杭州下沙河道底泥重金属检测及污染分析

Detection and pollution analysis of heavy metals in river sediment in Xiasha of Hangzhou

检测了杭州下沙河网区18条河道表层底泥重金属Cu、Zn、Pb、Cd、Ni的含量,分析了研究区域内的重金属污染情况,并用潜在生态危害指数法对河道底泥重金属污染情况进行评价,通过聚类分析法分析重金属的空间分布特征.结果表明,Cd污染最严重,超标率为94.44%,平均超标倍数为16.50,Cd的平均潜在生态风险为很高风险,Cu、Zn、Pb、Ni的平均潜在生态风险为低风险,重金属平均综合潜在生态风险属于高风险.重金属聚类分析结果显示Cd、Ni、Pb三种元素相关性显著,应受同一污染源因素影响;采样点聚类分析结果显示下沙河网河道底泥重金属污染分布较为均匀.

The concentrations of heavy metals of Cu, Zn, Pb, Cd and Ni in the river sediment from 18 rivers in Hangzhou Xiasha were tested. The heavy metal pollution was evaluated with potential ecological risk index. The spatial distribution of heavy metals was analyzed by cluster analysis. The results show that the pollution of Cd is the most serious with over standard rates of 100% and exceeding 16.50 times. The potential ecological risk index of Cd is the largest which means a very high risk. The potential ecological risk of Cu, Zn, Pb and Ni is low, but the average risk of total heavy metals is very high. The heavy metals cluster analysis shows that Cd, Ni and Pb are related, so they may be affected by the same pollution sources. Besides, cluster analysis of sampling sites shows the pollution of heavy metals in Xiasha＇s river network is relatively uniform.