降雨-蒸发-蒸腾与地下水耦合作用下的大型尾矿库重金属Cu^(2+)迁移模拟分析

Simulation Analysis on Heavy Metal Cu^(2+) Migration in Large Tailings Ponds Under the Coupling Action of Rainfall-Evaporation-Transpiration and Groundwater

考虑降雨-蒸发-蒸腾与地下水耦合作用,以本钢集团歪头山铁矿尾矿库为例,利用Geostudio软件中的SEEP/W、VADOSE/W和CTRAN/W模块,模拟降雨-蒸发-蒸腾作用下的尾矿库地下水渗流特性及重金属污染物的迁移规律。结果表明:尾矿库的垂直剖面孔隙水压力沿靠近坡面方向呈下降趋势,深层土壤的孔隙水压力基本不受降雨-蒸发-蒸腾作用影响;降雨-蒸发-蒸腾作用对重金属污染物的迁移起干扰作用;重金属污染物Cu2+在0~1095 d内沿初期坝方向迁移,重金属Cu2+浓度随时间推移而增大;考虑降雨-蒸发-蒸腾作用,一定程度上增加了重金属污染物在1095 d内的总移距和平均速度。研究结果为大型尾矿库环境地质评价和污染预测防治提供依据。

Considering the coupling action of rainfall-evaporation-transpiration and groundwater,the tailings pond in Waitoushan Iron Mine of Bengang Group was taken as an example,the SEEP/W,VADOSE/W and CTRAN/W modules in Geostudio software were used to simulate the groundwater seepage characteristics of the tailings pond and the migration rule of heavy metal pollutants under the effect of rainfall-evaporation-transpiration.The results show that,the pore water pressure in vertical profile of tailings pond decreases along the direction closing to the slope surface,and the pore water pressure of deep soil is not affected by rainfall-evaporation-transpiration basically.Rainfall-evaporation-transpiration interfere with the migration of heavy metal pollutants.The heavy metal pollutant Cu2+migrates along the direction of the initial dam within 0~1095 d,and the concentration of heavy metal Cu2+increases with time.Considering rainstorm-evaporation-transpiration,the total displacement and average velocity of heavy metal pollutants within 1095 d are increased to a certain extent.The study results provide a basis for environmental geological evaluation as well as pollution prediction and prevention of large tailings ponds.