新疆准噶尔盆地未开垦盐碱地土壤重金属评价及其来源  

Evaluation and Their Sources of Heavy Metals in Uncultivated Saline-Alkaline Soil in the Junggar Basin,Xinjiang

作　　者：米晓军 任雯 雒琼 马健[1,2] MI Xiao-jun;REN Wen;LUO Qiong;MA Jian(State Key laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy ofSciences,Urumqi 8300119 Xinjiang,China;Fukang National Station of Desert Ecosystem Observation and Research,Chinese Academy of Sciences,Fukang 831505,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049 y China)

机构地区：[1]中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室,新疆乌鲁木齐830011 [2]中国科学院阜康荒漠生态系统国家野外科学观测站,新疆阜康831505 [3]中国科学院大学,北京100049

出　　处：《干旱区研究》2019年第4期824-834,共11页Arid Zone Research

基　　金：国家科技基础性工作专项(2015FY110500)

摘　　要：为了解新疆准噶尔盆地未开垦盐碱地土壤中重金属的污染状况,在未开垦盐碱地采集土壤样品,测定汞(Hg)、镉(Cd)、铅(Pb)、铬(Cr)、镍(Ni)、砷(As)和硒(Se)7种重金属元素的含量。运用多元统计分析方法、污染指数评价方法,并结合新疆土壤背景值(Se采用乌鲁木齐市背景值)对不同土层(020cm,2040cm)进行调查和评价,并对重金属的来源进行分析。结果表明:研究区土壤中Hg、Cd、Pb、Cr、Ni、As、Se7种重金属元素在020cm土层平均值为0.023、0.165、17.999、62.587、29.928、16.325mg·kg^-1和0.696mg·kg^-1;在2040cm土层土壤中平均值为0.021、0.148、17.497、61.091、29.995、17.384mg·kg^-1和0.634mg·kg^-1。除Pb元素外,其他元素均不同程度超过对应的新疆土壤背景值,7种元素在2个土层中无污染、轻度污染样点所占比例分别为66.2%100%和74.7%100%;内梅罗综合污染指数评价结果以轻度污染为主,2个土层轻度污染样点占比均为78.4%。Cd、As、Se重金属元素的来源以自然因素为主,主要与土壤母质的组成和性质有关,影响因素包括山地岩石风化和季节性洪水搬运等;Cr、Pb、Hg元素的来源主要受人为因素的影响,工业开发、交通运输、煤炭燃烧产生的烟气中所携带的重金属沉降到土壤中,是造成未被开垦和破坏的自然盐碱地土壤背景值升高的主要原因;而Ni元素的来源可能是人为因素和自然因素共同作用的结果。The uncultivated saline-alkaline soil samples were collected from the Junggar Basin,Xinjiang. Seven kinds of heavy metals including Hg,Cd,Pb,Cr,Ni,As and Se in soil samples were examined. The multivariate statistical analysis and the pollution indexes were used in the survey,and the sources of heavy metals in different soil layers (0-20 cm and 20-40 cm in depth) were evaluated based on the soil background values of the heavy metals in Xinjiang (the soil background values of Se in Urumqi were adopted). The results showed that the average concentrations of Hg,Cd,Pb,Cr,Ni,As and Se in soil layer 0-20 cm in depth were 0. 023,0. 165,17. 999,62. 587,29. 928,16. 325 and 0. 696 mg·kg^-1,and those in soil layer 20-40 cm in depth were 0. 021,0. 148,17. 497,61. 091,29. 995,17. 384 and 0. 634 mg·kg^-1,respectively. Except for Pb,the contents of other elements were higher than the soil background values of the heavy metals in Xinjiang. The evaluation results of the single factor pollution index of each element in the study area were mainly pollution-free or slight pollution. The proportions of pollution-free and slight pollution of the seven elements in the two soil layers varied from 66. 2% to 100% and from 74. 7% to 100%,respectively. The Nemero comprehensive index showed that the slight pollution was dominant in the study area,and the proportions of the sites with slight pollution in the two soil layers were all 78. 4%. The sources of heavy metal elements such as Cd,As and Se were mainly natural factors,which are mainly related to the composition and properties of soil parent materials. The sources of Cr,Pb and Hg were mainly affected by human factors. Heavy metals carried by industrial development,transportation and coal combustion fall into the soil,which is the main reason for the increase of background values of uncultivated and undamaged natural saline-alkaline soil.The source of Ni may be the result of human and natural factors.

关 键 词：盐碱地 土壤重金属 背景值 污染评价 来源分析 准噶尔盆地 

分 类 号：X825[环境科学与工程—环境工程]