摘要
【目的】探究湘江支流灌溉渠道沉积物当中的重金属污染特征。【方法】以湘江一级支流—耒水中段灌溉渠道中的沉积物为研究对象,测定7种重金属(As、Cd、Cr、Cu、Ni、Pb、Zn)的总量及水溶态量。采用地积指数法、生态风险系数法评估沉积物中的重金属污染状况及生态风险;基于相关分析和主成分分析揭示渠道沉积物重金属污染成因。【结果】研究区灌溉渠道沉积物重金属污染严重,其中Cd污染最为严重,总量超出环境背景值的6.4倍,受人为干扰强烈;该区域生态风险较高,考虑到沉积物中重金属自身及其对灌溉的影响,Cd的生态风险最为严重,其次为As;研究区沉积物中As、Cd、Zn与Pb、Cu污染分别为不同工矿活动导致,Ni、Cr污染则主要为非人为因素导致。【结论】耒水渠道沉积物当中的重金属污染严重,需采取措施以防止其受工矿活动的污染。
【Objective】Environmental contamination by heavy metals is ubiquitous in many ecosystems.In this paper,we assess heavy metal pollution in sediments of the irrigation canals in the Xiangjiang River basin,as well as their ecological risks.【Method】Taking Lei Shui region,an important tributary of the Xiangjiang River,as an example,we analyzed the total contents of As,Cd,Cr,Cu,Ni,Pb and Zn,as well as their water-soluble forms in sediments of the irrigation canals.The geo-accumulation index method and ecological risk coefficient/index method were used to evaluate sediment contamination and its ecological risk.Correlation analysis and principal component analysis were used to elucidate the origin of the heavy metals found in the sediments.【Result】The sediments in the irrigation canals in the studied region were severely polluted,with a particularly notable concentration of Cd contamination.The total content of heavy metals in the sediments was 6.4 times the background value,predominantly caused by anthropogenic activities.Ecological risk in the area is hence high,especially the risk of Cd followed by As.The accumulation of As-Cd-Zn and Pb-Cu in the sediments was due to industrial and mining activities,respectively,while Ni,Cr and accumulation of As-Cd-Zn and Pb-Cu was caused by both industrial and mining activities.Ni and Cr in the sediments were naturally originated.【Conclusion】The sediments in the irrigation canals in the studied region were severely polluted,with Cd content pronouncedly high exceeding the geological background level by 6.4-fold.Such contamination was predominantly caused by anthropogenic activities.In terms of the ecological risk,Cd was most significant followed by As.The accumulation of As-Cd-Zn and Pb-Cu in the sediments emanated from industrial and mining activities.In contrast,Ni and Cr are naturally originated.
作者
马寅秋
李厚恩
杨军
赵琛
MA Yinqiu;LI Houen;YANG Jun;ZHAO Chen(Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;BGI Engineering Consultants Ltd.,Beijing 100038,China)
出处
《灌溉排水学报》
CAS
CSCD
北大核心
2023年第12期117-124,共8页
Journal of Irrigation and Drainage
基金
国家自然科学基金项目(No.42077134)。
关键词
灌溉渠道
沉积物
重金属
污染特征
生态风险
irrigation canal
sediment
heavy metals
contamination characteristics
ecological risk
