沂河临沂段表层沉积物重金属污染特征与生态风险评价

Pollution characteristics and potential ecological risk of heavy metals in the surface sediments from the Linyi section of Yi River

以沂河临沂河段为研究对象,采集15个河流表层沉积物样品,利用电感耦合等离子体质谱仪(ICP-MS)测量并计算6种重金属元素(Cr、Ni、Cd、Zn、Cu、Pb)的质量分数,运用地积累指数法和潜在生态风险指数法评价表层沉积物中重金属的污染程度和潜在生态风险,并利用相关分析和主成分分析解析其来源.结果表明:(1)除Cr元素以外,其他5种元素质量分数均超过山东省土壤背景值;(2)地积累指数评价结果显示,6种重金属污染程度由高到低依次为Cd、Cu、Zn、Ni、Pb、Cr,即研究区中Cd的污染程度最高;(3)潜在生态风险评价结果显示,研究区综合生态风险级别为极高生态风险,Cd对综合生态风险系数的贡献比例最高,是最主要的生态风险来源;(4)Cr、Cu和Ni为自然和工业排废复合来源,Zn和Pb来源于工业燃煤和交通污染等人为影响.

This study measured the mass fraction of 6 heavy metal elements(Cr,Ni,Cd,Zn,Cu,Pb)of 15 surface sediment samples using Inductively Coupled Plasma Mass Spectrometry(ICP-MS),which were collected from the Linyi section of Yi River.The contamination degree and potential ecological risk of heavy metals were evaluated by the index of geoaccumulation and potential ecological risk index.Based on correlation analysis and principal component analysis,the sources of these heavy metal elements were determined.The results showed that:(1)the contents of these elements were higher than the background values of soil in Shandong Province except Cr.(2)According to the evaluation of Igeo,the contamination degree of Cd in the study area was the highest,followed by Cu,Zn,Ni,Pb and Cr.(3)The assessment of potential ecological risk index showed that,the comprehensive ecological risk level in the study area was extremely high,and Cd was the main source of ecological risk due to its highest contribution to the comprehensive ecological risk coefficient.(4)Cr,Cu and Ni were associated with the combination of parent material and industrial emissions,while Zn and Pb were controlled by anthropogenic inputs such as industrial coal combustion and urban traffic pollution.