沙懿 张弦 王宇晖

摘要：通过静态释放实验，研究了水源切换造成原水中不同浓度的氯离子和碱度对管网管垢中重金属锰释放的影响。选取郑州市给水管网管段，设计模拟释放反应装置，配制不同浓度氯离子（5 mg/L、231 mg/L、60 mg/L、90 mg/L）和碱度（525 mg/L、125 mg/L、200 mg/L）的实验用水，比较分析氯离子浓度和碱度变化对管垢重金属锰释放的影响。根据实验结果初步推断：氯离子浓度和碱度与管垢中金属锰的释放浓度有较高相关性，且实验中氯离子浓度是影响管网管垢锰释放的首要因素。当氯离子浓度为30 mg/L，停留时间60 h，锰的释放量达到最大为108 mg/L，之后释放浓度趋于平稳。在氯离子浓度促进锰释放的条件下，碱度与管垢中锰的释放量表现出明显相关性。实验结果可为水源切换引起的水质差异对给水管网管垢锰释放问题提供一定参考。

关键词：氯离子；碱度；给水管网；锰释放；管垢

中图分类号：TU 991文献标志码：A文章编号：16721683（2018）03018306

The influence of chloride and alkalinity on the release of heavy metal

manganese in the drinking water network

SHA Yi，ZHANG Xian，WANG Yuhui

（College of Environmental Science and Engineering，Donghua University，Shanghai 201620，China）

Abstract：Static release experiments were designed to investigate the effect of different chloride concentrations and alkalinity of source water on manganese release in drinking water distribution systems.We sampled pipe scale from the drinking water network of Zhengzhou and prepared experiment water with different concentrations of chloride （5 mg/L， 231 mg/L，60 mg/L，90 mg/L） and alkalinity （525 mg/L，125 mg/L，200 mg/L）.A reactor was designed for simulating manganese release.We analyzed the effect of chloride and alkalinity concentration changes on the manganese release of water pipe scale.The results indicated that the chloride concentration and alkalinity were highly correlated with the manganese release in drinking water network.Chloride was the primary factor affecting the manganese release of water pipe scale.In this experiment， when the concentration of chloride was 30 mg/L，with a residence time of 60 hours，the manganese release reached the maximum of 108 mg/L，and then the release became steady.Under the condition that the concentration of chloride promoted manganese release，the alkalinity and the manganese release of pipe scale showed an obvious correlation.The results of the experiment can provide a reference for studying manganese release in drinking water distribution systems after water source switching.

Key words：chloride；alkalinity；drinking water network；manganese release；pipe scale

飲用水水质的保障一直受到供水行业的普遍关注。国内外的很多水厂在实际运行中发现，即使水厂出水各项水质指标都达标，但是经过水管输送，用户出水仍然可能出现一些指标超标的现象[12]。原因是自来水在水管中长距离长时间的输送、多水源供水以及季节性水源切换，水源和给水管网管垢发生了一系列的物理、化学和生物反应，从而产生了管网水质不稳定，甚至是恶化现象[3 4]。如南水北调中线工程[56]，自2014年中线工程竣工，北方部分城市启动了外调丹江口水库水源和本地水源水切换的供水模式。……