Laboratory studies investigating the processes leading to discolouration in water distribution networks
Laboratory studies investigating the processes leading to discolouration in water distribution networks
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DOI：
10.1016/j.watres.2008.07.026
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发表时间：
2008-10-01
期刊：
影响因子：
12.8
通讯作者：
Saul, A. J.
中科院分区：
文献类型：
--
作者：
Husband, P. S.;Boxall, J. B.;Saul, A. J.
结果报告自实验室实验，所述实验室实验被进行以研究配水系统内的变色过程，并且特别是支持Boxall等人提出的经验模型的概念[Boxall，J.B.，扫罗，A. J.，Skipworth，P.J.，2001.基于颗粒特性的输配干线泥沙运动模拟新方法。水软件系统1，263-273。并由Boxall和扫罗现场验证[Boxall，J.B.，扫罗，A. J.，2005.饮用水分配系统中变色的模拟。环境工程学报ASCE 131（5）。该模型是基于这样的假设，即变色是由细颗粒的侵蚀和运输引起的，在英国通常以铁和锰为主，这些细颗粒除了自重外还通过力附着在系统的管壁上。这些颗粒显示出类似粘性的特性，并在管壁上分层堆积，受系统内日常流动模式的影响。变色事件是由这些层的腐蚀引起的，腐蚀是由于系统水力学的变化，特别是管壁处的剪切应力的变化，例如由于需求的变化、消防栓的爆裂或打开。一旦从管壁清除层重新积聚在系统内的正常条件下。实验，以确定粘性层的行为和强度特性涉及的发展时期，然后由测量所产生的变色时，积累的材料被侵蚀的增加管壁剪切应力。结果支持经验模型的概念，因此它的应用。结果还表明，材料层的产生是受日常流动模式的范围，更大的变化减少材料积累，但不是由稳态水力条件的大小。(C)2008爱思唯尔有限公司保留所有权利。
Results are reported from laboratory experiments conducted to investigate the processes of discolouration within a water distribution system and specifically the concepts underpinning an empirical model proposed by Boxall et al. [Boxall, J.B., Saul, A.J., Skipworth, P.J., 2001. A novel approach to modelling sediment movement in distribution mains based on particle characteristics. Water Software Systems 1, 263-273.] and field validated by Boxall and Saul [Boxall, J.B., Saul, A.J., 2005. Modelling discolouration in potable water distribution systems. journal of Environmental Engineering ASCE 131(5).]. The model is based on the hypothesis that discolouration is caused by the erosion and transport of fine particles, typically dominated by iron and manganese in the UK, that are attached to the pipe walls of the system by forces in addition to self-weight. These particles display cohesive-like properties and build up in layers on the pipe wall, conditioned by the usual daily flow patterns within the system. Discolouration events are caused by erosion of these layers due to changes in the system hydraulics and specifically changes in shear stress at the pipe wall, for example due to change in demand, a burst or the opening of a fire hydrant. Once cleaned from the pipe walls the layers re-accumulate under the usual conditions within the system.Experiments to determine cohesive layer behaviour and strength characteristics involved development periods followed by the measurement of the resultant discolouration when accumulated material was eroded by an increase in pipe-wall shear stress. The results support the empirical model concepts and hence its application. The results also suggest that the generation of material layers is influenced by the range of daily flow patterns, with greater variability reducing material accumulation, but not by the magnitude of steady state hydraulic conditions. (C) 2008 Elsevier Ltd. All rights reserved.