某市给水管网中铁释放现象影响因素与控制对策分析

针对某市管网水中铁浓度的变化规律进行了系统的研究,确定了管垢向管网水中释放出的铁是管网水中铁超标的主要原因.研究中发现铸铁管和镀锌钢管中管垢的主要化学组分为铁.在给水管网中,管网水的溶解氧和余氯浓度低时,对应的管网水中铁释放现象严重,其原因是还原条件使管垢表面的致密钝化层被破坏,造成二价铁的大量释放.根据试验结果提出了给水管网中铁释放和“红水”现象的控制对策.

Analysis of Influence Factors and Control Methods on Iron Release Phenomenon in Drinking Water Distribution System

Variation rule of iron in drinking water distribution systems was studied,and it was found that the iron released from the scale to the bulk water was the primary reason for iron overstep.The main chemical composition of the scale in cast iron pipe and galvanized steel pipe was iron in a northern city in China.In the drinking water distribution systems,when the value of dissolved oxygen or chlorine residual was low,the iron release phenomenon was severe.The reason for that was the passivation layer of the corrosion scale was destroyed in reductive condition and the result was a great amount of iron in ferrous form was released.According to the research results,the control methods for iron release and 'red water' phenomenon were indicated.