古运河镇江城区段沉积物重金属分布特征及危险评价

Distribution Characteristics and Risk Evaluation of Heavy Metals in Sediments in the Ancient Canal of Zhenjiang Urban Section

对古运河镇江电力路桥段和南水桥段沉积物进行柱状采样,通过电感耦合等离子质谱法测定沉积物柱状样中Cu、As、Pb、Cd、Zn、Cr等重金属元素的含量,并对各污染物的污染水平、潜在生态危害和溯源进行系统分析。结果表明:①电力路桥段沉积物重金属污染主要为Pb、Cd,平均值分别为263、20 mg/kg;南水桥段沉积物重金属污染则主要为Cd、As,平均值分别为17、132 mg/kg。②对两个采样点沉积物重金属元素的单项潜在生态危害指数计算显示,其重金属生态分享程度大小顺序为Cd>As>Pb>Cu>Cr>Zn。③经底泥沉积物重金属相关性溯源分析,表明电力路桥段底泥中Pb、Cd、As的污染主要来自于人为排放,且来自于同一污染源;南水桥段底泥中Cu、Pb、As的污染主要来自于人为污染,且来自于同一污染源。

In this paper,contents of heavy metals in the vertical sediment samples such as Cu、As、Pb、Cd、Zn、Cr are determined,in which columnar is collected in the river of Power Bridge and Nanshui Bridge in the middle part of the Ancient Canal in Zhenjiang by inductively coupled plasmamass spectromety,and it is systematically analyzed the pollution level,ecological hazard and trace to the source.The results show that:①The main heavy metal contamination in the sediments of Power Bridge mainly include Pb and Cd and the average value is 263 mg/kg and 20 mg/kg respectively and those of Nanshui Bridge include Cd and the average value is 17 mg/kg,132 mg/kg respectively;②The calculation of the individual potential ecological risk index in the sediments of heavy metal element of two sample points shows that it is ordered as Cd>As>Pb>Cu>Cr>Zn;③The related sexual traceability analysis of heavy metals in the sediments indicates that pollutions of Pb,Cd and As in the sediments of Power Bridge and Cu,Pb and As in the sediments of Nanshui Bridge both mainly come from anthropogenic discharge and the same sources.