Integrated disinfection strategies for treatment of drinking water

在饮用水分配系统中，细菌和其他病原体往往聚集在管道表面，也就是所谓的生物膜的形成。消毒是最大限度减少这种形成的关键步骤，这种形成有可能导致病原微生物的增加。供应商经常出于不同原因在处理过程中混合使用初级消毒剂和次级消毒剂，尽管这是一种广泛使用的做法，但很少强调消毒剂之间协同增效的潜力。协同作用的好处将包括当消毒剂“共同工作”时，增强减少分配系统中细菌的能力。几乎没有发表过专门为研究协同作用而设计的研究，特别是利用紫外线处理饮用水。兰德博士之前所做的工作在实验室测试中证实，紫外线和氯基消毒剂之间存在协同作用，可以去除大肠杆菌。在实地研究中还发现，通过模拟分配系统，有可能产生协同效益。为了计算协同效应，这是Koivunen等人提出的一个概念。(2005)，其中指出，当联合消毒剂的清除量大于每种消毒剂单独清除量的总和时，就存在协同作用。尽管这是一个有用的等式，但它仅依赖于消毒剂的效果。因此，它很难在长期研究中应用，因为管道材料、水质、养分供应等问题会对生物膜的形成起到严重的作用。然而，如果能够现实地量化协同作用，这可能会导致供应商能够在不增加消毒剂剂量的情况下减少更多的致病微生物。这项研究的目的是调查不同条件下消毒剂之间协同作用的可能性，并开发一个模型来量化协同作用，以便公用事业公司能够在没有长期试验台和试点研究的情况下模拟其系统。

In drinking water distribution systems, bacteria and other pathogens tend to cluster on pipe surfaces, otherwise known as the formation of biofilm. Disinfection is a key step for minimizing this formation, which has the potential to lead to an increase in pathogenic microorganisms. Suppliers will often utilize primary and secondary disinfectants in combination in the treatment process for different reasons, and although this is a widely used practice little emphasis has been placed on the potential for synergistic benefits between disinfectants. Synergistic benefits would include an enhanced ability to reduce bacteria in distribution systems when the disinfectants "work together". There have been few studies published that were designed specifically to investigate synergy, especially using UV light for the treatment of drinking water. Previous work done by Dr. Rand has established in laboratory tests that synergy exits between UV light and chlorine-based disinfectants for removing Escherichia coli (E. coli). It was also found in field studies through simulating distribution systems that there was potential for synergistic benefits. To calculate synergy, a concept presented by Koivunen et al. (2005) was adopted, which stated that synergy was present when the removal of a combined disinfection strategy was greater than the sum of removals achieved by each disinfectant alone. Although this is a useful equation, it relies on disinfectant efficacy alone. Therefore, it is difficult to apply in long-term studies, where pipe material, water quality, nutrient supply and other issues would play a serious role in the formation of biofilm. However, if synergy could be quantified realistically, this could lead to suppliers being able to reduce more pathogenic microorganisms without increasing disinfectant dosages. The purpose of this research is to investigate the potential for synergy between disinfectants under different conditions and to develop a model to quantify synergy so that utilities might be able to simulate their systems without long-term bench and pilot studies.