开封市主要河道沉积物重金属时空分布特征及生态风险评价

城市河流沉积物重金属污染是影响河流生态系统健康的重要威胁.为探究开封市河流沉积物重金属时空分布特征，分别于2015年和2021年对河流表层沉积物进行采样，对比不同时期沉积物中Cd、 Cr、 Cu、 Ni、 Pb和Zn的含量，使用地累积指数、生物毒性风险评价和潜在生态风险指数法对两个时期重金属污染进行了评价.结果表明，2021年开封市河流沉积物重金属含量相较于2015年出现较大幅度的下降，Cd、 Cr、 Cu、 Ni、 Pb和Zn分别下降94.42%、 18.4%、 85.7%、 45.19%、 75.61%和92.28%,化肥河和惠济河两个时期重金属含量均高于其他河流.相关分析和主成分分析表明开封市河流沉积物重金属污染源具有高度的相似性，产业布局、道路交通和土地利用等人类活动是其主要污染源.不同时期主要污染物存在一定差异性，2015年Cd、 Cr、 Pb和Zn是主要污染物，2021年Cd、 Cu、 Pb和Zn是主要污染物.地累积指数、生物毒性风险评价和潜在生态风险指数评价结果表明，开封市河流沉积物重金属污染时空差异大，惠济河和化肥河污染状况依然严重，仍属于中、高污染等级，特别是Cd污染...

Spatial and Temporal Distribution Characteristics of Heavy Metals in Main Rivers Sediments and Ecological Risk Assessment in Kaifeng City

Heavy metal pollution in urban river sediments is an important threat to river ecosystem health. To explore the temporal and spatial distribution characteristics of heavy metals in river sediments of Kaifeng City, the surface sediments of rivers were sampled in 2015 and 2021, respectively, and the contents of Cd, Cr, Cu, Ni, Pb, and Zn in sediments at different periods were compared. The heavy metal pollution in the two periods was evaluated using the indices of geo-accumulation, bio-toxicity risk assessment, and potential ecological risk. The results showed that the content of heavy metals in river sediments of Kaifeng City in 2021 were decreased significantly compared with that in 2015. Cd, Cr, Cu, Ni, Pb, and Zn decreased by 94.42%, 18.4%, 85.7%, 45.19%, 75.61%, and 92.28%, respectively. The heavy metal content in the Huafei River and Huiji River was higher than that in other rivers in both periods. Correlation and principal component analyses showed that the heavy metal pollution sources of river sediments in Kaifeng City were highly similar, and human activities such as industrial layout, road traffic, and land use were the main pollution sources. However, the results showed that the main pollutants were different between the two sampling times. In 2015, Cd, Cr, Pb, and Zn were the main pollutants, and in 2021, Cd, Cu, Pb, and Zn were the main pollutants. The results of the geo-accumulation, bio-toxicity risk assessment, and potential ecological risk indices showed that the temporal and spatial differences in heavy metal pollution in river sediments in Kaifeng City were large. However, the heavy metal pollution of the Huiji River and Huafei River was still serious, with contents in the medium and high pollution levels, especially to Cd. The heavy metal treatment of rivers in Kaifeng City has a long way to go, and it is particularly necessary to strengthen the engineering treatment for key river sections and effectively monitor key pollution elements.