Managing biofilms and disinfection residuals to protecting drinking water safety

点击翻译按钮获取中文摘要

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.