阿哈水库沉积物中重金属分布特征及潜在生态风险评价  

Distribution and Ecological Hazard Risk Assessment of Heavy Metals in the Sediment of Aha Reservoir

作　　者：郭云 陈都 王铭 杨成 王志康 赵宇中 GUO Yun;CHEN Du;WANG Ming;YANG Cheng;WANG Zhi-kang;ZHAO Yu-zhong(College of Eco-Environmental Engineering,Guizhou Minzu University,Guiyang 550025,P.R.Chin)

机构地区：[1]贵州民族大学生态环境工程学院

出　　处：《水生态学杂志》2018年第4期24-30,共7页Journal of Hydroecology

基　　金：贵州省教育厅青年科技人才成长项目(No.黔教合KY[2016]158,KY[2017]134);贵州省科学技术基金(No.黔科合J字[2013]2145,No.黔科合基础[2016]1072,No.黔科合基础[2016]1071);国家自然科学基金(41563013)

摘　　要：研究阿哈水库沉积物中重金属空间分布特征和污染现状,评价潜在生态风险,为重金属污染防治提供参考依据和理论基础。2016年12月,在阿哈水库设置4个采样点,每个采样点采集20cm柱状沉积物,按5cm分层取样,检测分析铜（Cu）、锌（Zn）、镉（Cd）、铅（Pb）、铬（Cr）、镍（Ni）6种毒性重金属,用潜在生态危害指数法评价生态风险。结果表明,6种重金属含量在空间分布上有显著差异。水平方向,沉积物中Cu、Cr和Pb含量库心最高,Zn和Cd含量南郊水厂取水口最高,沉积物中的6种重金属含量在金钟河和游鱼河入库口都相对较低。垂直方向上,南郊水厂取水口和库心采样点Cr、Pb、Cu、Ni、Zn、Cd 6种重金属峰值均出现在10~15cm处。Zn、Cu和Pb平均含量都超过背景值,Cd富集系数最高,污染最严重。潜在生态风险评价结果显示,水库沉积物重金属潜在生态危害指数从大到小依次为Cd、Cu、Pb、Ni、Zn、Cr,Cd是生态风险主要贡献因子。阿哈水库沉积物重金属总体上存在轻微的生态风险及处于轻微的污染状态,南郊水厂取水口较高的生态风险应当引起足够的重视。Sediments are an important part of the aquatic environment,acting as both a source of nutrients and a repository for heavy metals.Aha Reservoir is an important source of drinking water for Guiyang City,but water quality has been affected by the rapid development of agriculture and industry,threatening regional water supplies,the environment and human health.Because heavy metals are entering in the reservoir,it is important to evaluate the pollution status and ecological risk of heavy metals in the sediments.In this research,heavy metals,including Cu,Zn,Cd,Pb,Cr and Ni in the sediment at four sampling points,the reservoir entrance of Youyu River,the water intake of south suburb water works,the center of the reservoir and the reservoir entrance of Jinzhong River numbered as A,B,C,D respectively,in Aha Reservoir were measured.Spatial distributions of the six heavy metals varied significantly.Horizontally,Cu,Cr and Pb were highest at the center of the reservoir,Zn and Cd were highest near the water intake of south suburb water works and all six metals were relatively low at the other two sampling sites.Vertically,the peak concentrations of all six metals were at a depth of 10-15 cm at the reservoir center and the water intake.Average concentrations of Cu,Zn and Pb exceeded background values.The accumulation coefficient of Cd was the highest and the potential ecological risk was in the order CdCuPbNiZnCr.Overall,the ecological risk of Aha reservoir sediment is slightly low and the reservoir is classified as slightly polluted,meanwhile,the high ecological risk near water intake should be paid more attention.

关 键 词：沉积物 重金属 分布特征 生态风险 阿哈水库 

分 类 号：X524[环境科学与工程—环境工程] X820.4