供水管网大口径管道管垢中污染物分布的径向差异

以管龄为11年的城市主供水管道上的DN300球墨铸铁管为研究对象,采用扫描电镜(SEM)、能谱分析(EDS)、晶体衍射结构分析(XRD)等手段对其径向不同位置的管垢进行了表征,并分析了其各类金属与有机污染物的分布差异.结果表明:管道下部的管垢总量高,平均粒径大.重金属在空间上的分布明显不同,铁、锰、锌、铅、铜和铬在上部的管垢中含量最高,而下部管垢中,铝的含量最高,该分布与管垢中其来源密切相关.管垢中累积了多种的有机污染物,除了微生物代谢形成的烃类物质之外,还累积了藻类的代谢产物及外源有机污染物,不同位置上出现的有机污染物类型也有所差异.该研究结果对将来饮用水管网生物化学安全的研究方法提出了更高的要求,并为管网的饮用水安全保障提供了理论依据.

Radial differences in contaminant distribution in large-diameter pipe scales of main pipelines in drinking water distribution system

The surface character of a 11-year-old DN300 ductile cast iron pipes of main pipelines in drinking water distribution system was investigated by atomic absorption spectrometry, GC-MS, EDS, and XRD, and the content of pollutants, such as metals and organic compounds, also detected. Results showed that, the pipe scales of the lower part had the maximum amount and the maximum average particle size. The spatial distribution of heavy metals was significantly different. The concentration of iron, manganese, zinc, lead, copper and chromium was highest in the upper pipe scales. While the highest content of aluminum was detected in the lower pipe scales. The distribution was closely related with its resource in pipe scales. Beside some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminant accumulated in pipe scales. And types of organic pollutants varied in different spatial locations. The finding put forward higher requirements on the research method about drinking water distribution system biochemical safety, and provided a theoretical basis for the drinking water safety.