我国南方城市给水入户管道管垢特征分析

Characteristics of scale in the household water pipes in city of South China

对我国南方某市3个地区的给水入户管道的腐蚀管垢进行了形貌特征、晶体结构和化学元素组成等试验分析。结果表明,腐蚀管垢普遍具有明显的3层结构:表面层、中间硬壳层和内部孔层。腐蚀管垢的形成不仅受水质条件直接影响,还可能与水力条件、使用时间等因素有关。不同地点、不同层次的腐蚀管垢在形貌特点、晶体结构、元素含量上存在差别,α-FeOOH和Fe3O4为腐蚀管垢中普遍存在的晶体。此外,腐蚀管垢中明显存在重金属、碳(C)、氮(N)、总有机碳(TOC),且这些物质主要集中在管垢的表面层,而硫(S)、铁(Fe)在内部孔层中的含量相对较高。

The morphology,crystalline structure and chemical element composition of the scale in the household galvanized iron water pipes from three areas in South China were analyzed by various methods.The results indicated that there were three major layers in corrosion scale,i.e.surface layer,intermediate shell-like layer and inner porous layer.The formation of corrosion scale was not only influenced by water quality directly,but also might be related to other factors such as hydraulic condition,service time and so on.The morphology,crystalline and element content of different corrosion scale layers varied in different areas.α-FeOOH and Fe3O4 were the dominant crystalline in corrosion scale.There were a lot of heavy metals,C,N and TOC in corrosion scale and they were mainly concentrated in the surface layer.However,S and Fe were relatively higher in inner porous layer.