干旱、半干旱地区高砷地下水形成机理研究:以中国内蒙古河套平原为例  

Research on the formation mechanism of high arsenic groundwater in arid and semi-arid regions:A case study of Hetao Plain in Inner Mongolia,China

作　　者：高存荣[1] 刘文波[1,2] 冯翠娥[1] 陈有鑑[1] 张国[1] 宋建新[1] 

机构地区：[1]中国地质环境监测院,北京100081 [2]中国地质大学(北京)水资源与环境学院,北京100083

出　　处：《地学前缘》2014年第4期13-29,共17页Earth Science Frontiers

基　　金：中国地质调查局项目"内蒙古河套高砷地区地下水勘查与供水安全示范"(1212010634702)

摘　　要：干旱、半干旱地区高砷地下水形成机理,是一较为复杂的地球化学和环境水文地球化学过程。通过多年来的实地调查、资料分析和试验测试等方法手段,详细研究了中国西部地区,特别是中国内蒙古河套平原,高砷地下水的分布特征及地质环境背景。研究并阐述了地下水中砷的来源,地层中砷的来源、聚集、溶出的地球物理、地球化学过程,提出了河套平原地层中砷聚集的3种模式,即断裂运移聚集模式,河、湖水胶体作用聚积模式和蒸发浓缩再聚集模式。研究表明:河套平原地下水中的砷,主要来源于地层,而地层中的砷主要来源于3个方面:周边的山区特别是存在高矿化带的西部山区、黄河上游和构造运移深部地下水;地层中砷的溶出主要与3个因素有关:地下封闭的还原环境、脱硫酸作用和大量灌溉水的入渗。The formation mechanism of high arsenic groundwater in arid and semi-arid area is a relatively complex geochemical and environmental hydrogeochemical process.Based on methods such as the field investigation,the data analyses and the experimental tests,detailed studies are carried out to understand the distribution characteristics and geological setting of high arsenic groundwater in Hetao Plain in Inner Mongolia.The source of arsenic in groundwater and strata,the physical and chemical processes of aggregation and dissolution are studied,and three patterns of arsenic aggregation in Hetao Plain formation are put forward,namely,the migration along the fault-accumulation patterns,the colloidal effect in river and lakeaccumulation pattern,and the evaporation and accumulation pattern.The research shows that the arsenic in groundwater in Hetao Plain is originated from the strata,and the main arsenic sources of the strata are of three aspects：（1）the surrounding mountains,especially in the western mountains with high mineralization belt,（2）the upper reaches of the Yellow River,and（3）the tectonically transported deep groundwater.The arsenic dissolution out from the strata is related to three factors,that is,the underground reducing environment,the de-sulphation and the infiltration of abundant irrigation water.

关 键 词：聚集模式 胶体作用 蒸发浓缩 断裂运移 还原环境 脱硫酸作用 

分 类 号：P641[天文地球—地质矿产勘探]