老旧灰口铸铁管对管网末梢水质影响及控制措施研究  

Study on the influence of old gray cast iron pipe on the water quality at the end of pipe network and its control measures

作　　者：林朋飞 董顶 陈超 张启文[2] LIN Pengfei;DONG Ding;CHEN Chao;ZHANG Qiwen(School of Environmental and Civil Engineering,Jiangnan University,Wuxi 214122,China;Research Institude for Environmental Innovation(Suzhou),Tsinghua,Suzhou 215163,China;School of Environment,Tsinghua University,Beijing 100084,China)

机构地区：[1]江南大学环境与土木工程学院,无锡214122 [2]清华苏州环境创新研究院,苏州215163 [3]清华大学环境学院,北京100084

出　　处：《给水排水》2024年第S1期354-359,共6页Water & Wastewater Engineering

基　　金：山东省重点研发计划项目(2020CXGC011406);苏州市水利水务科技项目(2020011)

摘　　要：为评估城市供水管网中部分老旧灰口铸铁管对末梢水质影响及控制措施,挖取长三角某城市供水管网中老旧灰口铸铁管,并加工成管段模拟反应器,模拟研究该管段配送过程中水质变化规律,并研究水质控制措施及效果。管段研究分为水质稳定期和水质控制期两个试验阶段。在水质稳定阶段,定量分析管段对末梢水质影响,发现管段主要影响末梢总铁和浊度,24 h可能导致浊度和总铁分别超标4~10倍和1~4倍。在水质控制试验阶段,分别研究了调节碱度、pH和投加缓蚀剂的控制效果。其中,将碱度从88 mg/L提高至150 mg/L后,出水浊度和总铁浓度下降了32.8%和45.7%;将pH从7.8提高至9.0后,出水浊度和总铁浓度下降了43.1%和64.2%;添加0.5 mgP/L的缓蚀剂六偏磷酸钠后,浊度和总铁浓度出现突升,随后下降,整体处于加剧腐蚀的状态,浊度和总铁浓度平均升高了149.1%和30.2%。结果表明,针对老旧灰口铸铁管引发的黄水问题,提高进水碱度和pH能有效控制,在一定条件下,碱度和pH与黄水控制效果呈正相关关系;添加六偏磷酸钠会加剧该城市老旧灰口铸铁管的腐蚀,建议不作为老旧灰口铸铁管的黄水控制措施。To evaluate the influence of the old gray cast iron pipes in urban water supply network on the peripheral water quality and control measures,this paper takes the old gray cast iron pipes in the urban water supply network excavated from a city in the Yangtze River Delta as the research object,and uses the simulated reactor device processed into a pipe section to study the water quality change law and possible yellow water control measures in the distribution process of the pipe section.The research is divided into two stages:water quality stability and yellow water control stage.In the yellow water control stage,the control effects of alkalinity,pH and corrosion inhibitor were studied.Among them,after adding NaHCO3 to the influent of pipe 1 to increase the alkalinity from 88 mg/L to 150 mg/L,the effluent turbidity and total iron concentration decreased by 32.8%and 45.7%,respectively.After adding NaOH into the influent of pipe 2 to increase the pH from 7.8 to 9.0,the effluent turbidity and total iron concentration decreased by 43.1%and 64.2%,respectively.After adding 0.5 mgP/L inhibitor sodium hexametaphosphate into the influent of pipeline 3,the turbidity and total iron concentration increased sharply,then decreased,and the corrosion was intensified.The turbidity and total iron concentration increased by 149.1%and 30.2%on average.The test results show that,improving the alkalinity and pH of the influent can effectively control the yellow water.Under certain conditions,the alkalinity and pH are positively correlated with the yellow water control effect.Adding sodium hexametaphosphate can aggravate the corrosion of old gray cast iron pipe,so it is not recommended as yellow water control measures for old gray cast iron pipe.

关 键 词：老旧管网 灰口铸铁管 管网水质 黄水控制 

分 类 号：TU990[建筑科学—市政工程]