温州河网沉积物中重金属分布特征与污染评价

Spatial Distribution and Contamination Assessments of Heavy Metals in Sediments of Wenzhou River Network

为了调查温州河网沉积物中重金属的分布特征与污染程度,共采集了29个样,用AFS-9230原子荧光光度计和ICP-OES全谱直读电感耦合等离子发射光谱法测定样品中重金属元素含量,克里格插值图反映重金属元素的空间分布,根据内梅罗指数法建立综合地累积指数进行污染评价,利用Pearson系数法,主成分分析法进行源分析。结果表明:在不同样点重金属含量差异明显,其中Cd和Zn含量最高点为主河道城市与工业集中区,As,Pb,Hg,Cu,Ni,Cr含量最高点为机械工业园区,沉积物受到Hg,Cd,Cu,Zn,Ni和Cr污染,区域污染程度机械工业园>主河道城市区>三垟湿地区>城市周边区>水源地区,Hg,Cd,Cu,Zn,Ni和Cr具有相似的源,且以人为源为主。

In order to investigate the spatial distribution pattern and degree of heavy metal pollution in river network sediments of Wenzhou,29 sediment samples were collected,and using atomic fluorescence spectrometry（AFS） and inductively coupled plasma-optical emission spectrometry（ICP-OES） heavy metal concentration in the samples were analyzed.The Kriging interpolation map reflected the spatial distribution of heavy metal.Comprehensive geo-accumulation index based on the Nemerow index method was established to assess the pollution degree.Pearson correlation analysis method and principal component analysis method were employed in sources analysis.Results show that heavy metal concentration varies significantly at different sites.The area with highest Cd and Zn concentrations is the centralized urban and industrial area of the main stream of this river network,while the highest concentrations of As,Pb,Hg,Cu,Ni and Cr were found to be in machinery industrial park.Sediments are contaminated by Hg,Cd,Cu,Zn,Ni and Cr.The order of degree of contamination is as follows： machinery industrial park〉urban areas of the main stream〉Sanyang Wetland〉outskirt and rural area〉drinking water source area.Hg,Cd,Cu,Zn,Ni and Cr have similar pollution sources which are mainly anthropogenic sources.