黄河甘宁蒙段重金属及其生态风险研究

黄河是中国西北地区最重要的水源，为了研究黄河上游甘宁蒙段水体的重金属含量及其潜在生态风险，本文分别使用AFS和HR-ICP-MS对黄河甘宁蒙段12个采样点过滤水和悬浮物中As，Hg，Cd，Pb，Cr，Ni，Cu 和 Zn等重金属元素的含量进行了测定。结果表明：各采样点过滤水中，除Cr (56.9~71.5 μg·L-1)外，其他重金属元素的含量均低于饮用水水质标准限值。TN，TP和 pH等水质参数的测定结果显示，除 S1 (2.48) 和 S9 (2.38)采样点的TN超过国家地表水环境质量标准第Ⅴ类标准外，其他各采样点参数值均较低。悬浮物中，Hg，Cd，Pb 和Zn的含量均高于各采样点所在地区相应元素土壤背景值。聚类分析结果显示Ni，Cu，Cr，Zn和Pb有相同污染来源，主要来源于不锈钢产业和石油产业;As，Cd和Hg三种重金属元素的来源各不相同，主要可能来自于农药，化肥，采矿和燃料以及煤的燃烧。应用RI和Er对各采样点以及单个重金属元素的潜在生态风险进行了评价。结果显示，除S1采样点为中度生态风险外，其他采样点均为显著生态风险(300.6 < RI < 508.6)，Er指数显示Hg在内蒙段为显著-高生态风险，Cd在S11 (396.0), S9 (384.0) 和 S5 (373.3)采样点为极高风险，说明Hg和Cd在这些采样点污染较为严重。以上研究结果可以为相关部门提供可靠的实验数据和理论依据。

Study on Heavy Metals and Ecological Risk Assessment from Gansu,Ningxia and Inner Mongolia Sections of the Yellow River,China

The Yellow River is the most important resource of water supply in northern China. The purpose of this work are to investigate the concentrations and potential ecological risk of heavy metals in the upper reaches of the Yellow River, the concentrations of eight heavy metals including As, Hg, Cd, Pb, Cr, Ni, Cu and Zn in filtered water and suspended particles from 12 sampling sites of Gansu, Ningxia and Inner Mongolia sections of the Yellow River of China were studied by atomic fluorescence spectrometry (AFS) and high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) in this paper. The results implied that all heavy metals in filtered water were lower than the limit standards for drinking water except for Cr (56.9～71.5 μg·L-1). Water quality parameters such as total nitrogen (TN), total phosphorus (TP) and pH were also determined and the contents were low along the river except for TN at S1 (2.48) and S9 (2.38), which exceeded the maximum permitted concentration of Class Ⅴ for the protection of surface water. In suspended particles, the concentrations of Hg, Cd, Pb and Zn were much higher than those in the background value of soil from local section. Cluster analysis (CA) indicated that same sources for Ni, Cu, Cr, Zn and Pb could be stainless steel and petrochemical industrial activities, while As, Cd and Hg derived from agrochemicals, fertilizers, mining, fuel and coal combustion, respectively. Ecological risk assessment was undertaken using risk index (RI) for sampling sites and ecological risk factor (Er) for heavy metals. Eleven suspension samples existed considerable ecological risk (300.6