白银市不同区域蔬菜地土壤重金属污染特征及生态风险评价  

Heavy metal pollution characteristics and ecological risk assessment of different vegetable soils of Baiyin,Gansu,China

作　　者：李有文[1] 曹春[1,2] 巨天珍[1] 赵旭涛[1,3] 牟瑞强 刘思琪[1] 杜名倬 

机构地区：[1]西北师范大学地理与环境科学学院,兰州730000 [2]兰州大学资源环境学院,兰州730000 [3]中国石油化工研究院,北京100083

出　　处：《生态学杂志》2015年第11期3205-3213,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41161080)资助

摘　　要：选取白银市城郊东大沟、西大沟蔬菜地土壤样品共128个,调查了Cu、Ni、Zn、Cr、As、Cd、Hg、Pb等8种重金属的含量,采用人为影响倍数、主成分分析法、地质累积指数法和潜在生态风险法研究评价了其污染状况。结果表明:白银市蔬菜地土壤Cu、Zn、As、Cd、Hg、Pb等6种重金属含量均超过甘肃土壤背景值,其中东大沟Zn、As、Cd和西大沟As、Cd超过了国家土壤质量二级标准。变异程度和人为影响倍数表明:东大沟Cd、Hg,西大沟Hg、As空间分布非常不均匀,受人为影响最显著。主成分分析表明:东大沟Cu、Cd、Pb和西大沟Zn、Cd含量由多种因素控制。地质累积指数(Igeo)表明:白银市蔬菜地Cd、As、Hg、Zn污染程度比较严重,达到了中度污染到强污染,尤其东大沟Cd污染部分甚至达到极强污染,Ni、Cr为无污染。潜在生态危害分析表明:单个潜在生态风险参数(Ei)和综合潜在生态风险指数(RI)均为东大沟>西大沟,其中Cd、Hg和As的单个潜在生态危害程度较高。虽然东大沟蔬菜地重金属污染严重于西大沟,但研究区整体污染程度和生态危害在逐年减轻。Here we monitored levels of 8 metals （Cu, Ni, Zn, Cr, As, Cd, Hg and Pb） in 128 soil samples collected from Dongdagou and Xidagou vegetable farms of Baiyin, Gansu, China, and used the anthropogenic influence multiple, principal component analysis, geological accumu- lation index and potential ecological risk assessment method to evaluate the pollution characteris- tics and potential risks. The results showed that the soil Cu, Zn, As, Cd, Hg and Pb contents exceeded the background values of Gansu, and the soil Zn, As and Cd contents at Do and the soil As and Cd contents at Xidagou were higher than the level II of the China＇ s ngdagou national soil standards. There were high variations in soil Cd and Hg contents at Dongdagou and in soil Hg and As contents at Xidagou, which were likely impacted by the anthropogenic pollution. Principal component analysis showed that soil Cu, Cd and Pb contents at Dongdagou and soil Zn and Cd contents at Xidagou were controlled by many factors. Geoaccumulation index showed that the soil Cd, As, Hg and Zn contents at vegetable farms of Baiyin were classified as moderate to heavy pollution, the soil Cd content of some samples at Dongdagou even as very heavy pollution, and soil Ni and Cr contents as ＂no pollution＂. The potential ecolozical risk analysis showed that the single potential ecological risk parameters （Ei） and comprehensive potential ecological risk index （RI） all followed a pattern of Dongdagou〉Xidagou, and the single potential ecological risks of Cd, Hg and As were relatively high. Overall, the pollution of heavy metals at Dongdagou was more severe than at Xidagou, and the pollution degree and ecological risk had fallen over the years.

关 键 词：蔬菜地 重金属 污染特征 生态风险评价 

分 类 号：X825[环境科学与工程—环境工程] X53