地下水供水区域水源切换腐蚀产物释放控制技术

A Novel Method of Controlling Iron Release in Groundwater Supply Area Pipes after Water Source Switch

为了应对水源切换后突发"黄水"的风险,提出对地下水供水区域管段,采用增加消毒剂用量和溶解氧浓度的方式来控制管垢稳定性的技术措施。试验管道中水流状态为白天循环运行,夜晚静止。结果表明,白天循环运行时,未养护管段切换为黄河水源后,出水总铁和浊度在运行15 d之后降至水质标准的规定限值;养护后管段切换水源后,运行5 d后出水总铁<0.3 mg/L,浊度<1 NTU。但隔夜浸泡后的出水仍然出现浊度、总铁较大幅度升高的现象,水源切换期间应加大管网末梢用户用水量,促进管网水的更新速率。地下水供水区域管段提前养护2个月,也只能减小"黄水"的程度,并不能杜绝"黄水"现象的发生。因此黄河水仍需与其他源水调配使用,控制拉森指数,以降低水源切换时突发"黄水"的风险。

To address the risk of ＇ red water＇ after the water source switch, a novel method to stabilize the corrosion scale by increasing the disinfectant dosage and dissolved oxygen （DO） concentration in groundwater supply area pipes was put forward. The states of water flow in test pipes were circulating in the daytime and stationary at night. During the circulating operation in the daytime, for pipes without maintenance, the effluent total iron and turbidity decreased to be lower than the standard limit after fifteen days of the water source switch to Yellow River water. For pipes with maintenance, the effluent total iron and turbidity were 〈 0.3 mg/L and 〈 1 NTU, respectively after five days of the water source switch. However, a significant increase in turbidity and total iron occurred after the stationary state. During the water source switch, the consumption of tap water should be increased, which could promote the replacement rate of pipe network water. For pipes in the groundwater supply area, maintenance for two months in advance could not avoid but only alleviate the ＇ red water＇. Therefore, in the case of the water source switch to Yellow River water, decreasing the Larson ratio by mixing it with other water sources is necessary to reduce the risk of ＇red water＇.