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，也称为生物膜的形成。 消毒是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。 供应商出于不同的原因，在处理过程中通常会结合使用一级和二级消毒剂，尽管这是一种广泛使用的做法，但很少强调消毒剂之间的协同效益潜力。 协同效益将包括当消毒剂“一起工作”时，减少分配系统中细菌的能力增强。 很少有研究专门用于研究协同作用，特别是使用紫外线处理饮用水。 兰德博士先前的工作已经在实验室测试中建立了紫外线和氯基消毒剂之间的协同作用，以去除大肠杆菌（E。coli）。 在通过模拟分配系统进行的实地研究中还发现，有可能产生协同效益。 为了计算协同作用，采用了Koivunen等人（2005年）提出的概念，该概念指出，当联合消毒策略的去除量大于每种消毒剂单独实现的去除量之和时，存在协同作用。 虽然这是一个有用的等式，但它仅依赖于消毒剂的功效。 因此，它很难应用于长期的研究，其中管道材料，水质，营养供应和其他问题将在生物膜的形成中发挥重要作用。 然而，如果协同作用可以实际量化，这可能导致供应商能够减少更多的病原微生物，而不增加消毒剂剂量。 本研究的目的是调查在不同条件下消毒剂之间的协同作用的潜力，并开发一个模型来量化协同作用，使公用事业公司可能能够模拟他们的系统，而无需长期的实验室和试点研究。

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.