嘉陵江上游矿区河谷沉积物中重金属污染危害评价  

Hazard assessment of heavy metal pollution of valley sediment in mining area of Jialing River upstream

作　　者：薛喜成[1] 刘刚[1] 

机构地区：[1]西安科技大学地质与环境学院,陕西西安710054

出　　处：《西北农林科技大学学报（自然科学版）》2015年第11期165-171,共7页Journal of Northwest A&F University(Natural Science Edition)

基　　金：陕西省自然科学基金项目(SJ08-ZT08-3);西安科技大学博士研究项目(B2009-18)

摘　　要：【目的】研究嘉陵江上游矿区河谷沉积物中重金属污染危害程度,为土壤重金属修复治理提供科学依据。【方法】在嘉陵江上游矿区河道的源头、上游、中游、下游分别采集河道表层沉积物样品,并用火焰原子吸收法和原子荧光光谱法测定沉积物中重金属Pb、Zn、Cu、Cd、Cr、Ni、As含量。用污染负荷指数法和潜在生态危害指数法,评价嘉陵江上游矿区河谷重金属污染危害程度,探讨重金属含量与pH、有机质的相关性。【结果】从整体上看,研究区内重金属Pb、Zn、Cu含量变化明显,Cd、Ni、As、Cr含量变化较小。污染负荷指数法评价结果表明,河道源头未受到重金属污染,上游重金属污染达中等级别,中、下游重金属污染达强污染;单项重金属污染贡献排序为Pb〉Cd〉Ni〉As〉Cu〉Zn〉Cr;采样区重金属污染程度大小排序为中游〉下游〉上游〉源头。重金属单项潜在生态危害程度排序为Cd〉As〉Pb〉Ni〉Cr〉Zn〉Cu;综合潜在生态危害指数值（RI）为33.38~131.03;源头所受生态危害轻微,上、中、下游重金属的生态危害均达中等水平。相关性分析表明,pH值与沉积物中重金属Pb、Cu、As含量呈极显著相关。有机质的变化显著影响沉积物中重金属Zn和pH值的改变。此外,当有机质增高时显著影响重金属Pb、Cu、Cr、Ni在沉积物中的积累。【结论】嘉陵江上游矿区河道地段的重金属污染已对环境造成了污染与危害,并且会危害到下游居民生活,生态环境亟需修复治理。【Objective】This research focused on the level of heavy metal pollution of watercourse sediment in mining area of Jialing River upstream to provide scientific basis for the remediation of heavy metal polluted soil.【Method】The surface sediments of the watercourse were taken at the source,upstream,middle reaches,and downstream for measurement of Pb,Zn,Cu,Cd,Cr,Ni,and As by Flame atomic absorption method and Atomic fluorescence spectrometry method.Then the pollution and hazard degrees of heavy metals in valley sediments of the mining area were evaluated by Tomlinson pollution load index and Hakanson potential ecological risk index.The correlations of heavy metal,pH and organic matter were also analyzed.【Result】Overall,the contents of Pb,Zn,and Cu changed significantly in the study area,while the contents of Cd,Ni,As,and Cr changed slightly.The pollution load index showed that the source of watercourse was not polluted,upstream was moderately polluted,and middle reaches and downstream were heav-ily polluted.The pollution levels were in a decreasing order of Pb〉Cd〉Ni〉As〉Cu〉Zn〉Cr.The order of total pollution degrees in study areas was midstream〉downstream〉upstream〉source.The order of potential ecological risk degrees was Cd〉As〉Pb〉Ni〉Cr〉Zn〉Cu.The comprehensive potential ecological risk values（RI）were 33.38-131.03.The source suffered low hazardous pollution,but the upstream,midstream and downstream suffered medium level pollution.Correlation analysis indicated that pH was significantly correlated with the contents of Pb,Cu,and As in sediment.The organic matter significantly affected the changes of heavy metal Zn and pH in sediment.In addition,the accumulation of Pb,Cu,Cr,and Ni in sediment decreased significantly as the increase of organic matter.【Conclusion】The pollution of watercourse in mining area of Jialing River upstream caused damage to the environment and affected the living of downstream residents.Treatment is urgently needed to the ecological environment.

关 键 词：重金属 沉积物 污染评价 嘉陵江上游矿区 

分 类 号：X53[环境科学与工程—环境工程]