关键词: 重金属污染; 污染源解析; 生态风险评价; 平原河网城市; 江阴市;

Abstract: In order to understand the pollution characteristics of heavy metals in surface sediments of plain river network city, the distributions characteristics of 8 heavy metals including Cu, Cr, Ni, Zn, Pb, Cd, As and Hg in sediment from 17 black-odor rivers and 10 non black-odor rivers in Jiangyin City were analyzed, and the potential ecological risks of each heavy metals were evaluated.The results showed that:(1) the concentrations of 8 metals in the sediment of both black-odor rivers and non black-odor rivers were higher than background sediments of Jiangsu Province, which showed an obvious trend of enrichment and accumulation, but the concentrations of 8 metals in the sediment of black-odor rivers and non black-odor rivers had no significant differences(p>0.05).(2) The results of correlation analysis and principal component analysis indicated that the source of most heavy metals in sediments were similar, mainly affected by industrial wastewater, agricultural non-point source, vehicle pollution and some natural geological processes.(3) The potential ecological risk of 8 heavy metals in surface sediments in black-odor rivers and non black-odor rivers were in the following order: Hg>Cd>Pb>Ni>Cu>As>Zn>Cr and Hg>Cd>Cu>As>Pb>Ni>Zn>Cr, with Hg and Cd contributing the most to the total potential ecological risk, accounting for more than 60% of both black-odor and non black-odor rivers.The potential ecological risk indices(RI)of 8 heavy metals at all sampling sites were from 53.1 to 961.5,in a low or medium potential ecological risk, but local reaches had high ecological risk.

Key words: heavy metal pollution; pollution source identification; ecological risk assessment; plain river network area; Jiangyin City;