奇台县地下水水文地球化学模拟研究

摘要

以揭示奇台县地下水水化学场的形成机理为主要研究目的,在水文地球化学模拟理论的指导下,应用PHREEQC软件进行水-岩作用的地球化学模拟,定量分析了研究区地下水的演化过程和形成机理.模拟结果显示,两条模拟路径具相同的矿物溶解及沉淀趋势,其中石膏和岩盐发生了溶解,方解石和白云石发生了沉淀,CO2从水中逸出,同时还发生了Na+、Ca2+和Mg2+之间的阳离子交替吸附作用.在溶解和沉淀作用共同影响下,研究区地下水化学组分发生了变化.%Based on the hydrogeological conditions in the Qitai County,Xinjiang,the regional chemical evolution characters of groundwater were analyzed.Under the guidance of hydrogeochemical simulation theory,by the PHREEQC software,a geochemical modeling for water-rock interaction was performed and the quantitative analysis for the evolution process and forming mechanism of groundwater were made.The conclusions were that the minerals in the two selected simulated paths showed the same dissolution and precipitation trends.In path 1 and 2,the main reactions occurred were the dissolutions of gypsum and rock salt,the precipitations of calcite,dolomite and CO2,and the cation exchange between Na+,Mg2+ and Ca2+.Groundwater chemical composition changes under the effects of the dissolution and precipitation of various minerals.