解释结果至关重要。
Ultraviolet UV absorbance measurements are subject to significant error using a standard spectrophotometer when particles or aggregates that scatter light are present. True UV absorbance for highly turbid waters should be measured using integrating sphere IS spectrophotometry that allows the collection of reflected and transmitted radiation simultaneously. This is especially important when the effects of scattering impact UV disinfection—such as with the presence of aggregates. The impact of light scattering of particle- aggregated microbes on UV disinfection was evaluated by comparing standard spectrophotometer and integrating sphere absorbance measurements for UV fluence determination. Spore-clay aggregates in simulated drinking waters and spore aggregates with natural particles from raw waters were induced by flocculation with alum. Coagulated systems significantly decreased the UV inactivation effectiveness compared to the noncoagulated system with the effects more pronounced for raw natural water. Absorbance measurement of suspensions and aggregates using standard spectrophotometry in the calculations of fluence resulted in overdosing whereas the use of IS spectroscopy did not. The results demonstrated that aggregation protected spores from UV disinfection, and that use of proper absorbance measurement techniques, accounting for particle scattering, is essential for correct interpretation of the results.