黄河郑州段河岸沉积物重金属污染评价及溯源

Heavy Metal Pollution in Sediments in Zhengzhou Section of the Yellow River:Assessment and Source Apportionment

为探究黄河郑州段河岸带沉积物重金属污染特征及来源,该研究于2022年丰水期对黄河郑州段河岸带沉积物样品进行采集,分析了镉、铅、砷、汞、铬等9种重金属的含量,采用Tessier五步顺序提取法对重金属形态进行具体分析,借助地积累指数(Igeo)评价重金属污染程度,利用内梅罗污染指数(PN)对其污染情况进行综合评价,然后利用主成分分析(PCA)和绝对主成分-多元线性回归模型(APCSMLR)分析其来源。结果表明,黄河郑州段河岸带沉积物中铅和镉平均含量超过河南省土壤重金属背景值,形态分析结果表明锰、镉、铅和汞环境活性相对较高。地累积指数评价结果表明,黄河郑州段重金属镉存在轻中度污染现象,内梅罗污染指数评价结果显示各元素均为安全级别。溯源分析结果表明,黄河郑州段河岸带沉积物重金属主要受到皮革制造和农业活动排放源、汽车零部件制造和自然源影响。

This paper refers to a survey conducted in Zhengzhou section of the Yellow River for the purpose of investigating heavy metal pollution characteristics and of exploring the pollution sources.Monitoring was thereby carried on August 29-31,2022 along the riparian zone collecting samples of the river sediments and analyzing the concentrations of nine kinds of heavy metal,including Cd,Pb,Cu,Zn,As,Hg,Cr,Ni and Mn.Then the Tessier five-step sequential extraction method was used for the morphological analysis of the heavy metals;the ground accumulation index(Igeo)was used to evaluate heavy-metal pollu⁃tion degree,with Nemero pollution index being applied to the comprehensive assessment of the pollution situation;and the principal component analysis(PCA)and absolute factor analysis-multiple linear regression analysis model(APCS-MLR)were used to analyze the source of the pollutants.Consequently,the survey showed that both of the mean concentrations of Pb and Cd in the sediments of the riverine zone of Zhengzhou section of the Yellow River exceeded the soil background value of heavy-metal in Henan Province.Results of the speciation analysis showed that the environmental activities of Mn,Cd,Pb and Hg were relatively high;the evaluation of geo-accumulation index(Igeo)indicated that Cd had resulted in slight to moderate pollution in the sediments of the River;and the evaluation results of the Nemero pollution index showed that all the abovementioned heavy-metal elements were on the safety level.Result of the source apportionment suggested that tannery industry,agricultural activities and automobile parts production,as well as the natural source were the major heavy-metal pollution sources in the riparian zone of Zhengzhou section of the Yellow River.