Managing biofilms and disinfection residuals to protecting drinking water safety

在不同的和不断变化的消毒制度下使用全尺寸管道回路设施将是解决本研究目标的核心和必要条件。管道回路设施将重建运行系统的物理（表面与体积比，水力包括剪切应力和湍流交换）化学（代表最终水质和残留物的变化）和生物（天然接种物）条件，以便获得有意义和适用的理解。针对给定的消毒制度开发生物膜。2.将消毒方式由氯改为氯胺化，考察其对乙醇胺生物膜的影响.游离氯的年度“冲击”负荷评估硝化细菌的控制。这通常用于美国系统，旨在缓解氯胺化系统中长期可能发生的硝化问题（仅适用于选项/选定的氯胺制度）。4.生物膜和本体水微生物在不同氯化制度下的特征及其对水力变化的响应，即它的粘附，捕获和释放特性影响水质分布等。在消毒方案变更之前和之后，表征消毒阶段和总体散装水质量6。调查与碳水平（TOC/AOC）和粘附/释放特性的联系，特别是关于改变消毒方案的联系。预计其中一个管道环路将位于计划进行消毒变更的现场，作为操作实践的一部分。将管道回路和运行网络之间的结果进行比较和对比，以确认所得知识的适用性。

The use of full scale pipe loop facilities under different and changing disinfection regimes will be central and essential to addressing the aims of this research. The pipe loop facilities will recreate the physical (surface to volume ratio, hydraulic including shear stress and turbulence exchange) chemical (representative final water quality and change in residual) and biological (natural inoculum) conditions of operational systems such that the resulting understanding is meaningful and applicable.A typical experiment programme for a given pipe loop facility would be:1. Develop the biofilm for a given disinfection regime.2. Change the disinfection regime from chlorine to chloramination to investigate the impact of change on eth biofilm.3. Annual 'shock' loading of free chlorine to evaluate control of nitrifying bacteria. This is often used in US systems intended to alleviate the nitrification problems that can occur in the longer term in chloraminated systems (Option / selected Chloramine regimes only). 4. Characterise the biofilm and bulk water microbiology under different chlorination regimes and it's response to hydraulic changes, i.e. it's adhesion, trapping and release properties that influence water quality in distribution, etc.5. Characterise the planktonic phase and overall bulk water quality both prior to and post changes to disinfection regimes6. Investigate links to carbon levels (TOC/AOC) and adhesion / release properties with particular regards to changing disinfection regimesIt is anticipated that one of the pipe loops will be located on a site where a disinfection change is planned as part of operational practice. Results to be compared and contrasted between pipe loop and operational network to confirm applicability of resulting knowledge.