Managing biofilms and disinfection residuals to protecting drinking water safety

在不同和不断变化的消毒制度下使用全尺寸管道环路设施将是实现本研究目标的核心和关键。管道环路设施将重建操作系统的物理(表面与体积比、水力，包括剪切力和湍流交换)、化学(具有代表性的最终水质和残留的变化)和生物(自然接种)条件，因此所产生的理解是有意义和可应用的。对于给定的管环设施，典型的实验计划将是：1.为给定的消毒方案开发生物膜。将消毒方式由氯化改为氯胺化，考察改变后对乙烷生物膜的影响。每年对游离氯进行“冲击”负荷，以评估硝化细菌的控制。这通常用于美国的系统，旨在缓解氯胺化系统中可能出现的长期硝化问题(仅适用于备选方案/选定的氯胺系统)。4.表征不同加氯方式下的生物膜和原水微生物及其对水力变化的响应，即影响水质分布的附着、捕集和释放特性等。描述变更消毒方案前后的浮游阶段和总体水质6。调查与碳水平(TOC/AOC)和黏附/释放特性的联系，特别是与改变消毒方法有关预计其中一个管道回路将位于作为操作实践一部分计划进行消毒改变的地点。将管网和管网之间的结果进行比较和对比，以确定所得知识的适用性。

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.