独立计量分区截断管水质时空变化规律

Spatiotemporal change rules of water quality in cut-off water pipelines in district metering areas(DMA)

为探究城市供水管网独立计量分区(DMA)建设过程中形成的分区截断管道和滞流区对供水管网水质的潜在影响,以管龄为9 a的实际供水管道为研究对象,设计并搭建试验平台,研究DMA分区截断管道内管网水关键水质理化指标、生物指标的时空变化规律.研究结果表明:随着截断管深度的增加,管壁生物膜和管垢脱落速度加快,水质恶化速率加快;铁释放、浊度和活菌浓度在不同管深处随时间的变化情况不同,12 h后,水质恶化速率明显加快;各水质指标恶化的相关性分析显示,截断管越深,水质受到主干管的扰动越少,各指标相关性水平越高.

The pilot platform was constructed with water pipelines of nine years old to study the spatiotemporal changes of essential physical,chemical and biological parameters of water in cut-off pipelines,in order to explore the potential impact of cut-off pipelines and stagnant areas which are created in the construction of district metering areas(DMAs)on water quality.Results show that,as the depth of cut-off pipeline increases,the biofilm and limescale fall off more quickly and the water quality deterioration rate gets faster;the temporal changes of iron release,turbidity and microorganism vary with time at different depths.After twelve hours,the water quality deterioration rate was significantly accelerated.The correlation analysis of the deterioration of water quality parameters shows that,the deeper the depth of cut-off pipeline is,the less the water disturbed by the main pipe is and the higher the correlation level of each parameter is.