兰州市宛川河中段表层沉积物中重金属元素迁移富集特征

通过对兰州市宛川河中段双店子河段表层沉积物元素分析，结合有机质含量和粒度测试，运用聚类分析和相关分析的方法，研究了重金属元素在河流表层沉积环境中的分布及迁移富集等地球化学行为与特征。结果表明Zn元素在研究河段有轻度污染；相关分析表明重金属元素含量与沉积物粒度之间无显著相关性，重金属元素主要是在固-液平衡体系中、通过多相化学反应形成沉淀。污染源分析表明，造纸污水的排放是造成研究区域中上游河段有机质含量较高的主要原因，大分子有机物质的存在不仅改变了此段河流沉积物粒度的变化，且有机质对重金属元素的富集有一定减缓作用。

Migration and Enrichment Characteristics of Heavy Metals in Surface Sediments of the Mid-reach of Wanchuan River in Lanzhou City

Element analysis combining with TOC and particle size test,cluster analysis and correlation analysis were applied to the study of surface sediments samples,which were collected from the Mid-reach of Wanchuan River near the Shuangdianzi Town of Lanzhou City,in order to reveal the geochemistry characteristics of heavy metals,such as distribution,removal and enrichment,in surface depositional environment.According to this result,only element Zn was in low-grade infectant.Correlation analysis indicated that there were no relation between heavy metal and particle size.Heavy metals transfered into sediments mainly from solid-liquid system by multiphase chemical reaction.As a result of the input of paper making wastewater the contents of TOC in mid-upside of sampling river were higher.And due to the big molecule of organic matter,particle size in mid-upside of sampling river became bigger.TOC could weaken the enrichment of heavy metals.