刁江水体多相介质中As,Zn和Pb的空间和季

调查了广西刁江河水中As，Zn和Pb的溶解态、悬浮颗粒态分布情况及季节变化，以及3种重金属在不同粒级沉积物中的分布情况. 结果表明:刁江流域河水与沉积物中3种重金属污染在流域尺度上的分布存在差异，沉积物污染更为严重. 与土壤污染一致，沉积物中3种重金属的污染范围扩散延伸到距离污染源近200 km的下游区域，其中车河矿区对As污染的贡献率明显高于大厂矿区，而对Pb污染的贡献率明显小于大厂矿区；不同重金属在水体中的赋存形态存在差异，河水中悬浮颗粒态Pb所占比例远高于As和Zn，这与3种重金属矿物的稳定性以及在不同粒级沉积物中的富集特征有关；河水中重金属的赋存形态存在季节差别，丰水期悬浮颗粒态重金属所占比例明显高于枯水期. 

Spatial and Seasonal Distribution Rules of As, Zn and Pb in Multi-phase Mediums of Diaojiang River

Spatial and seasonal distributions of arsenic (As), zinc (Zn) and lead (Pb) in dissolved and particulate fractions in river flows and the distribution of three heavy metals in different size fractions of sediments were investigated in Diaojiang River in Guangxi province. It was shown that the distribution of the three heavy metals contamination in the water was different from that in sediments in watershed scale. The contamination in the sediments was more serious. Sediments 200 km downstream from mining areas were also seriously polluted, as well as soils along the bank. The Chehe mining area contributed more As and less Pb than the Dachang mining area for the Diaojiang river basin pollution. The occurrence form of heavy metals in the river flow varied among elements. Pb in particulate form contributed greater for its pollution in river flow than dissolved Pb, while this trend was reversed for As and Zn. This was related to the different stabilities of the three heavy metal minerals and their varied accumulation characteristics in different size fractions of sediments. Seasonal variation showed that the proportions of particulate heavy metals in river flow were significantly higher in the wet season than that in the dry season.