铬在供水管道中的释放行为研究  

Investigation of Chromium Release Dynamics in Water Supply Pipelines

作　　者：刘菁 田一梅[1] 刘云慧 彭柱 申海亮 贾世超 LIU Jing;TIAN Yi-mei;LIU Yun-hui;PENG Zhu;SHEN Hai-liang;JIA Shi-chao(School of Environmental Science and Engineering,Tianjin University,Tianjin 300350,China;North China Municipal Engineering Design and Research Institute Co.Ltd.,Tianjin 300110,China;Computational Hydraulics International,Canada)

机构地区：[1]天津大学环境科学与工程学院,天津300350 [2]中国市政工程华北设计研究总院有限公司,天津300110 [3]计算水力国际,加拿大

出　　处：《中国给水排水》2024年第23期40-48,共9页China Water & Wastewater

基　　金：国家自然科学基金资助项目(51778409);天津市研究生科研创新项目(2021YJSB119)。

摘　　要：以实际管道中的腐蚀垢和水为研究对象,考察腐蚀垢中重金属的赋存情况,分析管道腐蚀垢中Cr的释放行为,利用管道动态循环装置探究不同水质环境对管道不同位置水中Cr释放的影响。结果显示,管垢各层均存在Cr、As、Pb等重金属,且含量呈现由表层向疏松多孔层递减的规律。双常数动力学模型对管垢中Cr释放过程的描述较为合理,Elovich动力学模型的拟合效果次之,表明管垢表面具有高度的非均质性,Cr的释放过程较为复杂且初始释放速率与腐蚀垢中的重金属富集量呈正相关。依据ANSYS水力模拟结果将管道内的水体分为主体水、稳态水和闭塞水三类。相同水质环境下,Cr释放量由大到小的顺序均为稳态水、主体水、闭塞水;水质条件对管道不同位置Cr释放有相似的影响,低pH、高水温、高浓度SO_(4)^(2-)有利于Cr释放;此外,流动状态下水流剪切力的作用会加速管道中Cr的释放。This study focuses on the corrosion scale and water present in actual drinking water pipelines.The presence of heavy metals within the corrosion scale was investigated,the release behavior of chromium(Cr)from pipeline corrosion scale was analyzed,and the impact of varying water quality environments on Cr release at different locations within the pipeline was examined using a dynamic pipeline circulation device.Heavy metals such as chromium(Cr),arsenic(As),and lead(Pb)were detected in all layers of the pipe scale,with concentrations diminishing from the surface layer to the underlying loose porous layer.The two-constant kinetic model effectively characterized the Cr release process from the pipe scale,while the Elovich kinetic model demonstrated a secondary fitting performance.This suggested that the surface of the pipe scale exhibited a significant degree of heterogeneity,indicating that the Cr release process was relatively intricate and that the initial release rate showed a positive correlation with heavy metal concentrations within the corrosion scale.Based on the hydraulic simulation results from ANSYS,the water within the pipeline was categorized into three distinct types:bulk water,steady water,and occluded water.Under identical water quality conditions,the sequence of chromium release from highest to lowest was as follows:steady water,bulk water,and occluded water.The water quality exhibited comparable effects on Cr release at various locations within the pipeline.Conditions characterized by low pH,elevated water temperature,and high SO_(4)^(2-)concentration facilitated the release of Cr.Furthermore,the hydrodynamic shear stress expedited the release of Cr within the pipeline.

关 键 词：供水管网 铬释放 稳态水 主体水 闭塞水 

分 类 号：TU991[建筑科学—市政工程]