自贡市龙潭镇土壤中重金属的地球化学基线及污染状况研究

摘要

地球化学基线是区分地球化学背景和异常的重要参数.在采集和测试自贡市龙潭镇内168个表层土壤样品的基础上,采用了地质统计学方法建立了研究区内重金属元素As、Cd、Cr、Pb、Hg、Cu、Ni、Zn的地球化学基线.在此基础上,应用地质累积指数方法评价了表层土壤重金属的污染状况.结果表明:区内各重金属元素基线值为As(3.86 μg/g)、Cd(0.183μg/g)、Cr(66.41 μg/g)、Pb(28.19 μg/g)、Hg(0.037 μg/g)、Cu( 23.1 μg/g)、Ni(24.5 μg/g)、Zn(62μg/g)；研究区内Cd和Hg的污染较突出,各重金属元素的地质累积指数排序为:Cd＞H g＞Zn＞Cu＞As＞Cr＞Ni＞Pb.%Geochemical baseline is an important parameter to distinguish geochemical background from contamination. After a total of 168 samples was collected and analyzed, by using of geostatistical method, the baseline of metal elements in topsoil such as As、Cd、Cr、Pb、Hg、Cu、Ni、Zn in the soil of Zigong Longtanzhen were calculated. Based on the baseline of metal elements, it is application of cumulative index of geology to evaluate heavy metal pollution in topsoil. The results indicate that each baseline of heavy metal is As (3. 86μg/g)、Cd(0. 183μg/g)、Cr(66. 41μg/g)、Pb (28. lμg/g)、 Hg (0. 037μg/g)、 Cu (23. lμg/g)、 Ni(24. 5μg/g)、Zn(62μg/g)、 And Cd and Hg of pollution are more prominent in the area. The range of individual cumulative index of geology is Cd> Hg>Zn>Cu> As>Cr>Ni>Pb.