氯离子浓度和碱度对给水管网管垢重金属锰释放的影响

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( 5mg/L、23.1 mg/L、60 mg/L、90mg/L) 和碱度( 52.5 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。 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 ( 5mg/L, 23.1mg/L, 60mg/L, 90mg/L) and alkalinity ( 52.5mg/L, 125mg/L, 200mg/L) . A reactor was designed for simulating manganese release. We analyzed the effect of chloride and a lkalinity 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 30mg/L, with a residence time of 60 hours, the manganese release reached the maximum of 108mg/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 . 国家科技支撑计划项目“南水北调中线水质差异应对关键技术研究与应用” (2015BAB07B09)