摘要
潮河作为北京市地表饮用水源密云水库的主要入库河流,其水质对饮用水源水质安全具有重要影响作用。为探讨潮河沉积物中重金属的污染特征及潜在生态风险,作者于2016年沿河流上游至入库口选取12处监测点采集表层沉积物,测定沉积物中As、Cu、Pb、Ni、Cr、Zn和Cd共7种重金属的含量。基于单因子指数、Hakanson综合污染指数和潜在生态风险指数来评价沉积物中重金属污染特征和潜在生态风险程度,结果表明:潮河沉积物中除重金属Ni和Pb外,其余5种重金属(As、Cu、Cr、Zn、Cd)含量均高于北京市土壤环境质量背景值,其中以Cd的累计程度最重;重金属的空间分布差异较大,呈现出不均匀分布状态,其中Cd和Cu呈现出高度离散性;综合污染指数表明各重金属污染程度为Cd>Cu>Cr>Zn>As>Ni>Pb,其中Zn-Cr、Ni-Cd-Pb-As之间存在较好的同源性;多元统计分析表明Ni可能来源于自然源,Zn、Cr和Cu可能来源于废水、农药化肥和交通污染源,Cd和Pb可能来源于汽车尾气、交通运输等污染输入源,As可能来源于废水;综合潜在生态风险指数表明重金属潜在生态风险等级由强至弱依次为Cd>Cu>As>Cr>Ni>Pb>Zn,其中仅Cd具有极高的潜在生态风险。潮河沉积物重金属总体上处于高生态风险等级,但除了京通线铁路和省道滦赤路河段监测点潜在生态风险危害等级较高外,其它采样点及密云水库入库口处监测点均处于低风险危害等级。
Chao River which is the surface drinking water in the main inflow river of Miyun Reservoir in Beijing has an important effect on the quality of drinking water.In order to explore the pollution characteristics and potential ecological risk of heavy metals in the sediments of Chao River,12 sediments were sampled along the upstream of Chao River to the reservoir and the concentrations of As,Cu,Pb,Ni,Zn,Cr and Cd in the samples were determined in 2016.Based on single factor index method,Hakanson comprehensive pollution index method and potential ecological risk index method,the pollution level and the potential ecological risk of heavy metals in the sediments were evaluated.The results indicated that,the average contents of heavy metals including As,Cu,Cr,Zn and Cd were slightly higher than their background values in the sediments of Chao River,among which the accumulative degree of Cd was the highest.The spatial distribution of heavy metals was dramatically different and uneven,especially,Cd and Cu presenting a high discreteness.The comprehensive pollution index indicated that the pollution degree of heavy metals followed the order of Cd>Cu>Cr>Zn>As>Ni>Pb,otherwise,Zn-Cr and Ni-Cd-Pb-As had significant homogeneity respectively.Multivariate statistical analysis showed that Ni may come from natural sources;Zn,Cr and Cu were associated with agricultural activities and traffic pollution.Cd and Pb may derived from automobile exhaust,transportation and other pollution input,and As may originate from wastewater.The comprehensive potential ecological risk index showed that the potential ecological risk of heavy metals followed the order of Cd>Cu>As>Cr>Ni>Pb>Zn,among which the potential ecological risk of Cd was the highest.The heavy metals in the surface sediment of Chao River is on a high ecological risk level on the whole.In addition,other sampling sites especially the sampling site closing to Miyun Reservoir all had a low potential ecological risk level expect sampling site closing to Jingtong line railway and Luanchi hi
作者
张義
于一雷
李胜男
朱耀军
韦玮
ZHANG Yi;YU Yilei;LI Shengnan;ZHU Yaojun;WEI Wei(Institute of Wetland Research,Chinese Academy of Forestry,Beijing 100091,China;Beijing Key Laboratory of Wetland Services and Restoration,Beijing 100091,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2020年第7期169-179,共11页
Environmental Science & Technology
基金
中央级公益性科研院所基本科研业务费中国林科院重点项目(CAFYBB2017ZA007)
中国林科院留学支持计划项目(CAFYBB2019GC001-22)
国家自然科学基金项目(41601037)。
关键词
潮河
重金属
潜在生态风险
沉积物
污染分级评价
Chao River
heavy metal pollution
potential ecological risk
sediment
grading evaluation of pollution
