海水入侵过程中水-岩相互作用的土柱试验研究  

Experimental study of column displacement in water-rock interaction during seawater intrusion

作　　者：刘茜[1] 郑西来[1] 任加国[1] 王继纲[2] 张晓辉[3] 林国庆[1] 

机构地区：[1]中国海洋大学海洋环境与生态教育部重点实验室,山东青岛266100 [2]国家海洋局第三海洋研究所,福建厦门361005 [3]国家海洋局珠海海洋环境监测中心站,广东珠海519000

出　　处：《海洋环境科学》2008年第5期443-446,457,共5页Marine Environmental Science

基　　金：国家自然科学基金项目(40572142)

摘　　要：利用青岛市大沽河下游海水入侵区的砂样、海水、地下水进行土柱试验,模拟海水入侵过程中可能发生的水文地球化学作用。结果表明,海水入侵过程中在混合作用的基础上,阳离子交换吸附作用是主要的,该作用通常发生在地下水与粘粒之间,尽管试验中所取砂样的粘粒含量很少(2.99%),但是现象非常明显,Na+与Ca2+、Mg2+发生逆向交换;Mg2+与Na+交换平衡后,又与Ca2+发生交换吸附;而K+与Ca2+仅发生了少量的交换吸附作用。同时海水占地下水比例40%左右,地下水中开始出现方解石和白云石沉淀;海侵过程中石膏始终是溶解的。以上研究有助于推动海水入侵、海退机理的研究,为海水入侵预测、定量评价与防治提供科学依据。The hydrogeochemisty in the process of seawater intrusion is simulated through the column displacement experiment in which the soil samples, seawater and groundwater collected in the seawater intrusion area of Dagu river in Qingdao. As the experimental results show that the most visible process is the cation exchange based on mixing action. This takes place betwean the clay and the groundwater but is quite clear in the sandy sediments as reverse exchange （removal of Na ^＋ from solution） of between Na^＋ , Ca^2＋ and Mg^2＋ ions. After the equilibrium between Na ^＋ and Mg^2 ＋ ions, Mg^2＋ exchange with Ca^2＋ , and there is a little exchange quantity between K^＋ and Ca^2＋ . Calcitilization and Dolomitization appear in groundwater containing about 40% seawater. Meanwhile the gypsum is always dissolved. The researches will help for understanding the mechanism of seawater intrusion and flushing and provide scientific basis for the forecast, estimation and prevention of seawater intrusion.

关 键 词：海水入侵 砂质含水层 阳离子交换 溶解/沉淀 

分 类 号：P734[天文地球—海洋化学]