地质构造单元交接带表土中重金属污染特征对比及源解析: 以重庆城口地区为例  

Comparison of the Concentrations,Sources,and Distributions of Heavy Metals in Topsoils of the Junction Zone of Geological Tectonic Units:A Case Study in Chengkou County,China

作　　者：刘永林[1,2] 吴梅 刘睿 李军[1,2] 倪润祥[3] 刘双燕[1,2] 田兴磊[4] 赵家宇 刘怡 夏传波 LIU Yong-lin;WU Mei;LIU Rui;LI Jun;NI Run-xiang;LIU Shuang-yan;TIAN Xing-lei;ZHAO Jia-yu;LIU Yi;XIA Chuan-bo(Geography and Tourism College,Chongqing Normal University,Chongqing 401331,China;Key Laboratory of GIS Application Research,Chongqing Normal University,Chongqing 401331,China;Rural Energy and Environment Agency,Ministry of Agriculture and Rural Affairs,Beijing 100125,China;Shandong Institute of Geological Sciences,Ji'nan 250013,China)

机构地区：[1]重庆师范大学地理与旅游学院,重庆401331 [2]重庆师范大学GIS应用研究重点实验室,重庆401331 [3]农业农村部农业生态与资源保护总站,北京100125 [4]山东省地质科学研究院,济南250013

出　　处：《环境科学》2022年第12期5742-5750,共9页Environmental Science

基　　金：国家自然科学基金项目(41502329);重庆市教育委员会科学技术计划项目(KJZDK202100504,KJQN201900519)。

摘　　要：中国地质构造复杂,不同地质构造区地质演化史差异显著,对其上发育的土壤重金属含量分布、污染特征及来源亦具有影响.以秦岭地槽和上扬子地台交界区重庆市城口县为研究区,采集表层土壤样品115件,综合运用地累积指数、污染指数和正定矩阵因子分解模型(PMF)分析不同地质构造单元区表土重金属含量分布、污染特征和来源.结果表明:①整体上,该区表土重金属处于中度污染水平,其中Cd为主要污染元素;②表土中Cd超标点位主要分布在乌坪断裂以北地区;③发育于秦岭地槽区埃迪卡拉纪-早寒武世地层之上的土壤中重金属含量显著高于上扬子地台区相同时代地层之上的土壤;④研究区表土重金属来源主要为成土母岩风化及交通和燃煤活动,其中成土母岩风化的贡献率为75%,是控制研究区表土重金属含量分布和污染的主要因素.这为研究不同地质构造区土壤重金属含量分布、富集和来源提供了范例和科学依据.The geological structure of China is complex,and the geological evolution history of different geological structure areas is significantly different,which also affects the distribution,pollution characteristics,and sources of heavy metals in the topsoils.In this study,Chengkou County of Chongqing Municipality,located in the junction between the Qinling geosyncline and the Upper Yangtze platform,was selected as a case study area.Statistical analysis and a positive matrix factorization model(PMF)were employed to assess the content,spatial distribution,pollution characteristics,and source apportionment of heavy metals in the topsoil derived from different geological tectonic units.The results showed that:①the heavy metals in the topsoils were at a moderate pollution level,and Cd was the major polluting element.②The topsoils in which Cd exceeded the standard were mainly distributed in the northern region of Wuping Fault.③The median values of Cd,Cu,Ni,Sb,and Zn in topsoils derived from the Lower Cambrian and Ediacaran strata of the Qinling geosyncline were higher than those of the Upper Yangtze platform.④The main sources of heavy metals in the topsoil of the study area were the weathering of parent rocks,transportation,and coal-burning activities,and the weathering of parent rocks contributed 75%,which was the main factor controlling the distribution and pollution of heavy metals in the topsoil of the study area.These results could provide a good example and scientific basis for further illustrating the distribution,enrichment,and source of topsoil heavy metals in different geological structure areas.

关 键 词：重金属 含量分异 秦岭地槽 上扬子地台 正定矩阵因子分解模型(PMF) 

分 类 号：X53[环境科学与工程—环境工程]