摘要
青海湖是我国最大的闭口咸水湖.近年来随着工农业及旅游业的迅速发展,湖泊受人为活动影响不断增加,引起广大学者关注.为了深入了解青海湖表层沉积物中的重金属分布情况,在调查Zn、Cu、Pb、Co、Ni、As、Cd和Cr这8种重金属含量的基础上,对其赋存形态进行了分析,并对其进行来源解析和生态风险评价.结果表明:①青海湖表层沉积物重金属除ω(As)(13.21 mg·kg^(-1))和ω(Cd)(0.21 mg·kg^(-1))超出环境背景值1.13倍和1.53倍,其余6种重金属均不同程度低于环境背景值,从空间分布来看,除As外其他7种重金属元素空间分布特征极为相似,高值主要分布在湖泊西北部及151码头附近;②除Cd外其他7种重金属的主要存在形态为残渣态,而Cd主要以生物有效态形式存在,对水生生物具有较高的潜在生物毒性;③结合相关性分析和主成分分析,沉积物中Zn、Cu、Pb、Co、Ni、Cd和Cr的来源以自然源为主,As的来源则受到农业生产等人为因素影响;④根据潜在风险分析结果,青海湖沉积物重金属整体处于轻微生态危害水平,但值得重视的是,各点位Cd的潜在生态危害水平及释放风险均高于其他金属元素,特别是在黑马河入湖口、尕海和沙岛附近等区域显示出较高的潜在释放风险,后续需持续关注这些区域沉积物中Cd对水环境及生态系统的潜在影响.
Lake Qinghai is the largest closed saltwater lake in China.In recent years,because of the rapid development of industry,agriculture,and tourism,the lake has been increasingly affected by human activities,which has attracted the attention of many scholars.In order to understand the distribution of heavy metals in the surface sediments of Lake Qinghai,the contents of Zn,Cu,Pb,Co,Ni,As,Cd,and Cr were investigated,the metal fractions were extracted,and the sources,as well as potential ecological risks,were analyzed.The results showed that:①theω(As)(13.21 mg·kg^(-1))andω(Cd)(0.21 mg·kg^(-1))in the surface sediments of Lake Qinghai were 1.13 and 1.53 times higher than the environmental background values,respectively,and the other heavy metal contents were all lower than the environmental background values.There were similar spatial distribution characteristics of analyzed metals except for As,with higher values measured in the northwestern area of the lake and the 151 Terminal.②Except for Cd,the analyzed heavy metals mainly existed in the form of the residual state;by contrast,Cd mainly existed in the form of the bioavailable state,which has high potential toxicity to aquatic organisms.③Combined with the results of the correlation and principal component analysis,the metals including Zn,Cu,Pb,Co,Ni,Cd,and Cr were thought to mainly come from the natural environment,whereas the source of As was related to human activities,such as agricultural production.④According to potential risk analyses,the average of the metal potential ecological risk factors was 76.57,which indicated a slight ecological hazard level.However,it should be noted that the potential ecological hazard level and release risk of Cd at each site were higher than those of the other metals,especially in the regions nearing the estuary of Heima River,Lake Gahai,and the sand island,which showed higher levels of enrichment and potential release risk.Therefore,further attention should be paid to the potential impacts of Cd in sediments of these regions on the water environment and ecosystem.
作者
张雅然
车霏霏
付正辉
许野
李薇
ZHANG Ya-ran;CHE Fei-fei;FU Zheng-hui;XU Ye;LI Wei(College of Environment Sciences and Engineering,North China Electric Power University,Beijing 102206,China;National Engineering Laboratory for Lake Pollution Control and Ecological Restoration,State Environment Protection Key Laboratory for Lake Pollution Control,Chinese Research Academy of Environmental Sciences,Beijing 100012,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2022年第6期3037-3047,共11页
Environmental Science
基金
国家自然科学基金项目(41907335)。
关键词
形态分析
风险评价编码法
来源解析
分布特征
青海湖
fraction analysis
risk assessment code
source identification
distribution characteristic
Lake Qinghai
