烟台夹河河口海水混合过程的地球化学特征研究

海(咸)水混入是河口河水重要的地质过程,深刻地影响河水地球化学过程。本文系统采集夹河河口水样,分析海淡水混合过程的地球化学特征。结果表明,远离河口段(J10~J14)为淡水性质,主要受水-岩作用及人类活动等影响;近河口段(J1~J8)海水混入严重,F~-、Cl~-、Br~-、SO~(2-)_4、Na~+、K~+、Mg~(2+)、Ca~(2+)、盐度等明显较高,主要受海水混入影响。近河口段存在Na-Ca离子交换过程,约占Na~+总量的0.9%~1.5%,离子交换量随海水混入比例增加而增加,Na~+离子交换量与K~+,Ca~(2+)、Mg~(2+)、Br~-、F~-、SO~(2-)_4离子交换量相关,且河水离子含量与盐度回归系数略低于与盐度、Na~+交换量回归系数,表明河口段河水离子交换影响河水地球化学特征。

Geo-chemical Characteristic Analysis of Seawater Mixture in Estuary of Jiahe River, Yantai City, China

Seawater (fresh water) mixture, an important geological procedure for estuarine water, affects deeply geo-chemical procedure. In this study, water samples were systemically collected and the geo-chemical characteristics of seawater mixture were analyzed. Water near the estuary (J1-J8) is seriously mixed by seawater. While the water away from the estuary is characterized by fresh water, which results in obviously higher contents of F^-, Cl^-, Br^-, SO₄^2-, Na⁺, K⁺, Mg²⁺, Ca²⁺ and salinity. Ion contents in water near the estuary are mainly affected by seawater mixture, and those away from the estuary are affected by rock-water interaction and human activities. Meanwhile, Na-Ca ion exchange occurs near the estuary, with an amount of 0.9%~1.5% of Na⁺ ions. The exchanged ions increase with increasing seawater ratio. The exchanged Na⁺ ions are significantly correlated with the exchanged ions of K⁺, Ca²⁺, Mg²⁺, Br^-, F^- and SO₄^2-, and the regression coefficients of ion contents with salinity are slightly lower than those with salinity and exchanged Na⁺ ions. All of above indicate that ion exchange influences geo-chemical characteristics of water near the estuary.