材料期刊网

对镇江市古运河河岸7个表层沉积物中重金属As、Cu、Pb、Cd、Zn、Cr含量进行测定，并通过富集系数、地累积指数法、潜在生态风险评价以及主成分分析等对沉积物重金属的分布特征进行综合分析与评价．结果表明：（1）古运河河岸带沉积物 Cr、Cu、Zn、As、Pb和 Cd元素的含量平均值分别为45．07、41．70、254．06、19?67、45．88、0．75 mg·kg－1，pH平均值为7．98．对比《国家土壤环境质量标准》可知，沉积物中Cu、Zn、Pb、As属于超一级标准，而Cd属于超二级标准．（2）6种重金属的富集系数表现为：As＞Cd＞Pb＞Zn＞Cu＞Cr，且综合富集系数在空间上表现为：G2＞G5＞G1＞G4＞G3＞G7＞G6；（3）古运河河岸表层沉积物地累积指数表现为As＞Cd＞Pb＞Cu＞Zn＞Cr，6种重金属中As富集量最大，Cr的富集量最小．（4）单项潜在生态危害系数结果表明，Cr、Cu、Zn、Pb均为轻微生态危害程度，As和Cd处于中等生态危害程度．从RI值判断，古运河河岸沉积物总体处于轻微生态危害．（5）相关性和主成分分析结果表明，Pb、Cu、Cr、Cd是决定第一主成分的4个主要因子，且Cu与Pb、Cd以及Pb与Cd元素具有相同的污染源．As、Zn在第二主成分中具有较高的载荷值，且As与Zn之间的相关性较弱，表明这两种重金属并非来自同一污染源．

In order to investigate the pollution loading of heavy metals in riverside sediments of Zhenjiang Canal, six heavy metals ( As, Cu, Pb, Cd, Zn, Cr) from 7 sediment samples were analyzed by using ICP , and the distribution characteristics of the heavy metals in the sediment were comprehensively evaluated through concentration coefficient, geo?accumulation index, potential ecological risk and principal component analysis. The results showed that:(1) the average contents of Cr, Cu, Zn, As, Pb and Cd were 45. 07, 41. 70, 254. 06, 19. 67, 45. 88, 0. 75 mg·kg-1, respectively. The average pH value was 7. 98. The average contents of Cu, Zn, Pb and As were higher than the primary standard of soil environmental quality standards. The average contents of Cd were higher than the secondary standards of soil environmental quality standards. (2) the order of concentration coefficient was As>Cd>Pb>Zn>Cu>Cr. And the order of comprehensive concentration coefficient was G2>G5>G1>G4>G3>G7>G6. (3) the order of geo?accumulation indexes was As>Cd>Pb>Cu>Zn>Cr. The accumulation of As was the highest and that of Cr was the lowest; (4) Cr, Cu, Zn, Pb were of light ecological risk and As, Cd were of medium ecological risk. By RI value judgment, the heavy metals in the riverside sediments of Zhenjiang Canal had slight potential ecological risk;(5) The correlation analysis and Principal Component analysis revealed that Pb, Cu, Cr, Cd were the main four factor dominating the first principal component and Cu, Pb and Cd, Pb, Cd could have similar pollution sources. As and Zn had a high loading values in the second principal components, while the correlation was not significant, which indicated that As and Zn could have different pollution sources.