瓯江下游流域河流沉积物重金属污染特征、来源及潜在生态风险评价  

Pollution characteristics, sources and potential ecological risk of heavy metals in surface sediment from the Lower Ou River

作　　者：车继鲁 余树全[1] 张鑫[1] 齐鹏[1] 梁立成 俞佳骏 

机构地区：[1]浙江农林大学林业与生物技术学院,临安311300

出　　处：《生态科学》2017年第4期176-184,共9页Ecological Science

基　　金：浙江省重点科技创新团队项目(2011R50027)

摘　　要：为了解瓯江下游流域及沿岸城郊入江河流沉积物中重金属的污染特征,对瓯江流域下游及温州城区河流43个表层沉积物中Cr、Co、Ni、Cu、Zn、As和Pb共7种重金属元素的含量特征进行分析,比较了城郊与城区、城区入江口与城区内部之间河流沉积物重金属含量的特征及差异并探讨其污染来源。结果表明:沉积物中7种重金属元素的含量由高到低依次为:Zn>Cr>Cu>Ni>Pb>Co>As,与浙江省土壤背景值相比,7种重金属的平均含量超标1.5—4.9倍,各种重金属的污染程度依次为:Co>Ni>Cr>Zn>As>Cu>Pb,综合污染程度已达到警戒线等级。来源分析表明,重金属元素Cu、Zn、Pb和Cr主要来自于工业污水排放及船舶交通等人类活动,Co和As主要来自于工业及农业生产活动,Ni主要来自于以工业为主的排污污染。潜在生态风险系数E_r^i评价结果显示,7种重金属潜在生态风险大小为:Co>As>Cu>Ni>Pb>Cr>Zn,Co元素处于较强生态风险等级;潜在生态风险指数RI介于72.05—107.80之间,其中55.5%的样点处于较强生态风险水平,44.4%为中等生态风险水平,研究区整体处于较强生态风险水平。In order to understand the pollution characteristics of heavy metals in surface sediment of the Lower Ou River and coastal urban river, we analyzed the concentrations of 7 heavy metals including Cr, Co, Ni, Cu, Zn, As and Pb in 43 sediment samples,compared the characteristics and differences between suburban with urban areas,estuary with internal of urban river and then explored the underlying source of heavy metals. The study results showed that 7 heavy metal contents of surface sediments followed the order： ZnCrCuNiPbCoAs, and all heavy metals were 1.5 to 4.9 times higher than those of Zhejiang natural soils background values.The pollution extent of heavy metals in surface sediments by Nemerow pollution index followed the order： CoNiCrZnAsCuPb, and the comprehensive pollution class was in alert level. Analysis of heavy metals source revealed that Cu, Zn, Pb and Cr were dominated by both drainage of industrial wastewater and vessel traffic. Co and As were dominated by both industrial and agricultural production activities. Ni was affected by industrial sewage pollution. The potential ecological risk of 7 heavy metals in sediments by the potential ecological risk factors Eri was in the following order： CoAsCuNiPbCrZn, and Co was at high ecological risk level. The potential ecological risk indexes RI of 7 heavy metals at all sampling sites were between 72.05 and 107.80, and 55.5% of the samples suffered from high ecological risks and 44.4% had moderate risks. Assessment on ecological risk indicated that the study area was at the high ecological risk level.

关 键 词：瓯江下游 重金属 沉积物 来源 潜在生态风险 

分 类 号：X522[环境科学与工程—环境工程] X131.2