解吸
吸附
蒙脱石
化学
离子强度
离子交换
吸附
无机化学
粘土矿物
离子键合
锶
环境化学
分析化学(期刊)
矿物学
离子
水溶液
物理化学
有机化学
作者
Hou-Chun Liu,Jia-You Hsieh,Yen-Hong Chen,Chen‐Feng You,Wei‐Teh Jiang,Hsin-Yi Wen
出处
期刊:ACS earth and space chemistry
[American Chemical Society]
日期:2022-08-18
卷期号:6 (9): 2250-2260
被引量:4
标识
DOI:10.1021/acsearthspacechem.2c00222
摘要
Montmorillonite is a widespread mineral, which affects the migration of Sr in the critical zone. Hydrochemical factors influencing Sr adsorption have been evaluated in the literature through laboratory batch experiments. Since those experiments were conducted using high-concentration and high-purity standard solutions, the influences of chemical matrices or element relative concentrations in water remain unclear. Here, we reassessed the adsorption and desorption behaviors of Sr on montmorillonite using natural waters with various chemical matrices and ionic strengths. Triple Sr isotopes (87Sr/86Sr and δ88/86Sr) were used to trace the exchange processes between the minerals and the waters. Adsorption and desorption occurred in all processed samples, but to varying degrees. These phenomena (especially desorption) were principally controlled by the ionic competition of divalent ions (i.e., Ca and Mg), rather than by ionic strength. Sr isotope fractionation occurred during adsorption. Isotopically lighter Sr was preferentially adsorbed: the mean Δ88/86Srmineral–water (a value independent from the clay type) was −0.17‰. Consequently, water δ88/86Sr depended on both the mixing of mineral-bound and initial water Sr and on the degree of Sr adsorption; moreover, the exchange process was a reversible reaction and reached its chemical and isotopic equilibrium within a short time.
科研通智能强力驱动
Strongly Powered by AbleSci AI