摘要
依据雷州半岛东岸的东寮岛滨海地下水测井潮周期取样测试数据,以Cl-为保守离子,应用海水稀释方法,探讨了在海水入侵过程中Ca2+的迁移性。结果显示,Ca2+含量随海水进退呈现波动势态,含量很高,远高于背景值和雷州半岛东岸其它测井,也明显高于海水中的含量;Ca2+表现出明显的非保守性和迁移性,实际数据点位于理论稀释线TDL的上方,存在明显的阳离子交换现象;Δ表示测井实测值与理论值的差异,可体现出海水入侵过程中孔隙介质对离子的吸附和释出。ΔCa2+平均为527.26~574.85mg/L,ΔNa+、ΔMg2+、ΔK+均<0,ΔCa2+与这三者逐时变化存在着反相特征,ΔNa++ΔMg2++ΔK+绝对值很高为阳离子充分置换提供了基础,ΔNa+当量比例超过50%,三种阳离子共同参与对Ca2+的置换,但以Na+为主;ΔCa2+时间变化趋势为基本不变,线性或者对数缓慢单增;Ca2+的阳离子置换促使Na+滞留于孔隙介质,降低了测井地下水的总溶解性盐类含量,但同时大量钙离子的迁出又使得测井地下水硬度增高。
According to the sampling test data of tidal cycle of logging in undergroud water in Dongliao island coastal area,east of Leizhou peninsula,taking Cl-as conservative ion,using the seawater dilution method,Ca2＋＇s migratory aptitude is discussed when the seawater invades. The result shows that the Ca^2 ＋content presents volatile situation with seawater advance and retreat,its content is very high,meanwhile it is higher than background value and the value of other loggings in east coast of Leizhou peninsula,and also the content in seawater. Ca^2＋ presents unconservatism and migration aptitude,the actual data points are above the TDL,the cation exchange phenomenon is obvious. Δ expresses the differences between measured and theory value,it can reflect the adsorbing and releasing to ion by porous media during the seawater invasion. The average value of ΔCa2＋ is 527. 26 - 574. 85 mg / L,The average value of ΔNa^＋、ΔMg^2＋、ΔK^＋are all less than 0,they presents contrary characteristics with ΔCa2＋. The absolute value ofΔNa^＋＋ ΔMg2 ^＋＋ ΔK^＋is high,it provides full basis to cation replacement. The equialent proportion ofΔNa^＋is higher than 50%. Three cations all take part in the replacement with Ca2＋,but it is mainly with Na^＋. The time changing trend of ΔCa^2 ＋is basically unchanged,the linear and logaritumic show slowly increasing. The cation exchange of Ca^2＋urges Na＋retention in porous media,the content of total dissolved salts reduces in logging in underground water,but its hardness increases by a large amount of calcium ion emigration.
出处
《勘察科学技术》
2015年第1期19-24,35,共7页
Site Investigation Science and Technology
基金
中国地质调查局"我国重点海岸带滨海环境地质调查与评价"(编号1212010914020)
关键词
地下水
钙离子
咸淡水混合方法
理论稀释线
海水入侵
underground water
calcium ion
mixed method of brackish and fresh water
TDL
seawater invasion behavior
