多水源供水管网中铁释放规律

针对水源切换而引起的水质超标现象,开展了多水源联合供水条件下管网中铁释放规律的研究。分析了北方某城市2种水源(滦河水和长江水)的水质特点,利用实验模拟反应器分别研究了水源完全置换和供水分界线处水源混合区域的铁释放规律。结果表明,多水源供水管网的铁释放速率与水源水质密切相关,特别是水中含高浓度SO2-4和氯化物时会加快铁的释放。不同水源之间的频繁切换会破坏管垢表面的钝化层,使铁释放速率迅速变化,随后会有所缓解,但新的平衡的形成需要较长时间。供水分界线处的水源混合区域,由于水质的不断变化造成管垢表面很难形成稳定的钝化层,铁释放速率持续偏高,只有当长江水所占比例高达75%以上时才能得到抑制。

Law of iron release in water supply network with multiple water resources

The phenomenon that water quality does not reach the standard always occur after the water source is switched, the research of the iron release law in water supply network with multiple water resources was carried out. Water quality characteristics of both water resources (the Luan River water and the Yangtze River water) of a northern city were analyzed, and iron release in the zone of water completely replacement and water supply dividing line were researched respectively by the experimental reactor. The result shows that the iron release rate is closely related to the water quality. Especially when the water contains high concentration of SO₄^2- and chloride, the iron release rate will speed up. The frequent switching between the different water resources will destroy the passivation layer on the surface of the pipe scale, the iron release rate will rapidly change, and then will be eased, but it requires a longer time to the formation of a new equilibrium. To the mixed water in dividing line, it is difficult to form the stable passivation layer because of the water quality changes constantly, the continued high rate of iron release occurs. It can be suppressed only when the proportion of the Yangtze River water is as high as 75% or more.