Biofilm structures (EPS and bacterial communities) in drinking water distribution systems are conditioned by hydraulics and influence discolouration
Biofilm structures (EPS and bacterial communities) in drinking water distribution systems are conditioned by hydraulics and influence discolouration
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DOI：
10.1016/j.scitotenv.2017.03.176
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发表时间：
2017-09-01
影响因子：
9.8
通讯作者：
Boxall, J. B.
中科院分区：
文献类型：
--
作者：
Fish, K.;Osborn, A. M.;Boxall, J. B.
来自处理厂的高质量饮用水在通过饮用水分配系统（DWDS）输送到客户水龙头的过程中会发生降解。在管壁-水界面处发生的相互作用是这种降解的核心，并且通常由复杂的微生物生物膜主导，而这些微生物生物膜尚不清楚。本研究采用新的应用共聚焦显微镜技术，以量化的细胞外聚合物（EPS）和细胞的DWDS生物膜的组合物，同时评价细菌群落。一个国际上独特的，全面的，实验DWDS设施被用来调查三种不同的水力模式后生物膜的影响，随后评估其响应增加剪切应力，连接生物膜的水质影响，如变色。生长过程中更大的流量变化与细胞数量增加，但与EPS细胞体积比和细菌多样性呈负相关。在所有条件下的冲洗过程中引起变色并动员EPS。最终，低变化的流量条件下开发的生物膜具有最低量的生物质，最大的EPS体积每细胞和最低的变色反应。这项研究表明，水力学和生物膜的物理和社区结构之间的相互作用是复杂的，但在老化的DWDS基础设施，以限制水质退化和保护公众健康的生物膜管理的关键。(C)2017作者由爱思唯尔公司出版
High-quality drinking water from treatment works is degraded during transport to customer taps through the Drinking Water Distribution System (DWDS). Interactions occurring at the pipe wall-water interface are central to this degradation and are often dominated by complex microbial biofilms that are not well understood. This study uses novel application of confocal microscopy techniques to quantify the composition of extracellular polymeric substances (EPS) and cells of DWDS biofilms together with concurrent evaluation of the bacterial community. An internationally unique, full-scale, experimental DWDS facility was used to investigate the impact of three different hydraulic patterns upon biofilms and subsequently assess their response to increases in shear stress, linking biofilms to water quality impacts such as discolouration. Greater flow variation during growth was associated with increased cell quantity but was inversely related to EPS-to-cell volume ratios and bacterial diversity. Discolouration was caused and EPS was mobilised during flushing of all conditions. Ultimately, biofilms developed under low-varied flow conditions had lowest amounts of biomass, the greatest EPS volumes per cell and the lowest discolouration response. This research shows that the interactions between hydraulics and biofilm physical and community structures are complex but critical to managing biofilms within ageing DWDS infrastructure to limit water quality degradation and protect public health. (C) 2017 The Authors. Published by Elsevier B.V.