摘要
选取鲁北地区浅层粉土、浅层地下咸水及大气降水为供试材料,进行室内淡水驱替咸水试验,分析地下淡水驱替咸水过程中水化学成分形成、演化过程,探讨内陆浅层咸水区地下淡水驱替咸水过程中发生的水文地球化学过程.试验结果表明：1驱替过程中,含水介质粘土矿物含量高,电导率≤0.83 ms/cm,粘土矿物＂膜效应＂使离子组分发生浓缩现象.2驱替过程中,白云石处于沉淀状态,岩盐处于溶解状态;电导率〉1.00 ms/cm,方解石处于沉淀状态;电导率≥6.22 ms/cm,石膏处于平衡状态.临界离子强度为0.20~0.25 mol/L,Mg/Ca-Na阳离子交换作用显著.电导率〉12.00 ms/cm,离子交换吸附作用显著.研究表明,内陆浅层咸水区淡水驱替咸水过程中发生复杂的水化学作用,主要包括吸附作用、离子交换作用、溶滤作用、脱白云岩化作用及混合作用.
Based on test materials,including of silt,shallow salt groundwater and atmospheric precipitation which were got in northwestern Shandong geochemistry action in the process of freshwater displacing saltwater were studied. The results indicated that（ 1） When content of clay was high in aquifer medium,and specific conductivity of exudate was less than or equal to 0. 83 ms / cm in the process of freshwater displacing saltwater,clay played a role of film effect in concentrating ion components.（ 2）Dolomite still kept precipitation with water,and halite still kept dissolution in the process of freshwater displacing saltwater. Calite precipitated when specific conductivity of exudate was more than 1. 00 ms /cm; Gypsum balanced with water when specific conductivity of exudate was more than or equal to 6. 22 ms / cm. Mg / Ca-Na exchange interaction was remarkable with critical ion strength being in 0. 20 ~ 0. 25 mol / L. Adsorption was remarkable while specific conductivity of exudate was more then 12. 00 ms /cm. Displacement experiment showed that hydrogeochemistry actions were happened in the process of freshwater displacing saltwater with adsorption,exchange interaction,lixiviation,dolomitization and mixing action.
出处
《华东师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2015年第4期132-143,共12页
Journal of East China Normal University(Natural Science)
基金
国家自然科学基金(41172222
41472216)
关键词
浅层咸水
水化学特征
水文地球化学作用
驱替试验
内陆地区
shallow salt groundwater
water chemical characteristics
hydrogeochemistry action
displacement experiment
inland region
