For centuries, Tonglushan area has been playing an important role for Cu-Fe ore-forming deposits along the middle-lower reaches of the Yangtze River. However, mining activities in Tonglushan area have caused serious contamination in its surrounding areas. In this work, 20 stream sediment samples along the Dagang River were collected and analyzed for susceptibility, particle size and heavy metal contents. Average enrichment factors and principal component analysis were used to analyze the relationship between heavy metals, assess the heavy metals pollution levels and identify the origin of the heavy metals. The results showed that: 1) compared to the background values of sediments in Daye, heavy metals are enriched in the sediments of the Dagang River, with Cu seriously enriched, and Pb, Zn, Cd and Cr relatively enriched; and 2) the migration of Cu is strongly associated with magnetite with the particle size between 16 to 32 μm. Moreover, the sources of heavy metals in stream sediments may be due to city sewage, mining activity and natural erosion.%大冶铜绿山铜铁矿是长汀中下游重要的金属矿山之一,近年来矿山周边环境问题引起了广泛的关注.测试分析了大港河20件水系沉积物样品中重金属含量、磁化率和粒度等指标,运用平均富集因子和主成分分析方法探讨了沉积物中重金属元素的含量变化特征及元素之间的共生组合规律,评价了重金属的富集程度,并分析了其可能来源,得到以下基本认识:(1)大港河水系沉积物中重金属富集明显,平均富集倍数由大到小依次为:FCu＞FPb＞FZn＞FCd＞FCr＞1.6；(2)沉积物中Cu等重金属的迁移与16～32 μm的磁铁矿颗粒关系密切.据此初步分析,大港河沉积物中重金属可能主要来源于城市污水、矿山活动以及自然风化成土过程.
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